What is the truth about Leo Szilard and his invention of the cyclotron?

[davidmich]

Hi
What is the truth about Leo Szilard and his invention of the cyclotron? Does he deserve credit for an invention? I can’t find enough information on his work on the cyclotron. Ernest Lawrence is credited as being the inventor and earned a Nobel Prize in Physics for it I believe.

I look forward to your feedback.

[davidmich]

@davidmich

Hi
What is the truth about Leo Szilard and his invention of the cyclotron? Does he deserve credit for an invention? I can’t find enough information on his work on the cyclotron. Ernest Lawrence is credited as being the inventor and earned a Nobel Prize in Physics for it I believe.

I look forward to your feedback.

You’d think wikipedia would mention Szilard in passing, but this article doesn’t .

Cyclotron

Was Szilard a Nikola Tesla-typpe, claiming inventions he never actually made or did he genuinely invent but just not patent on time. What happened in the case of the cyclotron? It seems from my reading that that is what he claimed.

http://members.peak.org/~danneng/lawrence.html
American physicist Ernest Lawrence received the 1939 Nobel Prize for inventing the cyclotron. Credit went to Lawrence, but Szilard invented it first.

[davidmich]

@davidmich

You’d think wikipedia would mention Szilard in passing, but this article doesn’t .
Cyclotron - Wikipedia
Was Szilard a Nikola Tesla-typpe, claiming inventions he never actually made or did he genuinely invent but just not patent on time. What happened in the case of the cyclotron? It seems from my reading that that is what he claimed.

Leo Szilard and Ernest O. Lawrence - 1935 photo
American physicist Ernest Lawrence received the 1939 Nobel Prize for inventing the cyclotron. Credit went to Lawrence, but Szilard invented it first.

I do think that Szilard invented independently and didn’t patent. He may have regretted it. I don’t know. But patenting isn’t enough to deserve credit. The inventor has to show that his or her invention works. Presumably Szilard didn’t do that and Lawrence did. I don’t know. I hope some of you do.

[CalMeacham]

I’m afraid I don’t know much about it myself, but a quick search turns up this Physics Today article from 2000 that gives Szilard full credit for coming up with the idea in 1929:

https://physicstoday.scitation.org/doi/pdf/10.1063/1.1325189

It even opens with a picture of Lawrence and Szilard together in 1935. It appears in his notes, but he doesn’t seem to have gone after a patent.

[MikeS]

There’s an article from Physics Today, October 2000, that discusses Szilard’s particle accelerator designs. (It may be paywalled for most readers, but my institution has a subscription.) The author doesn’t discuss much about why Szilard didn’t pursue these designs further:

@Valentine Telegdi

Of Szilard’s many inventions, the least recognized are those concerning devices for accelerating particles. That’s not really suprising: The contents of all these patent applications (two in Germany and one in Britain) never became public knowledge because he eventually abandoned all three applications. It is not clear why. Either Szilard lost interest in pursuing them or the patent examiners may have raised questions of novelty on the basis of some “prior art.”

This prompted a letter to the editor some months later, from Gene Dannen. (Note that this appears to be the same person who maintains the website you linked to above.) He notes that the linear accelerator design was actually rejected on the basis that it had no commercial application.

[davidmich]

@MikeS

There’s an article from Physics Today, October 2000, that discusses Szilard’s particle accelerator designs. (It may be paywalled for most readers, but my institution has a subscription.) The author doesn’t discuss much about why Szilard didn’t pursue these designs further:This prompted a letter to the editor some months later, from Gene Dannen. (Note that this appears to be the same person who maintains the website you linked to above.) He notes that the linear accelerator design was actually rejected on the basis that it had no commercial application.

Thank you MikeS. Really helpful!

[CalMeacham]

@davidmich

Thank you MikeS. Really helpful!

Hey, what am I, chopped electrons? I sent the same article 4 minutes earlier!

[davidmich]

@CalMeacham

Hey, what am I, chopped electrons? I sent the same article 4 minutes earlier!

Thank you too CalMaecham. Much appreciated!

[ftg]

Patents rarely have anything to do with a Scientific invention. The real question is did Szilard publish it?

A formal journal article would be best, but if the Germans did like the Americans do now and eventually publish patent applications, then that will count for something.

I mentioned a fact I proved in a grant application. But I didn’t publish it in anything formal. Others came along and independently proved it … and published it. It’s considered a famous result. (Especially the technique used.) So I have nearly zero recognition of this. (Even though that old grant paper is still available online.)

If I had only known that anyone else would have cared … (repeat several dozen times).

[Arjuna34]

One big point in Lawrence’s favor is that he actually built the first cyclotron, and also got it to work. I could imagine that several physicists of the day had ideas along the lines of circular accelerators, but Lawrence was the first to actually do it.

[Buck_Godot]

@CalMeacham

Hey, what am I, chopped electrons? I sent the same article 4 minutes earlier!

Ah, but did you patent it?

[bonzer]

While Telegdi’s article is probably the best reference, let’s spell out a few of the standard Szilard sources on the matter.
William Lanouette’s Genius in the Shadows has this (p102):

And Szilard had patented a cyclotron in 1929, a year before Ernest O. Lawrence built his fist machine at Berkeley.

Then, more importantly, Leo Szilard: His Version of the Facts (ed. by Weart and Szilard, MIT, 1980, p11):

I was thinking of how one could accelerate particles to high speeds. I hit upon the idea of the cyclotron, maybe a few years before Lawrence. I wrote it down in the form of a patent application which was filed with the German patent office. It was not only the general idea of the cyclotron, but even the details of the stability of the electron orbits, and what it would take to keep these orbits stable; all this was worked out on this occasion.