I just read that there's a 50% chance that a GRB caused one of the major extinctions on Earth in the past 500 million years.
Question… how do you protect yourself from a GRB if it hits Earth? Would lead-lining in your basement protect you? How much lead do you need to stop GRB?
By my rough calculations, there is approximately a 1 in 10,000,000 chance that a deadly gamma ray burst will hit the Earth in your lifetime.
In contrast, you have about a 1 in 100 chance of dying in a car crash.
What's the mechanism behind GRB? Maybe there are a neutrinos a few minutes prior. I guess hiding in some basement should be enough to survive. Although I have no idea how intense exactly those GRBs are. You never know with these huge cosmological phenomena.
>I thought massive neutrino burst caused the major extinction 500 million years ago.
Neutrino???? 10 BILLION neutrinos pass through the thumb of your finger every second. Yes, really.
Neutrino can't do shit to baryonic matter.
If our sun were to explode in a super nova (I know it can't) tomorrow, we wouldn't even survive to see it happening. Reason: Right before the visible super nova, an enormous neutrino burst happens that is in fact so intense that it kills (nearly) every living thing on earth. Neutrino cross sections in matter might be extremely small, but when you have a LOT of neutrinos, it's still enough to kill something.
I'm guessing you're getting that from that xkcd, which also notes that to be close enough to get a lethal dose of neutrinos from a supernova, you would have to be already inside the star that was exploding.
So, being literally inside a star (that is exploding) is probably more important than radiation poisoning.
>how do you protect yourself from a GRB if it hits Earth?
You don't. If you're on the hemisphere the burst hits, you will die instantly. If you're on the opposite hemisphere, you will die horribly over the course of several hours.
>massive neutrino burst
that was the plot device in the movie "2012"
this is nonsense. it's simply NOT TRUE! please show me a peer-reviewed paper showing that neutrinos can kill you. you're literally bathed in neutrinos right now. over a trillion of them pass through you ever sec.
What is so hard to get about this? There are reactions between neutrinos and matter, the charged current is potentially ionising. Now, you need a LOT of neutrinos, but of course at one point you have enough neutrinos to kill somebody. It's not that complicated, you just need lots of neutrinos. A super nova produces unimaginably high amounts of neutrinos, so that is covered.
Ok, not that i believe you or not, but im curious. I know you can detect neutrino only if it directly hits other particle, such as quark in nucleus, but does it have any effect on it besides bouncig of it? Can it destroy an atom somehow?
Yes, I got it, thank you.
There are two major ways neutrinos interact with matter, the neutral current and the charged current. The neutral current is something like
Neutrino + Nucleon --> Neutrino + Nucleon + neutral Pion. (Neutron is either Proton or Neutron)
The Pion can theoretically ionise matter in reactions like
Pion + Proton --> Neutron + Pion^+.
The charged current is something like
Neutrino + Nucleon --> Lepton + Nucleon + charged Pion.
The Lepton has potentially ionising effects on the surrounding matter, the charged pion as well.
>The chance to get hit by lightning is 1 in 1.000.000.
>The chance of an average person living in the US being struck by lightning in a given year is estimated at 1 in 500,000, while the chance of being struck by lightning in a lifetime is 1 in 6250 (estimated lifespan of 80 years).
>What is so hard to get about this? There are reactions between neutrinos and matter, the charged current is potentially ionising. Now, you need a LOT of neutrinos, but of course at one point you have enough neutrinos to kill somebody. It's not that complicated, you just need lots of neutrinos. A super nova produces unimaginably high amounts of neutrinos, so that is covered.
Dumbfuck, neutrinos cannot kill you. If that were true, there would be no life anywhere because our Sun produces an incredible number of them every second.
>The flux of solar neutrinos at the earth's surface is on the order of 10^11 per square centimeter per second.
can you grasp what "10^11 per square centimeter per second" means???
>Because you pulled them from your ass
Assume OP is ~20 year old male (reasonable since 4chan), then actuary tables give him 50 years to live. Assume gamma ray bursts of sufficient strength to kill OP hit the Earth on average every 500 million years (reasonable since that's the last time it happened). Probability is then approximately 1/10,000,000
In the United States, about 1.8% of deaths are car accidents (source: U.S. Census Bureau). I rounded it down to 1% chance for OP since I assumed he doesn't get out much (reasonable because 4chan).
Now fuck off.
Well, can you grasp what it means? I don't think so. I'm not talking about a realistic scenario, I'm just claiming it is theoretically possible if you have a neutrino flux that's big enough, which exist in the universe. The sun's neutrino flux is just not enough. Not even close. I know 10^11 sounds like a big number, but there are much, much bigger neutrino fluxes around.
> Assume gamma ray bursts of sufficient strength to kill OP hit the Earth on average every 500 million years (reasonable since that's the last time it happened).
This is not at all reasonable and it's unsourced too
>(reasonable since that's the last time it happened).
<(reasonable since that's the last time it happened).
Differentanon here, that's not reasonable, m8.
SN1987A was a supernova in the LMC, about 168 000 light years away. Kamiokande II for example registered 11 antineutrinos from this event. If the super nova was merely 1/60000 light years away (that's about 1 AE I think), Kamiokande would have detected 1.1e21 neutrinos. Now, the experiment had a test mass of about 3000 tons. A human is ~30000th of that. So that gives you 3.7e16 neutrino events inside one human body. These neutrinos have high energy, about a few dozen MeV or something, let's say 10 MeV on average. So the neutrinos deposit 3.7e17 MeV or about 60 kJ into your body. As mostly pions emerge from those reactions, that needs to be multiplied by a weighing factor of 2 to get the effective dose of 120/100 kSv = 1200 Sv. And that will kill you, more than once.
This is of course super simplified, but it gives you the idea. Supernovae emit 99% of their energy in the form of neutrinos. And supernovae are unimaginably energetic.