Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: meta-sci on 20/06/2009 04:17:41

Title: How much do all of the electrons on Earth weigh?
Post by: meta-sci on 20/06/2009 04:17:41
What is the separate particle mass total for the earth's mass?
i.e.  quark  ?%
      electron   ?%
Title: Re: How much do all of the electrons on Earth weigh?
Post by: labview1958 on 19/08/2009 12:48:20
Is it possible to create particles from plain energy? Reversing Einstein equation. m = E/c2.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: syhprum on 19/08/2009 13:01:22
The mass of the main constituents of matter Protons and Neutrons derives from the Quarks and the binding energy of the Gluon's this is still controversial but it is believed that the binding energy of the Guons forms the greater contribution.
Electrons having a mass of 1/1836 that of a Proton are a minor contributor.
The mass of the earth is approximately 6*10^24 Kg so you can do the arithmetic.

http://www2.slac.stanford.edu/vvc/theory/quarks.html
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Vern on 19/08/2009 17:24:06
We seem to be moving away from the concept of mass as a system. This I suspect is bad. My concept of mass is that it is a system consisting of the combination of the movement of energy fields. The fields may be bound in particles we like to call electrons, protons, neutrons, and  maybe even quarks. This is just my speculation. But, if you take away the electromagnetic fields, you take away all of the mass. So it is difficult to imagine "rest mass". Maybe all of massiveness is really only relative movement.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Farsight on 19/08/2009 18:04:34
Not quite, Vern. Put a photon inside a mirrored box. It exhibits no electric field, but the mass of the system has increased. IMHO it's better to think of "rest mass" as energy that is not moving in aggregate with respect to you. Essentially it's "rest energy", even though the photon is not actually at rest. Alternatively think of inertia as exhibiting a symmetry with momentum. If it's the photon moving, it's got momentum p=hf/c. If however it isn't moving in aggregate with respect to you, what you measure is mass. And of course to make a photon not move in aggregate with respect to you (at least not much) we use pair production, so creating mass and charge. To reverse the process, we use annihilation. Only in between these two events, we don't talk of photons, we talk of electrons and positrons. This is no speculation, this is experimental fact. I've now come to feel that pair production is like a hole in the heart of physics. Nobody has previously explained what's happening, and it seems that nobody has thought it important. Of course, the confusion and ambiguity surrounding the word mass doesn't help either.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Vern on 19/08/2009 19:07:20
What is a photon if not electromagnetic field? I have always seen photons explained as waves of changing electric and magnetic amplitude. I speculate that the electric and magnetic fields that comprise photons always go to saturation at two single points. This saturation property gives rise to quantum phenomena.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Nizzle on 20/08/2009 05:47:53
Mass is interaction of particles with the Higgs field
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Farsight on 20/08/2009 08:43:15
What is a photon if not electromagnetic field? I have always seen photons explained as waves of changing electric and magnetic amplitude. I speculate that the electric and magnetic fields that comprise photons always go to saturation at two single points. This saturation property gives rise to quantum phenomena.
It's an electromagnetic wave, Vern. Yes, there's electromagnetic field in there, it's varying in a sinusoidal fashion, hence there has to be an alternating current. But when we talk of waves and amplitude we don't say that the amplitude is changing as the wave passes by. The amplitude is the peak-to-trough measure. Look at a picture of the electromagnetic spectrum: 

(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fkirkwoodschools.org%2Ffaculty%2Fmcgeech%2Fupload%2F4845f11eadc9a.jpg&hash=7c4001f34324c82f148edc78b35b0fcb)

What do you see? A common amplitude. The amplitude is always the same

As to what it really is, the clues are scattered throughout history and in the evidence. You and Robert Kemp have found some I know, but for the life of me I don't understand why it's speculation and why none of it is in the curriculum: the photon conveys energy, and the dimensionality of energy is stress x volume. See Einstein's stress-energy-momentum tensor (http://en.wikipedia.org/wiki/Stress-energy_tensor) and think of space and pressure. See Minkowski's Space and Time where he talks about a wrench. Everybody misses this, but he's talking about the thread of a screw: think of the right hand-rule and imagine gripping a reamer or drill bit and pushing it up with your thumb. The electric field is analogous to the twist, the magnetic field is analagous to the turn. So think of the photon as a pressure pulse, and the shape of it is the integral of the sinusoidal electric waveform, because that's giving you the slope. Now think p=hf/c, see Planck's constant of action (http://en.wikipedia.org/wiki/Planck_constant) and note where it says: The dimensions may also be written as momentum multiplied by distance. See the original Maxwell and note his displacement current and his electric elasticity equation E=1/ε D. Now look at pair production and the electron's Compton wavelength (http://hyperphysics.phy-astr.gsu.edu/HBASE/quantum/compton.html) of 2.426 x 10-12m. That amplitude is a kind of saturation, but it's also a kind of elastic limit. And underlying it is a geometrical spatial extension, like a Weyl gauge-change. The common photon amplitude is a distance. Divide by 2π for the double-wrapped photon and it's 3.86 x 10-13m. That's the quantum of quantum mechanics. People say the gravitational field is curved spacetime, but that's the effect, not the cause. And what they miss, is that the electric field is curved space.

Title: Re: How much do all of the electrons on Earth weigh?
Post by: labview1958 on 20/08/2009 10:17:29
If a photon slows down does it become heavier? E=mc2. If m goes up then c comes down to keep E constant.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Nizzle on 20/08/2009 11:59:22
If a photon slows down does it become heavier? E=mc2. If m goes up then c comes down to keep E constant.

Or maybe the photon will have less energy when it slows down and it's mass stays constant  [;)]
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Vern on 20/08/2009 13:50:33
Quote from: Farsight
As to what it really is, the clues are scattered throughout history and in the evidence. You and Robert Kemp have found some I know, but for the life of me I don't understand why it's speculation and why none of it is in the curriculum: the photon conveys energy, and the dimensionality of energy is stress x volume.
So you are the Farsight I know from other places [:)] Good to see you here! I think we mostly agree about the photon construct. Too bad we haven't come up with some great principal that will make this view of nature useful for predicting experimental outcomes.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Vern on 20/08/2009 13:55:08
Quote from: Nizzle
Or maybe the photon will have less energy when it slows down and it's mass stays constant  [;)]
I think the consensus now is that the photon never really slows down. It simply follows a longer path to traverse certain materials. Maybe it is absorbed and re emitted by crystalline structures within materials etc.   
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Vern on 20/08/2009 14:36:58
Quote from: Nizzle
Mass is interaction of particles with the Higgs field.
The Higgs field is speculation at present. I suspect it will never be discovered. My own speculation is that mass is simply electromagnetic change. Any time you confine electromagnetic change within a system you give mass to the system.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Farsight on 21/08/2009 14:16:56
If a photon slows down does it become heavier? E=mc2. If m goes up then c comes down to keep E constant.
Not quite, because E=mc2 doesn't apply to a photon, we say E=hf instead. But broadly speaking, you're right. See "the Weight of Light" concerning Robert Pound and Glen Rebka: http://focus.aps.org/story/v16/st1. The frequency of the photon increases because c decreases. The energy stays the same. 

So you are the Farsight I know from other places [:)] Good to see you here! I think we mostly agree about the photon construct. Too bad we haven't come up with some great principal that will make this view of nature useful for predicting experimental outcomes.
Yep, that's me Vern, and yes I think we're talking the same language. I mention you and Photon Theory in my acknowledgements for Particles Explained, along with Robert Kemp re the common amplitude. But don't say too bad too soon. I've maybe got a couple of great principles. We'll see, and I think we're getting there. Good to see you here.

I think the consensus now is that the photon never really slows down. It simply follows a longer path to traverse certain materials.
I'd go along with that. In glass it's following a more convoluted path.

Everybody: Vern is one of my "unsung heroes of science". He and others have been on the right lines for years, but IMHO people tend to resist new ideas, and underestimate just how much competition and rivalry there is in physics. In the fullness of time I hope we come to realise just how much this has hampered scientific progress. 
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Nizzle on 21/08/2009 14:20:05
Yea, if you use E=mc² on a photon with mass 0, you'll get E=0...

Title: Re: How much do all of the electrons on Earth weigh?
Post by: lightarrow on 21/08/2009 20:28:45
But broadly speaking, you're right. See "the Weight of Light" concerning Robert Pound and Glen Rebka: http://focus.aps.org/story/v16/st1. The frequency of the photon increases because c decreases. The energy stays the same.
I'm sorry, what you say is wrong. The frequency increases because the energy increases. c stays constant.

See for example:
http://archive.ncsa.illinois.edu/Cyberia/NumRel/EinsteinTest.html
Quote
Gravitational Redshift
According to General Relativity, the wavelength of light (or any other form of electromagnetic radiation) passing through a gravitational field will be shifted towards redder regions of the spectrum. To understand this gravitational redshift, think of a baseball hit high into the air, slowing as it climbs. Einstein's theory says that as a photon fights its way out of a gravitational field, it loses energy and its color reddens. Gravitational redshifts have been observed in diverse settings.
Earthbound Redshift
In 1960, Robert V. Pound and Glen A. Rebka demonstrated that a beam of very high energy gamma rays was ever so slightly redshifted as it climbed out of Earth's gravity and up an elevator shaft in the Jefferson Tower physics building at Harvard University. The redshift predicted by Einstein's Field Equations for the 74 ft. tall tower was but two parts in a thousand trillion. The gravitational redshift detected came within ten percent of the computed value. Quite a feat!

See also:
http://en.wikipedia.org/wiki/Pound%E2%80%93Rebka_experiment
http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html
http://web.archive.org/web/20070630144936/http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
http://math.ucr.edu/home/baez/physics/ParticleAndNuclear/photon_mass.html
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Pmb on 21/08/2009 20:41:56
Yea, if you use E=mc² on a photon with mass 0, you'll get E=0...
The relationship between a particle's proper energy E_0 and its proper mass m is E_0 = mc^2. The relationship between a particle's total inertial energy E and its inertial mass M (aka mas/relativistic mass) is E = Mc^2.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: labview1958 on 22/08/2009 07:04:48
My hunch is that the "mass" of the photon increases thus causing the space in the glass to bend. Thus the light wave bends in the glass and goes back to its original path when it is out of glass.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: lightarrow on 22/08/2009 07:44:44
My hunch is that the "mass" of the photon increases thus causing the space in the glass to bend. Thus the light wave bends in the glass and goes back to its original path when it is out of glass.
Einstein's equation of general relativity says that energy too bends spacetime, not mass only.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Farsight on 24/08/2009 08:37:56
I'm sorry, what you say is wrong. The frequency increases because the energy increases. c stays constant.
It isn't wrong, lightarrow. It's unfamiliar to you and it isn't what you've been taught, but it isn't wrong. We measure the speed of light using clocks calibrated by the motion of light, hence we always measure the same value locally. But Einstein talked about the variable speed of light. See his 1911 paper On the Influence of Gravitation on the Propagation of Light (http://www.relativitybook.com/resources/Einstein_gravity.html) and note the c = c0(1 + Φ/c²). In your Baez link, look at the section on general relativity, and note this:

"Einstein went on to discover a more general theory of relativity which explained gravity in terms of curved spacetime, and he talked about the speed of light changing in this new theory.  In the 1920 book "Relativity: the special and general theory" he wrote: . . . according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [. . .] cannot claim any unlimited validity.  A curvature of rays of light can only take place when the velocity of propagation of light varies with position.  Since Einstein talks of velocity (a vector quantity: speed with direction) rather than speed alone, it is not clear that he meant the speed will change, but the reference to special relativity suggests that he did mean so. This interpretation is perfectly valid and makes good physical sense, but a more modern interpretation is that the speed of light is constant in general relativity".

Einstein talked about the variable speed of light. He really did. It might come as a shock, but the modern interpretation contradicts Einstein. And as per the falling plate, conservation of energy tells you that the blueshifted photon doesn't gain any energy from either the earth or the gravitational field.   


 
Title: Re: How much do all of the electrons on Earth weigh?
Post by: lightarrow on 24/08/2009 13:08:24
I'm sorry, what you say is wrong. The frequency increases because the energy increases. c stays constant.
It isn't wrong, lightarrow. It's unfamiliar to you and it isn't what you've been taught, but it isn't wrong. We measure the speed of light using clocks calibrated by the motion of light, hence we always measure the same value locally. But Einstein talked about the variable speed of light. See his 1911 paper On the Influence of Gravitation on the Propagation of Light (http://www.relativitybook.com/resources/Einstein_gravity.html) and note the c = c0(1 + Φ/c²). In your Baez link, look at the section on general relativity, and note this:

"Einstein went on to discover a more general theory of relativity which explained gravity in terms of curved spacetime, and he talked about the speed of light changing in this new theory.  In the 1920 book "Relativity: the special and general theory" he wrote: . . . according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [. . .] cannot claim any unlimited validity.  A curvature of rays of light can only take place when the velocity of propagation of light varies with position.  Since Einstein talks of velocity (a vector quantity: speed with direction) rather than speed alone, it is not clear that he meant the speed will change, but the reference to special relativity suggests that he did mean so. This interpretation is perfectly valid and makes good physical sense, but a more modern interpretation is that the speed of light is constant in general relativity".

Einstein talked about the variable speed of light. He really did. It might come as a shock, but the modern interpretation contradicts Einstein. And as per the falling plate, conservation of energy tells you that the blueshifted photon doesn't gain any energy from either the earth or the gravitational field. 

In that link:
http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html
you didn't quote all it's written:
Quote
General Relativity

Einstein went on to discover a more general theory of relativity which explained gravity in terms of curved spacetime, and he talked about the speed of light changing in this new theory.  In the 1920 book "Relativity: the special and general theory" he wrote: . . . according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [. . .] cannot claim any unlimited validity.  A curvature of rays of light can only take place when the velocity of propagation of light varies with position.  Since Einstein talks of velocity (a vector quantity: speed with direction) rather than speed alone, it is not clear that he meant the speed will change, but the reference to special relativity suggests that he did mean so.  This interpretation is perfectly valid and makes good physical sense, but a more modern interpretation is that the speed of light is constant in general relativity.

The problem here comes from the fact that speed is a coordinate-dependent quantity, and is therefore somewhat ambiguous.  To determine speed (distance moved/time taken) you must first choose some standards of distance and time, and different choices can give different answers.  This is already true in special relativity: if you measure the speed of light in an accelerating reference frame, the answer will, in general, differ from c.

In special relativity, the speed of light is constant when measured in any inertial frame.  In general relativity, the appropriate generalisation is that the speed of light is constant in any freely falling reference frame (in a region small enough that tidal effects can be neglected).  In this passage, Einstein is not talking about a freely falling frame, but rather about a frame at rest relative to a source of gravity.  In such a frame, the speed of light can differ from c, basically because of the effect of gravity (spacetime curvature) on clocks and rulers.

If general relativity is correct, then the constancy of the speed of light in inertial frames is a tautology from the geometry of spacetime.  The causal structure of the universe is determined by the geometry of "null vectors".  Travelling at the speed c means following world-lines tangent to these null vectors.  The use of c as a conversion between units of metres and seconds, as in the SI definition of the metre, is fully justified on theoretical grounds as well as practical terms, because c is not merely the speed of light, it is a fundamental feature of the geometry of spacetime.

Like special relativity, some of the predictions of general relativity have been confirmed in many different observations.  The book listed below by Clifford Will is an excellent reference for further details.

Finally, we come to the conclusion that the speed of light is not only observed to be constant; in the light of well tested theories of physics, it does not even make any sense to say that it varies.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: PhysBang on 24/08/2009 21:57:05
In that link:
http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html
you didn't quote all it's written:
If you do any research into Mr. John Duffield, you will discover that cherry-picking quotations is one of his specialties. For example, he has been shown time and time again that the paper from which he has drawn that quotation from Einstein is one that Einstein superceded with better work within 5 years of the publication of that paper. So even though he knows that choosing that quotation is a bad example for his argument from authority using Einstein, he does it anyway.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Nizzle on 25/08/2009 06:00:53
The use of c as a conversion between units of metres and seconds, as in the SI definition of the metre, is fully justified on theoretical grounds as well as practical terms, because c is not merely the speed of light, it is a fundamental feature of the geometry of spacetime.

I find all this very interesting.
Could someone explain how c is a fundamental feature of the geometry of spacetime please?
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Farsight on 25/08/2009 12:34:17
In that link: http://math.ucr.edu/home/baez/physics/Relativity/SpeedOfLight/speed_of_light.html you didn't quote all it's written:
I was going easy on the author. Look at the two important sections again:
 
"Einstein went on to discover a more general theory of relativity which explained gravity in terms of curved spacetime, and he talked about the speed of light changing in this new theory.  In the 1920 book "Relativity: the special and general theory" he wrote: . . . according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity [. . .] cannot claim any unlimited validity.  A curvature of rays of light can only take place when the velocity of propagation of light varies with position.  Since Einstein talks of velocity (a vector quantity: speed with direction) rather than speed alone, it is not clear that he meant the speed will change, but the reference to special relativity suggests that he did mean so. This interpretation is perfectly valid and makes good physical sense, but a more modern interpretation is that the speed of light is constant in general relativity".
   
"Finally, we come to the conclusion that the speed of light is not only observed to be constant; in the light of well tested theories of physics, it does not even make any sense to say that it varies".


On the one hand the article says the interpretation is perfectly valid and makes good physical sense, and later on it says it does not even make sense. It not only contradicts Einstein, it contradicts itself.

I'm not pulling the wool over your eyes with this. People like PhysBang defend the modern interpretation by directing ad-hominems at people like me without offering any evidence or logical argument, attempting to distract you from the very simple unassailable logic supported by the evidence that's there in the history and in the observation. The latter is "hidden in plain view". For example, imagine that I'm in a region of high gravitational potential holding a light clock in an orientation that avoids any issues of radial length contraction. PhysBang is holding an identical light clock in free space, and you're observing us both via telescopes and a TV monitor that puts both light clocks up on a split screen. What you see, is that my light goes slower than his. You attribute this to time dilation, but that's back to front, because the motion of light defines our standards of time and distance:

Under the International System of Units, the second is currently defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom....

The metre is the length of the path travelled by light in vacuum during a time interval of 1/299792458 of a second...

   
I experience gravitational time dilation because the light moves at a reduced rate where I am, not the other way around. I still measure the speed of light to be 299,792,458 m/s, as does PhysBang, but my seconds are different to his, and as you can see on your split-screen monitor, the two speeds are not the same. This really is Einstein's view. As an aside, the Baez article mentions Clifford M Will, who wrote this interesting paper: ttp://relativity.livingreviews.org/Articles/lrr-2006-3/. See section 2.1.2 where it says:

"Although special relativity itself never benefited from the kind of “crucial” experiments, such as the perihelion advance of Mercury and the deflection of light, that contributed so much to the initial acceptance of GR and to the fame of Einstein, the steady accumulation of experimental support, together with the successful merger of special relativity with quantum mechanics, led to its being accepted by mainstream physicists by the late 1920s, ultimately to become part of the standard toolkit of every working physicist".

Relativity was not completely accepted by mainstream physicists until the late 20s. However even this is debated by some, see http://en.wikipedia.org/wiki/Golden_age_of_general_relativity which says:

"The Golden Age of General Relativity is the period roughly from 1960 to 1975 during which the study of general relativity, which had previously been regarded as something of a curiosity, entered the mainstream of theoretical physics".  

What people are generally taught about relativity, is not quite how it is. Please note that I'm a strong supporter of relativity and Einstein, along with empirical evidence and experiment. Some people are not. 
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Farsight on 25/08/2009 12:52:31
I find all this very interesting. Could someone explain how c is a fundamental feature of the geometry of spacetime please?
See above re the second and the metre. The speed of light is a conversion factor between our measures of distance and time. All motion is calibrated against the motion of light, hence c is a fundamental feature of the world in which we live.

Note however that Einstein's original General relativity talked about equations of motion, not curved spacetime. Whilst spacetime is the mathematical space used for calculations and useful predictions, what's actually out there isn't a block universe, or world lines or light cones. You can't actually see these things because they're mathematical entities with no objective existence of their own. What's out there is space and motion through it. Hence it's a little misleading to say c is a fundamental feature of spacetime geometry.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: PhysBang on 25/08/2009 13:18:23
On the one hand the article says the interpretation is perfectly valid and makes good physical sense, and later on it says it does not even make sense. It not only contradicts Einstein, it contradicts itself.
Why must you provide such an obvious academic falsehood? And so poorly? You even quoted the sentence that shows that you're wrong: "Finally, we come to the conclusion that the speed of light is not only observed to be constant; in the light of well tested theories of physics, it does not even make any sense to say that it varies". Something can make good physical sense in the abstract but dramatically fail to make any sense in the context of other theories. The phlogiston theory makes great sense and even had significant amount of evidential support, but it no longer makes any sense to say that burning involves phlogiston because so many other theories make that claim nonsense.
Quote
I'm not pulling the wool over your eyes with this. People like PhysBang defend the modern interpretation by directing ad-hominems at people like me without offering any evidence or logical argument, attempting to distract you from the very simple unassailable logic supported by the evidence that's there in the history and in the observation.
It is not an ad hominem to point out that you have a documented history of using the same deceptive practices again and again. If you begin your logic with false premises, then it doesn't matter how good your logic is. If you were able to, on your own, derive a usable theory with a variable speed of light, then you might have a case. However, the best that you have is two mistakes made by Einstein. Indeed, you quote a single passage of text from Einstein but never address a single formula.
Quote
The latter is "hidden in plain view". For example, imagine that I'm in a region of high gravitational potential holding a light clock in an orientation that avoids any issues of radial length contraction. PhysBang is holding an identical light clock in free space, and you're observing us both via telescopes and a TV monitor that puts both light clocks up on a split screen. What you see, is that my light goes slower than his.
How could this be possible? This violates every test of the speed of light that we have ever performed. What one might see is that the light clock that you were holding is distorted by gravity. If we could see and measure the speed of light for your clock, we would see the light moving at c. If you can deomnstrate otherwise, let us see your calculations.
Quote
What people are generally taught about relativity, is not quite how it is.
Well, let's see how everyone has got the equations incorrect.
Quote
Please note that I'm a strong supporter of relativity and Einstein, along with empirical evidence and experiment. Some people are not. 
Some people are not supporters of people who have mistaken ideas about science with a book to sell.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: Farsight on 26/08/2009 09:40:24
Why must you provide such an obvious academic falsehood? And so poorly? You even quoted the sentence that shows that you're wrong: "Finally, we come to the conclusion that the speed of light is not only observed to be constant; in the light of well tested theories of physics, it does not even make any sense to say that it varies".
What's obvious is that Einstein talked about the variable speed of light. It's there in 1911, and in 1916. And yet here you are saying it's an "obvious academic falsehood". It just won't wash, Physbang, and phlogiston just doesn't cut it.

It is not an ad hominem to point out that you have a documented history of using the same deceptive practices again and again.
But I don't. I'm pointing out the clear evidence, there's no deception on my part. You're the one with the problem concerning the examination and discussion of this evidence. 

If you begin your logic with false premises, then it doesn't matter how good your logic is. If you were able to, on your own, derive a usable theory with a variable speed of light, then you might have a case. However, the best that you have is two mistakes made by Einstein. Indeed, you quote a single passage of text from Einstein but never address a single formula.
It's Einstein's premise, and it isn't false. He started with a postulate in Special Relativity saying the speed of light is constant, and later explained that it didn't apply to General Relativity. What we read in the 1920 translation is this:

"In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (eg of light).

But Einstein was German, he didn't speak English in 1916 when he wrote this book. The word he used wasn't velocity, it was geschwindigkeit, which means both velocity and speed. This and the context tells us that when he approved the translation, he was talking about speed, like the Baez article says. He was talking about speed because even something as simple as a mirror changes the velocity of a beam of light. This was a popular science book. The word velocity here is the common usage, as in "high velocity bullet". Claiming that he was talking about a vector-quantity velocity reduces this paragraph to a ridiculous tautology. He would have been saying light curves because it changes direction. His meaning is obvious, it’s clear as a bell. Read the original and there it is in black and white from the man himself: die Ausbreitungsgeschwindigkeit des Lichtes mit dem Orte variiert. Try a Google translate from German to English using

http://translate.google.co.uk/translate_t#de|en|die%20Ausbreitungsgeschwindigkeit%20des%20Lichtes%20mit%20dem%20Orte%20variiert

Sorry the hyperlink doesn't work, this website stops at the vbar. What you get is the speed of light varies with the locality.

How could this be possible? This violates every test of the speed of light that we have ever performed. What one might see is that the light clock that you were holding is distorted by gravity. If we could see and measure the speed of light for your clock, we would see the light moving at c. If you can demonstrate otherwise, let us see your calculations.
It's possible, and it's what we see. Lightarrow will see my light moving slower than yours on his split screen. And it doesn't violate every test of the speed of light we have ever performed. What the heck do you think the Shapiro time delay (http://en.wikipedia.org/wiki/Shapiro_delay) is? And the GPS clocks are atomic clocks, they use microwaves. That's light. And they need an adjustment: http://en.wikipedia.org/wiki/Global_Positioning_System#Special_and_general_relativity. They need this adjustment because the rate of motion of light is reduced down here at the surface of the earth compared to up in orbit. Now set aside any notions you have about time, read Time Explained, then look at the evidence, and see what's there. 
 
Well, let's see how everyone has got the equations incorrect.
The issue is one of interpretation, and Einstein's equations were the equations of motion, not of curved spacetime. Check it out for yourself in The Foundation of the General Theory of Relativity: http://www.alberteinstein.info/gallery/pdf/CP6Doc30_English_pp146-200.pdf. And read Pmb's paper "Einstein's gravitational field" on http://arxiv.org/abs/physics/0204044

Abstract
There exists some confusion, as evidenced in the literature, regarding the nature of the gravitational field in Einstein's General Theory of Relativity. It is argued here the this confusion is a result of a change in interpretation of the gravitational field. Einstein identified the existence of gravity with the inertial motion of accelerating bodies (i.e. bodies in free-fall) whereas contemporary physicists identify the existence of gravity with space-time curvature (i.e. tidal forces). The interpretation of gravity as a curvature in space-time is an interpretation Einstein did not agree with.


Some people are not supporters of people who have mistaken ideas about science with a book to sell.
I stand for scientific progress, nothing more. And it isn't me with mistaken ideas, or Einstein. It's you.
Title: Re: How much do all of the electrons on Earth weigh?
Post by: PhysBang on 26/08/2009 13:42:33
What's obvious is that Einstein talked about the variable speed of light. It's there in 1911, and in 1916. And yet here you are saying it's an "obvious academic falsehood". It just won't wash, Physbang, and phlogiston just doesn't cut it.
The obvious falsehoods are that you refer to something that Einstein explicitly rejected in his actual science and that you deliberately misquoted the webpage you referenced.
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I'm pointing out the clear evidence, there's no deception on my part. You're the one with the problem concerning the examination and discussion of this evidence. 
The problem of evidence that I and other have when you are around is that you never provide any. Gravitational physics is decided by the accuracty of measurement. Where are your measurements? What mathematics guides your interpretation that we could measure?
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It's Einstein's premise, and it isn't false. He started with a postulate in Special Relativity saying the speed of light is constant, and later explained that it didn't apply to General Relativity. What we read in the 1920 translation is this:

"In the second place our result shows that, according to the general theory of relativity, the law of the constancy of the velocity of light in vacuo, which constitutes one of the two fundamental assumptions in the special theory of relativity and to which we have already frequently referred, cannot claim any unlimited validity. A curvature of rays of light can only take place when the velocity of propagation of light varies with position. Now we might think that as a consequence of this, the special theory of relativity would be laid in the dust. But in reality this is not the case. We can only conclude that the special theory of relativity cannot claim an unlimited domain of validity; its results hold only so long as we are able to disregard the influences of gravitational fields on the phenomena (eg of light).

But Einstein was German, he didn't speak English in 1916 when he wrote this book. The word he used wasn't velocity, it was geschwindigkeit, which means both velocity and speed. This and the context tells us that when he approved the translation, he was talking about speed, like the Baez article says. He was talking about speed because even something as simple as a mirror changes the velocity of a beam of light. This was a popular science book. The word velocity here is the common usage, as in "high velocity bullet". Claiming that he was talking about a vector-quantity velocity reduces this paragraph to a ridiculous tautology. He would have been saying light curves because it changes direction. His meaning is obvious, it’s clear as a bell.
The meaning is obvious to someone who keept reading the book and does the mathematics: one has to find a way to "disregard the influences of gravitational fields on the phenomena." This is what the entire apparatus of the mathematics of GR and the use of generally covariant equations is designed to do.
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It's possible, and it's what we see.
It can't be what we "see", bacause nobody has done this test. It is what you tell us that we will see. Show us the math.
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Lightarrow will see my light moving slower than yours on his split screen. And it doesn't violate every test of the speed of light we have ever performed. What the heck do you think the Shapiro time delay (http://en.wikipedia.org/wiki/Shapiro_delay) is? And the GPS clocks are atomic clocks, they use microwaves. That's light. And they need an adjustment: http://en.wikipedia.org/wiki/Global_Positioning_System#Special_and_general_relativity. They need this adjustment because the rate of motion of light is reduced down here at the surface of the earth compared to up in orbit. Now set aside any notions you have about time, read Time Explained, then look at the evidence, and see what's there. 
The adjustment of the clocks is there because of the relativistic differences in time, not in light. Show us the math.
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The issue is one of interpretation, and Einstein's equations were the equations of motion, not of curved spacetime. Check it out for yourself in The Foundation of the General Theory of Relativity: http://www.alberteinstein.info/gallery/pdf/CP6Doc30_English_pp146-200.pdf. And read Pmb's paper "Einstein's gravitational field" on http://arxiv.org/abs/physics/0204044
A reference to a crank paper that managed to get into arXiv is not good. Especially ones that explicitly deny something said by Einstein in the document you linked to, namely: "Thus, according to the general theory of relativity, gravitation occupies an exceptional position with regard to other forces, particularly the electromagnetic forces, since the ten functions representing the gravitational field at the same time define the metrical properties of the space measured."(pg. 156) This is what "spacetime is curved by gravity" means.
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I stand for scientific progress, nothing more. And it isn't me with mistaken ideas, or Einstein. It's you.
Well, since you seem not to know what curved spacetime means, how can you possibly claim to stand for Einstein?
Title: How much do all of the electrons on Earth weigh?
Post by: lyner on 26/08/2009 14:05:53
It seems to me that this argument is not helping to improving understanding. One idea uses two variables to measure a third and the other idea chooses a different pair from the three and measures the remaining one. Aren't you both just looking at the same problem from two different directions?
Don't mislead yourselves into thinking there's only one way of looking at it.
Title: How much do all of the electrons on Earth weigh?
Post by: Farsight on 26/08/2009 18:23:13
We are looking at the same problem from two different directions, Sophie, but the difference is utterly crucial to understanding, and thence scientific progress. Both Pmb and myself have done original research that leads us to the conclusion that the "modern interpretation" of relativity is not in line with Einstein, and we offer historical and scientific evidence to support our view. PhysBang however offers denial and abuse, and only seeks to suppress discussion on the subject. Pmb and I do not agree on details, but we discuss points here with polite civility. Note that he has a PhD in physics, and is certainly not a crank.