# Neutrinos **URL:** \ **Category:** Great Debates\ **Created:** [October 11, 1999, 2:47pm UTC](https://boards.straightdope.com/t/neutrinos/17544 "1999-10-11T14:47:00Z")\ **Posts on this page:** 4\ **Page:** 2
**Author:** ![WallyM7](https://avatars.discourse-cdn.com/v4/letter/w/b5e925/32.png) [@WallyM7](https://boards.straightdope.com/u/WallyM7)\ **Post date:** [October 13, 1999, 1:42am UTC](https://boards.straightdope.com/t/neutrinos/17544/21 "1999-10-13T01:42:00Z")
Yeah. I tried the link earlier, but the page wouldn’t load. That’s why all the questions. I tried it again a few minutes ago and got in. Wow. Very interesting stuff. ---
**Author:** ![Michael\_Masterson](https://avatars.discourse-cdn.com/v4/letter/m/53a042/32.png) [@Michael\_Masterson](https://boards.straightdope.com/u/Michael_Masterson)\ **Post date:** [February 27, 2000, 6:22am UTC](https://boards.straightdope.com/t/neutrinos/17544/22 "2000-02-27T06:22:00Z")
the cool thing about nutrinos is that they do have a mass, and they’re so many of them that they may account for a decent percentage of the missing matter (10-20%) needed to halt the universal expansion (if indeed the expansion does reverse at some point in which it may not). ---
**Author:** ![SingleDad](https://avatars.discourse-cdn.com/v4/letter/s/9e8a1a/32.png) [@SingleDad](https://boards.straightdope.com/u/SingleDad)\ **Post date:** [February 27, 2000, 9:33am UTC](https://boards.straightdope.com/t/neutrinos/17544/23 "2000-02-27T09:33:00Z")
It was my understanding that they had set an upper limit for the rest mass of the neutrino (i.e. it can’t have more than x mass and still agree with experiments) rather than estimating its mass range. * * * He’s the sort to stand on a hilltop in a thunderstorm wearing wet copper armor, shouting ‘All Gods are Bastards!’ ---
**Author:** ![tracer](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tracer/32/20578_2.png) [@tracer](https://boards.straightdope.com/u/tracer)\ **Post date:** [February 27, 2000, 10:13pm UTC](https://boards.straightdope.com/t/neutrinos/17544/24 "2000-02-27T22:13:00Z")
In 1987, we detected a great big neutrino event almost exactly at the same time as the first light from Supernova 1987-A started to reach us. This strongly implies that neutrinos travel either **at** the speed of light, or so close to it that we can’t detect the difference. If that is the case, then neutrinos **cannot** have rest-mass without violating special relativity. [Previous page](https://boards.straightdope.com/t/neutrinos/17544.md?page=1)