General > General Technical Chat
Veritasium -- How Special Relativity Makes Magnets Work.
<< < (29/47) > >>
aetherist:

--- Quote from: HuronKing on April 07, 2022, 12:48:52 am ---
--- Quote from: aetherist on April 07, 2022, 12:10:24 am ---Does STR predict that fast moving electrons gain mass?  Something predicted that fast moving electrons gained mass, in the oldendays, but not today they say.

Does STR predict that a fast moving electron has a different longitudinal mass to its transverse mass (or longitudinal inertia  & transverse inertia if u prefer)
I am not up with what they say today about that. What did Einstein say?

E=mcc has zero to do with STR as far as i am aware. Hence it can't predict anything about the mass of fast moving electrons. Nor i think re anything to do with the momentum of fast moving electrons, nor energy.

But u seem to know what STR predicts re fast moving electrons.
--- End quote ---
I do because I've done my homework. Why don't you instead of continuing to bathe in ignorance?

https://en.wikipedia.org/wiki/Mass_in_special_relativity

https://www.feynmanlectures.caltech.edu/I_15.html
https://www.feynmanlectures.caltech.edu/I_16.html

Short answer - you don't know very much about relativity if you're stuck on understanding the meaning of 'relativistic mass' versus 'rest mass.' Feynman does teach it the older way but he makes it very clear this is about conservation of momentum and energy in reference frames.

You're also constantly using the wrong equation by referring to E = mc^2 exclusively. That's not the equation.
The proper equation is E^2 = (pc)^2 + (mc^2)^2 and it's a consequence of relativity (as shown by Feynman Lecture 16). Pedantic on my part? No, because E = mc^2 is a special expression of the mass-energy equivalence formula which means for a massless particle (like the photon) that has momentum we need to consider this in terms of momentum more than anything else.


--- Quote ---As an example of this effect, to deflect the high-speed electrons in the synchrotron that is used here at Caltech, we need a magnetic field that is 2000 times stronger than would be expected on the basis of Newton’s laws. In other words, the mass of the electrons in the synchrotron is 2000 times as great as their normal mass, and is as great as that of a proton! That m should be 2000 times m0 means that 1−v2/c2 must be 1/4,000,000, and that means that v differs from c by one part in 8,000,000, so the electrons are getting pretty close to the speed of light. If the electrons and light were both to start from the synchrotron (estimated as 700 feet away) and rush out to Bridge Lab, which would arrive first? The light, of course, because light always travels faster.1 How much earlier? That is too hard to tell—instead, we tell by what distance the light is ahead: it is about 1/1000 of an inch, or 14 the thickness of a piece of paper! When the electrons are going that fast their masses are enormous, but their speed cannot exceed the speed of light.
--- End quote ---
Feynman 15-8

Theory and experiment in perfect agreement. While aether rots in the grave.
--- End quote ---
I am not sure what aether theory says about electron mass.  But i see that Lorentz came up with the same equations at an earlier date than Einstein, using aether theory (not STR).  So, i doubt that u can bury aether here. Me myself i don’t like the smell of any ovem, they are both rotten.
http://philsci-archive.pitt.edu/16913/1/Potters_Kaufmann.pdf
Heuristics versus Norms: On the Relativistic Responses to the Kaufmannn Experiments✩ Jan Potters1
TimFox:

--- Quote from: aetherist on April 06, 2022, 11:31:35 pm ---
--- Quote from: TimFox on April 06, 2022, 11:02:20 pm ---"The acceleration of the aetherwind inside Earth will reach a max at some depth, & hence gravity will reach a max at that depth. Skoolkids of course all wrongly (today) think that gravity is a max at the surface (so did i)."

Isaac Newton showed that in the interior of a sphere (assuming that the mass density is only a function of the radius), the gravitational force at a point is that of the sphere whose radius equals that of the point. 
The gravitational forces due to the shell outside that radius cancels out.  Consult any textbook about that.
Now, to keep things simple, let us assume that the mass density within the earth is a constant W.
The gravitational force at a radius r inside the sphere is therefore:
     F = GMm/r2, where G is Newton's universal gravitational constant, m is the mass of the test object at that radius and M is the mass of the sphere inside that radius. 
That mass  M = WV, where W is the volume density and V = (4pi/3)r3 is the volume of the sphere inside the radius.
The "strength" or acceleration of gravity is g = F/m.
Therefore, as a function of radius inside the sphere, the acceleration of gravity is
     g = GM/r2 = (G/r2) x WV = (G/r2)x(4pi/3)GWr3 = (4pi/3)xGWxr,
which is directly proportional to r, the radius from the center of the sphere.
This is the physics class calculation:  a civil engineer can then introduce the dependence of the mass density W with radius r and get a slightly different answer, but it will still go to zero at the center.
--- End quote ---
Yes i am ok with all of that. Yes, the reason for the max g being at some depth is that the density is much greater in the say iron core. And yes the gravity is always zero near center.

BA.   However, all of that reminds me of the borehole anomaly. It has been found that the decrease of g with depth does not follow Newton.
G.   And, the measurement of Newton's big G indicates that big G is not a constant.
Me myself i am the only person around who has explained the BA catastrophe & the big G catastrophe. Perhaps my most brilliant discovery. I really must brush up on my Swedish.

--- End quote ---

Yes, when you include the variation in density with radius due to the heavy core (using geological models of the Earth's internal layers), the gravity deviates from the linear calculation above.  No aether required.
Which of your YouTube experts has evidence that the gravitational constant G varies substantially over a scale of the Earth's diameter (or even the Solar System dimensions)?
There have been critics of relativity who suggest a time-dependent variation in G:  serious experimental evidence places an upper limit of such variation at roughly 1 part in 1010 per year, while the accuracy of the experimental value itself has improved to about 22 ppm (NIST recommended values).
aetherist:

--- Quote from: TimFox on April 07, 2022, 02:00:01 pm ---
--- Quote from: aetherist on April 06, 2022, 11:31:35 pm ---
--- Quote from: TimFox on April 06, 2022, 11:02:20 pm ---"The acceleration of the aetherwind inside Earth will reach a max at some depth, & hence gravity will reach a max at that depth. Skoolkids of course all wrongly (today) think that gravity is a max at the surface (so did i)."

Isaac Newton showed that in the interior of a sphere (assuming that the mass density is only a function of the radius), the gravitational force at a point is that of the sphere whose radius equals that of the point. 
The gravitational forces due to the shell outside that radius cancels out.  Consult any textbook about that.
Now, to keep things simple, let us assume that the mass density within the earth is a constant W.
The gravitational force at a radius r inside the sphere is therefore:
     F = GMm/r2, where G is Newton's universal gravitational constant, m is the mass of the test object at that radius and M is the mass of the sphere inside that radius. 
That mass  M = WV, where W is the volume density and V = (4pi/3)r3 is the volume of the sphere inside the radius.
The "strength" or acceleration of gravity is g = F/m.
Therefore, as a function of radius inside the sphere, the acceleration of gravity is
     g = GM/r2 = (G/r2) x WV = (G/r2)x(4pi/3)GWr3 = (4pi/3)xGWxr,
which is directly proportional to r, the radius from the center of the sphere.
This is the physics class calculation:  a civil engineer can then introduce the dependence of the mass density W with radius r and get a slightly different answer, but it will still go to zero at the center.
--- End quote ---
Yes i am ok with all of that. Yes, the reason for the max g being at some depth is that the density is much greater in the say iron core. And yes the gravity is always zero near center.

BA.   However, all of that reminds me of the borehole anomaly. It has been found that the decrease of g with depth does not follow Newton.
G.   And, the measurement of Newton's big G indicates that big G is not a constant.
Me myself i am the only person around who has explained the BA catastrophe & the big G catastrophe. Perhaps my most brilliant discovery. I really must brush up on my Swedish.
--- End quote ---
Yes, when you include the variation in density with radius due to the heavy core (using geological models of the Earth's internal layers), the gravity deviates from the linear calculation above.  No aether required.
Which of your YouTube experts has evidence that the gravitational constant G varies substantially over a scale of the Earth's diameter (or even the Solar System dimensions)?
There have been critics of relativity who suggest a time-dependent variation in G:  serious experimental evidence places an upper limit of such variation at roughly 1 part in 1010 per year, while the accuracy of the experimental value itself has improved to about 22 ppm (NIST recommended values).
--- End quote ---
I have not looked at the latest numbers, but in 2005 the spread was 6.66742 plus or minus 0.0100, which is plus or minus  0.15%, which is plus or minus 1500 ppm, which they somehow claim is plus or minus 150 ppm.

I remember that various teams reported that their measurements of bigG on the surface of the Earth varied with time & location & time of year, ie after correcting for the usual.

Instruments might well measure to plus or minus 22 ppm, but bigG seems to vary by plus or minus  1500 ppm.
Aether theory might explain why bigG varies. I haven’t looked at the problem very closely.
TimFox:
Note that none of this discussion implies that G varies with space over dimensions comparable to the Earth.  There is speculation that G may vary slightly over time in a roughly periodic fashion.
Traditional measurements of G are extremely difficult:  some new quantum measurements (which still have largish uncertainties) may solve the question when they are improved sufficiently to get better repeatability.
Above all of this is an interesting phenomenon sometimes called "intellectual phase lock", which has been seen in the measurement of other fundamental constants over the years:  when you are setting up a difficult precision measurement, you first check to see if it is in the ballpark of the previous measurements, until the performance and uncertainty of the measurement technology improves to the point where you get a largish difference in the new value.

The status of the journal "Progress in Physics" is, shall we say, controversial.  It's history seems somewhat like that of social media.
aetherist:

--- Quote from: TimFox on April 08, 2022, 01:29:02 am ---Note that none of this discussion implies that G varies with space over dimensions comparable to the Earth.  There is speculation that G may vary slightly over time in a roughly periodic fashion.
Traditional measurements of G are extremely difficult:  some new quantum measurements (which still have largish uncertainties) may solve the question when they are improved sufficiently to get better repeatability.
Above all of this is an interesting phenomenon sometimes called "intellectual phase lock", which has been seen in the measurement of other fundamental constants over the years:  when you are setting up a difficult precision measurement, you first check to see if it is in the ballpark of the previous measurements, until the performance and uncertainty of the measurement technology improves to the point where you get a largish difference in the new value.

The status of the journal "Progress in Physics" is, shall we say, controversial.  It's history seems somewhat like that of social media.
--- End quote ---
Interesting.
The same exact paper (i think) was in arxiv Physics.
https://arxiv.org/pdf/physics/0512109.pdf
BigG duznt have to be very accurate to get good numbers for orbits etc, koz they use mGs (for each planet & Sun etc), & mGs are known very accurately.
But if the STR explanation for mmf near a wire has to include a frame correction for force, then the bigG teams should have STR & GTR corrections for their bigG measurements. I suppose that they do (i am too lazy to check).
Aetherwind would demand some kind of corrections for bigG too.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod