# Dropping some neutronium **URL:** \ **Category:** Factual Questions\ **Created:** [December 24, 2014, 8:19pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114 "2014-12-24T20:19:22Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [December 24, 2014, 8:19pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/1 "2014-12-24T20:19:22Z")
Mr. Sagan (I think) once warned that neutronium/strange matter/neutron star guts was so dense (and therefore heavy) that if you were to drop a teaspoon of the stuff from about chest height it would fall straight through the earth. Or something like that. Now this is good to know because I was kicking around getting my kids a do-it-yourself neutronium kit for Christmas. But they’re really careless and I could just see having dozens of holes in the bottom of my house that go clean through to…ok, the questions: 1. really? 2. would that generate a lot of heat (enough to melt stuff)? Or would it be akin to poking a hole in the ground with a stick, only with much less resistance? 3. how fast would it be going by the time it hit the center of the planet? How long would it take to get there? 4. Is that stuff stable outside of a neutron star, or would the lower pressures of space allow it to puff up some. How much would it puff? 5. If it doesn’t puff in a vacuum, and two neutron stars collided, could there be big hunks of neutron star whizzing around space just looking for a planet to crash into? ---
**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:** [December 24, 2014, 8:33pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/2 "2014-12-24T20:33:46Z")
> [@The Great Sun Jester](#): > > How long would it take to get there? Assuming that it falls freely (i.e. that the Earth is so flimsy that soil, rock and iron core provide no resistance to the neutronium), it would take 42 minutes to reach the center of the Earth. ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [December 24, 2014, 8:43pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/3 "2014-12-24T20:43:38Z")
Yeah, it would not be stable. The gravity provides force that overcomes neutron degeneracy pressure, take it out of the star and it would puff right up. Do not get your kids that diy neutronium kit, those things are very poorly made and the instructions are book-translated from Tagalog or something. If they screw up, they will destroy the earth, then where will we go? ---
**Author:** ![John\_DiFool](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_difool/32/19543_2.png) [@John\_DiFool](https://boards.straightdope.com/u/John_DiFool)\ **Post date:** [December 24, 2014, 10:00pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/4 "2014-12-24T22:00:50Z")
Would it expand from a baseball sized chunk into the size of a mountain? ---
**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:** [December 24, 2014, 10:06pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/5 "2014-12-24T22:06:19Z")
> [@eschereal](#): > > If they screw up, they will destroy the earth, then where will we go? On the other hand, it’s good practical experience for working at the LHC. ---
**Author:** ![AndrewL](https://avatars.discourse-cdn.com/v4/letter/a/3d9bf3/32.png) [@AndrewL](https://boards.straightdope.com/u/AndrewL)\ **Post date:** [December 24, 2014, 10:38pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/6 "2014-12-24T22:38:12Z")
> [@John\_DiFool](#): > > Would it expand from a baseball sized chunk into the size of a mountain? I expect that it would ‘expand’ by spitting out subatomic particles at very high speeds until it was all gone. A chunk of neutronium outside a gravity well is essentially an atomic nucleus with far, far too many neutrons, and would act like one. Not so much an expansion as an explosion. You wouldn’t want to be anywhere near it. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [December 24, 2014, 11:06pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/7 "2014-12-24T23:06:34Z")
> [@AndrewL](#): > > I expect that it would ‘expand’ by spitting out subatomic particles at very high speeds until it was all gone. A chunk of neutronium outside a gravity well is essentially an atomic nucleus with far, far too many neutrons, and would act like one. Not so much an expansion as an explosion. You wouldn’t want to be anywhere near it. Some googling got me [this](http://io9.com/5805244/what-would-a-teaspoonful-of-neutron-star-do-to-you) article, which claims that besides the “teaspoon of neutronium” expanding with immense force due to the sudden lack of pressure, the neutron decay would put out a _huge_ amount of energy. > [@](#): > > Take the mass of the neutron and subtract the masses of the proton, the electron, and the negligible mass of the antineutrino, and that’s the mass lost. Multiply that by the speed of light squared, and you have the energy released. In the case of neutron decay, about 0.08% of the mass gets converted to energy in the process, which doesn’t sound like too much, but multiply it over your teaspoon of neutron star, and it ends up producing an equivalent energy of about 10^27 J — or roughly the energy put out by the sun in 2 or 3 seconds. > > Maybe you don’t have a great intuitive feel for exactly how much energy that is, so another way of putting it is that the neutron decays release the equivalent energy of a trillion megaton nuclear device. To put things in perspective, this about 50 trillion times the energy of the first nuclear bombs, and would easily be enough to destroy all life on earth. And googling gravity + teaspoon + neutronium gets me multiple results from the SDMB; people seem to like the concept here. ---
**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:** [December 25, 2014, 12:04am UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/8 "2014-12-25T00:04:05Z")
> [@Andy\_L](#): > > Assuming that it falls freely (i.e. that the Earth is so flimsy that soil, rock and iron core provide no resistance to the neutronium), it would take 42 minutes to reach the center of the Earth. D’oh. About 21 minutes, not 42. ---
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [December 25, 2014, 12:44am UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/9 "2014-12-25T00:44:52Z")
What would happen to the ground as the teaspoon of neutronium fell through? If i push my finger into damp sand the electrons in my finger repel the electrons in the sand, leaving a hole my finger pushed aside. how do electrons interact with neutronium? ---
**Author:** ![eschereal](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eschereal/32/18939_2.png) [@eschereal](https://boards.straightdope.com/u/eschereal)\ **Post date:** [December 25, 2014, 3:00am UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/10 "2014-12-25T03:00:16Z")
According to wikipedia, a teaspoon of neutronium would have a mass of a couple billion tons. A lot, but not a ridiculous amount. And we think of it as a lump of stuff, but without the normal electromagnetic properties of non-degenerate mundane matter, there is not way for it to for any kind of internal structure, so it tends to be called a gas. It is not clear that it would even penetrate the Earth’s solid surface, other than by an enormous explosion that would probably reduce the earth itself to a dust cloud. Those home neutronium kits are pretty hazardous. They use some kind of arcane degenerator field to form the neutronium and confine and stabilize it. Most people experience a problem when they turn the field off and the energy stored in it gets released. As I recall, there is a way to hook up eight D batteries so you can safely unplug the thing, and they will hold the field for about 17 minutes before they run out. You can rig up a plug that will work in your car, so if you actually manage to throw that much stuff into the thing, enough to make a pinpoint size droplet, you will at least be able to take the unit out in the desert or something so that your own neighborhood does not get cratered when the field shuts off. It is pretty amazing that you can convert your household clutter into neutronium for such a small energy input. I think we need to make sure there are not any crazy terrorists getting their hands on one of these. Sane terrorists would be fine, though. ---
**Author:** ![si\_blakely](https://avatars.discourse-cdn.com/v4/letter/s/d9b06d/32.png) [@si\_blakely](https://boards.straightdope.com/u/si_blakely)\ **Post date:** [December 25, 2014, 9:19am UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/11 "2014-12-25T09:19:23Z")
And to be clear, evaporating neutronium goes [skooom](http://www.schlockmercenary.com/2005-06-15) ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [December 25, 2014, 1:38pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/12 "2014-12-25T13:38:04Z")
> [@eschereal](#): > > Yeah, it would not be stable. The gravity provides force that overcomes neutron degeneracy pressure, take it out of the star and it would puff right up. Do not get your kids that diy neutronium kit, those things are very poorly made and the instructions are book-translated from Tagalog or something. If they screw up, they will destroy the earth, then where will we go? I am, of course, shocked to find that the science of Star Trek was wrong. > **["Star Trek" The Doomsday Machine (TV Episode 1967) ⭐ 8.6 | Action, Adventure,...](https://www.imdb.com/title/tt0708461/?ref_=ttep_ep6)** > > 50m | TV-PG ☹ ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [December 25, 2014, 5:49pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/13 "2014-12-25T17:49:34Z")
> [@Enola\_Straight](#): > > What would happen to the ground as the teaspoon of neutronium fell through? > > If i push my finger into damp sand the electrons in my finger repel the electrons in the sand, leaving a hole my finger pushed aside. > > how do electrons interact with neutronium? That’s an extremely interesting question that I hadn’t thought of. Could “neutronium”, if it could possibly be stable, essentially pass through normal matter with minimal interaction? Let’s say for the sake of discussion that we have the equivalent of neutronium: something that dense but stable; and I’ll specify further that it attracts enough electrons to interact conventionally with normal matter. Say, strange matter clumps with just enough charge that they behave like super-heavy atoms. I think the first thing that would happen when your billion-tonne teaspoon-full hit the ground would be that the ground would have to get out of the way **FAST**. So much force would be concentrated in so small an area that the ground would offer essentially zero resistance. In loose soil or porous rock like sandstone that would scarcely matter; but as soon as it hit solid rock the rock would be blasted out the way fast enough to vaporize it. So what you’d probably get is a small local earthquake and a geyser of plasma shooting out of the ground until it got deep enough. ---
**Author:** ![get\_lives](https://avatars.discourse-cdn.com/v4/letter/g/ecb155/32.png) [@get\_lives](https://boards.straightdope.com/u/get_lives)\ **Post date:** [December 25, 2014, 7:06pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/14 "2014-12-25T19:06:53Z")
What would happen if you could release the pressure on a teaspoon of neutronium slowly? What element would it have decayed to by the time it got to room temp and 1 atmosphere of pressure? ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [December 26, 2014, 1:44am UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/15 "2014-12-26T01:44:36Z")
Do you realize how fast you could bake a potato with this stuff? ---
**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:** [December 26, 2014, 1:48am UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/16 "2014-12-26T01:48:17Z")
Release it slowly, and you’ll definitely end up with mostly iron, plus a few other elements in that vicinity. Release it quickly, and you’ll probably end up with the same, but it’s harder to predict. ---
**Author:** ![get\_lives](https://avatars.discourse-cdn.com/v4/letter/g/ecb155/32.png) [@get\_lives](https://boards.straightdope.com/u/get_lives)\ **Post date:** [December 26, 2014, 3:21pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/17 "2014-12-26T15:21:06Z")
> [@Chronos](#): > > Release it slowly, and you’ll definitely end up with mostly iron, plus a few other elements in that vicinity. Release it quickly, and you’ll probably end up with the same, but it’s harder to predict. Why wouldn’t it be something more dense, like gold/iridium? ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [December 26, 2014, 3:43pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/18 "2014-12-26T15:43:44Z")
> [@Enola\_Straight](#): > > What would happen to the ground as the teaspoon of neutronium fell through? > > If i push my finger into damp sand the electrons in my finger repel the electrons in the sand, leaving a hole my finger pushed aside. > > how do electrons interact with neutronium? > [@Lumpy](#): > > … > Let’s say for the sake of discussion that we have the equivalent of neutronium: something that dense but stable; and I’ll specify further that it attracts enough electrons to interact conventionally with normal matter… Let’s stay real here. 🙂 But this state of matter is that of unobtainium, right? Nary an electron in the real world, when this thought experiment trouble starts? “A reactor vessel of a typical nuclear power plant (PWR) endures in 40 years (32 full reactor years) of operation approximately 3.5×1019 n/cm² (E\>1MeV).” Wiki “neutron flux.” But it leads off with this, which I don’t understand, how the OP’s neutron star scenario relates, because supernova is after the fun starts. Neutron flux in asymptotic giant branch stars and in supernova is responsible for most of the natural nucleosynthesis producing elements heavier than iron. In stars there is a relatively low neutron flux on the order of 105 to 1011 neutrons per cm2 per second, resulting in nucleosynthesis by the s-process (slow-neutron-capture-process). By contrast, after a core-collapse supernova, there is an extremely high neutron flux, on the order of 1022 neutrons per cm2 per second, resulting in nucleosynthesis by the r-process (rapid-neutron-capture-process). Atmospheric neutron flux, apparently from thunderstorms, can reach levels of 3•102 to 5•102 neutrons per cm2 per sec.[3] (That atmosphere part is intriguing as well.) ---
**Author:** ![Leo\_Bloom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/leo_bloom/32/10377_2.png) [@Leo\_Bloom](https://boards.straightdope.com/u/Leo_Bloom)\ **Post date:** [December 26, 2014, 3:50pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/19 "2014-12-26T15:50:26Z")
Btw, when I read OP hed I first thought it was about dropping acid, but with neutronium instead of LSD. (See, I just did it again, by accident. That example hed could also be read two ways.) ---
**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\ **Post date:** [December 26, 2014, 5:23pm UTC](https://boards.straightdope.com/t/dropping-some-neutronium/708114/20 "2014-12-26T17:23:33Z")
> [@Leo\_Bloom](#): > > Btw, when I read OP hed I first thought it was about dropping acid, but with neutronium instead of LSD. > > (See, I just did it again, by accident. That example hed could also be read two ways.) Heavy man; heavy! [Next page](https://boards.straightdope.com/t/dropping-some-neutronium/708114.md?page=2)