4 ms·

> Amongst the different kinds of GRBs, long ones are most dangerous. So what effect would a long, direct GRB have on earth? Are we talking scorched, molten ear

> Amongst the different kinds of GRBs, long ones are most dangerous. So what effect would a long, direct GRB have on earth? Are we talking scorched, molten earth and boiled seas, or put extra sunscreen on for a week?

idlewords 12y ago
"For [UV-B] radiation with a wavelength of 290 nm, the intensity at the top of the atmosphere is 350 million times stronger than at the Earth's surface." That's due to ozone (https://en.wikipedia.org/wiki/Ozone_layer https://en.wikipedia.org/wiki/Ozone_layer). So we would need some really solid sunscreen. Also the oceans would turn into a big vat of plankton chowder, which would make for an exciting last few years for all of us.
- jessaustin 12y ago
  It would (eventually, once the bacteria recovered) smell bad, but is this a human extinction event? The natural processes that form ozone wouldn't cease, and human action could supplement that. The specific types of plankton in a recovered ocean might be different, but surely we don't think all plankton would die out entirely over the entire earth?
  - goblin89 12y ago
    > but is this a human extinction event? Seems like there's no prognosis as to what consequences a GRB event may have on humans specifically in the paper quoted on Wikipedia: “The greatest danger is believed to come from Wolf–Rayet stars, regarded by astronomers as likely GRB candidates. … if WR 104, at a distance of 8,000 light-years were to hit Earth with a burst of 10 seconds duration, its gamma rays could deplete about 25 percent of the world's ozone layer. This would result in mass extinction, food chain depletion, and starvation.” I suppose this topic is hard to speculate on, as it requires substantial knowledge on a variety of disciplines.
  - VLM 12y ago
    I believe the conceptual problem most people are stuck on is the couple second at most gamma burst by itself is quite harmless to life on the surface. The guys on the ISS are likely totally screwed. Anyway massive radiation spike in the upper atmosphere has a rather well understood and very unfortunate chemical effect on the ozone layer, where its basically eliminated for about a calendar season. A demonstration can be provided COTS from marine reef tanks, you can buy UV sterilizers which continuously zap flowing water with UV, quite effectively killing all floating algae and pretty much anything else floating in the water. The problem in the ocean is for some months they'll literally be nothing for plankton to eat at all, and the sheer level of rot and rot byproducts would be pretty spectacular making life really difficult. And the recolonization process once UV levels drop enough to make it possible will result in some really weird blooms, and algae blooms lead to busts so the oscillations will likely be pretty exciting after the initial crash. A few million years later they'll be a lovely layer of petrochemicals to mine. On land, the couple month UV hit would be very much like hitting the entire surface of the planet with defoliants. You might survive the lack of food, but no clean water for awhile and no harvest this season and everything green pretty much just died and started washing away in the rain might be a bigger mess. In a way the best place to hang out might be a desert. All the cacti will die, but there won't be many mudslides. A forest might be a good place to chill out too, all the leaves will die and the trees themselves might die but the roots won't rot for a long time, keeping dirt in place. Grassland areas will be pretty much screwed.
    - daveloyall 12y ago
      Don't dead plants and animals fail to rot in sterile environments?
deleted 12y ago
[deleted]

idlewords 12y ago

"For [UV-B] radiation with a wavelength of 290 nm, the intensity at the top of the atmosphere is 350 million times stronger than at the Earth's surface." That's due to ozone (https://en.wikipedia.org/wiki/Ozone_layer https://en.wikipedia.org/wiki/Ozone_layer). So we would need some really solid sunscreen. Also the oceans would turn into a big vat of plankton chowder, which would make for an exciting last few years for all of us.

jessaustin 12y ago
It would (eventually, once the bacteria recovered) smell bad, but is this a human extinction event? The natural processes that form ozone wouldn't cease, and human action could supplement that. The specific types of plankton in a recovered ocean might be different, but surely we don't think all plankton would die out entirely over the entire earth?
- goblin89 12y ago
  > but is this a human extinction event? Seems like there's no prognosis as to what consequences a GRB event may have on humans specifically in the paper quoted on Wikipedia: “The greatest danger is believed to come from Wolf–Rayet stars, regarded by astronomers as likely GRB candidates. … if WR 104, at a distance of 8,000 light-years were to hit Earth with a burst of 10 seconds duration, its gamma rays could deplete about 25 percent of the world's ozone layer. This would result in mass extinction, food chain depletion, and starvation.” I suppose this topic is hard to speculate on, as it requires substantial knowledge on a variety of disciplines.
- VLM 12y ago
  I believe the conceptual problem most people are stuck on is the couple second at most gamma burst by itself is quite harmless to life on the surface. The guys on the ISS are likely totally screwed. Anyway massive radiation spike in the upper atmosphere has a rather well understood and very unfortunate chemical effect on the ozone layer, where its basically eliminated for about a calendar season. A demonstration can be provided COTS from marine reef tanks, you can buy UV sterilizers which continuously zap flowing water with UV, quite effectively killing all floating algae and pretty much anything else floating in the water. The problem in the ocean is for some months they'll literally be nothing for plankton to eat at all, and the sheer level of rot and rot byproducts would be pretty spectacular making life really difficult. And the recolonization process once UV levels drop enough to make it possible will result in some really weird blooms, and algae blooms lead to busts so the oscillations will likely be pretty exciting after the initial crash. A few million years later they'll be a lovely layer of petrochemicals to mine. On land, the couple month UV hit would be very much like hitting the entire surface of the planet with defoliants. You might survive the lack of food, but no clean water for awhile and no harvest this season and everything green pretty much just died and started washing away in the rain might be a bigger mess. In a way the best place to hang out might be a desert. All the cacti will die, but there won't be many mudslides. A forest might be a good place to chill out too, all the leaves will die and the trees themselves might die but the roots won't rot for a long time, keeping dirt in place. Grassland areas will be pretty much screwed.
  - daveloyall 12y ago
    Don't dead plants and animals fail to rot in sterile environments?

deleted 12y ago

[deleted]