What Happened

The US government conducted many nuclear bomb tests above ground but the harmful effects of these test were realized so they decided to conduct underground test. The very first of these test was conducted on August 27, 1957 and they had never done one of these types of test before so they didn’t know what would happen. They simply dug a long cylindrical hole and dropped the bomb in there with a two ton concrete plug on top and a 4 inch thick manhole covering the hole. They then exploded the bomb.

When the bomb exploded the concrete plug vaporized into a gas and rapidly expanded up to the manhole cover like a gun but with a nuclear bomb instead of gunpowder. The gas then hit the manhole cover and sent the manhole cover flying a 6 times earth’s escape velocity or roughly 125000/mph. This speed was calculated by a camera that had 1000fps or shot one frame every millisecond but the camera only caught one frame of the manhole cover before it went out of sight. Some manmade satellites have reached speeds faster than than this manhole cover but they used the gravitational pull of planets which is not manmade propulsion.

RELATED STORIES:

https://www.jpl.nasa.gov/infographics/the-fastest-man-made-objects-in-the-universe

https://www.businessinsider.com/fastest-object-robert-brownlee-2016-2

https://en.wikipedia.org/wiki/Operation_Plumbbob

https://theconversation.com/have-we-made-an-object-that-could-travel-1-the-speed-of-light-170849

https://science.howstuffworks.com/environmental/energy/exploding-manhole1.htm

https://www.zmescience.com/science/news-science/fastest-manmade-object-manhole-cover-nuclea-test/