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Declassified videos of atmospheric nuclear tests (2017) (llnl.gov)
80 points by kerouanton 3 months ago | hide | past | web | favorite | 64 comments



> Nuclear detonations show two characteristic light pulses. This double-pulse phenomenon is evident in the video of the “Harlem event,” a 1.2 megaton test that took place 13,645 feet above the Christmas Island area of the Pacific on June 12, 1962. The first pulse peaks almost immediately as the shockwave first forms (0:09 in the video). The brightness then decreases as the superheated air, which is opaque when heated to above 3,300 degrees Kelvin -- or 5,480.33 degrees Fahrenheit -- shields the light from inside the fireball (0:10 in the video). As the shockwave cools to below 3,300 Kelvin, the air becomes transparent and the hot gasses begin to show through, creating the second pulse (0:21 in the video).

This is so interesting. I've always noticed the iconic double flashing in nuclear detonations but I never knew why it happened.

> Software developed by LLNL computer scientist Jason Bender scans each frame of the films to automate the measurement process. Bender’s software notes the timestamp of both pulses of light, as well as the darkest frame between them. With this data, Spriggs can calculate the test’s yield.

Sounds like a fun project, writing algorithms to parse 50yr old classified films of nuclear detonations.


I am concerned that uploading the videos to YouTube isn't archiving. I realize they perhaps maintain their own backups of the digitized versions, but one cannot otherwise preserve them by sharing them with the world via YouTube.


Presumably, YouTube is merely a distribution point for those amongst us who would make local copies for redundant archival purposes.


Downloading videos from YouTube is a violation of their policy, and there is no inherent way to do this from their interface. YouTube (or other video streaming services) are for viewing purposes only, not distribution.

I realize perhaps the intention of uploading to YouTube was more to advertise this project, rather than actually archiving it.

Distribution should be done via a website with links to files, e.g. ESO's gigapixel mosaic of the central parts of the Milky Way, a full size of 24.6 GiB [1]

[1] http://eso.org/public/images/eso1242a/


> YouTube (or other video streaming services) are for viewing purposes only, not distribution.

Vimeo specifically has an option for allowing the viewer to download the video. I use this frequently when sending videos to clients. They can download the original file, and I don't have to use dropbox. Win-win


> Downloading videos from YouTube is a violation of their policy

Unless it is licensed under Creative Commons, in which case they themselves provide a download button.


G Drive would be a better alternative.


Subject to the YouTube compression algorithms and meta data changes of course...


Typically the preservation copies are very large and unwieldy, as they are just a high resolution scan of every frame of the video. Whats on youtube is just a prevention copy. There are interesting software problems around how to store safely, work with, and preserve economically the many petabytes of data the preservation digitization projects like this create.


One type of archival process that avoids petabytes of data is to scan the original film, process it however deemed appropriate, and then record the finished digital files back to film negative. They will even go to the lengths of separating the digital files into their RGB channels, and then record each channel to B&W film negative. This allows for much greater information to be preserved per channel. It also makes restoring this archive interesting. All 3 negatives must be scanned, and then aligned in post.

I used to work for a company that had a 16-bit film recorder that did this. The recorder was very finicky to environmental conditions especially related to humidity.


Thinking of nuclear weapons, why is there too little mainstream political support for unilateral nuclear disarmament in western democracies. I do not think there is much necessity for atleast UK and France to keep and further develop nuclear deterrence. For now atleast in UK the major reason for maintenance and renewal of nuclear weapons and their delivery platform seems to be that, they needs to be done lest thousands lose their jobs, which is a reason so out of 'Yes, Prime Minister'.


Why would UK and France get rid of their nuclear weapon ?

It's a pretty good deterrent in case Russia gets a bit too cocky in Europe.


Or the US balks at the idea of going to war with Russia and decides to remove its nuclear Umbrella from Europe/fails to retaliate after a a strike in Europe.


It's basically the purest example of the Prisoners Dilemma in the real world.


No surprise, since much of game theory was invented as part of analyzing nuclear strategy.


Unless China and Russia do the same, there is little point in weakening yourself and your allies


China, IIRC, only has 300 nukes. The US and Russia have ~2000 each. The US and Russia could go to 1000 each without feeling any need to wait for anyone else to disarm. (They'd probably want to do it in lockstep with each other, though...)


If you're a current nuclear planner in the UK/France, you're planning for the distinct possibility of the US being a no-show in terms of nuclear umbrella. (Or any assistance)

The US has lost and continues to lose huge amounts of credibility over the last two years. The damage is bad enough that even if we fix the current problem, any reasonable person will assume that we'll just repeat a similar wave of stupidity at some later election.

Combine that with the fact that Russia is actively trying to cleave Eastern Europe from Central Europe, and you really can't propose unilateral disarmament without also suggesting Europe pledge fealty to Putin.

Disarmament requires stability. We (the US) shat a giant orange turd onto that idea.

And not only is disarmament not happening, as non-proliferation policy continues to crumble, nuclear armament will more and more move to smaller states who need a credible threat of "Well, then we'll take you with us" to larger regional forces. After Iran gets there, the next Domino in that region is likely Turkey.


If you're a current nuclear planner in the UK/France, you're planning for the distinct possibility of the US being a no-show in terms of nuclear umbrella. (Or any assistance)

This is a much bolder claim than I think people outside of the NBC world would realize and seems to have insider knowledge. Especially given the UK and France are nuclear powers.

Can you provide any Open Source documentation of this attitude being the trend? I'm not disagreeing I'm just curious.


There were fears at the height of the cold war that the US wouldn't launch their nuclear weapons if soviet tanks literally entered Paris because of the resulting mutually assured destruction. This lead to the formation of ideas like the tripwire force [1]. If you're interested in such topics, I can recommend "The Strategy of Conflict" by Thomas C. Schelling.

If there were credibility problems then, when America was on a much more martial and pro-free-europe footing, the situation is hardly any better now. Although there is a lot less fear of Russian tanks entering Paris, certainly!

[1] https://en.wikipedia.org/wiki/Tripwire_force


For France, this is a good starting point: https://www.csis.org/analysis/understanding-implications-fra...

Quoth: The Strategic Review focuses on preserving France’s strategic autonomy, which is centered on maintaining and updating a credible maritime and air-based nuclear deterrent

Will France say publicly that they don't trust the US? Not in so many words, no. But given that Trump refused to reaffirm article 5, read the following sentence: At the Warsaw and Brussels NATO summits, France decisively and unambiguously reaffirmed its commitment to NATO’s Article 5 and mutual assistance.

Unless you subscribe to the reality TV school of diplomacy, this is quite clear.


> The US has lost and continues to lose huge amounts of credibility over the last two years.

> Disarmament requires stability. We (the US) shat a giant orange turd onto that idea.

One could reasonably argue this goes back to the Ukranian conflict. The previous administration hardly bolstered the notion that the US would hold up to promises and supposed red lines.


Is this based on the misconception that the US violated the Budapest Memorandum by not defending Ukraine? For some reason this idea has a lot of traction, but the agreement doesn’t actually require the signatories to defend Ukraine from a non-nuclear attack, it merely prohibits them from attacking. Russia has violated the agreement but the US has no obligations to act on that.


Yes and no, and I suppose it is a bit misleading on my part to not explicitly clarify in the original post. (One cannot simply post on HN...)

The US need not, contractually, support the Ukraine but it makes one realize that the US isn't the World's Police and a defender like some have believed. Nations need fend for themselves.

That, of course, is not the only foreign policy / military issue which highlighted US pullback from global policing actions. At least overt, in-the-news, type actions, as various special forces type operations are going on all the time.

The point is, the US populous is seemingly tired of the forever wars and politicians and their supporting media have grown wise to keep things under the rug as much as possible.


I don’t understand. The US has never played world police in any sort of blanket fashion. It’s always been subject to whims and almost always limited to situations where it serves our interests in some way (or at least the interests of those in power). I don’t see how there would have been any expectation of US intervention in Ukraine given our past behavior.

You immediately followed the Ukraine reference with “The previous administration hardly bolstered the notion that the US would hold up to promises and supposed red lines.” But there were no promises or red lines. Was that intended as a separate point?


> I don’t understand. The US has never played world police in any sort of blanket fashion.

The US has been regularly accused of playing "World Police." We literally have major studio films parodying that fact.

> But there were no promises or red lines.

Syrian chemical weapons use?

To be frank, I cannot tell if you're being needlessly obtuse in order an attempt to draw me into some sort of rhetorical noose to prove me wrong, or if you're simply ignorant of post-WWII history.


Neither, I just thought you were still taking about Ukraine there, since the whole point of your comment (as I understood it) was that Ukraine was some sort of turning point.


Sorry if I was being needlessly provocative.

> that Ukraine was some sort of turning point.

I would argue that it is, that history books paint that as a turning point, of America turning away from the world stage should the trend continue.

After all, it wasn't that long ago the US (via NATO) was involving itself in peace keeping missions in Eastern Europe.

Of course this is contrasted with the rise of JSOC and drone missions (and our forever war in the Middle East), so perhaps not a full turn-away but a shift to a more muted, discrete influence? The US no longer overtly "going to bat" for "Democracy".

> I just thought you were still taking about Ukraine there, since the whole point of your comment

The point was more so that to provide a counter-point to the groby comment that the current administration marks the turning point away from the world stage, policing and protection, etc. We've arguably done that for most of this decade.


Russia shot down a civilian airliner and lied about it. Overr 50 Dutch citizens died. No kinetic response such as destroying Buks in the separatist zone.


It wasn’t the first time. The USSR even killed a sitting Congressman in one of them. The US did nothing then either.


It is worth pointing out the US has also shot down a civilian airliner[0] of a non-friendly nation and it didn't escalate into war so perhaps accidental shoot-downs are not generally accepted as casus belli?

[0] - https://en.wikipedia.org/wiki/Iran_Air_Flight_655


And we apologized, paid money, and took responsibility.


>Thinking of nuclear weapons, why is there too little mainstream political support for unilateral nuclear disarmament in western democracies.

MAD has kept the peace better than anything so far. It may be uncomfortable for a variety of reasons but the fact of the matter is that nuclear powers don't get in shooting wars with each other and nobody picks a fight with a nuclear power no matter how small.


If say South Africa has done away with nuclear weapons capabilities, then why can't UK? Besides countries like Germany, Italy, Spain, Japan do not have their own nuclear deterrent capabilities.


It's easy to give up your weapons when you don't perceive any threat, have strong friends and/or everyone around you has a very big interest in regional stability.

European nations have nuclear neighbors (France, UK) they can rely on if need be. Japan has the US to shield it from China (even still China pushes them around a little) and both China and the US to shield it from NK. South Africa is the dominant power in the region (Zimbabwe won't be annexing them anytime soon) and they have friends that like intervening in matters on the other side of the world (US, UK).

Ain't nobody with half a brain giving up their nukes after what happened to Libya. I'm surprised that Iran is disarming as much as it supposedly is. Quite frankly I'd like to see more proliferation among smaller nations because it keeps regional powers from acting like jerks. Look at how well nuclear weapons have kept the peace between India and Pakistan. Would Russia would have pushed around a nuclear Afghanistan, Georgia or Ukraine? Would Iraq picked a fight with a nuclear Iran or Kuwait? Would the US have invaded a nuclear Iraq?

Nuclear disarmament is a lot like gun control. The people who have reason to feel the most secure tend to be the first to tell everyone else to give up their arms and the guy in a neighborhood the police respond to "when they get around to it" who's upstairs neighbors are probably cooking meth wonders what kind of lunatic wouldn't want the ability to defend themselves if the need arose.


Nuclear weapons work great to keep the peace... until they don’t. The notion that they greatly reduce the occurrence of war seems to be spot on... but you’re trading an ongoing problem for an ongoing small chance of a complete catastrophe.

Your proposal to promote peace through nuclear proliferation would probably work great for a while. Then twenty or fifty or a hundred years down the line, something will go wrong and civilization will die. That doesn’t seem like a good tradeoff to me.


> If say South Africa has done away with nuclear weapons capabilities, then why can't UK?

South Africa only did it because the right-wing white minority regime knew it was falling to internal opposition that was not only racially different but perceived to be of diametrically opposed ideological and, at least potentially, geopolitical orientation, and didn't want to supply nuclear arms to a hostile group. I suppose if the British government expected to fall to, say, a domestic Chinese-aligned quasi-Maoist opposition and had sufficient lead time to do so, it might disarm, too.

If you don't know why most nations don't voluntarily disarm in any other circumstances, the example of one of the few that did—Ukraine—might clear that up.


> Besides countries like Germany, Italy, Spain, Japan do not have their own nuclear deterrent capabilities.

All four of these countries are under the US's nuclear umbrella and so don't need nuclear weapons. Which suits their politicians just fine: they get to have the safety of a nuclear deterrent without having to take the PR hit of supporting a nuclear weapons program.

But take note of groby_b's comment that America's commitment to the nuclear shield is suddenly looking very shaky. While they're still very much the minority for the moment, a few politicians on the Japanese right are gently bringing up the possibility of Japanese nuclear weapons, and if Trump keeps snuggling up to Putin, it wouldn't surprise me at all if Germany, Italy and Spain started seeing the same thing.


>and if Trump keeps snuggling up to Putin, it wouldn't surprise me at all if Germany, Italy and Spain started seeing the same thing.

Can't they just snuggle up to their close neighbor and EU/NATO partner France? France is a nuclear power too, don't forget. UK is one too, and still part of NATO.


South Africa was pressured to a point where they were unable to operationalize their weapons. Their strategic value was also limited.


"When he dug in to find out why there was a discrepancy, he discovered that the manual measurements made in the '50s and '60s were off, in some cases by 20 percent to 30 percent."

I'd heard that during the war the US exaggerated the power of nuclear weapons but this is the first time I've seen evidence to substantiate the claim. Was the data high or low? I perused the article twice and couldn't find clarification.


> Measurements taken in the '50s and '60s focused on the rate of growth of the fireball. These measurements were done manually by projecting each frame onto a grid, with an analyst jotting down the eyeballed measurement before the projector’s heat began to melt the frame.

What?


>> before the projector’s heat began to melt the frame.

> What?

The projector uses a hot lightbulb to display the frame in the film onto a wall or screen. The film sits just in front of this bulb, and of course the heat can risk damaging or melting the plastic film if the film is not quickly accelerated past the bulb (as is the case for watching a video - a sequence of frames).

Keeping one frame visible on a wall is to measure the visible size of the fireball, but doing so means one frame stays in front of the bulb long enough to risk it melting.


The grid on the photo, the camera field of view, the landscape, sounding rocket contrails, etc, etc are all of known size. It's like using a beer can for scale in a photo.


Sure, I'm more interested in the "melting the frame" issue


You must be too young to have used a home film projector. Even in a little 8mm projector, the light bulb is very hot, to get the brightness needed. Any film that sits in front of the bulb will simply melt from the heat. The only reason it normally doesn't is because the film is being moved through the projector so quickly that it doesn't have time to get that hot, but when the advancing mechanism gets stuck, it only takes a few seconds for that frame of the film to melt away.


Here's a good example - the film was loaded incorrectly and started to burn whenever it slowed down:

https://www.youtube.com/watch?v=aCNR6rnl8LQ


In the final one (Operation Teapot - Turk) there are these criss-crossed diagonal streaks in the background. What are those from?


I haven’t watched it, but probably sounding rockets to measure the blast wave? https://en.wikipedia.org/wiki/Sounding_rocket


Looks like it, except that the rocket itself isn't taking measurements, it's just there to create a smoke trail which can be analyzed later?

http://www.atomcentral.com/atomic-smoke-trails.aspx http://nuclearweaponarchive.org/Usa/Tests/SmokeTrails.html


Yes, exactly. Immediately before detonation you send up rockets in a grid pattern, then film it with high speed cameras. You can then look at the grid deformation over time to get an idea of the shape of blast wave.


There's a guy that's digitizing them to get more accurate classifications as to the strength of the blasts and the sad thing is he's finding that some of the canisters are full of basically dust from some of the film disintegrating. :(


probably with a strong smell of vinegar. i've seen my share of damaged film, but you don't even need to see it to know it's damaged just by the smell


If you ever get a chance, check out the Smithsonian-affiliated National Atomic Testing Museum in Las Vegas, NV.


Such vandalism and for what?


Cold war. Better than hot war.


It wasn't exactly a cold war.


It was. We are very lucky there was never a direct confrontation between the different sides at the height of their strength. If the USSR and China had been able to create a common cause and gone fully aggressive in the 70s, there would've been a good chance of either a nuclear war or WWIII sweeping the world. That is a hot war.


Tell that to the Vietnamese and the Koreans.


Except for all those pesky wars, Korea, Vietnam, Afghanistan


Vietnam was 1.5 millions casualties, give or take, civilians included.

WW2 was 60 million.

It's not about disparaging the importance of Vietnam and all, but the war could have been way hotter than what is was.


It was the middle of winter in the arctic compared to any shooting engagement between the Warsaw Pact nations and NATO.

Proxy wars every decade are basically world peace compared to any realistic scenario as to how a shooting war between the major powers would have played out.


> It wasn't exactly a cold war.

Nah, it was oxygen-frozen-solid most of the time. Once it got a bit tepid near Cuba, but that was about it; good thing it didn't boil over.


Peace




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