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Science

Researchers Measure Atom With Half-Life of 18 Sextillion Years (livescience.com) 123

Posted by BeauHD from the first-time-ever dept.
A detector designed to hunt for dark matter has succeeded in detecting one of the rarest particle interactions in the universe. "According to a new study published today in the journal Nature, the team of more than 100 researchers measured, for the first time ever, the decay of a xenon-124 atom into a tellurium 124 atom through an extremely rare process called two-neutrino double electron capture," reports Live Science. "This type of radioactive decay occurs when an atom's nucleus absorbs two electrons from its outer electron shell simultaneously, thereby releasing a double dose of the ghostly particles called neutrinos." From the report: By measuring this unique decay in a lab for the first time, the researchers were able to prove precisely how rare the reaction is and how long it takes xenon-124 to decay. The half-life of xenon-124 -- that is, the average time required for a group of xenon-124 atoms to diminish by half -- is about 18 sextillion years (1.8 x 10^22 years), roughly 1 trillion times the current age of the universe. This marks the single longest half-life ever directly measured in a lab. Only one nuclear-decay process in the universe has a longer half-life: the decay of tellurium-128, which has a half-life more than 100 times longer than that of xenon-124. But this vanishingly rare event has only been calculated on paper.
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Researchers Measure Atom With Half-Life of 18 Sextillion Years More

Researchers Measure Atom With Half-Life of 18 Sextillion Years

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  • How did it come into being? (Score:4, Interesting)

    by johnsie ( 1158363 ) on Thursday April 25, 2019 @05:46AM (#58488172)
    How do these atoms, and more importantly their sub-components come into being?
  • and proton decay [wikipedia.org] with an estimated half-life of at least 1.67×10^34 years?

    • Re: (Score:2)

      by Sique ( 173459 )
      Those are even more theoretical than the calculated decay of tellurium-128 into xenon-128 with a calculated halftime of 2.2 * 10^24 years as mentioned in the article. The last one at least is probably real, just not yet observed. The proton decay is a theoretical possibility outside the Standard Model of Particle Physics, as it would violate the Conservation law for the Baryon number.

    • Proton decay isn't even a thing, as far as we know.

  • Half life 3 confirmed! (Score:1)

    by Anonymous Coward

    in just 18 sextillion years!

  • A thing about statistics .... (Score:5, Informative)

    by 140Mandak262Jamuna ( 970587 ) on Thursday April 25, 2019 @08:25AM (#58488738) Journal
    When people say, "one in a million chance ...", if there are billion "chances", it would happen 1000 times. Half life is 1.0e022 years, ok. But every 131 kg of Xenon has 6.021e23 atoms. If you have 131 kg of Xenon, you would see it 5 times a month, or so. At 50 ppb concentration in our atmosphere, we probably have several hundred tons of this gas on earth and this thing should be happening every minute. It just so happened, it occurred close to the detector.

    My numbers are approximate, but the point I am trying make is, "the event is not all that rare in the universe or on Earth. This event happening close to the detector is rare. That is all."

    • "every 131 kg of Xenon has 6.021e23 atoms"
      I know it was just a typo, or trying-to-dash-off-a-reply-simple oversight, but -
      every 131 kg of Xenon actually has 6.021e26 atoms.
      Avogadro's number is 6x10^23 atoms per mole, which is in grams, not kilos.
      For a kilo-mole, the number is 6x10^26.

      Otherwise than that, your point is well taken.

  • Do all elements have a half-life? When they say, "the single longest half-life ever directly measured in a lab," do they mean among a subset of elements that undergo nuclear decay? Or do all elements decay, but we don't care because most of them are so slow?

    • Re: (Score:2)

      by Terwin ( 412356 )

      As protons decay, I can't imagine anything made of them would not, but for 'stable' elements, it would not be a very fast process.

    • Comment removed based on user account deletion

    • Do all elements have a half-life? When they say, "the single longest half-life ever directly measured in a lab," do they mean among a subset of elements that undergo nuclear decay? Or do all elements decay, but we don't care because most of them are so slow?

      It's hypothetically possible that isotopes* that are stable actually have a half-life so long that scientists have never observed the decay of an atom of those isotopes. As far as I know, though, scientists have no reason to believe that this is the case, so they're considered stable and have no half-life. So yes, "the single longest half-life" excludes stable isotopes, which have no half-life.

      * Elements do not have a half-life, because different isotopes of each element have a different half-life. Every

    • Yes, everything ought to decay. We don't actually know, but it would be very odd if everything complex didn't decay eventually into their fundamental particles, if there is such a thing and they are left alone long enough. Whether that happens depends on the final state of the universe.

      With things like proton (hydrogen nucleus) decay, we have had models such as the Salam-Weinberg theory that predict a lifetime of 10^34 years or thereabouts since the seventies. To observe these decays, we could have to lo

  • wonder if anyone will be around to refill the experiments xeon tank in 18 Sextillion Years

  • I am pretty ignorant of nuclear physics.

    My understanding was that for all elements, decay had been observed (at least twice), and the period between two decay events is used to extrapolate the half-life. That's how I thought they determined half-lives.

    But if Xenon decay hadn't ever been observed at all, then how did anyone knows its half-life? Even with only one new observation, you still wouldn't know; you need two so that you can measure the time between, to get the period.

    I know I'm wrong about someth

    • A lot of half-lives, including this Xenon decay, are calculated before they are observed. Nuclear physics is pretty well understood and the calculations are good. The calculations (and half-lives) depend on the mass difference between the parent and daughter nuclei along with a bunch of other factors such as if there is a straightforward decay mechanism and which conservation laws have to be observed. A starting rule is that the greater the mass difference the quicker the decay, but that comes with a who

  • This clearly asks for a class action suit from every creationist! Demand your money back from the creator!

  • Who cares about these young flash-in-the-pan Xenon atoms?. All the protons in the universe are going to decay at 10^32 years, the universe will be quark soup and I'll probably be dead by then anyways.

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