
Declassified videos of atmospheric nuclear tests (2017) - kerouanton
https://www.llnl.gov/news/llnl-releases-newly-declassified-test-videos
======
dmix
> 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.

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eatbitseveryday
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.

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

~~~
eatbitseveryday
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/](http://eso.org/public/images/eso1242a/)

~~~
dylan604
> 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

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billfruit
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'.

~~~
groby_b
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.

~~~
AndrewKemendo
_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.

~~~
michaelt
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](https://en.wikipedia.org/wiki/Tripwire_force)

------
Mary-Jane
"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.

------
platz
> 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?

~~~
eatbitseveryday
>> 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.

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

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

~~~
quicklime
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://www.atomcentral.com/atomic-smoke-trails.aspx)
[http://nuclearweaponarchive.org/Usa/Tests/SmokeTrails.html](http://nuclearweaponarchive.org/Usa/Tests/SmokeTrails.html)

~~~
robin_reala
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.

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ryanmercer
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.
:(

~~~
dylan604
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

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

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rhodrid
Such vandalism and for what?

~~~
jonsen
Cold war. Better than hot war.

~~~
paulie_a
It wasn't exactly a cold war.

~~~
mrkstu
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.

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

~~~
Majestic121
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.

