Confirmed: The Last Great Prediction Of The Big Bang
1–10 of 33 posts
Re: Confirmed: The Last Great Prediction Of The Big Bang
#2"Two degrees above absolute zero was never so hot.":)
Re: Confirmed: The Last Great Prediction Of The Big Bang
#3I was under the impression that direct detection of cosmic neutrinos would be a lot more informative than this indirect method. Anyone know more?
Re: Confirmed: The Last Great Prediction Of The Big Bang
#4Sounds like this isn't quite finished until we get the temperature confirmation.
Re: Confirmed: The Last Great Prediction Of The Big Bang
#5Link to the paper requires registration at PRL. Anyone got the actual paper?
BTW, linking to a story about a paper that is not available is mental masturbation. FOAD.
Re: Confirmed: The Last Great Prediction Of The Big Bang
#6I was under the impression that direct detection of cosmic neutrinos would be a lot more informative than this indirect method. Anyone know more?
The article notes that we have enough trouble directly detecting neutrinos in the mega-eV range, while the ones we need to measure for this purpose are in the micro-eV range. Yes it would be more informative, but so hard that we assume direct measurement is practically impossible ... but the article describes an alternative method (phase-shift) of deducing temperature from other consequences of that value.
Re: Confirmed: The Last Great Prediction Of The Big Bang
#7I was under the impression that direct detection of cosmic neutrinos would be a lot more informative than this indirect method. Anyone know more?
Direct detection would be a lot more informative. It's also hard.
There are a lot of systematic effects (foregrounds, etc.) that can matter to CMB measurements.
Any indirect glimpse is still quite valuable, as deviations from the standard plan might be apparent. Any measurement of the neutrino temperature at decoupling is interesting.
(Edit: I'd also note that the last great prediction of the Big Bang is 'inflation', something about which we know next to nothing.)
Re: Confirmed: The Last Great Prediction Of The Big Bang
#8I was under the impression that direct detection of cosmic neutrinos would be a lot more informative than this indirect method. Anyone know more?
The article notes that we have enough trouble directly detecting neutrinos in the mega -eV range, while the ones we need to measure for this purpose are in the micro -eV range. Yes it would be more informative, but so hard that we assume direct measurement is practically impossible ... but the article describes an alternative method (phase-shift) of deducing temperature from other consequences of that value.
There are people who are trying hard to find ways to see the CNB. The primary approach is to try to do something called 'coherent neutrino scattering'. If you can find the right material/metamaterial, you're off to the races.
The number of CNB neutrinos passing through your body right now is considerable.
Re: Confirmed: The Last Great Prediction Of The Big Bang
#9I was under the impression that direct detection of cosmic neutrinos would be a lot more informative than this indirect method. Anyone know more?
Direct detection would be a lot more informative. It's also hard. There are a lot of systematic effects (foregrounds, etc.) that can matter to CMB measurements. Any indirect glimpse is still quite valuable, as deviations from the standard plan might be apparent. Any measurement of the neutrino temperature at decoupling is interesting. (Edit: I'd also note that the last great prediction of the Big Bang is 'inflation',…
OK, so indirect gets us neutrino temperature at decoupling, and direct gets us current neutrino temperature and (I guess) feeds into neutrino mass measurements and the PMNS matrix. Anything else?
Re: Confirmed: The Last Great Prediction Of The Big Bang
#10I was under the impression that direct detection of cosmic neutrinos would be a lot more informative than this indirect method. Anyone know more?
The article notes that we have enough trouble directly detecting neutrinos in the mega -eV range, while the ones we need to measure for this purpose are in the micro -eV range. Yes it would be more informative, but so hard that we assume direct measurement is practically impossible ... but the article describes an alternative method (phase-shift) of deducing temperature from other consequences of that value.
Yes I understand all that, but direct detection is definitely not impossible. The PTOLEMY experiment at Princeton is attempting to do just that, although it's very very hard. Might still be decades away.