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During the 1950s, the mushroom clouds, from the 100 atmospheric tests, could be seen from almost 100 mi (160 km) away. The city of Las Vegas experienced noticeable seismic effects, and the mushroom clouds, which could be seen from the downtown hotels, became tourist attractions. St. George, Utah, received the brunt of the fallout of above-ground nuclear testing in the Yucca Flats/Nevada Test Site. Westerly winds routinely carried the fallout of these tests directly through St. George and southern Utah. Marked increases in cancers, such as leukemia, lymphoma, thyroid cancer, breast cancer, melanoma, bone cancer, brain tumors, and gastrointestinal tract cancers, were reported from the mid-1950s through 1980.

Source: Wikipedia article 'Nevada Test Site'

Um... Is this a vandalized article? Is this for real? They used atom bombs as tourist attractions? Five years after the horrible end of WWII? When they bombed Japan and they confirmed (if any doubt had existed up until then) that those a-bombs are extremely dangerous and carry with the explosion lethal invisible rays which basically make your skin rot and brain burn?

Once again, I must ask: "Am I missing something here?"

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    You are missing the "almost 100 mi (160 km) away". Not sure how far Las Vegas actually is from the test site, but radiation dilutes and gets absorbed by the atmosphere, and the test site might have been selected in a location where the fallout would not hit Las Vegas.
    – Jan
    Commented Jun 25, 2020 at 11:07
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    The effects of radiation and nuclear fallouts wasn't seen as dangerous and subtle in its consequences to health and the environment as it is today, that mind set had yet to develop. Maybe you can find more information, avoiding wikipedia and eye whitness reports from decades later would by my suggestion, and try finding studies from geoscience (you could ask the question over at the geoscience department as well, leaving the tourist part aside) and medicine ?
    – user43870
    Commented Jun 25, 2020 at 11:30
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    With your "skin rot and brain burn", you're way to the other side of the mushroom clouds as tourist attractions :-( Also consider the effect of distance, and the fact that you're a mere 93 million miles from a fairly large nuclear explosion :-)
    – jamesqf
    Commented Jun 25, 2020 at 17:16
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    There is in fact a museum dedicated to this chapter of Atomic Era history in Vegas: nationalatomictestingmuseum.org. If you ever get the chance, it's worth a visit!
    – Bear
    Commented Jun 25, 2020 at 19:52
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    The edit war diminishes the site - please raise a question on meta, discuss it, and abide by the resolution.
    – MCW
    Commented Jun 27, 2020 at 11:31

5 Answers 5

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Yes. There are many articles supporting this claim. Here's one from Bloomberg:

For four decades, the U.S. Department of Energy tested more than a thousand nuclear devices at the Nevada Test Site, a desert expanse just 65 miles northwest of Las Vegas. The 1951 detonation of a warhead 1,060 feet over the desert floor marked the beginning of the above-ground trials, whose famous mushroom clouds were easily visible from the nearby tourist magnet.

“They would light up the sky,” says Allen Palmer, executive director of the National Atomic Testing Museum. “It turned night into day.”

In true Las Vegas style, the city capitalized on the atomic spectacle. The Chamber of Commerce printed up calendars advertising detonation times and the best spots for watching. Casinos like Binion’s Horseshoe and the Desert Inn flaunted their north-facing vistas, offering special “atomic cocktails” and “Dawn Bomb Parties,” where crowds danced and quaffed until a flash lit the sky. Women decked out as mushroom clouds vied for the “Miss Atomic Energy” crown at the Sands. “The best thing to happen to Vegas was the Atomic Bomb,” one gambling magnate declared.

If you're more into videos, you might like this Smithsonian article.

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    LOL. Ahh, simpler times when things like cigarettes were 'refreshing" and "healthful" and you could spend a relaxing evening on vacation watching a mushroom cloud rise. Commented Jun 26, 2020 at 13:58
  • How did the Chamber of Commerce get ahold of the dates and times of nuclear tests? I'd've expected that those would be pretty highly classified information...
    – Vikki
    Commented Jun 26, 2020 at 21:04
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    @Sean Why? You don't want to accidentally fry a few hikers and at least issue a NOTAM (notice to airmen) to civilian airtraffic to maybe not look in that particular direction when the flash goes off. It would be similar to NASA telling ships to stay outside of a delimited zone at such-and-such time. That would be good stuff for a followup question. Commented Jun 26, 2020 at 21:28
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    The notion of atomic cocktails reminds me of quarantinis. Commented Jun 27, 2020 at 13:14
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    @Sean: For the most part, just the opposite is true: it's highly unclassified information, at least after you've decided to go ahead with the test. You want to make sure your adversaries know when you're testing so they are watching. Testing serves multiple goals, including testing new designs and communicating to your adversaries that your deterrent really does work. They'll certainly know when and where you tested after the fact Commented Jun 27, 2020 at 14:11
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In regards the secondary question, namely

Am I missing something here?

Yes; absolutely. You have neglected both the shielding effect of the 65 miles of air between Las Vegas and the bomb explosions, and the fact that the actual radiation intensity falls off as the square of the distance.

The study The Children of Atomic Bomb Survivors: A Genetic Study. by National Research Council (US); National Academy of Sciences (US); Neel JV, Schull WJ, editors. notes for Hiroshima:

On the other hand, both from these two curves and on the basis of our own observations regarding the shape of the distance-dosage curve, it seems likely that persons at distances in excess of 3,000 meters received little if any radiation. [right above Figure 4.3]

Air Shielding Attenuation

Consider the air-shielding effect first. To a first approximation the shielding material is irrelevant, except so far as different materials have different densities. The shielding effect can be approximated by calculating the material density times the thickness. For Hiroshima survivors beyond 3,000 metres I will assume:

  • 3000 metres of air at 1.2754 kg/m³ = 3,826 kg/m²

  • 30 metres (1%) of pine at 420 kg/m³ = 12,600 kg/m²

  • total shielding effect = 16,400 kg/m²

For Las Vegas Bomb Tourists assume:

  • 65 miles * 1600 m/mile at 1.2754 kg/m³ = 248,700 kg/m²; roughly 15 times that of Hiroshima survivors just outside the 3,000 metres "no significant radiation" suffered radius.

Distance Attenuation

At a distance of 65 miles = 104,000 metres, roughly 34.7 times as far from the blast centre as the Hiroshima survivors beyond 3,000 metres, the radiation reaching Las Vegas *Bomb Tourists has been distance-attenuated 34.7² = 1200 times as much as for the Hiroshima survivors outside the 3,000 metres radius.

Total Attenuation (of Direct Radiation)

While the precise calculation is undoubtedly more complex, certainly both attenuation effects must be regarded as combining. This means that the direct radiation experienced by Las Vegas Bomb Tourists will have been somewhere in between 1/1200 = 0.08% and 1/(1200*15) = 0.0005% that experienced by Hiroshima survivors outside the 3,000 metres "experienced no significant radiation" radius.

Yes, this analysis ignores the effects of radioactive fallout - that calculation being so intrinsically dependent on meteorological particularities of each blast. However I hope the above makes clear that the distance of Las Vegas from the test site was far more than sufficient to protect occasional visitors. Permanent residents might be another story - but that's a different question.


From comments below, and expanded

Yield Considerations

The largest nuclear device ever detonated was the Russian Tsar Bomba, at 50 Mega Tons (and it was s research device, not an intended weapon). The largest device ever designed and detonated by the U.S. was the MK-41 at 25 Mega Tons: about 1600 times the Hiroshima bomb (15 Kilo Tons of TNT).

For back-of-the-envelope considerations, even the 1600 times yield increase from Hiroshima is much smaller than the 1200 * 15 = 18,000 times attenuation provided by sheer distance from the bomb blast.

However all such devices are thermonuclear, not pure atomic, devices with a second fusion stage triggered by a primary fission stage (and possibly also incorporating a third, fission) stage.

As thermonuclear weapons represent the most efficient design for weapon energy yield in weapons with yields above 50 kilotons of TNT (210 TJ), virtually all the nuclear weapons of this size deployed by the five nuclear-weapon states under the Non-Proliferation Treaty today are thermonuclear weapons using the Teller–Ulam design.

From here any discussion of radiation (and fallout) profile is very specific for each particular bomb design - by intent. One must distinguish between the different effects and penetrating power of all of:

  • Alpha particles - high energy helium nuclei;

  • Beta particles - high energy electrons (and possibly positrons);

  • Gamma rays - high energy photons;

  • High (and low!) energy neutrons; and

  • Radioactive fallout such as strontium-90 (a long-term environmental hazard only unless one is immersed directly in the speed of weather only disbursed radioactive cloud, and even that is constrained to spread roughly as the square of distance traveled).

However energy is energy; it spreads outwards from an epicentre; and the inherently geometric effects described above cannot be avoided.

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    @a_donda: Incorrect. The quote is a conclusion drawn from close observation. The point is that a "back of the envelope" calculation quickly shows that there is several orders of magnitude additional attenuation for *bomb tourists" compared to Hiroshima survivors seen to have received no significant radiation, did to distance from the blast epicentre. Commented Jun 25, 2020 at 15:32
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    @Jurp, not knowing (or wanting to track down) the biggest bombs detonated in Utah, and assuming the radiation properties of A- and H-bombs are the same (they're not, but way more detail would be needed than would fit in a comment) we can still do a rough calculation. Tsar Bomba was 50Mt and Little Boy was 15kt, a factor of ~3000 (figures vary a little). So even if Tsar Bomba was tested in Utah, by Pieter's calculation the tourists would have been fine assuming little air-shielding.
    – Chris H
    Commented Jun 25, 2020 at 20:48
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    @Jurp, yield of a bomb grows much faster than the amount of ionizing radiation released. By the time you get into the megaton range, the radius for radiation poisoning is inside the fireball.
    – Mark
    Commented Jun 25, 2020 at 22:41
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    Prevailing winds had a bit to do with it. Quite famously, the movie The Conqueror was filmed in Utah, 220 km downwind of the test site, and the many cancer deaths among the cast and crew are blamed on fallout from the tests.
    – Spencer
    Commented Jun 25, 2020 at 23:00
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    This article details how milk became a vector for cancer after the tests - and that over 500,000 Americans may have died this way. There's also a photo of five soldiers standing at ground zero of an air-burst - because doing so was SAFE! article: qz.com/1163140/… and study: cms.qz.com/wp-content/uploads/2017/12/…
    – Jurp
    Commented Jun 25, 2020 at 23:16
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For another account on the (this time informed) contemporary attitude, read Richard Feynman's book Los Alamos from Below published here in full or quoted here.

The gist is, he figured that at 20 miles distance he would be safe behind a car's windshield and would see more without dark glasses.

... But just a few minutes before it was supposed to go off the radio started to work, and they told us there was 20 seconds or something to go, for people who were far away like we were. Others were closer, 6 miles away.

They gave out dark glasses that you could watch it with. Dark glasses! Twenty miles away, you couldn't see a damn thing through dark glasses. So I figured the only thing that could really hurt your eyes - bright light can never hurt your eyes - is ultraviolet light. I got behind a truck windshield, because the ultraviolet can't go through glass, so that would be safe, and so I could see the damn thing. OK.

Time comes, and this tremendous flash out there is so bright that I duck, and I see this purple splotch on the floor of the truck. I said, “That ain't it. That's an after-image.” So I look back up, and I see this white light changing into yellow and then into orange. The clouds form and then they disappear again; the compression and the expansion forms and makes clouds disappear. Then finally a big ball of orange, the center that was so bright, becomes a ball of orange that starts to rise and billow a little bit and get a little black around the edges, and then you see it's a big ball of smoke with flashes on the inside of the fire going out, the heat. ...

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  • Would you be able to include Feynman's quote inside your answer? If that link goes dead, your answer will become pretty threadbare.
    – F1Krazy
    Commented Jun 26, 2020 at 9:30
  • "bright light can never hurt your eyes" - To what extent is this true? It sure hurts my eyes to look directly at my (non-UV-generating) bright LED ceiling lights.
    – Dai
    Commented Jun 26, 2020 at 20:50
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    @Dai: Pain and damage are separate things. e.g. Infrared can damage your retinas by cooking them (looking into a fire, or a forge), but you don't feel pain because your photoreceptor cells don't sense those wavelengths. Bright enough light in visible wavelengths could damage your retinas, but it would have to be extremely intense to do that before you flinched away from looking at it. e.g. accidentally looking into a laser. photobiology.info/Rozanowska.html mentions photomechanical, photothermal, and photochemical. (I googled for more but found a lot of blue / LED possible FUD.) Commented Jun 26, 2020 at 21:36
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I just wanted to add this link to what has been said. Yes, the mindset was that radiation from the bombs was not as dangerous. If you want proof of there, here is a youtube video of five army guys STANDING AT GROUND ZERO during an air burst. (The missile explodes several miles directly above them)

In fact, the army did drills where troops would hunker down near ground zero, to get the troops used to the idea of fighting during a nuclear war.

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  • I've seen pictures of the Australian/British testing in the Australian outback where they put on glasses and turned their back to the explosion. It seems quite clear that the only concern was to eyesight and not radiation. My grandfather did research into the effect of radiation (his colleague was Louise Harold Grey, a well know researcher). Much of this research was in parallel rather than predating the weapons testing. Commented Jun 25, 2020 at 23:50
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    Prompt radiation falls off rather quickly with distance (as Pieter showcased in his answer), and the warhead of that missile was a very small one (1.5 kt). The aircrew ordered to fly through the cloud of the explosion a couple of minutes afterwards received a much higher dose, because it's the residual radiation / fallout where it's at...
    – DevSolar
    Commented Jun 26, 2020 at 10:58
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There's an important social aspect to this that hasn't been addressed so far. Until August 1949, when the USSR performed its first nuclear test, the atom bomb was the source and symbol of the USA's status as the sole superpower. After that, the improvement of atom bombs and development of hydrogen bombs was an important part of American actions to maintain their status.

Such things tend to be viewed vary positively in the American style of patriotism, and dangers from them tend to be ignored, at least for a while. Tom Lehrer satirised the matter rather well in 1953.

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