Ever since the life listing was added this is something I have been saying. From a chemistry point of view the environments where life is found and the listing abiogenesis is given it makes very little sense.
It's not but it should be in the future if realism is the goal.
And currently you can find systems with 7 planets with life in globular clusters. I don't know how limiting this would be possible in the engine, but I do agree with you on how rare life should be.
The GRB has to be pointed in the right/wrong direction. As far as the other stuff is concerned, the universe is a very strange place and no telling if we ever find life out there if we'll even recognize it as such. There's no reason why inorganic life can't exist.Ever since the life listing was added this is something I have been saying. From a chemistry point of view the environments where life is found and the listing abiogenesis is given it makes very little sense.It's not but it should be in the future if realism is the goal.And currently you can find systems with 7 planets with life in globular clusters. I don't know how limiting this would be possible in the engine, but I do agree with you on how rare life should be.
Regarding the galactic habitable zone that might not apply entirely. There is no guarantee, even with a high number of stars, that a planet will be hit by a GRB, so while it may be more probable it should still be possible to find life near the center of a galaxy.
is that actual distance or comoving distance? I thought I read somewhere that in actual distance the farthest one we've found is 32 billion light years away.Pretty sure this is the Farthest Galaxy from the Milky Way, RG 0-8-9586980-1138. From the center of the CBH (Central Black Hole), The Milky Way is 28.24 Giga Lightyears away.
We have no idea how rare life is because we're stuck in the boonies of a nondescript galaxy. There are also different degrees of life- microbial life, multicellular plant life, nonsentient animal life, and sentient animal life stuck to its own planet, and then you can conjecture from that point forward. And of course I left out the other types of life that are possible that are not plant or animal.Ever since the life listing was added this is something I have been saying. From a chemistry point of view the environments where life is found and the listing abiogenesis is given it makes very little sense.It's not but it should be in the future if realism is the goal.And currently you can find systems with 7 planets with life in globular clusters. I don't know how limiting this would be possible in the engine, but I do agree with you on how rare life should be.
Regarding the galactic habitable zone that might not apply entirely. There is no guarantee, even with a high number of stars, that a planet will be hit by a GRB, so while it may be more probable it should still be possible to find life near the center of a galaxy.
Well, there are a lot of galaxies as large or larger than the Milky Way too- our neighbor Andromeda being a prime example. Galaxies tend to get larger with time through mergers and collisions.Radiation is one thing still lacking in Space Engine. Even if it is not shown as a field, I wonder if it is taken into account for determining the chances of life. Perhaps only temperature, hours of light, atmosphere etc are part of the formula. I think there is way way WAY too many instances of life being found. I think the chances of finding a habitable, breathable planet suitable for humans but still devoid of life are astronomically higher in the real world. Pardon the pun.
On the role of GRBs on life extinction in the Universe
The most deadly kind, Long Bursts (over 10 seconds) of Gamma Ray radiation, occur when massive stars burn out, collapse, and explode. They are rarer than the short ones but release roughly 100 times as much energy. A long burst can outshine the rest of the universe in gamma rays, and occur mainly in star-forming regions with relatively low metallicity, or levels of elements heavier than hydrogen and helium. If the explosion were close enough, the gamma rays would set off a chain of chemical reactions that would destroy the ozone layer in a planet's atmosphere. With that protective gas gone, deadly ultraviolet radiation from a planet’s sun would rain down for months or years—long enough to cause a mass die-off.
Some astrophysicists have suggested a gamma ray burst may have caused the Ordovician extinction, a global cataclysm about 450 million years ago that wiped out 80% of Earth's species. They find that the chance Earth has been exposed to a lethal blast in the past billion years is about 50%. The sheer density of stars in the middle of the galaxy ensures that planets within about 6500 light-years of the galactic center have a greater than 95% chance of having suffered a lethal gamma ray blast in the last billion years. Compared with the Milky Way, most galaxies are small and low in metallicity. As a result, 90% of them should have too many long gamma ray bursts to sustain life. What’s more, for about 5 billion years after the big bang, all galaxies were like that, so long gamma ray bursts would have made life impossible anywhere. If we are going to really look for extraterrestrial life, it should be away from the center of our galaxy. That's not to mention looking at stars other than the flaring Red Dwarfs.
One other thing we shouldn't forget. Some types of life are far more resilient than we are. Some species of bacteria can survive 10 million times the amount of radiation we can and we've even found lichen growing on the outside of the ISS- in the near-vacuum of space! So we have to qualify this with what kind of life we are talking about. Mass extinction does not mean everything goes extinct- 10% or more of the species can still survive.Radiation is one thing still lacking in Space Engine. Even if it is not shown as a field, I wonder if it is taken into account for determining the chances of life. Perhaps only temperature, hours of light, atmosphere etc are part of the formula. I think there is way way WAY too many instances of life being found. I think the chances of finding a habitable, breathable planet suitable for humans but still devoid of life are astronomically higher in the real world. Pardon the pun.
On the role of GRBs on life extinction in the Universe
The most deadly kind, Long Bursts (over 10 seconds) of Gamma Ray radiation, occur when massive stars burn out, collapse, and explode. They are rarer than the short ones but release roughly 100 times as much energy. A long burst can outshine the rest of the universe in gamma rays, and occur mainly in star-forming regions with relatively low metallicity, or levels of elements heavier than hydrogen and helium. If the explosion were close enough, the gamma rays would set off a chain of chemical reactions that would destroy the ozone layer in a planet's atmosphere. With that protective gas gone, deadly ultraviolet radiation from a planet’s sun would rain down for months or years—long enough to cause a mass die-off.
Some astrophysicists have suggested a gamma ray burst may have caused the Ordovician extinction, a global cataclysm about 450 million years ago that wiped out 80% of Earth's species. They find that the chance Earth has been exposed to a lethal blast in the past billion years is about 50%. The sheer density of stars in the middle of the galaxy ensures that planets within about 6500 light-years of the galactic center have a greater than 95% chance of having suffered a lethal gamma ray blast in the last billion years. Compared with the Milky Way, most galaxies are small and low in metallicity. As a result, 90% of them should have too many long gamma ray bursts to sustain life. What’s more, for about 5 billion years after the big bang, all galaxies were like that, so long gamma ray bursts would have made life impossible anywhere. If we are going to really look for extraterrestrial life, it should be away from the center of our galaxy. That's not to mention looking at stars other than the flaring Red Dwarfs.
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This is why I said it is no guarantee a planet or system will ever be hit, it is all pure chance.
That is conjecture but I don't disagree. It seems more likely however that life will be similar to Earth life, at least in terms of chemistry given the availability of the materials in the universe.
Until I see otherwise and given the current information on the formation of the Earth and how specific the situations had to be for self replicating molecules to form, I will assume that life is exceptionally rare.
On Earth sure, but there is no guarantee outside of microbes that any of those things will happen on other planets. The move from single celled organisms to multicellular life took billions of years. The first known life was over 3bil years ago and in current records the first multicellular life didn't appear until around 600mil years ago. Given how long it took and how frequent mass extinction events occur, it is highly unlikely that we will find life and humans are probably a fluke.
This would be interesting but also damning to the notion of finding intelligent life. Statistically speaking if life is that common and we still haven't found any signs of intelligent life, it suggests there may be filters ahead of us and not behind. Finding life on Mars or other bodies in the solar system that isn't Earth life would not be a good sign.
Actual Distance.is that actual distance or comoving distance? I thought I read somewhere that in actual distance the farthest one we've found is 32 billion light years away.Pretty sure this is the Farthest Galaxy from the Milky Way, RG 0-8-9586980-1138. From the center of the CBH (Central Black Hole), The Milky Way is 28.24 Giga Lightyears away.
Yes, I totally agree about the filter idea. Humanity may be an example if we continue on our path of using up our resources, so perhaps this is relatively common and this could be a reason why the universe seems so "silent" (the extreme distances are also a factor of course.) I actually believe the largest filters lay ahead of us not behind. Leaving this planet and exploring space might be the biggest filter of all. Since you are also a reader of Kip Thorne, he talks about wormholes and how we could use them for traveling through space but the amount of energy necessary is stupendous- on the Kardashev scale, it would still take us over 7,000 years to do so. I wonder what we will be like as a species in 7,000 years (or if we'll even still exist.) Biological evolution takes a very long time, but technological and societal evolution occur much faster- of course these have their own issues and we might just use up our resources way too quickly and not last that long.A-L-E-X, a bit extreme on the multiple posts, might be better if you condense it all into one post.
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This is why I said it is no guarantee a planet or system will ever be hit, it is all pure chance.
That is conjecture but I don't disagree. It seems more likely however that life will be similar to Earth life, at least in terms of chemistry given the availability of the materials in the universe.
Until I see otherwise and given the current information on the formation of the Earth and how specific the situations had to be for self replicating molecules to form, I will assume that life is exceptionally rare.
On Earth sure, but there is no guarantee outside of microbes that any of those things will happen on other planets. The move from single celled organisms to multicellular life took billions of years. The first known life was over 3bil years ago and in current records the first multicellular life didn't appear until around 600mil years ago. Given how long it took and how frequent mass extinction events occur, it is highly unlikely that we will find life and humans are probably a fluke.
This would be interesting but also damning to the notion of finding intelligent life. Statistically speaking if life is that common and we still haven't found any signs of intelligent life, it suggests there may be filters ahead of us and not behind. Finding life on Mars or other bodies in the solar system that isn't Earth life would not be a good sign.
To me simple physics is a filter. Anything that can go wrong, will go wrong given enough time and complexity within a system.
You and I think so much alike it's crazy lol. People call me a "doomsayer" and say that Malthus' predictions haven't come true- but they certainly are coming true. The planet's sixth mass extinction is underway and it's because of human overpopulation crowding out the rest of the species on the planet and altering the balance. The idea that it's humans vs nature is a false dichotomy as humans are actually part of nature, so what we do to the planet we also do to ourselves. Rising rates of various illnesses is actually indicative of that happening.To me simple physics is a filter. Anything that can go wrong, will go wrong given enough time and complexity within a system.
Human population, while suggested to plateau around 2050 to 2100, is still growing as is our need for more energy. Extrapolating current growth rates you reach a point in the not too distant future we reach a point where energy available to the average human is in the Gigawatts to Terawatts range or greater, just imagine what could go wrong if the average person has that much energy available and in a population in the 10s of billions. Factor in today's problems of genetic engineering, nuclear research, fusion, nanotechnology, and artificial intelligence and it starts to look like the game is rigged against long term survival of intelligent life.
It's nice to be optimistic about the future, but it is unlikely humanity will survive long term, or any intelligent species will. What is the Type 1 civilization equivalent to a nuclear meltdown or accidentally spilling your coffee on your keyboard? For that matter what happens when something goes wrong for a Type 2 civilization?