Where Has All the Xenon Gone? 225
LucidBeast writes "Xenon, the second heaviest of the noble gasses, is only found in trace amounts in the atmosphere. Atmosphere contains less xenon than other lighter noble gasses. Missing xenon has perplexed scientists and it has been speculated that it is hiding in the Earth's mantle. Now, a group at the University of Bayreuth in Germany thinks it might have found the answer. It turns out that xenon does not dissolve easily into magnesium silicate perovskite, and thus it cannot hide there. Because it had no place to hide, it is now gone forever."
Re:It's in all those funny looking headlights (Score:3, Informative)
Wrong question (Score:5, Informative)
TFS makes no sense at all; TFA is not much better. It seems that, rather than asking, "Why is there so little xenon in the atmosphere" and coming up with a purely speculative answer, the researchers might have questioned why anyone expected to find more.
Re:"gone"? did it ever exist? (Score:5, Informative)
RTFA. It says that it was probably in the early earth's atmosphere, and the earth's atmosphere was probably blown away by some event, and then re-established itself xenon-free from gasses bubbling up from the molten landscape.
They also wonder why Mars has no xenon.
Another terrible summary (Score:5, Informative)
"Xenon, the second heaviest of the noble gasses, is only found in trace amounts in the atmosphere.
So far so good.
[The] [a]tmosphere contains less xenon than other lighter noble gasses.
Could be read as meaning that the other noble gasses contain more xenon than the atmosphere, but as a sentence it's passable.
...it is hiding in the earths mantle.
It's called [the] Earth, and you forgot the possesive apostrophe.
Now a group at the University of Bayreuth in Germany think that they might have found the answer.
"The answer," given the context, can only seem to mean that they've found out where the xenon is hiding, but...
I[t] turns out that xenon does not dissolve easily into magnesium silicate perovskite, thus it cannot hide there. And because it had no place to hide, it is now gone forever."
Oh, okay, so "the answer" seems to be "we still don't know, but it's not where we thought it was"? Rather than "it is now gone forever" it seems (from reading one of articles, shock horror) that it was never actually there in the first place - perhaps substituting "come from" in place of "hide" would have made more sense.
Yours sincerely,
Captain Pedantic
Re:It's in all those funny looking headlights (Score:5, Informative)
Actually pretty close. A bunch went into display/effects laser systems in the 1990s, before cheap diode lasers because available in a variety of colours. If you ever saw non-red/non-green lasers at shows in the 1990s, they were either YAG (different tech altogether), or Argon/Neon/Krypton/Xenon blends for different colours. Now they're pretty much all solid-state, and cost $500 instead of around $100k.
Re:Wrong question (Score:4, Informative)
It seems that, rather than asking, "Why is there so little xenon in the atmosphere" and coming up with a purely speculative answer, the researchers might have questioned why anyone expected to find more.
I thought everyone (well, scientists anyway) expected more Xenon than we observe on Earth because of meteorite samples: apparently meteorites have more xenon than we see in our atmosphere.
Unless... did you mean why didn't the Bayreuth researches test (e.g. question) any those theories? I thought they did test one of those theories by trying to saturate a mineral (perovskite) with xenon, said mineral being found in the Earth's mantel. (IANAGS, so perhaps an actual geo-scientist could comment on whether perovskite was a good choice for a test like this; I'm willing to give the Bayreuth researchers the benefit of the doubt, given that they are actual geoscientists and probably gave some thought to candidate minerals for their test).
Interesting? Sure... I never knew about a "xenon discrepancy"; so mildly interesting.
Informative? Sort of... I would have liked to see another paragraph on xenon comparing content for extra vs. terrestrial rocks. I'm willing to give the geo-scientist community the benefit of the doubt of having thoroughly considered the "xenon deficiency" to the point where they actually gave it a name.
From TFA:
“This model is enough to explain the whole xenon deficiency,” says Svyatoslav Shcheka, a geochemist at the University of Bayreuth in Germany. He and Hans Keppler, also of Bayreuth, report the finding online October 10 in Nature.
Compared with meteorites that formed out of primordial solar system stuff, Earth and Mars have far less xenon in their atmospheres. Scientists have proposed many possible explanations, such as minerals that locked up xenon in the upper parts of Earth’s middle layer, the mantle.
Re:It's in all those funny looking headlights (Score:5, Informative)
Xenon is in QUALITY headlights. the blue and purple crap the posers put on their cars is not Xenon but actually low grade halogen bulbs with a color coating on them.
I thought xenon was most chemically active (Score:4, Informative)
http://en.wikipedia.org/wiki/Noble_gas_compound [wikipedia.org]
Yes, see the link: of all the noble gases we've studied, it is the most chemically active, we've created many more compounds with xenon than any other noble gas. It's the most reactive.
Radon is heavier and has more complex electron shells and therefore is probably more reactive, theoretically. But it is also radioactive, so it isn't more chemically active when we take into account the concept the idea of sticking around and staying in the compound.
So xenon is the most chemically active noble gas, period.