3 ms·
Radioactivity detected from a half-life of once every trillion universes
- gus_massa 8y agoNote that this is almost "as expected". If you have only one xenon atom in a box, to see that it decayed you should wait a "1.8 x 10^22 years—or about a trillion times the age of the Universe". If you have two atoms in a box, you must wait approximately half of the time to see the decay. They have 2 tons of xenon. I'm not sure if 1 ton = 1000kg or 907 kg, but it doesn't change the result too much. With 2 tons you have 2 x 907 * 1000 / 131 x 6.02x10^23 = 8E28 xenon atoms, so you expect to have a few decays per hour (if I did the calculations correctly). I'm not sure if they can detect the 100% of the decays and the noise level, so it probably takes a longer time to detect a good signal.