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History Of Physics: A Bomb Without Einstein E=Mc2?


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#18 Dubbelosix

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Posted 13 June 2019 - 11:44 AM

Here we go again... Sanctus, please put this in speculations.



#19 exchemist

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Posted 15 June 2019 - 03:28 PM

To close my OP, based on the lack of relationship between Einstein's 1905 paper about E=mc2 and

the 1945 A-bomb, I quote two historical references:

 

From the 1923 English translation of Einstein paper, these are the closing paragraphs:

 

"The mass of a body is a measure of its energy-content; if the energy changes
by L, the mass changes in the same sense by L/9 × 1020, the energy being
measured in ergs, and the mass in grammes.

It is not impossible that with bodies whose energy-content is variable to a
high degree (e.g. with radium salts) the theory may be successfully put to the test.

 

If the theory corresponds to the facts, radiation conveys inertia between the
emitting and absorbing bodies
."
 

As it can be read here, the relationship between mass and energy is given in the

old cgs system of units (centimeter, gramm, second), where 1 erg = 1 g.cm2.s-2.

 

So, for Einstein, E = mc2 gives an energy  E = 9.1020 erg/gram.

 

The following is a copy of a lecture given in 1943 (element is codified under the number 25),

to physicists that would work at the Manhattan Project.

This document is declassified and published in the OLD book (sold at Amazon):

 

The Los Alamos Primer
The first lectures on how to build an Atomic Bomb

 University of California Press
1992 by Robert Serber (edited by Richard Rhodes)

 

which can be read at this link:

https://www.academia...s_Alamos_Primer

 

As everyone can read at the middle of the document, even when is somehow codified

and the conversion values of units have changed since 1943 up today, there is the expression

of the yield of energy expected per gram (gramme for UK) of the fissionable element 25 (U-235).

 

Quote:

 

"Since the weight of 1 nucleus of 25 is 3.88 .10-22 gram/nucleus, the energy release is

 

                                 7.1017 erg/gram "

 

So, 1905 Einstein's E=mc2 gives an energy amount 1285.71 times higher that the calculations

performed by Oppenheimer, and his team of scientists, as is related by Robert Serber.

 

So, no relationship between a 1905 formula E=mc2 and a 1943 theory about energy-matter relationship.

 

27-6e7ecf777e.jpg

This seems to be rather a silly post. Nobody is so stupid as to claim that all the mass in a gram of uranium or whatever is turned into energy during fission. After all, the process results in new atoms being formed, which still have mass.

 

What the mass defect shows us is that the difference in mass betwen starting materials and products is equivalent to the energy released, according to E=mc².  


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#20 exchemist

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Posted 16 June 2019 - 02:49 PM

I'm not saying that Einstein thought about U-235 fission. I doubt that such isotope was known by 1905.

Einstein was talkinkg about mass-energy transformation (which was the annihilation of matter - it vanished - and

became pure energy). It's written by himself at the end of the paper, which I literally copy again:

 

From the 1923 English translation of Einstein paper, these are the closing paragraphs:

--------------------------------------------------------------------------------------------------------------

"The mass of a body is a measure of its energy-content; if the energy changes
by L, the mass changes in the same sense by L/9 × 1020, the energy being
measured in ergs, and the mass in grammes.

-------------------------------------------------------------------------------------------------------------

 

In this paragraph, Einstein stated that, by m=E/c2, it verifies (using cgs units) that

1 gramme (or gram) of matter is equivalent to 9.1020 ergs.

 

And I compared that value with the 7.1017 ergs/gram of U-235 that Gerber calculated

as ELECTROSTATIC energy produced by the fission of 1 gram of U-235.

Then Gerber extend his calculations to 1Kg of U-235 being fissioned.

 

That's how I try to show how is that E=mc2 is unrelated to the A-bomb development.

 

I saw that Ghad liked your comment, what is not good, as I have a good opinion about him.

 

So, I ask him to interpret what I said: Gerber said E=mc2 didn't have a take in the development,

as the fission process is not-relativistic, due to the low speeds involved.

 

One thing is KE liberated due to electrostatic energy (repulsion) and a completely different thing

is the result of computing the energy contained in 1 gram of matter, which is obliterated and

transformed into energy. Two different processes.

 

Now, either you understand what I was explaining (by Gerber's mediation) or reject my comment,

no matter what.

 

I didn't write Gerber's paper nor I misunderstood what is VISIBLY written in there.

 

I may not be fluent on English, but the copy of the pages of the "Los Alamos Primer" is quite clear for me.

 

Anyway, I abandon this subject because it obviously irritates some unexpected forists/moderators.

 

I can see that even if I get a copy of a paper signed by Oppeheimer, Bethe, Lawrence and Fermi

(explaining the fission energy in 1943-1945 terms of knowledge), it would be in vain.

 

A shame, I think, that what I've found and presented here (from legit sources) be treated as if it

was something I invented. So, I give up here with this topic.

You don't seem to appreciate that E=mc² does not just apply to what you call relativistic processes (by which I assume you mean those in which there is relative motion at a significant fraction of c).

 

The implication of the mass-energy equivalence relation is that It applies to all energy changes, everywhere, of whatever kind. A charged torch battery thus will have more mass than a discharged one (though the change will be far too small to measure).

 

The unique thing about nuclear reactions is that the energy change per atom is large enough for the associated change in rest mass to be measurable. And it has been measured. And the change in mass does indeed correspond to the energy released, in full accordance with E=mc².

 

Thus, as I showed you, the 170 MeV released in a U235 fission event is reflected in the measured loss of mass of the products (daughter nuclei plus neutrons), compared to the atom they came from.  This is an experimental fact. 

 

(On a per atom basis, your quoted figure of 7 x 10¹⁷erg/gram corresponds to 235 x 7 x 10¹⁷/6.02 x 10²³ = 2.73 x 10⁻⁴erg/atom, which is 170MeV per atom of U 235.  This is the difference in binding energy between U 235 and its products, calculated from measurement of the mass difference between U235 and its products.) 

 

E=mc² is a relation predicted from relativity but which has completely general applicability.  


Edited by exchemist, 16 June 2019 - 03:18 PM.


#21 Dubbelosix

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Posted 16 June 2019 - 03:56 PM

For the record, it is spelled ''dyslexic'' secondly, your post has been reported.



#22 exchemist

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Posted 17 June 2019 - 02:01 AM

You keep twisting my words relentessly. Not a game anymore, unless you are dislexic.

 

You wrote: E=mc² does not just apply to what you call relativistic processes.

 

That's not what I wrote! In this:

 

"So, I ask him to interpret what I said: Gerber said E=mc2 didn't have a take in the development,

as the fission process is not-relativistic, due to the low speeds involved."

 

Gerber said it, not me.

 

But, in order to have the last word, you resort to this mechanism of changing what I wrote in my post, twisting it

and pretending that is what I said.

 

You are beyond excuses and, finally, I don't trust you anymore and I have no further use for you.

 

And, due to last postings from you and Dubbelosix, I suggest that you both (being so akin) digress on future threads

about physics or whatever. You were born to team togheter.

 

Me: I'm a stupid person for making efforts to explain a point, a concept or a theory. Good luck to you both togheter,

and keep rising the rationality of this forum.

 

Keep with your goal of "teaching" physics and chemistry (even math) here or at other forums. Maybe you can help

others to write equations that do make sense.

Gerber? Gerbil? I think you mean Robert Serber.

 

So far, you have not even quoted what Serber said. Instead you give us your interpretation of what he meant. And you have got this wrong.

 

So, to try to clear this up, I will now quote his actual words:-

 

"Somehow the popular notion took hold long ago that Einstein's theory of relativity, in particular his famous equation E = mc², plays some essential role in the theory of fission. Albert Einstein had a part in alerting the United States government to the possibility of building an atomic bomb, but his theory of relativity is not required in discussing fission. The theory of fission is what physicists call a non-relativistic theory, meaning that relativistic effects are too small to affect the dynamics of the fission process significantly."

 

This is quite consistent with what I have been explaining. At no point does Serber say that E=mc² does not apply to the process. He just says, rightly, that it does not play a part in the theory of fission.

 

 But it certainly does play a part in nuclear physics, in the form of the mass defect measurements, and hence binding energy tables, that I have been referring to throughout, which allow us to calculate the energy release from a given nuclear reaction. To use a chemical analogy, the mass defect and binding energy data tell us the nuclear thermodynamics, but not the kinetics. It is the kinetics of the fission process one needs to understand, to make a nuclear reaction happen.

 

However you, on the other hand, seem to have misunderstood Serber's comments as implying that E=mc² does not apply to nuclear fission, because it is not a relativistic phenomenon. That is nonsense: E=mc² applies to everything, relativistic or not, nuclear fission included, and Serber's remarks  do not say anything to the contrary.  


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#23 Dubbelosix

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Posted 17 June 2019 - 02:57 AM


 

So, to try to clear this up....

 

 

He'll still try and find news ways to argue back, stating that ''we are wrong'' or ''relativity is wrong,'' the usual crap.



#24 Dubbelosix

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Posted 17 June 2019 - 03:26 AM

Though I wouldn't technically say it applies to everything, a more correct statement it that it applies to a wide range of physics, most importantly pointing out that it is a rest solution of mass.



#25 Dubbelosix

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Posted 17 June 2019 - 09:28 AM

[math]\frac{1}{n^2} - \frac{1}{n^2} + \frac{1}{n^2} = 1 + f [/math]
 
[math]\frac{1}{n^2} + \frac{1}{n^2} + \frac{1}{n^2} + f = 1 [/math]
 

 

And?



#26 Dubbelosix

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Posted 17 June 2019 - 09:29 AM

I am going to ask very politely, what is your point? Are you asking you don't know how it is derived?

 

I've already had a physicist, AN actual physicist look through my work, so what could you possibly object to?



#27 Dubbelosix

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Posted 17 June 2019 - 10:26 AM

Dubbelosix, I can't believe that you don't see your mistakes!

 

In the first line you get: f = n-2 - 1, from which you deduce your second line f = 1 - n-2.

 

If you can't see this non-equality that you generated in only two consecutive lines, I'm beyond words.

 

Worse yet, you mix Fresnel "n" index with quantum "n", which are integers.

 

Your entire thread is flawed.

 

I'm reporting you again. You can't do algebra, you can't follow algebra and I am beyond words, I am not here to teach you. - but I'll tell you what, why don't you go find Matti Pitkannen on facebook, a specialist in general relativity who has checked my work. So if you don't believe me, you don't believe him... then the issue is with you, not me.

 

Next back chat, you'll be reported again. I asked very nicely what it was you didn't understand, and I was almost willing to take you through it, but its all about arguments with you. Now... either do what I said, or shut up.


Edited by Dubbelosix, 17 June 2019 - 11:09 AM.


#28 Dubbelosix

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Posted 17 June 2019 - 10:55 AM

No, its because you don't read, you don't listen... in fact, you don't even apply yourself to understand. You are your worst own enemy. I was going to take you through it... but you deserve no respect from me because you have shown no one here respect. Reported again...



#29 exchemist

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Posted 17 June 2019 - 11:11 AM

Gerber, Serber. I keep mixing these physicists. I'm dyslexic too, you see?

 

I like how do you "sequester" quotes from other posts and make them your own.

 

I quoted Serber many times (and I introduced his book here) that I didn't think it's necesary to quote him again.

 

I remarked in red and blue what Serber wrote about E=mc2.

 

Regarding your last paragraph, I'm spechless about how you twist and distort.

 

To keep sanity here, I propose you to CREATE YOUR OWN THREAD, so you can play with your own words, instead

of purposedly changing the meaning of what I wrote. I believe that you are trolling me and that you enjoy it very much.

 

I dare you to CREATE a new thread, instead of sucking up the blood and life of other people's thread.

 

But I think that you can't do it, because you are prone to criticize but you're afraid to be criticized. I don't

have such a problem, as my skin is thick enough and my brain big enough.

 

Go ahead: Invent some topic and make a new thread. Any subject. Go!

My sole purpose in these threads of yours is to keep the physics straight, as far as I can, for the sake of other readers if not you, yourself.

 

If you think I am twisting your words, as you claim, nothing would be easier for you than to set me straight by making clear that, contrary to what I think about you, you do in fact understand perfectly well that E=mc² applies to non-relativistic processes such as nuclear reactions, and that your point is only that the formula does not help in understanding the reaction mechanism.

 

If you care to do that, the underlying falsehood that I see embedded in what you are writing in this thread will disappear. 


Edited by exchemist, 17 June 2019 - 11:25 AM.

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#30 Dubbelosix

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Posted 17 June 2019 - 11:15 AM

My sole purpose in these threads of yours is to keep the physics straight, as far as I can, for the sake of other readers if not you, yourself.

 

If you think I am twisting your words, as you claim, nothing would be easier for you than for you to set me straight by making clear that, contrary to what I think about you, you do in fact understand perfectly well that E=mc² applies to non-relativistic processes such as nuclear reactions, and that your point is only that the formula does not help in understanding the reaction mechanism.

 

If you care to do that, the falsehood that I see embedded in what you are writing in this thread will disappear. 

 

But he can't... look above, he took two formula's from work of mine and can't even follow how they were reached at. He is actually incapable. Like all trolls and cranks, they pretend to know more than they actually know, hoping somehow the smoke and mirrors will lead us on a path that somehow makes them right. The problem is we know they are not right, not because we are attacking them, but because they don't bother learning.

 

People who actually contribute to the site has spent many years learning physics, others in different area's. Some people here have even published papers... and all of them will tell him and his other monikers, that he is wrong. But it's so hardwired he thinks we are out to get him, he lashes out at what he does not understand.



#31 Dubbelosix

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Posted 17 June 2019 - 11:37 AM

Good bye, exchemist and Gareth Meredith!

 

Enjoy your duties at this forum. Physics has to be protected from people like me, so somebody

choose you both to preserve the truth and, when possible, expand it.

 

 

Bye, probably see you under a new moniker, but bye for now.



#32 exchemist

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Posted 17 June 2019 - 03:39 PM

Good bye, exchemist and Gareth Meredith!

 

Enjoy your duties at this forum. Physics has to be protected from people like me, so somebody

choose you both to preserve the truth and, when possible, expand it.

Well if you are leaving us I'm not surprised. You won't find many other science forums nearly as tolerant of your crank views as this one is.

 

But as so often with cranks, I have learnt from arguing with you. I have learnt:

 - who Serber was,

- where to find binding energy data on all the elements in the Periodic Table,

-  that the energy release in fission of U 235 is ~170MeV, followed by a further ~30MeV of subsequent decay processes of the fission products, making the total energy release ~200MeV. 

 

And I've got some beautiful pictures from you, illustrating the Fourier transform relationship behind the Uncertainty Principle. 

 

So on balance it has probably been worth it, for me. 

 

P.S. As a colleague, on another forum, remarked recently, about someone quite different, "Why is always electrical engineers that pop up with crank views about physics?" An interesting question, for another day...... 


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#33 GAHD

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Posted 17 June 2019 - 08:48 PM


 

P.S. As a colleague, on another forum, remarked recently, about someone quite different, "Why is always electrical engineers that pop up with crank views about physics?" An interesting question, for another day...... 

Probably have Maxwell to blame for that. You also have various theoretical Physics Ma and Phd to blame: I know 3 different ones who screwed up "just simple electric motors" rather hard because they have zero practical to go with the theoretical and wanted to be useful in a mechanical room. Seriously, get a theoretical grad student to hook up anything 3-phase someday. (With fuses and breakers in place first because safety.) The results will most likely be both incredibly hilarious and incredibly time consuming.


Edited by GAHD, 17 June 2019 - 08:58 PM.
afterthought


#34 exchemist

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Posted 18 June 2019 - 03:45 AM

Probably have Maxwell to blame for that. You also have various theoretical Physics Ma and Phd to blame: I know 3 different ones who screwed up "just simple electric motors" rather hard because they have zero practical to go with the theoretical and wanted to be useful in a mechanical room. Seriously, get a theoretical grad student to hook up anything 3-phase someday. (With fuses and breakers in place first because safety.) The results will most likely be both incredibly hilarious and incredibly time consuming.

I would hope most theoretical physicists (and a fortiori chemists!) would not touch 3-phase electrical machines and would defer to the expertise of an electrical engineer. Personally, I would not volunteer for such a potentially life-shortening experience. I have a lot of respect for electrical engineering and find it interesting. (At one time I was the product manager for electrical insulating oils at Shell, so I had a fair amount of contact with the industry.)    

 

But as to why one finds electrical engineers with crank ideas about c.20th physics, it may be Maxwell, as you say. I suppose electrical engineering could be seen as a sort of apotheosis of c.19th physics.  And then, engineering more generally is the subject epitomising human mastery and control of nature. By contrast, the uncomfortable ideas of quantum theory and relativity shake the foundations of this confidence in human mastery, by denying the absolute and deterministic nature of things. So perhaps they could come to be seen, in the minds of some, as a sort of "enemy" of the engineering tradition.

 

Rhertz certainly expressed contempt and disbelief of both QM and relativity. But he had a particular animus against Einstein in particular, seeming to think him a charlatan who stole other people's ideas and rebranded them as his own. Seems to me rhertz failed to understand that the whole of science progresses by building incrementally on the ideas of those who have gone before. It was Newton himself who said that, if he saw further than other men, it was because he was standing on the shoulders of giants. 


Edited by exchemist, 18 June 2019 - 03:47 AM.