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Gamma-ray Bursts May Explain Fermi's Paradox
An anonymous reader writes: A new study confirms the potential hazard of nearby gamma-ray bursts. It quantifies the probability of an event near Earth, and more generally in the Milky Way and other galaxies over time: "[Evolved] life as it exists on Earth could not take place in almost any galaxy that formed earlier than about five billion years after the Big Bang." This could explain the Fermi's paradox, or why we don't see billion-year-old civilizations all around us.
I'm not really sure what you are saying, but TFS is the CERN courier, reporting on an article in Physical Review Letters. I think your clickbait fears are more than a little unfounded.
From TFS:
They further estimate that GRBs prevent complex life like that on Earth in 90% of the galaxies.
So, life possible on 10% of the galaxies means that those are none at all? What about our own one? This smells of clickbait.
The Fermi paradox basically states that if life on Earth is the typical result of similar conditions, the probability is far higher that there are older, more advanced civilizations, and eventually on timescales far smaller than the universe has existed we should eventually have bumped into one of them as they spread throughout the galaxy, even the universe.
The paper suggests two effects of gamma ray bursts that alter that calculation. First, a given location was more likely to be exposed to a gamma ray burst at earlier times in the universe, when the population of large hot stars was higher and overall density of the universe was higher. Therefore, its possible that even though the universe is 14 billion years old during a significant percentage of that time the universe was too dense and the frequency of gamma ray bursts too high to allow a sufficiently high technological civilization to arise. That's why there aren't any really old civilizations, or alternatively why there are so few that they tend to be very far away statistically. Second, even after the universe had expanded enough to make gamma ray bursts less likely to completely sterilize all planets everywhere its still the case that most parts of most galaxies are still too dense to avoid getting hit by them.
So its possible the reason why we have not yet seen a very old highly advanced civilization is that the actual probability of one being old enough, and close enough, for us to have bumped into (or rather for them to have bumped into us) is a lot lower than we might assume, even if the conditions to initiate life are pretty common. Nearly all of them have been wiped out before they could advance to the point of being able to colonize on an interstellar level and avoid being driven to extinction by gamma ray bursts.
There is one potential candidate pointed right at us. Don't feel too bad, even the Bad Astronomy guy said "I might have been wrong" when he found out about WR 104. "Data show that the orientation of the spin-axis of the system, with respect to our vantage point from Earth, is almost exactly aligned. As nearly as we can tell, we are looking directly down upon the polar direction of the spinning binary stars. " It's about 8,000 light years away; it could have already blown and we're just waiting for our planetary extinction GRB wave front to hit us.
Total bollocks? :)
There's one thing nuclear propulsion cannot do, and that's exactly what you claim it can do in your opening sentence: lift that payload from the surface to orbit.
Project Orion would be using a long series of nuclear explosions to almost literally hammer the spaceship forward. You're proposing that as a LIFTOFF engine to be used within the atmosphere?
Quoting from the same wikipedia page, one of the reasons why the project was shut down:
"There were also ethical issues with launching such a vehicle within the Earth's magnetosphere: calculations showed that the fallout from each takeoff would kill between 1 and 10 people."
That's from launching within the magnetosphere, not even close to launching from the surface.
Yes, total bollocks, clearly :)
There are some articles on the internet about this. Basically: one side would be fried, the atmosphere would be superheated, and you would have nasty smog all over earth afterwards, making sure that seeds wouldn't grow because Earth would be pretty dark. Oh, and the ozone layer would be stripped off, so the bottom of the ocean might be survivable but apart from that you'd want to be underground during daylight.
In 2008 there was a GRB that occurred about 7.5 billion lightyears away - it was visible with the naked eye, and was aimed straight at Earth. Just imagine what something at 75000000 million lightyears would do - let alone at 7500, about where WR104 is.
Therefore, by the (faulty) logic you're using, you're just a cow with a keyboard - osu-neko (2604)
99% of alien life can be undetectable for whatever reason. If 1% is expansionist, a representative of that 1% could colonize every star system in a galaxy the size of the Milky Way in less than 3 million years, a cosmic eye blink.
The Moore-Murphy Law: The number of things that will go wrong will double every 2 years.