# How much energy is in neutrino radiation? **URL:** \ **Category:** Factual Questions\ **Created:** [February 19, 2021, 2:28pm UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286 "2021-02-19T14:28:19Z")\ **Posts on this page:** 13\ **Page:** 2
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [February 19, 2021, 9:50pm UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/21 "2021-02-19T21:50:06Z")
Huh. I always thought that scrith was cool - but now I know it’s cold. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [February 19, 2021, 10:14pm UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/22 "2021-02-19T22:14:50Z")
> [@Darren\_Garrison](#): > > Somebody should write a book with those! The books point out another problem with unobtainium (called _catchcloth_ in their universe): it significantly reduces your maneuverability options. The momentum vector for absorbed particles is strictly away from the sun. But for reflection, it can be a vector with a 180 degree range. Which means you can head towards the sun, and tack, and do other neat things. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [February 19, 2021, 10:22pm UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/23 "2021-02-19T22:22:16Z")
> [@Darren\_Garrison](#): > > Somebody should write a book with those! > > [Oh, wait](https://en.wikipedia.org/wiki/Revenger)… That’s a great book series - someone should make an RPG campaign setting out of it! ---
**Author:** ![mandala](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mandala/32/95_2.png) [@mandala](https://boards.straightdope.com/u/mandala)\ **Post date:** [February 20, 2021, 2:57am UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/24 "2021-02-20T02:57:57Z")
If a solar neutrino can pass through a light-year thick block of lead without interacting, how do neutrino detectors on earth capture solar neutrinos? I believe several solar neutrinos are detected each day. ---
**Author:** ![Babale](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/babale/32/15666_2.png) [@Babale](https://boards.straightdope.com/u/Babale)\ **Post date:** [February 20, 2021, 3:15am UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/25 "2021-02-20T03:15:16Z")
It CAN do that, but if you have a big enough pool of water and you blast it with enough neutrinos (and the sun puts out a staggering amount of them), eventually one of them will interact with the water. ---
**Author:** ![Dr.Strangelove](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr.strangelove/32/6613_2.png) [@Dr.Strangelove](https://boards.straightdope.com/u/Dr.Strangelove)\ **Post date:** [February 20, 2021, 3:23am UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/26 "2021-02-20T03:23:14Z")
Same principle that a radioactive material with a billion-year half-life will still have detectable decays in the first minute. The half-life, or “light-year of lead” is just an average. Some of the events will happen early. And as **Babale** notes, there are a staggering number of neutrinos. Nevertheless, it takes a huge detector to capture a reasonable number them. ---
**Author:** ![Darren\_Garrison](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darren_garrison/32/92_2.png) [@Darren\_Garrison](https://boards.straightdope.com/u/Darren_Garrison)\ **Post date:** [February 20, 2021, 3:44am UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/27 "2021-02-20T03:44:49Z")
Obligatory XKCD: [https://what-if.xkcd.com/73/](https://what-if.xkcd.com/73/) ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [February 20, 2021, 2:32pm UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/28 "2021-02-20T14:32:01Z")
Come to think of it, if you had a supply of both the reflective ultaunobtainium and the absorbtive regular unobtainium, you could make a pretty nice burning-glass. The problem with an ordinary burning-glass (solar-focusing “death ray”) is that, at best, all you can do is couple your target to the radiative surface of the Sun, and so the sun’s surface temperature (a few thousand degrees) is the highest temperature you can possibly hit. But if you make a parabolic mirror out of the ultraunobtainium, and put a lump of the regular unobtainium at the focus, you could instead couple to the core of the Sun, at millions of degrees. One difficulty would be that, since the core of the Sun is much smaller than the photosphere, your target point would also be correspondingly smaller. And you couldn’t heat up anything but unobtainium directly (though you could still use the hot unobtainium to heat up other things indirectly). ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [February 20, 2021, 7:35pm UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/29 "2021-02-20T19:35:00Z")
> [@Buck\_Godot](#): > > Given that neutrinos are near massless and travel at nearly the speed of light, the relationship between Neturino energy and momentum with be similar to that of a photon so momentum=energy/c I thought that E = pc was only used if truly massless. If it has **any** mass no matter how neglectable momentum would be _gamma times mv_. Is that wrong? ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [February 20, 2021, 7:40pm UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/30 "2021-02-20T19:40:21Z")
I haven’t done the math, but I suspect that in the limit pc will grow increasingly close to gamma mv ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [February 20, 2021, 9:30pm UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/31 "2021-02-20T21:30:35Z")
For any particle E/c is sqrt (m^2\*c^2+ p^2) so as long as momentum is large relative to mc, E/c will be a decent approximation of p ---
**Author:** ![Zakalwe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zakalwe/32/270_2.png) [@Zakalwe](https://boards.straightdope.com/u/Zakalwe)\ **Post date:** [February 21, 2021, 3:15am UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/32 "2021-02-21T03:15:51Z")
> [@Chronos](#): > > Come to think of it, if you had a supply of both the reflective ultaunobtainium and the absorbtive regular unobtainium, you could make a pretty nice burning-glass. And if we build it in the next 9 years, it will be a 2020’s-style death ray! I’ll show myself out. ---
**Author:** ![Northern\_Piper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/northern_piper/32/5304_2.png) [@Northern\_Piper](https://boards.straightdope.com/u/Northern_Piper)\ **Post date:** [February 21, 2021, 3:42am UTC](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286/33 "2021-02-21T03:42:38Z")
> [@Babale](#): > > It CAN do that, but if you have a big enough pool of water and you blast it with enough neutrinos (and the sun puts out a staggering amount of them), eventually one of them will interact with the water. See the Sudbury Neutrino Observatory for an example: > **[Sudbury Neutrino Observatory](https://en.wikipedia.org/wiki/Sudbury_Neutrino_Observatory)** > > The Sudbury Neutrino Observatory (SNO) was a neutrino observatory located 2100 m underground in Vale's Creighton Mine in Sudbury, Ontario, Canada. The detector was designed to detect solar neutrinos through their interactions with a large tank of heavy water. > The detector was turned on in May 1999, and was turned off on 28 November 2006. The SNO collaboration was active for several years after that analyzing the data taken. > The director of the experiment, Art McDonald, was co-awarded the Nobel... [Previous page](https://boards.straightdope.com/t/how-much-energy-is-in-neutrino-radiation/933286.md?page=1)