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Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: PmbPhy on 27/06/2015 03:42:22

Title: Did Einstein's make a mistake in his 1905 SR paper?
Post by: PmbPhy on 27/06/2015 03:42:22
In his 1905 paper Einstein derived an expression for the transverse mass of a particle. This is the ratio of transverse force to transverse acceleration. His result is wrong because he used the force in one frame and the acceleration in another frame. Thus his definition was different than that used today.

This is addressed in the book Einstein's Mistakes by Hans C. Ohanian. The author talks about this in the section he refers to as s Einstein's Third Mistake. It's on pages 105 to 107. For those who wish to read it I uploaded it onto my website at http://www.newenglandphysics.org/Other/Ohanians_Third_Mistake.pdf

His mistake is thus based on a wrong definition. So the question here is: Do you think a definition can be referred to as being wrong? Personally I don't believe so. I posted this because I thought it was an important thing for members to know but according to forum protocol, all posts must be questions.
Title: Re: Did Einstein's make a mistake in his 1905 SR paper?
Post by: Bill S on 27/06/2015 22:07:32
One of the strongest impressions I took away from Ohanian's book was that Einstein had come to a lot of right answers via a lot of mistaken paths. 

If one takes a scientific definition as a statement or description of the fundamental character or scope of something; then, surely it must be possible for the person framing that definition to be in error.  In that event, could the definition not be said to be wrong?
Title: Re: Did Einstein's make a mistake in his 1905 SR paper?
Post by: PmbPhy on 27/06/2015 22:40:28
Quote from: Bill S
One of the strongest impressions I took away from Ohanian's book was that Einstein had come to a lot of right answers via a lot of mistaken paths.
Do you have this book and read the whole thing?

Quote from: Bill S
If one takes a scientific definition as a statement or description of the fundamental character or scope of something; then, surely it must be possible for the person framing that definition to be in error.
I don't understand what that means. Can you please explain it for me? Thanks.
Title: Re: Did Einstein's make a mistake in his 1905 SR paper?
Post by: Bill S on 27/06/2015 23:31:04
Quote from: Pete
Do you have this book and read the whole thing?

Yes; it was some time age I read it, so I have just a general recollection and feeling that I struggled a bit in places. 

Quote
I don't understand what that means.

I'll probably run that past my wife, because at the moment I can't see what there is to not understand.  I've no doubt Donette will clarify that for me, and I'll come back to you.
Title: Re: Did Einstein's make a mistake in his 1905 SR paper?
Post by: Bill S on 27/06/2015 23:46:47
Quote
If one takes a scientific definition as a statement or description of the fundamental character or scope of something; then, surely it must be possible for the person framing that definition to be in error.

Donette looked at this and said: There was a time when the Earth was defined as being flat; now we know it is a sphere, so the earlier definition was wrong.  Does that help?
Title: Re: Did Einstein's make a mistake in his 1905 SR paper?
Post by: alancalverd on 28/06/2015 00:02:54
Difference between defined and described, I think.

Scientifically, the earth is defined as the third rock from the sun, or the planet we live on, depending on whether you are an alien or a human, and described as "devoid of intelligent life" or "an oblate spheriod" likewise.

But I guess that Einstein was ascribing a mathematical definition to his parameters, and mathematical definitions are entirely arbitrary: you can define A as the angle between two lines and B as the number of monkeys in a barrel. The point here is that whilst the definitions are unarguable, the ratio A/B will be meaningless if A and B are not coordinates in the same space.
Title: Re: Did Einstein's make a mistake in his 1905 SR paper?
Post by: PmbPhy on 28/06/2015 04:07:39
Quote from: Bill S
Donette looked at this and said: There was a time when the Earth was defined as being flat; now we know it is a sphere, so the earlier definition was wrong.  Does that help?
No. If that's true then it's of no help. It's incorrect to assert that something is defined to have a particular shape. That can only be assumed to me true as determined by experiment or observation. It's incorrect to say that it's defined that way. So Donette may have believed that to be the case but even if the Earth was flat like a plate then his assertion There was a time when the Earth was defined as being flat is wrong while his assertion now we know it is a sphere is correct.

Who is Donette anyway?

Quote from: Bill S
I'll probably run that past my wife, because at the moment I can't see what there is to not understand.  I've no doubt Donette will clarify that for me, and I'll come back to you.
Please do so. I'll explain why I don't understand it. You wrote:
Quote from: Bill S
If one takes a scientific definition as a statement or description of the fundamental character or scope of something; then, surely it must be possible for the person framing that definition to be in error.
This has the following logical form

If A or B then C where

A = one takes a scientific definition as a statement

B = one takes a description of the fundamental character or scope of something

C = it must be possible for the person framing that definition to be in error

What does it mean to take a definition as a statement and is such a thing even possible? Is that even possible or meaningful? I don't see how it could be possible for a definition to be a statement. E.g. inertia is defined as the resistance that a body has to changes in it's momentum. What is the statement here?

What does it mean to take a description of the fundamental character or scope of something?
Title: Re: Did Einstein's make a mistake in his 1905 SR paper?
Post by: Bill S on 28/06/2015 20:06:54
Quote
Difference between defined and described, I think.

Thanks Alan, that’s a valid, if sometimes nice, distinction.

If “the planet we live on” can be taken as a definition, would you accept that a flat-earthist could define the Earth as the discoid on which we live, and that this would be an erroneous definition?

I suspect we are slipping into semantics here, which will probably do little to help with Pete’s OP.
Title: Re: Did Einstein's make a mistake in his 1905 SR paper?
Post by: Bill S on 28/06/2015 20:26:36
Quote from: Pete
Who is Donette anyway?

Sorry, I thought it would have been obvious from the context that Donette is my wife.

Quote
. E.g. inertia is defined as the resistance that a body has to changes in it's momentum. What is the statement here?

This contains, at least implicitly, the statement: “Inertia is the resistance that a body has to changes in it's momentum.”

I think I see where your confusion arose.  You took an “If A, then B” and turned it into something more complex.

Try the logical form:

A = If one takes a scientific definition as a {statement or description} of the fundamental character or scope of something;

B = It must be possible for the person framing that definition to be in error

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