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New Theories / What are radio waves, how are they formed ?

« on: 24/05/2021 05:52:39 »

          Radio-waves are a type of electromagnetic radiation. The explanation for how radio waves are formed is that radio waves are radiated by charged particles when they are accelerated.  The peculiar property of radio-waves is that they possess identical properties to that of optical frequency photons (Wavelength of 1nm to 10,000nm). They are electrically neutral, they possess no charge. They always travel with the speed of light, they preserve their energy intact over enormous distances. They exhibit Doppler shift. They are mass less. They are never still but always travel at the speed of light.

     But there are also differences. While optical photons and photons possessing higher frequencies possess wave-lengths on the order of 500 nm, radio waves can be massive. A 60 Hz signal (super low frequency on the frequency chart) can possess a wavelength of 5,000,000 m. How can an electron with a classical radius of  about 3 x 10 ^-15 m possibly radiate strongly enough to produce a wavelength that is 5,000,000 m long.  If one is perfectly sincere, an electron with such infinitesimal size, can’t possibly produce such gigantic wave-lengths, even if it is accelerated; it is an impossibility. Further, still thinking logically, how is it possible to have two explanations for the same phenomenon? Optical photons in the range of  10nm to 10,000nm are emitted directly by the electron due to excitation of the electron but radio-waves are radiated by accelerated electrons.

          The differences can get even more evident: radio-waves  are created due to synchronised,  periodic change of electric or magnetic field. Depending on how this periodic change occurs and the power generated, different wavelengths of electromagnetic spectrum are produced. In a vacuum, electromagnetic waves travel at the speed of light, commonly denoted c. In homogeneous, isotropic media, the oscillations of the two fields are perpendicular to each other and perpendicular to the direction of energy and wave propagation, forming a transverse wave. Fine but where do photons come into all this?

                 In quantum mechanics, an alternate way of viewing EMR is that it consists of photons, uncharged elementary particles with zero rest mass which are the quanta of the electromagnetic field, responsible for all electromagnetic interactions.  Quantum electrodynamics is the theory of how EMR interacts with matter on an atomic level.  How can a 5,000,000 m (5 x 10 ⁶ wave interact with an atom having a radius of  5 x 10^-10 m ?

           One possible conclusion is that botyh quantum mechanics and classical mechanics are wrong.

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New Theories / Einstein, Relativity and light:

« on: 14/05/2021 04:50:05 »

          Towards the end of the nineteenth century, a strange situation prevailed in the science of physics.  For hundreds of years physicists had been speculating on the manner in which light propagated.  An observation of the properties of light: it travelled in straight lines, its intensity varied inversely with the square of the distance travelled, while the area over which it spread out, varied directly with the square of the distance travelled, it had a finite speed that never varied; all seemed to indicate that light travelled through a medium. It was in trying to identify the medium through which light travelled that difficulties arose.   Numerous efforts to identify the medium ended in failure, but some idea of the properties that this medium must possess were identified. It was non-tactile, it was invisible, it was odourless, it had no mass, it had extremely low interaction with matter, it was permeable to all solids to the extent that the planets and the stars could pass through it without being obstructed to any discernible degree. Physicists were satisfied that some kind of medium must exist to both limit the speed of light and account for these properties but were content to leave it at that, even if such a medium was not immediately identifiable. They called this medium the aether.   

             Then in 1865 everything changed with the publication of James Clerk Maxwell’s: “A Dynamical Theory of the Electromagnetic Field.”  This paper predicted the existence of electromagnetic waves that could travel through the air, although it took another 20 years before these waves were finally discovered in 1887 by Henrich Hertz. Maxwell identified light as a transverse electromagnetic wave.  This created a whole new dimension for the properties of the aether; it now had to possess a rigidity several times that of steel in order to accommodate a transverse wave moving with a speed of 3 x 10 ⁵ km/s. This rendered the whole concept of an aether completely ridiculous.

            The death knell to the aether theory was sounded when Michelson and Morley in their experiment of 1887 to detect the aether ended up with a null result.  There was no aether.  Sheer disbelief that light was able to propagate without a medium resulted. Scientists came up with all kinds of theories as to how the aether could have escaped detection. The Irish Physicist Fitzpatrick, half jokingly suggested that the aether might not be discoverable because lengths contracted in the direction the aether was measured. The Dutch physicist and mathematician Henri Lorentz pondering the issue and with time on his hands, in a half whimsical frame of mind, formulated a  mathematical basis for Fitzpatrick’s theory which came to be known as the Lorentz transformations. 

              In 1905 Einstein published his paper on special relativity, dismissing the aether on the grounds that it was no longer needed and that Maxwell’s explanation for the propagation of light (electromagnetic waves) precluded the need for an aether; the two types of fields being self sustaining, the one increasing while the other was decreasing and vice-versa, resulting in a self-sustaining mechanism that could propagate forever.   Einstein’s special theory of relativity had two very important postulates:

1)   The laws of physics remain the same in all inertial frames of reference.
And
2)   The speed of light in a vacuum is a universal constant.

         With regard to the first postulate, take a train moving at a constant speed, four people are sitting around a card table in the train and playing cards, their experience would be identical to four people sitting on a stationary platform and playing cards. There is no difference; the laws of physics remain the same in both circumstances.

            As to the second postulate, in what sense is it used? Does it mean that the speed of light in a vacuum is so constant and accurate that all other speeds can be measured against it? Or does it mean that nothing can move faster than the speed of light? Or does it mean that the speed of light remains constant regardless of the motion of its source or observer? It turns out that the postulate of the speed of light as a universal constant means none of these things, what it does mean is that the speed of light remains  the same regardless of the frame of  reference of the observer.
 
           There are two important consequences of Maxwell’s equations. The first, as has been mentioned, is the possible existence of electromagnetic waves. The second unforeseen consequence is the breakdown of Newtonian mechanics, leading to Einstein’s relativity theory.

              According to Einstein; Newton’s laws are incompatible with Maxwell’s equations.  While Newtonian mechanics obey Galilean laws and are invariant with time and distance; the time at which an event takes place remaining constant everywhere in the Universe and the distance measured being likewise constant, Maxwell’s equations are not invariant with Galilean transformations. Maxwell’s equations are, however, invariant with Galilean transformations when the Lorentz transform is used. This situation raises two important possibilities that will now be examined:

1)   Maxwell’s equations are wrong.
2)   There is only one special reference frame in which Maxwell’s equations are true, namely the rest frame of the so-called aether.

             Taking the first point:  Is it possible that Maxwell’s equations are wrong? Certainly, quantum mechanics has had a tough time trying to rationalise Maxwell’s wave theory with quantum particle theory by using processes such as normalization and re-normalisation etc., without making much headway in reconciling the two properties, wave and particle, of electromagnetic radiation.  In short Maxwell’s equations are outdated a new theory has to be formulated. So, unlike the situation that prevailed at the end of the nineteenth century when Maxwell’s equations were deemed inviolate, today their validity can be questioned.

             Galilean transforms add and subtract; thus two cars moving towards each other at 50 km/h and 60 km/h would have a combined speed of  110 km/h, the same cars moving away from each other would have a relative speed of 110 km/h. If the cars are moving in the same direction, the car moving at 60 km/h would be moving away from the other car at a relative speed of 10 km/h.

          The second option proposed is one that discusses the possibility of a preferred frame of reference. The special or preferred frame of reference, if it exists would invalidate Einstein’s special relativity. But what does it mean?

           Consider a huge empty space crowded with people, Grand Central station in New York, comes to mind. Consider that each of these people is carrying a lit torch. Some are moving towards each other, some are moving away from each other, some are moving fast, others are moving slowly, some are climbing stairs others are descending stairs and so on.  You can imagine the confusion if one tries to calculate how fast the beams of light are moving in each frame of reference using Galilean transformations. There would be thousands of different readings, the light from each torch would be moving at a different speed depending on the frame of reference from which it was seen.   

         How does Einstein rationalise this situation?  Put simply Einstein uses Lorentz transformations in order to keep the speed of light constant for all observers.  This means that in the example given of Grand Central Station, distances and time would have thousands of different values for the speed of light to remain constant for all observers. Distances would have to contract and times would have to dilate in order to ensure that the speed of light remained constant in all frames of reference.

             On the earth, in the solar  system, in the whole of the vast Universe, there is one, and only one, possible frame of reference in which the speed of light remains constant in all frames of reference. Thus in this special or preferred frame of reference, the speed of light would remain constant regardless of whether an observer were moving towards or away from the source and regardless of whether the source or the destination itself were moving and more importantly whether inertial or accelerated frames of reference were involved! This preferred frame of reference is the aether. Yes,  in the presence of a medium, the speed of light would remain constant in any frame of reference; regardless of the movement of the source or if the observer were approaching or moving away from the light.  The existence of an aether (or medium) is what Maxwell based his equations on.

          Which theory is more probable? Consider dark matter, its presence was detected much before Einstein made an appearance.

    “Dark matter is a form of matter thought to account for approximately 85% of the matter in the universe and about 27% of its total mass–energy density or about 2.241 × 10⁻²⁷ kg/m³. Its presence is implied in a variety of astrophysical observations, including gravitational effects that cannot be explained by accepted theories of gravity unless more matter is present than can be seen.” -  https://en.wikipedia.org/wiki/Dark_matter

             When physicist agree that 85 % of all matter in the Universe is dark matter and that they don’t know what it is or how to detect it; it is astonishing that the ‘aether’ with exactly similar properties, could be summarily dismissed on the grounds that it could not be detected. 

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New Theories / On the speed of light as invariant:

« on: 26/04/2017 20:58:47 »

Physicists have often been amazed at the  invariance of the speed of light. This means that regardless of whether the source is moving or the destination is moving or even if both are moving, the speed of light remains constant at 3 x 10⁵ km/s approx.  What is so unusual about this? Unusual ! It goes absolutely against every practical experience known to mankind! In the normal world things obey what are known as Galilean transformations. Thus  take two fast cars 150 Kms apart and travelling towards each other. Car (a) going at 150 kmh and car(b) at 100 kmh. If they both start off at exactly the same time when will they meet ?  It might surprise you at first to learn that the time at which they will meet is governed by their combined speed or 100 kmh + 150 kmh = 250 kmh. They will therefore meet after  36 minutes during which time  car (a) would have covered 90 Km and car (b) would have covered 60 km. The same would apply if the cars were moving away from each other here, the speed of the two cars is again combined but this time they are moving away from each other, thus they are departing from each other at a relative speed of 100 km + 150 kmh = 250 kmh.  If both cars are moving in the same direction then the speed of car (a) relative to the speed of car (b) would be the difference in speed 150 kmh - 100 kmh = 50 kmh.  These cars are moving according to Galilean transformations.

Imagine then the surprise of scientists when they found that light does not obey these Galilean transformations. Take the following case. Suppose you have a light at a fixed source (A) shining towards a point (B) that is 100,000 Kms. away then we know that since the speed of light is 300,000 km/sec that it should take 0.33 secs for the light to travel from point A to Point B.  And this is how long it does take. (note: Actually according to relativity this is by no means certain) Now suppose you fit the light onto a superfast train travelling at 150,000 km/s then surely it should take the light whose combined speed is 300,000 km/s + 150,000 km/s = 450,000 km/s and it should now take the light only 0.222 s to reach point B! Wrong! Say the scientists it would still take the light 0.33 secs to cover the distance from (A) to (B)!
 


How could this be true? More important how could it be proved to be either true or false? I was thinking about this problem when it occurred to me that the speed of sound (because it is a wave)  is also invariant. Just like light the speed of sound is also independent of the speed of the source or of the destination or even if both were moving together. How could this be. I was thinking about something else when the answer came to me and it is ridiculously simple.  Look at this problem. First you have a stationary sound at (A) travelling towards a point (b) which is 600 m distant.  Consider that sound travels at 1257.12 kmh therefore it will take approximately 1.72 secs to cover the distance to (B). Now imagine that the sound (Siren or whatever) is fitted onto a car travelling at 150 kmh , then the sound should now take 600/ (150 kmh  + 1257.12) = 1.53 sec to cover the distance to B, right ? Wrong say the physicists the sound will still take 1.72 sec to travel from point A to point B.  How could this be ?

It becomes very simple to understand when we take into account that the speed of the car depends on its mass, the force with which it can press onto the tarmac, the speed with which the wheel revolves, the force of gravity etc., While the speed of sound is solely dependent on the properties of the medium it is travelling through. The two velocities have nothing to do with each other. It is like comparing apples and oranges you can't do it!  So the sound will still take 1.72 secs to travel from point (A) to point (B) while the car would take 14.35 secs to cover the distance from (A) to (B).
 That's all there is to the invariance of the speed of light or of the speed of sound.  Apples and oranges.

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New Theories / Re: Does F = ma and E = mc^^2 mean F = E?

« on: 11/04/2017 03:26:25 »

Alan Calverd :  It's interesting to be told that we are all wrong, especially by a bloke who doesn't know the difference between velocity and acceleration. "Out of the mouths of babes", perhaps? 

This is the kind of moronic reiteration namely repeatedly repeating the same mistake and attributing it to someone else that is a result of too much self-absorption. To illustrate here is what I said about acceleration and velocity.

McQueen : On the left side, a stands for acceleration, which has units of length divided by time squared.

also

McQueen:   E  is not equal to force x displacement  (as claimed by Alan Calverd nuclear physicist!) , it is W = F x s (Work = force x distance ) and E = Fa : Energy = Force x velocity / time .

Alan Calverd: It would be even more interesting to be told why our stuff actually works

How did the early theory of the propagation of electricity in a wire formulated by Drude and Lorentz survive for so many years before being replaced by the even more inaccurate quantum version.

That said it seems to be pointless to reply to these toothless and  inaccurate barbs which I will ignore in the future.

Bored Chemist : Common sense is wrong.

 That is indeed a useful refuge in which to seek safety but in this case it is not just common sense it is  everything else that is also wrong the most glaring and obvious of which of which is the maths.

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New Theories / Re: Does F = ma and E = mc^^2 mean F = E?

« on: 01/04/2017 11:00:20 »

alancalverd : No, obviously. Energy is force x distance.

Absolutely true, also true is that anything travelling at a constant speed is not accelerating. Was a negative at the start of the sentence necessary ?


Also E  is not equal to force x displacement , it is W = F x s (Work = force x distance ) and E = Fa : Energy = Force x velocity / time

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Chemistry / Re: Can wavelength and frequency of EM waves be changed by the media the encounter?

« on: 28/04/2016 14:45:04 »

I'm sorry if my reference to virtual photons offends you. Some people take virtual photons very seriously, in the context of light propagating through media.

Sorry , my bad, I was out of line to make such a statement. Incidentally I do believe that 'virtual photons' exist and play an indispensable part in the working of the world and the Universe. P.S. On re-reading my post I realise that it is even worse than I had originally thought. Once again my apologies.

Please clarify why light waves, ocean waves,  gravitational waves and radio waves cannot carry energy.

Out of  these  "waves" only ocean waves are true waves that disperse their energy across the wave front i.e., the energy is shared in common,  all of the others ( leaving aside gravitational waves) have discrete energies as demonstrated by Max Planck..

Coming back to the topic of light slowing down as it travels through  glass..... Here is another quantum mechanics explanation that also involves absorption and emission of photons by electrons as they travel through glass:

"To make the classical picture quantum, we say that a single photon entering the material will potentially be absorbed and re-emitted by each of the atoms making up the first layer of the material. Since we cannot directly measure which atom did the absorbing, though, we treat the situation mathematically as a superposition of all the possible outcomes, namely, each of the atoms absorbing then re-emitting the photon. Then, when we come to the next layer of the material, we first need to add up all the wave-functions corresponding to all the possible absorptions and re-emissions.

Thus, we more or less reproduce the Huygens’s Principle case, and we find that just as in the classical case, the pieces of the photon wave-function corresponding to each of the different emissions will interfere with one another. This interference will be constructive in the forward direction, and destructive in all the other directions. So, the photon will effectively continue on in the direction it was originally headed. Then we repeat the process for the next layer of atoms in the medium, and so forth.
It’s important to note that when this picture is valid the probability of being absorbed then re-emitted by any individual atom is pretty tiny– when the light frequency is close to a resonance in the material, you would need to do something very different. (But then, if the light was close to a resonant frequency of the material, it wouldn’t be a transparent material…) while the probability of absorption and re-emission is tiny for any individual atom, though, there are vast numbers of atoms in a typical solid, so the odds are that the photon will be absorbed and re-emitted at some point during the passage through the glass are very good. Thus, on average, the photon will be delayed relative to one that passes through an equal length of vacuum, and that gives us the slowing effect that we see for light moving through glass."

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Chemistry / Re: Can wavelength and frequency of EM waves be changed by the media the encounter?

« on: 28/04/2016 09:24:02 »

The photon point of view which is that light slows due to emission and absorption

Carbon (graphite), with its many connected atoms in many structures has a wide conduction band, and absorbs photons over a very wide range of frequencies.
In contrast, glass is a non-conductor, and does not have the same broadening of energy levels in its electron orbitals. The atoms and molecules of pure glass do not have energy levels which absorb and re-emit real photons in the visible range. That's why it is transparent.
I can't comment on virtual photons...
https://en.wikipedia.org/wiki/Transparency_and_translucency#Introduction

Stop your gloating, with your derisive reference to 'virtual photons' ! What happens when a quoted  source (a) contradicts itself (b) has experimental proof that what the source say can't happen does in fact happen ? Do you apologise or just go ahead with your gloating safe in the belief that the majority view supports you ?

Look at the following article quote:

"As an extreme example of light "slowing" in matter, two independent teams of physicists claimed to bring light to a "complete standstill" by passing it through a Bose–Einstein condensate of the element rubidium, one team at Harvard University and the Rowland Institute for Science in Cambridge, Mass., and the other at the Harvard–Smithsonian Center for Astrophysics, also in Cambridge. However, the popular description of light being "stopped" in these experiments refers only to light being stored in the excited states of atoms, then re-emitted at an arbitrarily later time, as stimulated by a second laser pulse. During the time it had "stopped," it had ceased to be light. This type of behaviour is generally microscopically true of all transparent media which "slow" the speed of light. "
https://en.wikipedia.org/wiki/Speed_of_light

And of course if you consider it from this point of view the idea that light in the form of photons can breeze through a material without interacting in any way with the material and still be slowed down is ridiculous. Further if light is slowed energy is involved, if energy is involved then photons not waves are involved. Because at the level of atomic structure it is all individual interactions, between photons and electrons.

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Chemistry / Re: Can wavelength and frequency of EM waves be changed by the media the encounter?

« on: 27/04/2016 13:09:41 »

There appears to be a misunderstanding here.

Light that enters a denser material (eg Flint glass, refractive index 1.61) is slowed down by a factor of 1.61, and it's wavelength is compressed by the same factor of 1.61, while its frequency remains constant.

Point taken, energy is conserved in the form of frequency, while wave-length and velocity may change as light enters a medium. That is the wave point of view and it is valid, however, the photon point of view is also valid. Light slows down and the direction of the light undergoes change.  The wave explanation of this bending is particularly beautiful since it is attributed to the leading edge of the wave entering the medium first and travelling a shorter distance, followed by the rest of the wave taking a longer route hence the bending or refraction of light. The photon point of view which is that light slows due to emission and absorption claims that when light slows its direction naturally undergoes change. The photon point of view might carry more weight because scientific experiment has shown that the material  of the  medium contains atoms that contain electrons which can absorb photons of those energies.

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Chemistry / Re: Can wavelength and frequency of EM waves be changed by the media the encounter?

« on: 25/04/2016 18:49:12 »

If the wavelength changes , the frequency changes. The two are inextricably connected.

This appears to be true only if the velocity remains constant, it is possible for either frequency or wavelength to change while the other remains constant. In most instances, it is frequency that remains constant while the wavelength undergoes change. The frequency of a sound depends on its source and does not change, the wavelength does.

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Chemistry / Re: Can wavelength and frequency of EM waves be changed by the media the encounter?

« on: 25/04/2016 13:42:12 »

The amount the wavelength is compressed is determined by the index of refraction of the material.

By saying that the wavelength is "compressed", I tried to imply that the wavelength is shorter when light is travelling through a material of higher index of refraction.

This agrees with the numerical example provided.

(overlap with Colin2B...)

Sorry to sound contentious BUT if you are speaking in terms of electromagnetic radiation travelling through a medium, then surely if the wave-length is compressed, the light that entered the medium won't be the light that comes out, different wavelength, different frequency. This is the point I was trying to make, namely that light in the form of photons may slow through a medium, due to absorption and emission and THEREFORE the wave-length is compressed without affecting frequency, when the light exits the medium the wave length will also increase due to the change in the speed of light. However, in a wave situation this is not possible.  If the wavelength changes , the frequency changes. The two are inextricably connected.

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Chemistry / Re: Can the wavelength, and frequency of any EM wave be increased, or decreased, as

« on: 25/04/2016 06:58:50 »

As I understand it, the frequency can't be changed, but the wavelength can, when passing through a "linear" transparent optical material like glass, or your eyeball. This is how glasses and your eyeball can focus light.

This is really quite mystifying because IF the speed of light slows down when moving through a medium AND the frequency remains the same, then the wave-length should decrease not increase:

Suppose the speed of light in a vacuum  is 3 * 10 ⁸ metres.
The frequency of the light is 500 * 10 ¹⁴ Hz.
Then the wavelength

Suppose while travelling through a medium the speed of light is reduced to 2.5 * 10⁸ metres
The frequency remains the same at 500 * 10 ¹⁴ Hz.
Then the wavelength

Thus the conclusion that the frequency of light remains unchanged while its wave length increases with its passage through a medium is wrong it has to be wrong! On the other hand IF the frequency of the light remains unchanged upon its exit from the medium, it means that the speed of light has slowed due to the process of emission and absorption, without in anyway affecting its frequency or wavelength.