# What is the truth about Leo Szilard and his invention of the cyclotron? **URL:** \ **Category:** Factual Questions\ **Created:** [April 1, 2019, 1:53pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854 "2019-04-01T13:53:34Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![davidmich](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@davidmich](https://boards.straightdope.com/u/davidmich)\ **Post date:** [April 1, 2019, 1:53pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/1 "2019-04-01T13:53:34Z")
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. ---
**Author:** ![davidmich](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@davidmich](https://boards.straightdope.com/u/davidmich)\ **Post date:** [April 1, 2019, 2:07pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/2 "2019-04-01T14:07:08Z")
> [@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](https://en.wikipedia.org/wiki/Cyclotron)** > > A cyclotron is a type of particle accelerator invented by Ernest Lawrence in 1929–1930 at the University of California, Berkeley, and patented in 1932. A cyclotron accelerates charged particles outwards from the center of a flat cylindrical vacuum chamber along a spiral path. The particles are held to a spiral trajectory by a static magnetic field and accelerated by a rapidly varying electric field. Lawrence was awarded the 1939 Nobel Prize in Physics for this invention. > The cyclotron was the ... 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](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. ---
**Author:** ![davidmich](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@davidmich](https://boards.straightdope.com/u/davidmich)\ **Post date:** [April 1, 2019, 2:19pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/3 "2019-04-01T14:19:38Z")
> [@davidmich](#): > > You’d think wikipedia would mention Szilard in passing, but this article doesn’t . > [Cyclotron - Wikipedia](https://en.wikipedia.org/wiki/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. > > [Leo Szilard and Ernest O. Lawrence - 1935 photo](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. 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. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [April 1, 2019, 3:22pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/4 "2019-04-01T15:22:29Z")
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](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. ---
**Author:** ![MikeS](https://avatars.discourse-cdn.com/v4/letter/m/919ad9/32.png) [@MikeS](https://boards.straightdope.com/u/MikeS)\ **Post date:** [April 1, 2019, 3:26pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/5 "2019-04-01T15:26:59Z")
There’s an article from _Physics Today_, October 2000, that [discusses Szilard’s particle accelerator designs.](https://physicstoday.scitation.org/doi/10.1063/1.1325189) (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.](https://physicstoday.scitation.org/doi/10.1063/1.1366083) (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. ---
**Author:** ![davidmich](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@davidmich](https://boards.straightdope.com/u/davidmich)\ **Post date:** [April 1, 2019, 3:40pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/6 "2019-04-01T15:40:49Z")
> [@MikeS](#): > > There’s an article from _Physics Today_, October 2000, that [discusses Szilard’s particle accelerator designs.](https://physicstoday.scitation.org/doi/10.1063/1.1325189) (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.](https://physicstoday.scitation.org/doi/10.1063/1.1366083) (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! ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [April 1, 2019, 3:55pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/7 "2019-04-01T15:55:08Z")
> [@davidmich](#): > > Thank you MikeS. Really helpful! Hey, what am I, chopped electrons? I sent the same article 4 minutes earlier! ---
**Author:** ![davidmich](https://avatars.discourse-cdn.com/v4/letter/d/e56c9b/32.png) [@davidmich](https://boards.straightdope.com/u/davidmich)\ **Post date:** [April 1, 2019, 4:08pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/8 "2019-04-01T16:08:07Z")
> [@CalMeacham](#): > > Hey, what am I, chopped electrons? I sent the same article 4 minutes earlier! Thank you too CalMaecham. Much appreciated! ---
**Author:** ![ftg](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ftg/32/2801_2.png) [@ftg](https://boards.straightdope.com/u/ftg)\ **Post date:** [April 1, 2019, 9:15pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/9 "2019-04-01T21:15:55Z")
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). ---
**Author:** ![Arjuna34](https://avatars.discourse-cdn.com/v4/letter/a/eb8c5e/32.png) [@Arjuna34](https://boards.straightdope.com/u/Arjuna34)\ **Post date:** [April 1, 2019, 11:30pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/10 "2019-04-01T23:30:03Z")
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. ---
**Author:** ![Buck\_Godot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/buck_godot/32/6573_2.png) [@Buck\_Godot](https://boards.straightdope.com/u/Buck_Godot)\ **Post date:** [April 2, 2019, 4:00am UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/11 "2019-04-02T04:00:05Z")
> [@CalMeacham](#): > > Hey, what am I, chopped electrons? I sent the same article 4 minutes earlier! Ah, but did you patent it? ---
**Author:** ![bonzer](https://avatars.discourse-cdn.com/v4/letter/b/45deac/32.png) [@bonzer](https://boards.straightdope.com/u/bonzer)\ **Post date:** [April 3, 2019, 11:12pm UTC](https://boards.straightdope.com/t/what-is-the-truth-about-leo-szilard-and-his-invention-of-the-cyclotron/831854/12 "2019-04-03T23:12:30Z")
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.