Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: mxplxxx on 03/06/2014 07:52:27
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The famous e=mc2 equation seems to imply that mass and energy are interchangeable. Most people have this view. However, most bosons in the standard model are massless but do contain energy. This seems to strongly refute the interchangeability theory. I have also read recently that e=mc2 is just a conversion of mass units into energy units. This makes just so much sense when you try and think where the weird "speed of light squared" fits into the picture. So it may be that the equation is all about concepts rather than reality.
Also, can anyone tell me where I can obtain a picture of the standard model that contains how many quanta (these will be whole numbers) are present in each particle in the table? And also, how do I convert quanta into mass?
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That equation only works for masses at rest with respect to you (the observer) and indicates the energy content of the mass of that object if you were to measure it at rest. However, you're right that a Boson has zero mass, so how can it have energy? Well, a zero-mass Boson can't be at rest! So this equation doesn't hold for moving particles. The correct form of the more general equation is:
E2=m2c4+p2c2
where p is momentum. So a moving Boson can (and does) have momentum and therefore energy, even though its mass is zero.
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The famous e=mc2 equation seems to imply that mass and energy are interchangeable. Most people have this view. However, most bosons in the standard model are massless but do contain energy. This seems to strongly refute the interchangeability theory. I have also read recently that e=mc2 is just a conversion of mass units into energy units. This makes just so much sense when you try and think where the weird "speed of light squared" fits into the picture. So it may be that the equation is all about concepts rather than reality.
Also, can anyone tell me where I can obtain a picture of the standard model that contains how many quanta (these will be whole numbers) are present in each particle in the table? And also, how do I convert quanta into mass?
In addition to what JP wrote:
1. "it may be that the equation is all about concepts rather than reality" is nonsense in physics: either an equation is valid in a certain domain (and so it describes physical reality in that domain) or is not.
2. You cannot convert quanta into mass for the reason explained JP: massless particles can have energy (and so quanta of it) but, indeed, zero mass.
3. You cannot even find the number of quanta of energy in a particle of which you know the energy, if you don't have other informations. For example, for the quanta of electromagnetic field (photons) you have, at least, to know also the frequency of the field.
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lightarrow
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That equation only works for masses at rest with respect to you (the observer) and indicates the energy content of the mass of that object if you were to measure it at rest. However, you're right that a Boson has zero mass, so how can it have energy? Well, a zero-mass Boson can't be at rest! So this equation doesn't hold for moving particles. The correct form of the more general equation is:
E2=m2c4+p2c2
where p is momentum. So a moving Boson can (and does) have momentum and therefore energy, even though its mass is zero.
Thx JP. Problem with this equation is that p is momentum which is mass * velocity and many bosons do not have mass.
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momentum is not always defined as: p=m*v. In the case of a photon, p=h/λ.
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momentum is not always defined as: p=m*v. In the case of a photon, p=h/λ.
Thx for that. p=h/λ in units is Kg m/s=Joules.second/metres which seems on first glance to not make much sense at all (lets face it, what is Joules.sec anyway - I have an interesting post on this at http://www.thenakedscientists.com/forum/index.php?topic=41125.0). Bye the bye, getting units for all these types of equations is ridiculously hard.
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In a computer, reality is basically the digits (0/1) that make up the memory and the ability to manipulate the memory. Computer languages translate concepts into digits. Reality appears to be made up of space, time and fields (energy being a property of a field) plus, maybe, a meta-field. Everything else seems to be some kind of an abstraction (concept) of these basic elements, much like a computer. Hope I am not making a fool of myself here:).
What do you think of the possibility that e=mc2 is just a units of mass to units of energy conversion?
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3. You cannot even find the number of quanta of energy in a particle of which you know the energy, if you don't have other informations. For example, for the quanta of electromagnetic field (photons) you have, at least, to know also the frequency of the field.
Thx lightarrow. My reading of a quantum is that h equals energy times 1 second. The energy, e, in e=hf is energy per second. All quanta, no matter what their frequency contain h amount of energy in total. The frequency relates to the power of a quantum, i.e. how fast the h amount of energy is transferred. Energy is a constant but power varies.
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Yes.
Energy-mass-energy conversion is an everyday phenomenon. If a sufficiently energetic (> 1.02 MeV) photon interacts with a nucleus it can produce an electron-positron pair (1.8 x 10^-30 kg) which then self-annihilates to generate two 511 keV photons.
This phenomenon is exploited in radionuclide imaging.
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Yes.
Energy-mass-energy conversion is an everyday phenomenon. If a sufficiently energetic (> 1.02 MeV) photon interacts with a nucleus it can produce an electron-positron pair (1.8 x 10^-30 kg) which then self-annihilates to generate two 511 keV photons.
This phenomenon is exploited in radionuclide imaging.
Thx alancalverd. Interesting stuff.
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That equation only works for masses at rest with respect to you (the observer) and indicates the energy content of the mass of that object if you were to measure it at rest. However, you're right that a Boson has zero mass, so how can it have energy? Well, a zero-mass Boson can't be at rest! So this equation doesn't hold for moving particles. The correct form of the more general equation is:
E2=m2c4+p2c2
where p is momentum. So a moving Boson can (and does) have momentum and therefore energy, even though its mass is zero.
Thx JP. Problem with this equation is that p is momentum which is mass * velocity and many bosons do not have mass.
That equation has no problems: if you put m = 0 in it (photons, gluons) then E = c*p: the energy of a photon is c times its momentum (light has momentum even in classical electrodynamics).
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lightarrow
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3. You cannot even find the number of quanta of energy in a particle of which you know the energy, if you don't have other informations. For example, for the quanta of electromagnetic field (photons) you have, at least, to know also the frequency of the field.
Thx lightarrow. My reading of a quantum is that h equals energy times 1 second. The energy, e, in e=hf is energy per second. All quanta, no matter what their frequency contain h amount of energy in total. The frequency relates to the power of a quantum, i.e. how fast the h amount of energy is transferred. Energy is a constant but power varies.
I answer to what I have underlined of your post.
No! First, h is not energy, is "action". Second, the quantum of energy in the EM field is h*f where f is the frequency, so the value of the quantum *does* depend on its field frequency.
Example: in a blue laser beam with (exact) wavelenght = 400 nm, every photon has an (exact) energy of 3.1 eV; in a red laser beam with (exact) wavelenght = 700 nm, every photon has an (exact) energy of 1.77 eV.
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lightarrow
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In a computer, reality is basically the digits (0/1) that make up the memory and the ability to manipulate the memory. Computer languages translate concepts into digits. Reality appears to be made up of space, time and fields (energy being a property of a field) plus, maybe, a meta-field. Everything else seems to be some kind of an abstraction (concept) of these basic elements, much like a computer. Hope I am not making a fool of myself here:).
It's always difficult to discuss about what reality is or should be; I am talking about physical reality, that is what can be measured, directly or indirectly, in the physical world.What do you think of the possibility that e=mc2 is just a units of mass to units of energy conversion?
It is something more than that: it tells you (if you have already applied the equation: E2 = (cp)2 + (mc2)2 with p = 0) that, in a frame of reference where the system has total momentum = zero, its total energy is m times c2.
But if the system has not zero momentum, for example a car which is moving at speed v, then its total energy is not m times c2, so, mass and energy are not interchangeable in that case.
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lightarrow
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The famous e=mc2 equation seems to imply that mass and energy are interchangeable.
It depends on what you mean by that. To understand what it means you should follow the derivation at http://home.comcast.net/~peter.m.brown/sr/mass_energy_equiv.htm
I wrote a very highly detailed article on mass. It's online at
http://arxiv.org/abs/0709.0687
See also
http://home.comcast.net/~peter.m.brown/sr/inertial_mass.htm
http://home.comcast.net/~peter.m.brown/sr/invariant_mass.htm
http://home.comcast.net/~peter.m.brown/sr/einsteins_box.htm
Here is what it means. If you have an object which is at rest in your frame of reference and its energy decreases by the amount dE then the mass decreases by the amount dm where dE = dm*c2. Energy is never converted to mass and mass is never converted to energy because if there is a conversion process going on then there must be a change in energy. However since energy is a conserved quantity it means that no conversion can possibly take place. What is actually going on is that things like photons are created from particles which have non-zero proper mass and vice versa.
Most people have this view.
Not the ones who know what they’re talking about. One has to be very careful when discussing this subject because its easy to go astray. This is all explained very carefully in the article Does nature convert mass into energy? by Ralph Baierlein, Am. J. Phys., 75(4), Apr. (2007). The abstract reads
First I provide some history of how the equationE=mc 2 arose, establish what “mass” means in the context of this relation, and present some aspects of how the relation can be understood. Then I address the question, DoesE=mc 2 mean that one can “convert mass into energy” and vice versa?
However, most bosons in the standard model are massless but do contain energy. This seems to strongly refute the interchangeability theory.
It has to do with not being careful on the definition of mass. I’ve read your posts and it’s clear to me that when you use the term “mass” you mean “relativistic mass” since that’s define as the M in p = Mv. When defined like that even a photon has mass by virtue of its momentum. If this seems strange to you then don’t worry about it. I know what I’m talking about and can site you all the references in the best relativity textbooks that are out there to confirm what I’m saying. When you say ”The mass of a photon is zero.” What you’re really doing is contradicting what you said elsewhere since you used a different definition of mass when you said it. You meant the same thing that JP did when he defined mass. When you plug in the relationship between momentum and energy in his equation you’ll get zero.
I have also read recently that e=mc2 is just a conversion of mass units into energy units.
Whoever said that doesn’t know what they’re talking about.
This makes just so much sense when you try and think where the weird "speed of light squared" fits into the picture. So it may be that the equation is all about concepts rather than reality.
And also, how do I convert quanta into mass?
Please explain what you mean by this
Thx JP. Problem with this equation is that p is momentum which is mass * velocity and many bosons do not have mass.
Your dilemma is easily resolved when it is realized that the term mass hasn’t been defined yet and there are definitions being used here, one by you and one by JP.
Mxplxxx: the M in p = Mv
JP: the m in E2 = m2c4 + p2c2
The two are related by the expression
M = m/sqrt[1 – (v/c2)]
If you’d like to see a list that someone put together regarding a sampling of books on special and general then I recommend looking at On the abuse and use of relativistic mass by Gary Oas, Education Program for Gifted Youth, Stanford University, Feb 2, 2008. It’s online at http://arxiv.org/pdf/physics/0504110.pdf
As you can see most of the authors in that list in the years leading up to the publication of the articleuse relativistic mass. If an author uses the term in his text or a book then it doesn’t necessarily mean that they use it in their professional work. However it seems to me that they probably think in those terms at times. For example; a friend of mine is a well-known cosmologist who doesn’t use it in his work but uses it in his lecture notes at one point. He told me that “Sometimes its useful to think of photons has having mass.” For example; if you were to look at Principles of Physical Cosmologyby P.J.E. Peebles, Princeton University Press, (1993), page 643, Peebles states the expansion rate equation in Eq. (25.60) and refers to the second term as the relativistic mass in radiation…
Before I go on to addressing the question at hand I want to explain why JP wrote That equation only works for masses at rest with respect to you? He wrote this because he’s using a different definition of mass than you are.
Any questions?
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I should point out that what's going on in situations like pair annihilation/production is that the form of the matter is what's being converted.
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3. You cannot even find the number of quanta of energy in a particle of which you know the energy, if you don't have other informations. For example, for the quanta of electromagnetic field (photons) you have, at least, to know also the frequency of the field.
Thx lightarrow. My reading of a quantum is that h equals energy times 1 second. The energy, e, in e=hf is energy per second. All quanta, no matter what their frequency contain h amount of energy in total. The frequency relates to the power of a quantum, i.e. how fast the h amount of energy is transferred. Energy is a constant but power varies.
I answer to what I have underlined of your post.
No! First, h is not energy, is "action". Second, the quantum of energy in the EM field is h*f where f is the frequency, so the value of the quantum *does* depend on its field frequency.
Example: in a blue laser beam with (exact) wavelenght = 400 nm, every photon has an (exact) energy of 3.1 eV; in a red laser beam with (exact) wavelenght = 700 nm, every photon has an (exact) energy of 1.77 eV.
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lightarrow
Judging by the number of people in physics asking the meaning of e=hf, it is reasonable to ask if the equation is correct. Many in the physics community are deciding that it is not. I explain why in http://www.thenakedscientists.com/forum/index.php?topic=41125.0. The post has been viewed by 1537 people and only one reply has been forthcoming. Not certain what this means but am sure if I was talking rubbish I would get many challenges. Basically, the proposition being put by many physicists (and me) is that the quantum is one of energy, not action. This proposition takes so much weirdness out of quantum mechanics. Lets face it, no one really knows how a quantum of action relates to reality.
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My reading of a quantum is that h equals energy times 1 second.
That's quite wrong. If you wrote it out then you'd see that your statement is dimensionally incorrect. I.e. Let
J = Joule = dimension of energy
S = Second = dimension of time
E = hf ==> E[J] = h[J*S] f[1/S]
h = E/f ==> h[J*S] = E[J]/f[1/S] = (E/f) [J*S]
That’s how you’d check to see whether an expression is dimensionally correct. Let’s try your assertion. You claim that if you multiplied Planck’s constant, h, by 1s then you’d get energy (although you never told us what this quantum is. Is it a photon?). Let’s try it
h[J*S] 1s = h [J*S^2]
which is wrong. QED
Here is what E = hf means. First off it applies to zero mass particles only.
The energy, e, in e=hf is energy per second.
That is incorrect. That expression has units of energy, not power. It is the energy of one quantum. For example; if there is a photon whose frequency is f then the energy that the photon has is E = hf
All quanta, no matter what their frequency contain h amount of energy in total.
That’s incorrect. h is not an amount of energy. You’ve never studied quantum mechanics, have you? Let’s take photons an example. Different quanta can have different values of energy. You’re incorrectly claiming that’s wrong. The expression E = hf is the expression which tells you how much energy a photon has given the frequency of the photon. The greater the frequency of the photon the greater the photon’s energy. What you said above is quite wrong
The frequency relates to the power of a quantum, i.e. how fast the h amount of energy is transferred. Energy is a constant but power varies.
No. You have it all wrong. See above. Energy is delivered in lumps, not the way you think it does.
Where on Earth did you get these ideas from?
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Judging by the number of people in physics asking the meaning of e=hf, it is reasonable to ask if the equation is correct. Many in the physics community are deciding that it is not.
That's quite untrue. That postulate has been around for nearly 105 years now and is has been born out buy experiment countless times during the last 105 years. No professional physicist would ever make such an assertion.
I explain why in http://www.thenakedscientists.com/forum/index.php?topic=41125.0.
Seriously flawed. That it has to be in the New Theories forum tells us as much. I read that page and it's clear that it's written by someone who never sat down and studied physics head to toe but only picked up small disconnected peices all over the place and can't make heads or tales out of it as a result.
The post has been viewed by 1537 people and only one reply has been forthcoming.
That's because it's meaningless.
Not certain what this means but am sure if I was talking rubbish I would get many challenges.
No. That's not the reason. The reason is that we recognize that you'd be unable to understand the responses. After many years experience in doing this we've come to see first hand what happens when we tried and it's never pretty. So we stop trying. For example:
"A photon IS one cycle of an electromagnetic wave."
All physicists know that one of the reasons that classical EM fails on the subatomic level is that such a continuos electromagnetic wave interacting with atoms doesn't behave in the way that it's predicted to when one does the calculation. We know that photons don't behave like electromagnetic waves. Your comment here shows us that you're not taking that into account and are ignoring experimental facts.
Basically, the proposition being put by many physicists (and me) is that the quantum is one of energy, not action.
I find that impossible to believe. If what you claim is true for "many" physicists then you should be able to name just one. Please do so.
This proposition takes so much weirdness out of quantum mechanics. Lets face it, no one really knows how a quantum of action relates to reality.
Total nonsense. All physicists know what Planck's constant is and how it relates to reality.
No wonder I don't like this subforum.
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Total nonsense. All physicists know what Planck's constant is and how it relates to reality.
Hi PmbPhy. I was talking about the Quantum of Action. If you can define and explain this entity, then I take my hat off to you. Care to have a try? You are aware, I assume, that all quanta contain the same amount of action. I am sorry to say that many physicists do not understand Planck's constant - at least that is what I glean from my adventures on physics forums. In fact, many physicists seem unaware of the Quantum of Action (this discussion of mine on Physics Forums makes this quite clear http://www.physicsforums.com/showthread.php?t=367434).
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I find that impossible to believe. If what you claim is true for "many" physicists then you should be able to name just one. Please do so.
Juliana Brooks Mortenson at generalresonance.com
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That is incorrect. That expression has units of energy, not power. It is the energy of one quantum. For example; if there is a photon whose frequency is f then the energy that the photon has is E = hf
My belief is that the energy e in e=hf is per second energy, not total energy. I would have thought this was obvious from the fact that we are multiplying by frequency which is cycles per second.
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FIRST of ALL !!!
Gravitation mass and Inertia mass = two different problem
We can not MIX gravitation and Acceleration !!!
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2F3.bp.blogspot.com%2F-08J2bAsyv_U%2FU2fdx7je6aI%2FAAAAAAAAByg%2FZf7--jpyd2E%2Fs1600%2Feinstein%2Bp1.jpg&hash=fa52dc9f45f6bb7602c1bcf917c79a9e)
Gravitation = 3D shape
Acceleration is Flat
http://3.bp.blogspot.com/-zWrJa0V2u2Q/U2fd4adG6II/AAAAAAAAByo/pLqM7hwI_rc/s1600/einstein+p2.jpg
We can make test !!!
Pendulum inside rocket !!!
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2F1.bp.blogspot.com%2F-lAcbXNZ7Fps%2FU05i6HcI7SI%2FAAAAAAAABug%2FPdaTlpQlPKA%2Fs1600%2F1234.jpg&hash=6989ec7c499dc1388c0b1662d2342c15)
MASS M is MOVING ? Gravitation between mass M and other mass around M can be ZERO !!!
but INERTIA ... can be very huge
p1..p2...p3...p4...p5...p6...M >>> Motion
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2F4.bp.blogspot.com%2F-m2UsEuBlhoI%2FUsfk349TEiI%2FAAAAAAAABj0%2FHAsT6a4W818%2Fs1600%2Fee.JPG&hash=ba9c8ca2407ee47339efa02c64773ba1)
INVERSE SQURE LAW
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.zipheron.com%2Fimages%2Fprojects%2FislMeter.jpg&hash=8585c8ce22603a93e250d3e9f08dd29b)
More far from place where signal started = lower intensity of signal
( "lower brightness" )
1R = X , 2R = X/4 , 3R = X/9
X- brightness, R- radius
the same energy portion but different area
Proffesional TEST Michelson Morley Brightness
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2F3.bp.blogspot.com%2F-8wjLt-hPeu0%2FUtvr6OSc5II%2FAAAAAAAABkc%2F4lngY1EJC9o%2Fs1600%2Ftower%2B1.JPG&hash=b5d742f58630fd76435d4d278916f613)
How is moving bulb in the universe ?
Energy is going isotropy respect to point where signal started !!!
Energy motion can not be describe respect to observer !!!
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2F4.bp.blogspot.com%2F-dS-cUmBntzA%2FUoRVdV1-UdI%2FAAAAAAAABQQ%2FTF91UPHWIk8%2Fs1600%2F1aaa.JPG&hash=32443b218b4606cd9fa0f27b3132fe46)
Bulb ------5 metres ------camera
Bulb -------------------------10 metres----------------camera
Bulb ------5 metres ------camera ----> 10 km/s
Bulb ------5 metres ------camera -------------------------> 1000000 km/s
there is no any time shift !!!
Intensity is different time is the same !!!
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Before this gets too far off track, mxplxxx, in the sites you use to define "quantum of action" (both here and on the physicsforums thread) are pushing pseudoscience. It's no wonder that the information you get from them disagrees with most physicists: your sites are incorrect.
As was also pointed out in that physicicsforums thread, you're working from wrong definitions, but are acting as if you're an expert and we're all the ones who are wrong about this. That will get you nowhere (and probably get this moved to New Theories given the content of your misinformation). If you honestly want to learn quantum mechanics, even at a basic level, it will take a lot of work and definitely require discarding the current ideas you have about it.
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Thank you for your input. I would not be stupid enough to try and argue quantum physics with experts unless I knew a significant amount about it. I was pretty naïve in my earlier posts but am much more sophisticated now. My search for someone who can provide a definition of the Quantum of Action continues. I remain convinced that most of the physics community cannot provide this definition and so do not understand the basis of quantum physics (I may live to regret saying this!) . The following OneNote files on Planck's constant should really interest you. https://onedrive.live.com/redir?resid=8147C9C160CC0049!8992&authkey=!ANrs85XOV9SKW90&ithint=folder%2c
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My search for someone who can provide a definition of the Quantum of Action continues. I remain convinced that most of the physics community cannot provide this definition and so do not understand the basis of quantum physics (I may live to regret saying this!) .
Well that's easy, but it won't clear up your confusion on the subject.
Planck's constant, h, has units of action: energy*time.
In quantum theory, things that are quantized come in packets that are proportional to h. Therefore h describes (is proportional to) the "size" of a "quantum" of something that is quantized.
Therefore, we call it the quantum of action.
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Interestingly, if we rewrite the e=hf equation as et=h then it can be seen that as we increase energy, time decreases and vice versa. And if we increase time, energy decreases and vice versa. It could be argued that time and energy are interchangeable, much like energy and mass.
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No, because T=1/f, where T is period of oscillation, so as we increase period energy decreases and vice versa.
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e=hf so h=e/f so h=e * 1/f so h=eT what is wrong with my logic?
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You said T was time, and it is not. It is period of oscillation.
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Period is time isn't it? I should have been more precise about the original equation. So h=eT and so it would appear in some sense energy and time are interchangeable. Given that this is happening inside a quantum, it seems to be a fundamental transformation. What about conservation of energy though? Energy cannot just vanish can it. So maybe the equation is flawed in some way? Hard to see unless e=hf itself is flawed in some way.
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Period is not time. Period is a measurement of the length of time it takes for the field to go through one full oscillation. This oscillation is a physical process describing a fundamental property of the field. This is important because if you change the value of period, you're describing a fundamentally different physical process-- a field with fundamentally different properties.
It therefore makes sense that ET=h, since if you change the field you're describing, it is natural that the energy of its quanta change as well.
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Hi PmbPhy. I was talking about the Quantum of Action. If you can define and explain this entity, then I take my hat off to you. Care to have a try?
Why? You already know what it is and what it means, don’t you? It’s what most people call Planck’s constant. In fact some texts, such as Principle of Modern Physics by Leighton refers to this constant on page 65 as Planck’s quantum of action and is given the symbol h. In case you don’t know your physics history and don’t know why Planck define this term I’ll explain: There were problems in thermodynamics for which all attempts using classical physics failed to solve the problem. Planck was working on the problem of black body radiation. He was able to solve the problem theoretically by making a few assumptions, namely that the walls of the cavity inside a black body contained harmonic oscillators and that each oscillator could only radiate energy having the value E = nhf where n is a positive integer and f the frequency of the oscillator. In order for Planck’s theory to fit the observed data Planck’s constant has to have the value h = 6.6252x10^(-34)Js
You are aware, I assume, that all quanta contain the same amount of action.
Not only is that wrong but it’s meaningless. Quanta such as a photon can never be said to “contain” action. It’s total nonsense to suggest such a thing
I am sorry to say that many physicists do not understand Planck's constant ..
Quite wrong. All physicists know what Planck’s constant is. You don’t know what youre talking about.
- at least that is what I glean from my adventures on physics forums.
Then you gleaned wrong. Worst case scenario –physicists don’t recall that Planck’s constant used to sometimes be referred to as Planck’s quantum of action. That’s about it. However that’s merely history. Not physics. Or perhaps they don’t know why Planck’s constant is also called Planck’s quantum of action. But certainly not what you’re claiming.
In fact, many physicists seem unaware of the Quantum of Action (this discussion of mine on Physics Forums makes this quite clear http://www.physicsforums.com/showthread.php?t=367434).
That’s merely a name. A simple alternate term which hardly ever used. Not knowing this alternate terms means nothing other than people don’t memorize dictionaries.
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I find that impossible to believe. If what you claim is true for "many" physicists then you should be able to name just one. Please do so.
Juliana Brooks Mortenson at [NO SPAMMY LINKS PLEASE]
You have to be kidding me!! There's nothing on that page but a companies website. Merely posting that URL in no way addresses my question
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Judging by the number of people in physics asking the meaning of e=hf, it is reasonable to ask if the equation is correct. Many in the physics community are deciding that it is not.
I’m still waiting for your reply. I also want to know who it is that you’re referring to when you speak of the Many in the physics community. Are you referring to actual professional physicists? First, let’s be clear as to what a professional physicist is as the term is used by members of the profession. A professional physicist is a person who works at a job that requires special education in the various branches of sciences including physics, chemistry and math. That person may or may not get paid for their work as a physicist. So what proof do you have that that the majority of such people are as confused as you claim they are?
I explain why in http://www.thenakedscientists.com/forum/index.php?topic=41125.0. The post has been viewed by 1537 people and only one reply has been forthcoming.
So what? I can’t blame them. You’re all over the map with your accusations and from the posts you’ve made it’s clear that your understanding of quantum mechanics is seriously flawed. It’s quite possible that people may be ignoring you because they don’t thing that you’d be able to understand the explanation that they give you.
Take Planck’s constant as an example. In explained its origin above. I believe it was later on, after he defined it and after Einstein used it, that the synonym quantum of action was coined. There was a very good reason for it in the Old Quantum Theory described in Wikipedia at
http://en.wikipedia.org/wiki/Old_quantum_theory
Look at the first integral is known as a Phase integral (caution: the term phase integral, like so many other words in English, has other meanings). It has units of action. As you can see, the first integral in that page is the integral of pdq where p is the generalized momentum conjugate to the generalized coordinate q. Do you know physics well enough to know what these terms mean?
The action is probably different than you’re used to seeing it. Typically action is defined as the time integral of the Lagrangian which means that it has units of “energy” x “time”, i.e. J*s. Recall that the units of Planck’s constant also has units of action. If you sat down and worked out the units of the integral of p*dq you’d also see that it too has units of action. If we were to apply this to the hydrogen atom then we’d get the results known as the Wilson-Sommerfeld quantization rules. According to these rules, the phase integral of any variable over a complete cycle of its motion must be equal to an integer times Planck’s constant. That’s exactly why h is also referred to as the quantum of action. Since this is from the old quantum theory it’s wrong and no longer used anymore. That’s why nobody uses it.
Bohr came up with the idea that
(1) each electron in an atom revolves about the nucleus in a fixed orbit satisfying the condition that the angular momentum is an integral multiple of hbar == h/2*pi
(2) an electron does not radiate while occupying one of the quantized orbits but light s emitted or absorbed when an electron changes from one orbit to another.
So everything you’ve said about quantum mechanics, Planck’s constant h and the Quantum of Action is therefore wrong. All of what I’ve said can be found in the textbook Principles of Modern Physics by Robert B. Leighton, McGraw-Hill Book Company (1959) in chapter two.
Not certain what this means ….
It’s simple enough to find out what it means. Simply send a select number of members a PM asking them if they read it. When you find some of those who read it then ask them why they didn’t respond. When people read what other people believe and see that it’s all wrong experience has shown them that the people who post their beliefs rarely if ever, change them even after they’ve been corrected. More often than not they are unable to understand the corrections and then go ahead and claim its wrong. I’ve seen this a countless number of times. A very large number of physics enthusiasts learn what they know of physics from popular physics books on particular subjects. They rarely pick up an actual physics textbook such as the ones used in a college course. The reason most likely being that it requires a lot of math (algebra, geometry, trigonometry, calculus, etc), which they hated in high school and certainly don’t want to experience as an adult. This results in a very poor foundation, which then causes all sorts of misunderstandings.
…but am sure if I was talking rubbish I would get many challenges.
There’s absolutely no reason to believe that at all. Most people are likely very comfortable letting you believe whatever it is that you want to believe. People will only correct you when you attempt to explain something to someone else that’s wrong. For example; if you want to believe that the Earth is flat then all the power to you. However if someone comes here asking about how the shape of the Earth was discovered and you try to convince them that the surface of the Earth is flat then people will correct you very quickly.
Basically, the proposition being put by many physicists …
Please provide proof of this assertion.
(and me) is that the quantum is one of energy, not action.
Your poor understanding of quantum mechanics is causing you some problems now. You don’t seem to know what the term quantum means. Please learn the correct definition of quantum and other terms such as [I[quantized[/i] at http://en.wikipedia.org/wiki/Quantum
Let me give you some examples of how one uses the term.
Example 1) A electron is a quantum of the charge on a Van de Graaff generator.
Example 2) An atom is a quantum of matter.
Example 3) A photon is a quantum of light.
Example 4) The states of a particle in a potential well are quantized.
Example 5) The z-component of the spin of any particle is quantized.
Lets face it, no one really knows how a quantum of action relates to reality.
This is quite a false statement and is based on your ignorance of quantum mechanics.
Note: By ignorance I merely mean lack of knowledge, and not anything like stupidity or a state of being unwise. I don’t mean any disrespect by what I’ve talked about above.
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I should point out that what's going on in situations like pair annihilation/production is that the form of the matter is what's being converted.
Tell me more! AFAIK a photon is not matter. We start with a quantum of energy, transform it through an intermediate phase of mass, and end up with two quanta of energy.
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Tell me more! AFAIK a photon is not matter.
That depends on how you define the term matter. In his 1916 paper on general relativity Einstein defined it as follows
We make the distinction hereafter between "gravitational field" and "matter" in this way, that we denote everything but the gravitational field as "matter." Our use of the word therefore not only includes matter in the ordinary sense, but the electromagnetic field as well.
This appears in some texts publishedwithin that last 10-20 years as well such as some by the relativist Hans C. Ohanian.
This whole "converstion" thing can be phrased without using the term "matter." The invariant mass of a system of particles is given by
M_system = Sum m_i + Sum K_i/c^2
where m_i is the proper mass of the ith particle and K_i is the kinetic energy of the ith particle. Since the proper mass of a photon is zero the proper energy of a photon also zerp. Since the enery of any particle is the sum of its proper energy and kinetic energy it follows that the energy of a photon is all kinetic energy. Therefore part the mass of constituents has been coverted into energy. But it must be kept in mind that total mass and total energy remains the same in all reactions. Only the makeup of the system has changed.
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I repeat what I have said about action. Energy comes in wave packets called quanta. All quanta expend the same amount of action when interacting - Planck's constant h. Action is the expenditure of energy per unit of time. This is given by the equation h=ET.
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I repeat what I have said about action. Energy comes in wave packets called quanta. All quanta expend the same amount of action when interacting - Planck's constant h. Action is the expenditure of energy per unit of time. This is given by the equation h=ET.
Why on Earth are you changing the subject to something that nobody cares about?
Let me recall for you what you asked of me and what you said the return would be
You asked the following question:
I was talking about the Quantum of Action. If you can define and explain this entity, then I take my hat off to you. Care to have a try?
I took the time and effort to explain exactly what you were looking for, ad this is what I get for my trouble, i.e. you igored it and stated some bogus nonsense rooted in your ignorance in physics?
BTW - I asked you where and/or how you learned physics but you never answered. Why is that? Explaining this to me will help me help you learn
I explained why most people aren’t familiar with it, i.e. it's from the old, and thus invalid, quantum theory and its probably no longer taught even in undergraduate quantum mechanics courses. I know it because I've been physicist for well over 20 years now and studying physics for 30 years now. I learned it in my undergraduate quantum mechanics course.
and I was kind enough to take the time to answer it. You’ve been looking for that answer for sometime now. The least you could do is acknowledge that you now have your answer and why you were wrong. However we have no expectations of you thanking us when we help you. But this response is clearly your attempt to get around not acknowledging that you have proof of why you made a serious mistake like that.
You should have listened to JP. He’s very smart and very knowledgeable person. Better yet, you should learn physics, the right way this time. Then learn how to engage in a scientific discussion. In that kind of discussion you don’t simply ignore what the other person is saying. You either present an argument in which you demonstrate that their wrong or you admit that you’re wrong. Of if you’re the type who is too arrogant to admit to their mistakes then gracefully bow out of the argument. Under no condition do you instead change the subject to something totally irrelevant where nobody cares about the subject, like you just did here.
However you learned it up until now, it led you to have many misconceptions. One of these misconceptions has to do with your obsession with the term quantity of action. Even though I explained to you, and even showed you the Wiki page about the old quantum theory, you ignored me. We call it the Old Quantum Theory because (1) it predates modern orthodox quantum mechanics and (2) its not used anymore because it has major flaws in it (e.g. in the Bohr model an electron in the ground state has the value h/pi whereas in the correct theory, i.e. orthodox quantum mechanics, L = 0).
One of the major problems with it, which is not mentioned there, is that its derivation is based on classical trajectories. For example; in the Bohr theory the electron moves in circular orbits. In the Wilson-Sommerfeld theory the electrons can also move in elliptical orbits.
Another misconception you have is your statement Energy comes in wave packets called quanta which is wrong. You’re thinking of particle ot energy. Particles are the real physical entities that experience the wave-particle duality. Energy is merely a mathematical concept related to what’s observed in nature. All we know about energy is that it comes in various forms and the sum of the various forms for a closed system remains constant in time, i.e. is conserved.
You’re claim that All quanta expend the same amount of action when interacting - Planck's constant h is quite misguided. First off its based on action which comes from a wrong, outdated theory. However if, for example, you’re talking about a photon and are referring to the relation E = hf where h = Planck’s constant, f = frequency of photon and E = energy of the photon and are claiming that all photons have the same energy, then you’re absolutely wrong. If you’re thinking about the old theory and are referring to Integral pdq= nh then you’re wrong there too.
You should have listened to JP. He knows what he's talking about.
In my next post I'll explain what E = hf means in excruciating detail
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All quanta expend the same amount of action when interacting - Planck's constant h. Action is the expenditure of energy per unit of time. This is given by the equation h=ET.
There's no such thing as expending action. Action is not a thing that exists in nature. The same is almost true about energy but with energy there is something corresponding to the mathematical bookkeeping concept that defines energy. So it's not all together un-meaningful to speak of expending energy but one has to be very clear about what one means when talking about it. But you're once again confusing period with time, thus once more ignoring what JP said. You're confusing time with period because they're related and have the same units.
Consider time to start with. We will set up a laboratory and in the laboratory we will set up a clock. On Jan. 1 at 12:00am 2015 we will set the clock to read zero. It reads the absolute value of time, in seconds(s), after the zeroing event and not the time of day like other typical clocks read. Let this value be “t”. It represents the time that the clock reads. It represents the time parameter that appears in Maxwell’s equations. It’s a constantly increasing number. If we might repeat an experiment starting at exactly the same time each day then when we start the experiment the clock will read the time it read yesterday plus 86,400 s.
In the lab we will have 3 sources of photons. Each source emits individual photons. One emits blue photons (wavelength= 720 nanometers), one emits red photons (wavelength = 440 nanometers) and the last source emits green photons (wavelength = 833 nanometers). There is a photo detector that detects the photons and reads out the energy of the photon. All the photon detectors are identical. The wavelengths I used for sources is merely representative of those colors. In reality there is an entire spectrum of red, green and blue light.
Each morning we launch a red photon from the red photon emitter to its corresponding detector and measure the energy of the photon. An hour later we repeat this experiment. An hour after that we do the same thing but with green photons and then repeat it. Finally we repeat the whole thing using blue photons. The value of “t” keeps increasing at a constant rate since that’s what time does. However T will have one single value in the first set of experiments corresponding to the period of red photons. T will have an entirely different yet single, value in the second set of experiments and finally T has another value corresponding to blue. So you see, the “period” of a photon as a very different meaning than time itself. In each experiment “t” – time had a different value. However T = period had the same value in the first and second experiments. T had the same value in the third and fourth experiments. T had the same value in the fifth and sixth experiments.
It takes about the same time to emit each photon and about the same time to detect each source. The frequency of the photons shouldn’t be taken too literally. All it means is that the phase of the photon changes as it propagates at the rate given by the frequency of the photon. The period of the photon is also not related to how long it takes to absorb the photon either. We don’t even think of the period of the photon as the time it takes for the photon to pass a certain plain parallel to its direction of propagation. The frequency of a photon has the following meaning: It is the amount of time for the phase of the photon to change by the value of 2pi.
Now we look at the energy of each photon, E = hf. Let L = wavelength, T = period, c = speed of light. We can derive expressions for how they’re related by using the fact that they have their usual meaning when applied to electromagnetic waves and these relations remain the same when going back to quantum theory. Therefore
c = L/T = Lf => f = c/L
E = hf = hc/L
h = 6.626 x 10^(-24) Js, c = 3.00 x 10^8 m/s
L_red = 440 nm, L_blue = 720 nm, L_green = 833 nm
hc = [6.626 x 10^(-24) Js][3.00 x 10^8 m/s] = 1.9878 x10^(-15) Jm
E_red = hc/L_red = 1.9878 x10^(-15) Jm /440 x 10^(-9) m
E_red = 4.518 x 10(-9) J
E_green = hc/L_green = 1.9878 x10^(-15) Jm /833 x 10^(-9) m
E_green = 2.254 x 10(-9) J
E_blue = hc/L_blue = 1.9878 x10^(-15) Jm /720 x 10^(-9) m
E_blue = 2.761 x 10(-9) J
The way you’re using E = h/T is all twisted since you keep misinterpreting what T is. And your obsession with “quantum of action” is just a waste of time since it originated from an old theory, one no longer in use. The reason it’s a waste is because this old theory is old because it’s wrong. No such action can be defined in modern quantum mechanics because the classical trajectories that it’s defined relative to don’t exist.
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I do not have the time to reply to your copious posts. Pick your battles. I do not reply full-stop to people who come across as unfriendly and you most certainly do. I am only replying to your last post because you have toned down your language. I have studied quantum physics as a hobby for many, many years. I have university maths A & B qualifications. Also Computer Science. I am a software developer who specialises in State Machines. Also a degree-qualified life coach. I firmly believe physics has somewhat missed the boat by concentrating so much on mathematics in an attempt to explain reality. The purity of mathematics and the messy nature of reality do not go together well. Computer-based state-machine simulations (with, maybe, a mathematical core) are the only way to go, in my opinion, to explain reality. I study physics because it is fascinating and because I am trying to create an artificial reality based on state machines and the principles of physics. I am a world-class software developer who has a real talent for simplifying complex phenomena.
I try to learn physics based on concepts rather than mathematics. I can learn a concept in minutes whereas it may take me weeks to understand the mathematics that attempt to underpin the concept. Unfortunately physics seems to have few champions who can talk in conceptual rather than mathematical terms. Unfortunate, also, that physics is full of often competing theories that just don't make much sense in the big picture and don't explain the "how" of reality. Last time I heard there were about 10 string theories that do all an equally good job of explaining the standard model. If I were you, I would not hold onto your precious theories with any degree of certainty.
I all my copious research on quanta and my equally copious discussions in physics forums I have never found out that h is not a quantity of action (I am aware that action is the integral of energy over time by the way). I am aware that energy is a disturbance in a field and that this equates to a particle (the field makes a comeback!). I am also aware that there is one field for each type of particle. And that a field occupies all of space. This is remarkably like the class/object relationship in software development. I am aware of symmetry's role in force and totally agree with susy's prediction that there will be a type of fermion that corresponds to each type boson.
Finally, I don't actually accept h as a unit of action. Rather that it is a unit of energy and that all quanta "contain" h amount of energy. But this has been discussed before in the post. Hopefull you have read these onedrive files https://onedrive.live.com/redir?resid=8147C9C160CC0049!9056&authkey=!AI7DhJ90MuZE08U&ithint=folder%2c.
I am a long, long way from being an expert on physics and try and make it clear that I am no expert when discussing it - not always successful in this!
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Knew all this. Pretty basic stuff. I am not talking about photons. I am talking about energy. It comes in wave packets called quanta. All quanta "contain" a constant amount of action, h (joules.sec). This is the basis of quantum physics and is a most remarkable fact. If action is obsolete then E=hf is also obsolete. The equation h=ET (a version of E=hf) illustrates the nature of a quantum (T is the period of the wave packet). If h = 10, then ET can be e.g. 10*1, 5*2, 1*10 etc.. Increase the energy and you decrease the period. And vice versa. Since energy is present in all particles in the standard model, the particles are said to be quantized.
But I am repeating myself.
Thank you all so much for your time, and a very interesting thread.
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I repeat what I have said about action. Energy comes in wave packets called quanta. All quanta expend the same amount of action when interacting - Planck's constant h. Action is the expenditure of energy per unit of time. This is given by the equation h=ET.
Apart the concept of "expenditure of energy", which I don't know what it means, what I coloured red of your post is wrong: action is energy*time, not energy/time. You don't even know what "per unit time" means?
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lightarrow
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I repeat what I have said about action. Energy comes in wave packets called quanta. All quanta expend the same amount of action when interacting - Planck's constant h. Action is the expenditure of energy per unit of time. This is given by the equation h=ET.
Apart the concept of "expenditure of energy", which I don't what it means, what I coloured red of your post is wrong: action is energy*time, not energy/time. You don't even know what "per unit time" means?
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lightarrow
Hi lightarrow. I always try and enlighten when I criticise a post. "Action is energy*time" is not an explanation of action. It is like saying energy is mass*speed of light squared. What does energy*time actually mean in reality? Noone knows. Probably I should not have attempted to try to explain it, especially as I have previously argued in this post that h is better thought of as energy, not action. Time to wind up this thread I think.
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momentum is not always defined as: p=m*v. In the case of a photon, p=h/λ.
That is incorrect. You're confusing a definition with an equality. The expression p = mv defines mass m (as well as momentum p). To understand what that ,seemingly confusing, statement means please see Eq. (7) at
http://home.comcast.net/~peter.m.brown/sr/inertial_mass.htm
Basically one defines m such that mv is conserved.
The expression p=h/λ does not define momentum. It is merely a relationship/equality between the momentum of a photon and its wavelength. However this thread was about special relativity, not qauntum memechanics. The former is a classical theory whereas the later is not. However the mass of a photon is well known to be defined the same way as for all other particles. In terms of magnitudes p = mv so that the mass of the photon in terms of its momentum is m = p/v. Since v = c for a photon we have m = p/c. The relationship between a photons energy and its mass is E = pc so that p = E/c. The mass of the photon in terms of the photons energy is then m = (E/c)/c = E/c2.
When mass is defined as m = p/v its sometimes referred to as relativistic mass. For more on the mass of a photon please see
http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html
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Mxplxxx: Let me explain something before I continue. I used to post using the handle Pmb. I’ve been a member since July 2009, i.e. for five years now. I’ve posted over 1,800 posts which has earned me the title Hero Member. However, due to the lack of proper moderation there are few members here who the moderators permit to be rude and violate the forum rules. Since you can’t quit this forum and I was too tempted to come back and attempt to forget those horrible people I changed my account so that I couldn’t use it. I went away and created my own successful forum. The hosting company went out of business so until I recreate my forum I’ll be posting here. I miss helping people to much.
I’m in the unfortunate position of being disabled. I have chronic pain that has not only ruined my professional life but makes me impatient. I also get angry easily as a result of what the pain does to my mind. So if I appear to be impatient you now know why.
However you’re not acting in way that makes me wish to continue after this post. My experience of posting online over the last 20 years has shown me that when you ask then a direct question about their knowledge of physics, i.e. how they learned it, where they learned it, how long they’ve been studying it, etc. in perhaps 95% of the time people will act as if you never asked the question and ignore you. They then repeat all the same nonsense that already corrected as if you never said anything at all. I will not bother helping people as inconsiderate as that. And that’s what you’re doing. I clearly asked you about the source of your education and you ignored me. If you’re ashamed of it then I have no time for you. But in order to help you I must know it. How else am I to understand what explanation you will or won’t be able to understand? As far as I know, the way you’ve chosen to handle explanations you can’t grasp is to ignore it as if I never posted it and then go on like I never posted it. Also, how can I possibly know how to explain something to you when I don’t know whether you can grasp it or not. E.g. you keep talking about action but I have no way to know whether you even know what action is and how it’s used in physics. From your responses and comments about it you speak as if you’re totally clueless about what it is. For example, you keep talking as if particles can actually “posses” or “contain” action which is complete nonsense. Any physicist will tell you that someone who says things like that doesn’t know what they’re talking about.
I have no wish to be rude. In fact I’m actually quite a polite person in life off the Internet.
But since you’ve chosen to ignore me then I’m going to place you in my “block sender” list. I simply can’t see talking to someone who’s ignoring what I write. Especially since your claim that you were to take your hat off to me was clearly a lie. When I proved what you wanted me to you ignored me.
Knew all this. Pretty basic stuff. I am not talking about photons.
Correction. You were talking about the relationship E = hf = h/T and kept making incorrect assertions about it. You keep confusing T (period) with t(time) and that’s what I was talking about. I used an example to drive my point home and you can’t use an example unless you chose a type of particle to use in the illustration for which E = hf. Since that expression works for photons and all free particles I used photons to make it easier since the frequency has a more direct meaning that anyone can understand. E.g. a statement like “the photon is blue” can’t be applied to electrons.
I am talking about energy.
Not really. You keep confusing energy with particles.
It comes in wave packets called quanta.
This is where your confusion lies and I already explained why its wrong. Why did you ignore me? If you’re going to ignore what I’m telling you then there’s no reason for me to make any attempt to help you, is there? If you claim than I’m wrong then please make an attempt to demonstrate it. But please don’t simply ignore my correction and repeat your mistake over and over again. It’s frustrating.
All quanta "contain" a constant amount of action, h (joules.sec).
So. Once again you’re ignoring me and repeating your mistake. Let me let you in on something. When you wrote If you can define and explain this entity, then I take my hat off to you. Care to have a try? I was kind of impressed. I thought Hmmm. Perhaps
w
Don’t you understand how much that kind of exchange violates the very foundations of science? Since you don’t appear to understand that please read the definition of science defined by the American Physical Society which is online at
http://home.comcast.net/~peter.m.brown/ref/what_is_science.pdf
This is the basis of quantum physics and is a most remarkable fact.
That is incorrect. The basis of quantum mechanics is the postulates of quantum mechanics. They’re also online at
http://hyperphysics.phy-astr.gsu.edu/hbase/quantum/qm.html
If action is obsolete then E=hf is also obsolete.
You keep ignoring what you’re being told. h is not action like you keep claiming that it is. I keep telling you why that’s wrong and you keep ignoring that with all the other things I’m trying to explain to you. Do you understand how irritating that is?
I’ll explain it one last time and then I’ll never try to help you understand it again until you learn it.
h is defined as a constant which appears in many places in quantum mechanics. Most notably it appeared when quantum mechanics was first being discovered. The very first instance that it occurred was the place it was defined. I already explained this above, i.e. by Max Planck in order to account for black body problem radiation. Planck conceived of a black body as being composed as a collection of harmonic oscillators. To each oscillator he assigned it energy of the form E = hf, where h is a constant determined by experiment, f took on a variety of values. Later on in 1905 Einstein published a paper for which he was awarded the Nobel Prize. It was on the photoelectric effect.
The photoelectric effect is defined as follows: when light falls on a metal surface electrons are sometimes given off. Such electrons are referred to as photoelectrons. They are no different than any other kind of electron. They have that name only because of the way they are emitted. Prior to Einstein physicists envisioned electrons absorbing energy from electromagnetic waves. The electrons are imagined to being shaken by the electric field until it has enough kinetic energy to be emitted from the surface of the metal that the light is being shined on. In order to explain the experimental results Einstein postulated the existence of photons, i.e. Einstein postulated that light is quantized (the light exists in discrete amounts) in units which came to be given the name photon. According to Einstein’s photon concept the basic process is the absorption of a quantum of energy E = hf by an individual particle.
Later on it was shown that when the energy of any free particle is measured it has a value given by E = hf whether it’s a photon, an electron, a pion, a neutrino, etc. The relationship E = hf is not a condition of quantinization. For a free particle the energy can have any value in a continuous spectrum of possible values. So be aware of making that mistake. As a counter example consider the two examples all quantum mechanics students must learn; a particle of mass m in (1) an infinite square well of width a and (2) an harmonic oscillator of natural angular frequency w. The values of energy are (let n be a positive integer, i.e. n = 1, 2, 3, ….)
Infinite square well) En =hbar kn2/2, where kn = n pi/a
Harmonic Oscillator) En = (n + ½)hbar w
If you’re not careful then you’re going to confuse the E = hf as being the energy of any particle whatsoever. When you do that you’ll be making a mistake.
For a free particle E = hf is only one of a possibly continuous spectrum of values that the energy can have. E.g. a wave-packet for a free particle moving in one dimension is a superposition of plane waves, each of which has a different energy. Any function be represented as a Fourier series of sines and cosines so Fourier methods are used to create the superposition.
The equation h=ET (a version of E=hf) illustrates the nature of a quantum (T is the period of the wave packet).
That’s not true. E = hf tells you absolutely nothing about a wave-packet. In fact if the only possible energy that the particle can have is E = hf then there’s no wave-packet at all. The wave is a plane wave. Only when you add up plane waves of different energies do you get a wave-packet.
Increase the energy and you decrease the period. And vice versa. Since energy is present in all particles in the standard model, the particles are said to be quantized.
That’s quite wrong. Energy could always have been said to be present in particles dating back to the invention of kinetic energy. Classical mechanics gives the presence of energy in a particle. That in no way, shape or form makes the particles quantized.’
By the way, you’re misusing the term standard model. That’s a widely misused term. The term Standard Model refers only to the theory of elementary particle physics. See http://en.wikipedia.org/wiki/Standard_Model
The only other use in physics is “Standard Model of Cosmology”.
If action is obsolete then E=hf is also obsolete.
Good Lord! Where did you ever get that idea from? It’s only the “quantization of action” defined as Integral pdq = nh which is wrong. That in no way implies that E = hf is in anyway wrong. They have nothing to do with each other. This is what you get for being obsessed with “quantum of action” at the expense of all else. You too an alternate name for h and then claimed that since the motivation for that name is wrong then so to is all theories which motivated the term. Do you understand how illogical that deduction is? Wow! Its use in its current and original form has remained the same since it was created by Planck and Einstein. Don’t confused Wilson and Sommerfeld’ s wrong turn as being the end all and be all of all of the quantum physics connected with Planck’s constant h.
Thank you all so much for your time, and a very interesting thread.
What? No “hat’s off” yet for solving your problem, huh? False promises like that make people like me not want to help you ever again. This is about false statements, not arrogance of being under appreciated. Do what you promise to do or don’t make any promises again.
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I repeat what I have said about action. Energy comes in wave packets called quanta. All quanta expend the same amount of action when interacting - Planck's constant h. Action is the expenditure of energy per unit of time. This is given by the equation h=ET.
Apart the concept of "expenditure of energy", which I don't what it means, what I coloured red of your post is wrong: action is energy*time, not energy/time. You don't even know what "per unit time" means?
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lightarrow
Hi lightarrow. I always try and enlighten when I criticise a post. "Action is energy*time" is not an explanation of action.
First, differently from you, I have never tried to provide such an explanation...
Second, I simply have corrected a mistake of you.
Third, if you want to discuss about physics concepts you have to use them properly...It is like saying energy is mass*speed of light squared.
I wish you could! To define energy in general is not so simple, my friend! What does energy*time actually mean in reality? Noone knows.
Tell it to Richard Feynman: he showed its meaning creating the "Path Integral" approach of quantum mechanics.Probably I should not have attempted to try to explain it, especially as I have previously argued in this post that h is better thought of as energy, not action.
But you cannot give your personal meaning to physics concept which are already defined: they have *that* meaning and it's all. More so, you cannot do it with *physical quantities*: you cannot give the meaning of "energy" to a physical quantity which is instead "energy multiplied time", as you cannot, for example, give the meaning of "time" to a quantity which actually is a "lenght".
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lightarrow
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Returning to my original question, E (kg⋅m2/s2) = m (kg) c (m/s)2 looks remarkably like a units conversion to me! Is mass just concentrated energy? How can a unit that relies on gravity to define it come to represent energy at an atomic level?
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For a much easier to understand approach to quantum physics, including equations that do not include Planck's constant, I recommend Jonathan Deutsch's Time's Dual Nature. I promise you it is a real game-changer.
http://www.amazon.com/Times-Dual-Nature-Common-Sense-Approach/dp/1453780998/ref=sr_1_1?s=books&ie=UTF8&qid=1402385625&sr=1-1&keywords=times+dual+nature (http://www.amazon.com/Times-Dual-Nature-Common-Sense-Approach/dp/1453780998/ref=sr_1_1?s=books&ie=UTF8&qid=1402385625&sr=1-1&keywords=times+dual+nature)
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Returning to my original question, E (kg⋅m2/s2) = m (kg) c (m/s)2 looks remarkably like a units conversion to me! Is mass just concentrated energy?
We had a lot of threads about mass in this forum.
You can define a system's mass as its energy (divided by c2) computed in a frame of reference where the system is still (= its total momentum is zero).But, as I and others have already written to you, if the system it's not still, its energy is not its mass multiplied c2.How can a unit that relies on gravity to define it come to represent energy at an atomic level?
Because (and Einstein exploited this fact in GR) gravitational mass and inertial mass are the same thing.
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lightarrow
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Because (and Einstein exploited this fact in GR) gravitational mass and inertial mass are the same thing.
Let’s be precise about this. Inertial mass, which I’ll label mi is not the same thing as gravitational mass. They are not identical, they are proportional.
What follows is how this is all explained in the physics literature, not merely something I came up with. Although it is something I highly agree with.
Einstein used the emperical fact that the inertial mass of an object is proportional to the bodies passive gravitational mass which I’ll label as mp. This is the mass on which gravity acts. If we let active gravitational mass as ma, which is the source of gravity. The gravitational force on the body due to the source, Fg, is then
Fg = Kmamp/r^2
where K is a constant of proportionality. Then since Fg = mai
a = (mp/mi)Kma/r^2
What Einstein exploited was the fact that there exists some constant c such that
mp = c*mi
a = (cmi/mi)Kma/r^2
a = cKma/r^2
Define the constant G = cK and call it the gravitational constant. Then
a = Gma/r^2
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We had a lot of threads about mass in this forum.
And you’ve been ignoring the other definition of mass which is widely used and what is confusing mxplxxx who wrote It is like saying energy is mass*speed of light squared to which you responded I wish you could! To define energy in general is not so simple, my friend!, the accuracy of which depends on which definition of mass one is referring to. Did you ever tell him that there actually is a definition for which his statement is true?
All one has to do is look at the definitions of two main sources on the internet for physics information, i.e. the Usenet Physics FAQ
http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
and Wikipedia
http://en.wikipedia.org/wiki/Mass_in_special_relativity
http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence
But, as I and others have already written to you, ..
But not all of us. You left the opposing side out, i.e. me. In which case your assertion
if the system it's not still, its energy is not its mass multiplied c2.is wrong.
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Because (and Einstein exploited this fact in GR) gravitational mass and inertial mass are the same thing.
Let’s be precise about this. Inertial mass, which I’ll label mi is not the same thing as gravitational mass. They are not identical, they are proportional.
What follows is how this is all explained in the physics literature, not merely something I came up with. Although it is something I highly agree with.
Einstein used the emperical fact that the inertial mass of an object is proportional to the bodies passive gravitational mass which I’ll label as mp. This is the mass on which gravity acts. If we let active gravitational mass as ma, which is the source of gravity. The gravitational force on the body due to the source, Fg, is then
Fg = Kmamp/r^2
where K is a constant of proportionality. Then since Fg = mai
a = (mp/mi)Kma/r^2
What Einstein exploited was the fact that there exists some constant c such that
mp = c*mi
a = (cmi/mi)Kma/r^2
a = cKma/r^2
Define the constant G = cK and call it the gravitational constant. Then
a = Gma/r^2
Good. And which is the value of that constant c = mp/mi? Which kind of experiment allow/will allow us to measure it?
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lightarrow
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We had a lot of threads about mass in this forum.
And you’ve been ignoring the other definition of mass which is widely used and what is confusing mxplxxx who wrote It is like saying energy is mass*speed of light squared to which you responded I wish you could! To define energy in general is not so simple, my friend!, the accuracy of which depends on which definition of mass one is referring to. Did you ever tell him that there actually is a definition for which his statement is true?
mxplxxx wrote:
<<Returning to my original question, E (kg⋅m2/s2) = m (kg) c (m/s)2 looks remarkably like a units conversion to me! Is mass just concentrated energy? >>
and I replied that we had a lot of threads about mass, so he could look for them and understand that E = mc2 is not simply a units conversion. You don't agree with me? I thought you did.
And about the fact "mass is just concentrated energy" you agree with him?
About what you wrote I intentionally didn't want to argue with you, infact in my replies to him I have used the (generally accepted in modern physics) same equation that you mentioned in one of your first posts of this thread:
E2 = (cp)2 + (mc2)2.
You want to say that it's possible to write E = Mc2 if M is the "relativistic mass"? Say it, if you like.
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lightarrow
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..and I replied that we had a lot of threads about mass, so he could look for them and understand that E = mc2 is not simply a units conversion.
And not only do people never do that but if they tried it'd probably be too hard to find, especially the points that needed to be made.
You don't agree with me? I thought you did.
Of course I agree with that.
And about the fact "mass is just concentrated energy" you agree with him?
Of course not. There is nothing in anything that I've ever posted in this forum that indicates otherwise on these last two points.
I suggest that you try not to be so adverse to when others think that the entire story needs to be explicitly stated rather than assume the reader can dig out the point they wish to make by a vauge suggestion to "search the forum for mass."
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I suggest that you try not to be so adverse to when others think that the entire story needs to be explicitly stated rather than assume the reader can dig out the point they wish to make by a vauge suggestion to "search the forum for mass."
But on the fact "the entire story needs to be explicitly stated" I certainly agree. I suggested him to look for other threads just because I didn't want to write again what I (and you and others) have already written many times about what he needed to know.
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lightarrow
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But on the fact "the entire story needs to be explicitly stated" I certainly agree. I suggested him to look for other threads just because I didn't want to write again what I (and you and others) have already written many times about what he needed to know.
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lightarrow
I know and fully agree. Unfortunately people like him never do that.
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This was a weird read :)
Interesting but weird. A constant is a constant, and it's there, until proven wrong. Physics doesn't once and for all define anything to be 'true for ever', and that goes for everything. Well, as far as I get it at least. When it comes to Planck's constant it's exactly as Pete write. It's a mathematical concept from the beginning to make a possible explanation (black body radiation in this case) for a otherwise very strange behavior. And it has been tested innumerable times and found valid. To call it some kind of 'action'? I don't know? I prefer to think of it as a constant defining a behavior myself. Then again, I'm very partial to constants, you might call me a believer :)
And it's nice to see you writing again Lightarrrow, long time no see.
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And it's nice to see you writing again Lightarrrow, long time no see.
Thank you, yor_on, the same for me about you.
Unfortunately I have just little time to write in this forum.
Bye!
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Hi All - thought I would throw my two cents worth in. Planck ORIGINALLY worked on electromagnetic theory with energy, an energy constant (energy/EM oscillation), measurement time (of the EM irradiation) and frequency (osc/sec). His original relationship was thus E = energy constant X measurement time X frequency.
When he wrote his famous paper deriving the formula for black-body radiation, he had to resort to the use of Boltzmann's methods (Planck was not very fond of Boltzman) and this in turn caused him to multiply his original energy constant and measurement time into the single value "h".
The product of energy and time is called "action" so Planck's constant "h" was and is referred to as an action constant. Planck didn't really like it at first as he had an energy constant in mind, not an action constant. It produced the odd result that the fundamental particle of light came in an infinite variety of energies, rather than having a constant defining energy ... a defining constant characteristic such as the charge on an electron. The units didn't balance either because the "oscillations" in frequency (osc/sec) were unbalanced.
But the number worked and people started using his equation so he went with it.
If we restore his original formula we have E = E/osc X measurement time (sec) X frequency (osc/sec). Units balance and total energy can be determined. If you irradiate for 2 seconds instead of one you measure twice as much energy. The energy constant from Planck's original formulation turns out to be the energy of a single EM oscillation. The energy is conserved over time and space, and appears to be therefore the true quantum of energy for EM waves.
Because the units did not balance in Planck's condensed E = hf, the engineers and scientists got together back in the thirties and officially changed the nomenclature for frequency from osc/sec to sec-1. That got rid of the pesky oscillations hanging out of the equation and everything balanced.
So far so good, but it was incomplete mathematical notation and that never helps anything. Kind of like describing your miles per hour speed as just hour-1. You would have to start putting in a lot of fudge factors to account for the fact that it was miles and not kilometers or yards you were measuring. Same thing happened in quantum mechanics. More and more fudge factors had to be brought because the foundational quantum equation was abbreviated and incomplete in a mathematical sense.
A lot of the problems in quantum mechanics go away if one uses Planck's original and complete quantum formula.
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The product of energy and time is called "action"…
That is incorrect. You’re confused. There are only two quantities which carry the name action and they are I = Integral L dt where L = Kinetic Energy – Potential Energy = T – V. The other is Integral pdq = nh where n is an integer and h is Planck’s constant. It’s this later integral from the Old Quantum Mechanics that it got one of its alternative names quantum of action. Just because something has the units of action you can’t say that it “is” action. So to be correct product of energy and time is “has units of action.”
… so Planck's constant "h" was and is referred to as an action constant.
That’s incorrect. It was referred to as the “quantum of action.
Planck didn't really like it at first as he had an energy constant in mind, not an action constant. It produced the odd result that the fundamental particle of light came in an infinite variety of energies, rather than having a constant defining energy ... a defining constant characteristic such as the charge on an electron.
Planck postulated that the walls of a black body could be modeled as being composed of harmonic oscillators. However it was Einstein who postulated that light was quantized.
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Thanks for your thoughtful response PmbPhy. I am just using the language that Planck and Einstein and the other fathers of quantum language used. Maybe the translations from German to English are off a little, but I would encourage you to go back and read some of the original papers. Fascinating reading!
I stumbled across Planck's original relationship a bit by accident. After digging back through all his old papers and his quantum derivation, I wrote it all up in a nice paper. Hans Peter Duerr and I (Hans Peter ... Director Emeritus Max Planck Institute for Physics, and Heisenberg protege) sat down together and went through the mathematics step by step. Afterwards he smiled and said in his wonderful German accent, "Well your mathematics are correct ... the question now is the interpretation!"
Interestingly, Hans Peter had not read Planck's original papers, and I suspect many other physicists have not read them either. When I presented the work at the annual APS meeting, there was only one physicist in the audience who had read any of them!
The point is that if we use Planck's ORIGINAL relationship, we gain many more degrees of freedom. Measurement time is no longer a standardized value of 1 second. And the clear chemical and materials effects of EM radiation below the molecular bond threshhold (IR, MW and RF) no longer violate quantum relationships. We suddenly have a real constant for light that is conserved over time and space, yielding a wonderful candidate for the fundamental quantum of light. When you think it through, many of the paradoxes - those that Heisenberg, Bohr and others struggled with - just dissappear!
So Planck's complete equation has many interesting applications.
PS - The cites to the original papers by Planck, Einstein and others can be found in my papers at www.EinsteinsHiddenVariables.com. The mathematics I reviewed with Hans Peter are laid out in good detail in papers #1 and #2.
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I guess we should ask the question "what attribute(s) of mass distinguish it from energy?". Is it in fact a type of particle?
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Maybe the translations from German to English are off a little, but I would encourage you to go back and read some of the original papers. Fascinating reading!
Thanks, by I've already read them. [:)]
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PS - The cites to the original papers by Planck, Einstein and others can be found in my papers at www.EinsteinsHiddenVariables.com. The mathematics I reviewed with Hans Peter are laid out in good detail in papers #1 and #2.
Juliana, I'm not a scientist but I would like to read the slides you cite in your homepage but those links don't work. I have downloaded the pdf documents in the page "links" to read them. Are they the same of the slides?
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lightarrow.