WARPED: Cosmic microwave background radiation collected by telescopes on the earth and in space has been subtly distorted by dark matter. By tracing the distortions, physicists can chart the dark matter's structure, which has been shaped by neutrinos and can, in turn, place strict limits on neutrino mass.
Image: George Retseck
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Measuring the minuscule mass of neutrinos has so far proved impossible—and not for lack of trying. Numerous laboratory experiments over the past few decades have succeeded only in placing loose limits on the three neutrino masses.
We have very compelling reasons to expect that the best way to measure the mass of these tiny particles is, surprisingly, to look for their influence at the largest scales of the universe. For although neutrinos are virtually massless and nearly invisible, their sheer numbers—some 1089 in the universe—make them very consequential players in the cosmos.
This article was originally published with the title The Neutrino's Secrets, Written on the Sky.
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7 Comments
Add CommentThe inset image's caption states:
Reply | Report Abuse | Link to this"Cosmic microwave background radiation collected by telescopes on the earth and in space has been subtly distorted by dark matter. By tracing the distortions, physicists can chart the dark matter's structure, which has been shaped by neutrinos and can, in turn, place strict limits on neutrino mass."
It's more correct to say that the CMBR has been subtly distorted by GRAVITATION, which has been attributed to dark matter by astrophysicists.
While tracing the distortions' effects can chart the distribution and structure of matter in the universe, there is no reliable way to separate the distortion produced by ordinary matter from any distortion produced by any potential dark matter.
I'll be very interested to learn how it's thought that "dark matter's structure, which has been shaped by neutrinos and can, in turn, place strict limits on neutrino mass."
Since high velocity neutrinos only weakly interacts with any matter, and cold dark matter interacts with matter even more rarely, even at very large scales other factors, such as the gravitation produced by ordinary matter and spacetime expansion that fundamentally shape the structure of matter within the universe, are far more likely to influence the distribution and structure of matter in the universe.
I don't see any unambiguously testable hypothesis here!
Reply | Report Abuse | Link to thisI wonder how many free parameters will be involved in going from astrophysical observations to neutrino masses.
In other words, how well-constrained would the mass estimates be?
1089 neutrinos in the universe don't sound like a whole lot... I'm guessing you mean 10^89, maybe?
Reply | Report Abuse | Link to thisI postulate that everything is a consequence of the overall Electromagnetic Field. As measured as the CBMBR.
Reply | Report Abuse | Link to thisWe are in an Electromagnetic bubble that is our Universe
The EMF is 10^42 times greater than the attractive force we call gravity.
All +ve matter is attractive.
Therefore it only takes a difference of one part in 10^42 of the Electromagnetic Field Strength, between one piece of matter and another for there to be the attractive force we call gravity.
Gravity as such, is not a force but a Differential.
The force is Electromagnetic.
The late great Prof. R.P. Feynman. Showed that if you take Two grains of sand One mm across and placed them 30 mts apart. Then stripped the electrons from one of them. The attractive force between them would be 30x 10^6 tons.
That is the type of enormous force we must consider.
Correction CBMBR should read CMBR
Reply | Report Abuse | Link to thisTry Feynman's sand experiment with a piece of cardboard in between to insulate them - the EM attraction, mediated by an exchange of electrons flowing between them, will be blocked. EM insulating materials do not block gravitational effects. Gravitational effects are not electromagnetic in nature, and are not mediated by any detected particle flow.
Reply | Report Abuse | Link to thisBTW, I think the sand experiment is essentially the same as the one where you rub a balloon on your hair and stick it to the wall, or hold it near a friend's hair - try the cardboard...
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