Born secret – the heavy burden of bomb physics
nature.com
nature.com
Some of my favorite posts:
On the changing and unclear knowledge of Truman about how and where the bombs would be used: http://blog.nuclearsecrecy.com/2018/01/19/purely-military-ta...
On information leakage through the very act of censorship: http://blog.nuclearsecrecy.com/2016/02/12/solzhenitsyn-smyth...
On the inherent human judgment and inconsistency of redaction, and the information leaks that creates: http://blog.nuclearsecrecy.com/2013/04/12/the-problem-of-red...
And lastly, some people here may also know him for NUKEMAP, a rough tool for estimating nuclear explosion effects (https://nuclearsecrecy.com/nukemap/)
I have to say, there are a number of historians who write about complex historical events in a very accessible way. This blog post is definitely one of them, I also count Rutger Bergman amongst them.
In 1944, John W Campbell, the legendary editor of Astounding Science Fiction, had a visit from the FBI. It concerned a published story that had just too much detail about the atomic bomb. Campbell pointed out that the information was available, and other details could be extrapolated...
https://en.wikipedia.org/wiki/Deadline_(science_fiction_stor...
A proud day for science fictioneers!
You could say a similar thing about the atomic bomb: the science was well established, but actually building one was still a pretty big undertaking.
1938 to the Trinity test in 1945 was about seven years.
Going by the wikipedia article on RNA vaccines, people have been experimenting with them since 1989, but there was a major advance in 2010 on getting mRNA into cells without triggering an immune response. Even then, there were a lot of attempts at treating various diseases and viruses that didn't pan out. So, it sounds like mRNA vaccines were kind of a long slow slog of running into problems and fixing them, whereas in the case of the atomic bomb, the idea was around for a long time but no one really knew how to get started until suddenly they did, and they immediately got busy building it.
Turns out giving billions of people multiple doses is actually a hard problem.
The very few EU facilities have to supply the entire rest of the world (sans RU, CN). And now the US is talking about doing a third dose per patient before exporting any doses at all.
mRNA is bigger than a bomb, and fully peer reviewed.
1. preventing suicide by ecocide is next
I study WW2, and just off the top of my head, the Manhattan, B-29 and V-2 projects took longer and cost around $2 billion each in 1945 dollars. The economies involved spent over 50% of GDP on war materiel. So no, corona wasn't even the biggest war project.
> We shut down huge tracts of human life and attendant economies to save the lives of the oldest and weakest. We're still doing it.
I'm not sure it was a good tradeoff, and I would say there wouldn't have been a lockdown if there was enough ICU capacity, which BTW didn't seem to increase in the past year (China built new hospital buildings, but I don't know if they were equipped.)
I would argue that corona was the first smartphone pandemic, which pushed control down from the federal govt. to state govt. and individuals, causing sensationalism and distraction (ie. "do masks work or not?", "omg the number of patients increases every day!", "how is this going to affect my White House run (Newsom)", etc.)
> mRNA is bigger than a bomb, and fully peer reviewed.
WW2 arms were amply demonstrated.
https://www.webmd.com/vaccines/covid-19-vaccine/news/2021031...
https://www.oxfam.org/en/press-releases/two-thirds-epidemiol...
I could imagine scenarios where civilization depended on our ability to create energy or grow food on a scale that required ramping up fission or fusion reactors really fast. For instance, an asteroid or volcanic eruption blocks out the sun and we need to figure out how to keep our cities from starving.
Another technological approach to avert starvation in the same sort of ecosystem collapse scenario is to develop and implement human hibernation, like the cryo-sleep pods from science fiction movies. Thus we drastically reduce the calorie needs of the average person, so that a much smaller population can try to work out the problems and get the world back into a state where it can support a larger population. (There was a movie called Downsizing that was about that kind of solution, except that in the movie they literally shrank people so that their demands on the ecosystem are dramatically reduced, and cost of living is almost nothing.)
It might take me being further from covid for how similar it is to the Manhattan project response to really sink in. Might be too “fresh.”
Maybe this is a chance to learn something about those times. So until the bomb was dropped, the public wouldn’t have had any conception of it being a way out of the war. Yet if the war was in decline when the bombs dropped, I suspect we can agree the bombs did make the finality pretty certain. (Edit-I would argue the bombs absolutely did end the war in a way that wasn’t assured without them dropping, but that’s a point for another time.)
As someone living through covid, the vaccine was something we all were essentially waiting around for while others developed it. We’re aware of it, even if we don’t know how much work was needed to develop the mRNA vaccines. So in WWII your average person could have perceived much more terror from not even fathoming the end of the war at various points.
My knee-jerk was that hibernation doesn't save a ton of calories - a passive day and a highly active day are only a factor of 2 different (something I learned when getting my resting calorie spend as a volunteer medical test subject).
But, pausing aging - that's different than just sleeping all day and keeping your caloric spend to base. If you aren't aging I suspect no calories can be spent.
Is that possible? I know there are the "Walt Disney's head is frozen to be revived later" concepts, but do we have any evidence it is possible to pause aging entirely?
I'd bet that controlled and sustained fusion is closer. And, that seems like fantasy.
If I understand correctly, one of the barriers to the science-fiction approach of freezing people is that ice crystals form and destroy tissue if one were to actually literally freeze a person. In order to survive that, you'd need some way of inhibiting ice formation. Maybe it could be solved by injecting people with some non-toxic antifreeze solution, or immersing them in fluid at such high pressures that ice doesn't form, or you could just maintain a temperature just above freezing. And then there's the problem of how to thaw a person back out. I don't know if that's solved, but I guess there is a body of knowledge around reviving extreme hypothermia cases.
Less extreme forms of hibernation might look like medically induced coma or like a bear hibernating through the winter. I don't know if bears age significantly while they're sleeping. I'd guess that they age somewhat, but at a slower rate than normal.
In a morbidly curious way, I wonder what society's reaction and government reactions would have been in the emergence of an airborne pathogen MUCH worse than covid19. Not some fanciful human species killing event like in "The Stand", but with a potential to kill 10-20% of the planet if left unchecked.
I hope that wealthy countries' reactions to finding a vaccine, cure and preventing the spread would make the Manhattan Project look like building a back yard tool shed, but I don't know for sure how we would have handled the global catastrophe.
It did kill people - of course - due to the criticality experiments - but that was in part caused by cavalier experimentation by a researcher (over the objection of colleagues at the time to boot).
Contrast to biotech: you can't do human targeted biological experimentation without humans. At it's core you put lives at risk doing the most mundane things in biotech. You can easily wind up killing people trying to develop something and the further you're reaching the more likely it is. We don't have disposable, non-sentient human bodies to experiment on with complicated biotechnology and won't for a very long time.
Also, was your introduction to wandering earth the movie? If so I suggest reading the trilogy.
Indeed nature of the story is to focus on individuals. Still for example interstellar, you fully follow the dad/daughter and all that tubular space station building just happens completely off screen. And its assigned to the brilliance of the daughter instead of the coming together of people (how i interpret it!) curious how you view that for example :)
I think the 3body problem has a similar theme, the protagonist is central to the story, without him stuff does/doesnt happen, but the infrastructure (which in the main happens off camera) is built and deployed by the many not an individual, of course some solutions (trying not to spolier anything) are dependant on one individual.
I guess my point is that there isnt much difference between western and chinese sci-fi but chinese sci-fi also has to please the chinese government to be allowed to be published, so that also needs to be considered.
https://en.wikipedia.org/wiki/The_Progressive#United_States_....
Multilevel Security was a response to lessons learned in 1973, which worked, quite well. Those lessons were apparently ignored when Unix and PCs took off, and far too many people never looked back.
Some history - https://www.cl.cam.ac.uk/~rja14/Papers/SEv2-c08.pdf
The NSA is primarily an offensive organization. They spend almost no time on securing US networks or devices. It's like how the FBI catches spies, not the CIA.
The interactions of NSA and NIST reveal that the NSA is not just an offensively postured organization, they are perfectly willing to destroy US security in the large if it allows them to deliver tasty intercepts in the small.
While fusion does not end at iron 56 (whose nucleus has the lowest mass per nucleon), the quantities of heavier nuclei produced by fusion decrease very steeply with increasing atomic mass, becoming low beyond the isotopes of nickel, very low beyond the isotopes of zinc and negligible beyond the isotopes of germanium.
The elements heavier than zinc are produced mostly or completely by other kinds of reactions, e.g. neutron capture.
The nuclei you're producing needs to have a higher binding energy than the nuclei you're fusing do on their own. There is nothing you can fuse with iron, or any heavier nucleus, that will produce a stable element with greater binding energy than its components. Nickel-62 is actually the most stable nucleus, with the most binding energy per nucleon, but stellar nucleosynthesis ends with Nickel-56 which decays into Iron-56, which has the lowest mass per nucleon. All nuclei heavier than Nickel-62 are produced endothermically.
62Ni(p,2n)61Cu
Copper-63 has spin of 3/2 while nickel-62 has a spin of 0, so you can't simply add a proton (whose spin is 1/2), you need at least 3 fermions to participate in the reaction.
The Copper-61 and two neutrons of course have a higher mass than the Nickel-62 and the proton.
> That doesn't make any sense, the difference between nickel-62 and copper-63 is one extra proton. It's also bullshit, since the differences in spin get equalized by neutrinos.
First, nuclei are not simply the sum of their protons and neutrons. They have structure. While copper-63 happens to have 1 more proton than Nickel-62, in its stable, lowest-energy form it also has 2 neutrons that are in a different configuration. This is why it's spin is not simply the sum of Nickel-62's spin and a proton's spin. Spin needs to be preserved. Producing neutrinos to carry off spin would violate conservation of lepton number. You need to create a lepton pair, which is exactly how Nickel-63, produced by neutron capture, is able to beta decay into Copper-63.
> Also note that this closely corresponds to what we see: A star would be expected to burn by fusing hydrogen into heavier nuclei, which shed helium as alpha particles once they get too heavy, eventually ending up with mostly lead and helium.
This is not what we see. Stars burn hydrogen by two different methods into helium via the pp process and the CNO cycle. Carbon is formed in the triple-alpha process where three alpha particles fuse. Heavier elements are formed along the alpha ladder by adding alpha particles, a process that stops at iron-56. There are some other side processes like Carbon, Oxygen, Neon, and Silicon burning which also end at iron-56. Heavier elements like lead are not produced during the star's lifetime, but rather during events like supernovae and neutron star collisions by neutron capture in the s and r processes.
> No need for "exotic" physics. And it also explains the persistent failure of fusion energy
Fusion reactors fail because of plasma instabilities which have nothing to do with nuclear reactions.
> as it tries to build upon nonexistent mechanisms made up to confuse people trying to build nuclear weapons.
Basic principles like conservation of spin are not exotic physics nor are they a conspiracy. If the American government did sabotage fusion research to preserve nuclear secrets, why don't any of those powers who discovered those nuclear secrets anyways like Russia or North Korea have working fusion reactors?
Please take the time to read up on nuclear physics, it's a fascinating topic and very enlightening about why many things in the universe are the way they are.
Yes you need a neutrino/antineutrino pair. I don't see what is being violated.
>This is not what we see. Stars burn hydrogen by two different methods
No such observation has been made.
>why don't any of those powers who discovered those nuclear secrets anyways like Russia or North Korea have working fusion reactors?
They also don't want to reveal how these weapons work.
The observation has been made. We can use emission spectra to look at the composition of stars, we can detect neutrinos given off by the stellar fusion processes and measure their energies. Do not mistake ignorance of the data for lack of data.
So if everyone from Washington to Pyongyang is in on the conspiracy, exactly who are they trying to keep these details a secret from?
>exactly who are they trying to keep these details a secret from?
Pretty much everyone. There are not that many countries with thermonuclear weapons (Pyongyang doesn't have one) and you don't want e.g. ISIS make a clandestine 10Mt bomb.
The most lead rich stars ever detected are less than 0.000000000000005% lead by mass. Stars are formed from stellar nebulae which are the remnants of supernovae that create heavy elements - except for the very first stars in the universe all of them contain heavy elements. As a star ages and its temperature changes, it can bleed off some material, which will preferentially remove lighter elements (because it takes less energy for them to escape), leaving behind an increased concentration of the heavy elements.
Anyone who conducted even rudimentary nuclear experiments would be able to identify if the most basic tenets of quantum mechanics were a lie. Maintaining the ruse would require pretty much all the physicists in the world to be in on it. And if all the physicists are in on it, who exactly that is not in on it would be building these thermonuclear weapons? No, the basic physics of thermonuclear weapons are well known, but the engineering is incredibly difficult and resource intensive.
You get a nickel-63 if a nickel-62 captures a neutron. You can't get a positron/neutrino pair directly, you get a w+ boson which will decay into a positron/neutrino pair, but that w+ boson, like the z0 boson in the other case, is prohibitively heavy so this reaction doesn't take place. If you want, you can think of the 62Ni(p,2n)61Cu as a Nickel-62 fusing with a hydrogen to produce an excited state of Copper-63 which then immediately decays by double neutron emission to Copper-61, but the fact is the end product being Copper-61 is observed reality, and any model that doesn't predict its production is at best an elegant fiction.
Good. So you agree that p+p fusion into deuterium cannot occur?
>Maintaining the ruse would require pretty much all the physicists in the world to be in on it.
Any time anyone figures out they get shut down as described in the article.
>the basic physics of thermonuclear weapons are well known, but the engineering is incredibly difficult and resource intensive.
They figured making false principles well known would make keeping the real mechanism secret easier.
Until the iron 56 isotope, the average mass per nucleon decreases quickly, then it increases slowly with increasing atomic mass.
For reactants heavier than iron 56, fusion is not possible, but for some reactants lighter than iron 56 it is possible to fuse into nuclei a little heavier than iron 56, belonging to the few elements placed immediately after iron, where the average mass per nucleon has not increased much yet, so it is still lower than that of many of the lighter elements.
That doesn't equal to the binding energy per nucleon though, as you add a nucleon.
And since most of the results of hydrogen hitting something are unstable, this happens almost immediately, leaving the total process looking more like fission (a proton hitting a nucleus, and producing two nuclei of smaller mass than the original). Which is, in fact, how uranium fission works, only with neutrons rather than protons.
You can overshoot iron, but you'll decay back to it.
If you fused into something bigger, it would still be more efficient to split that atom and fuse it's nucleons into more Iron.
Atoms are mostly empty space - chemical lattices are mostly empty space - so in something like a star you can make super-dense iron and turn anything else kicking around into more iron.
EDIT: I feel like the problem here if you're assuming that the size of an atomic nucleus is anything other then negligible compared to it's electron shells. There's no situation under which a non-neutron star will "fit" more of a heavier nucleus in, compared to just densifying iron.
Of course, but that doesn't easily happen, as the nucleons are already bound together into heavier nuclides. In fact I guess that might happen in supernovas: The main sequence burns into lead, which is then reconstituted into the iron-nickel mixture that we know from iron meteorites, which also releases energy due to the higher average binding energy per nucleon, but needs extreme conditions to occur.
So in a star creating regular fusion events, even an errant heavier nuclei is going to eventually be decayed down to Fe (or head off to become a heavy element in the upper crust).
Binding energy is a negative energy value; iron having a high binding energy means it is a low energy state, so adding zero-binding-energy hydrogen to that system and decreasing the binding energy increases the potential energy of the system from the low value of iron.
Below iron fusing nucleons gives you energy; above iron it takes energy. If binding energy increased all the way up you wouldn't be able to have nuclear fission.
You would, because the smaller nuclides have higher total binding energy than the large nuclides. That doesn't contradict every step inbetween being favorable. You are adding hydrogen with zero binding energy.
i.e. total binding energy literally goes down as you get to larger nuclides.
> That doesn't contradict every step inbetween being favorable.
Yes, it does. Energy is strictly additive.
> You are adding hydrogen with zero binding energy.
Exactly. You are taking a bare nucleon, with zero binding energy, adding it to a system, and reducing the total binding energy (i.e. increasing the potential energy of the system). By conservation of mass-energy, this requires you to put in energy, and increases the total mass of the system.
No, it goes up. Iron-56: 492.26 MeV Uranium-238: 1801.7 MeV