Claim: "Modern nuclear weapons don't have the radiation problem"

[Rory]

Talking to Bill Maher recently Neal deGrasse Tyson said that:

"Modern nukes don't have the radiation problem. Just to be clear really you're still blown to smithereens but yeah it's a different kind of weapon than the Hiroshima and Nagasaki nuclear weapons. But if it's a hydrogen bomb [it doesn't have a radiation problem].

We used to have to worry about it with fallout and all the rest of that. What you really have to worry about is being vaporized and after that, if you're not vaporized, being blown to bits by the shockwave.

What I want to say is there's a reaction to nukes that is a little bit out of proportion with what they actually do."

Maher then says he hopes deGrasse Tyson is right and deGrasse Tyson says:

"Well if they use fission bombs that would be [a problem]."

Maher than asks (at 3:30) if that's what they have and deGrasse Tyson doesn't answer, just kind of bluffs and smiles and after about ten seconds of silence Maher moves on.

So is NdGT right that "modern nuclear weapons [such as the ones at Putin's disposal] don't have the radiation problem"? Or is he, as his demeanour suggests, clutching at straws and talking a bunch of hot air? (It wouldn't be the first time.)

Clip:


Source: https://www.youtube.com/watch?v=QGa4ItIOCRg

 

[Rory]

According to Alex Wellerstein, a historian of science specialising in the history of nuclear weapons:

Somewhat stunned by the ignorance displayed by @neiltyson in this clip from the @billmaher show, in which he repeats a serious misconception about thermonuclear weapons containing less fallout potential than pure fission weapons.

Thermonuclear weapons are a) triggered by fission bombs, so they always have SOME fission as part of their yield (there are no "pure fusion bombs"), and b) USUALLY use those fusion neutrons to trigger further fission reactions.

So a modern strategic thermonuclear weapon is probably at least 50% fission yield. So if the total yield is 300kt (as many modern warheads are), then that's 150kt worth of fission. Which would produce TEN TIMES the fallout of the Hiroshima bomb.

So you should assume, unless you have REALLY REALLY REALLY good reasons otherwise (which he doesn't), that any thermonuclear weapons today are going to be a lot "dirtier" than the WWII weapons.

www.twitter.com/wellerstein/status/1581725339218497536

 

[Mendel]

Remember, Tyson is more of a theoretical physicist (not a weapons expert!), and in theory he's right:

Article:

A pure fusion weapon is a hypothetical hydrogen bomb design that does not need a fission "primary" explosive to ignite the fusion of deuterium and tritium, two heavy isotopes of hydrogen used in fission-fusion thermonuclear weapons. Such a weapon would require no fissile material and would therefore be much easier to develop in secret than existing weapons. [...]

Pure fusion weapons offer the possibility of generating arbitrarily small nuclear yields because no critical mass of fissile fuel need be assembled for detonation, as with a conventional fission primary needed to spark a fusion explosion. There is also the advantage of reduced collateral damage stemming from fallout because these weapons would not create the highly radioactive byproducts made by fission-type weapons. These weapons would be lethal not only because of their explosive force, which could be large compared to bombs based on chemical explosives, but also because of the neutrons they generate. [...]

Despite the many millions of dollars spent by the U.S. between 1952 and 1992 to produce a pure fusion weapon, no measurable success was ever achieved.

Source: https://en.m.wikipedia.org/wiki/Pure_fusion_weapon

 

[FatPhil]

Remember, Tyson is more of a theoretical physicist (not a weapons expert!), and in theory he's right:

Article:

A pure fusion weapon is a hypothetical hydrogen bomb design that does not need a fission "primary"
...
Despite the many millions of dollars spent by the U.S. between 1952 and 1992 to produce a pure fusion weapon, no measurable success was ever achieved.

Source: https://en.m.wikipedia.org/wiki/Pure_fusion_weapon

I would presume Tyson is aware that pure fusion doesn't exist, and that what's in use are hybrid devices. Those hybrid devices only need enough fissile material to start off the fusion reaction, so there's way [EDIT!]more[/EDIT] fission in a megaton of pure-fissile yield than in a megaton of h-bomb yield.

To be honest, Tyson looked more annoyed than flustered - I presume someone had previously said something that was as naive as Maher's later display that he didn't know the difference between fission and hybrid fusion devices, and their ignorance of the subject matter they were discussing was winding him up.

[Edit: less->more. Thanks for the catch, Mendel]

 

[jplaza]

Deuterium + Tritium reactions produce alpha particles and high energy neutrons.

So you do have alpha radiation as a primary by product (that can be easily blocked).

Neutrons on the other hand, can hit materials and produce further nuclear reactions that activate them, so they can emit gamma radiation that decays in time. How long it lasts, or how dangerous it is, depends on the materials, and the neutron dose absorbed.

So, technically speaking, you can have radiation as a consecuence of fussion, even if it is a secondary effect.

I guess what Tyson means is that with fusion you don't get a collection of radioactive isotopes scattered all over the place that take their times to decay, as you do in fission reactions.

 

[Rory]

and in theory he's right

Nah, he wasn't talking in theory about hypothetical weapons, he was talking about the real world present moment situation.

To be honest, Tyson looked more annoyed than flustered

To me he seemed annoyed at the existence of war, but his overall demeanour seemed par for the course when he's speaking on TV.

I would presume Tyson is aware that pure fusion doesn't exist, and that what's in use are hybrid devices.

It wouldn't appear that way based on what he said to Maher.

Let's not make excuses for the man, his words were clear enough. I think we can base any debunk/explanation on them alone rather than his degree title or what someone else may or may not have said, etc.

 

[Mendel]

Let's not make excuses for the man

The excuse would be that this was a talk show and not a topic he'd have been able to prepare beforehand—mistakes will be made, and this was one.

I'm sure he's aware as a physicist that fusion=clean, fission=dirty, but not aware (because he's not a weapons export) that a fusion bomb needs fission to work.

So my mental headline here is, "unprepared expert was wrong on a matter outside his field of expertise, in a situation of no consequence", which is a nothingburger.

 

[Rory]

The excuse would be that this was a talk show and not a topic he'd have been able to prepare beforehand—mistakes will be made, and this was one.

If it's a topic one isn't not sure about we're best off keeping quiet and not confidently stating apparent facts. And it's not like anybody asked him a question about it, the other guy was talking and the issue was whether nukes could be shot down. He just blurted it out apropos of nothing.

Also, it's not the first (or second, or third) time he's done something like this: he has a track record of confidently stating factual errors in areas he's clearly lacking knowledge in when on screen. It's a pattern with him.

So my mental headline here is, "unprepared expert was wrong on a matter outside his field of expertise, in a situation of no consequence", which is a nothingburger.

Perhaps true. But that's irrelevant to whether or not he was spouting bunk, which is what we're addressing here.

 

[FatPhil]

Perhaps true. But that's irrelevant to whether or not he was spouting bunk, which is what we're addressing here.

He was already wound up - we didn't get to see why. Shortcuts get taken when patience is low.

 

[Ravi]

Many people think that because someone has a PhD in Physics, he/she knows everything.. I cannot get this. I know plenty of people with a PhD in Physics, and not all of them are as clever as you think they are, and surely not everyone is a nuclear expert.

What I don't like is these media-hyping tiktok using folks, the chatting about things they have no expertise in (but they think they have).

 

[Rory]

He was already wound up - we didn't get to see why. Shortcuts get taken when patience is low.

What got him wound up?

Disclaimer: I've seen the full episode.

 

[deirdre]

He was already wound up - we didn't get to see why. Shortcuts get taken when patience is low.

started with a discussion of the January 6th hearings (vid segment in article). But Mahr was pretty lefty about it all, so Tyson not upset.so looks like Tyson was upset purely about the Ukraine insinuations and/or an attack on science..since science made nukes. and Tyson goes on about this, defending nukes.

Article:

Maher asked about the January 6th hearings and how Tyson squared those with his calls for a rational approach to the world. Tyson addressed the need for people to be educated in spotting disinformation. "We don't have the tools coming out of our school system in order to combat that," Tyson said.

"The other issue — besides the death of democracy — that's been on my mind this week is nuclear war," Maher said, which is pretty unnerving, as segues go. Tyson was impassioned about science, while Maher occasionally got meta about sports metaphors. Eventually, the trio discussed the potential effects of nuclear weapons — with Tyson pointing out that conventional weapons can often be deadlier than nuclear weapons.

Source: https://www.insidehook.com/daily_brief/television/bill-maher-asteroids-neil-degrasse-tyson-real-time

note..full episode on Apple podcasts his only sports metaphor was the quarter back throws the ball to where the receiver is going to be when the ball gets there. https://podcasts.apple.com/au/podcast/real-time-with-bill-maher/id98746009

 

[AmberRobot]

It seemed to me that Bill Maher was making the point that if nuclear weapons are used in the Ukraine war it affects us all because of the transport of nuclear fallout. Then Neil implies that is not true because modern nuclear bombs don't use radioactive materials, which clearly seems to be wrong.

 

[FatPhil]

It's from 1959 (and badly OCR-ed, I'd guess), so tech may have changed somewhat (different tamper material, for example), but this abstract implies there's no difference in harm from radiation:

Radioactive hazard resulting from the explosions of a 'clean' hydrogen bomb and of a conventional fission bomb☆
O.I.Leipunskii
https://doi.org/10.1016/0891-3919(59)90135-8

Abstract

An estimate is made of the danger to the world population arising from the creation of long-lived radioactive isotopes in nuclear explosions and from their dissemination over the globe. An ordinary fission bomb and a clean hydrogen bomb, taken to be a deuterium-tritium reaction, are considered. With a hydrogen bomb the principal agents are 14C and 8H, and with an ordinary bomb 90Sr, 137Cs and 1°C. The doses delivered to the gonads and bones are calculated, and this leads to figures for the number of people born subsequently with hereditary defects and the number of cases of leukaemia (cancer of the blood). In this calculation the distribution of radioisotopes in animate and in inanimate matter is taken into account. The special aspects of a ground-level hydrogen explosion are considered. The total amount of energy liberated in radioactive decay by products of the explosion is three times greater in the case of a deuterium-tritium bomb than for an ordinary bomb. However, taking an estimate over the whole period of decay of the reaction products, it is found that ten-megaton bombs of the two types give rise to roughly the same dose of radiation to the tissues, and claim approximately the same number of victims. In round figures we expect: Deuterium-tritium bombFission bomb Dose to the tissues50,000 x 10−6 r40,000 x 10−6 r, Dose to the bones50,000 x 10−6 r88,000 x 10−6 r Number of mutations (in a population of 2·5 x 109)50,00040,000 Number of cases of leukaemia (in a population of 2·5 x 108)15,00026,000 Thus on the score of radiation injury to the world population, a clean hydrogen bomb operating by the reaction of. deuterium and tritium cannot be considered less dangerous than an ordinary atomic bomb.

https://www.sciencedirect.com/science/article/abs/pii/0891391959901358

 

[Rory]

with Tyson pointing out that conventional weapons can often be deadlier than nuclear weapons.

Yes, that was him doing the thing awkward geeky teenagers do after they've learned about the firebombing of Tokyo or Dresden (probably from reading Slaughterhouse 5) and someone mentions Hiroshima/Nagasaki (ie, insert a fact they hope makes them look smart, even though it's irrelevant, in lieu of having something useful to add or just listening).

Interesting that they framed it in that way rather than "with Tyson pointing out that nuclear weapons these days 'don't have the radiation problem'".

Probably somebody fact-checked it and thought better of it.

It's from 1959

I think because deGrasse Tyson's claim is "modern nuclear weapons don't have the radiation problem" it would require a more modern source if one wished to support it.