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The visible universe is so large it is effectively infinite. And that’s just the visible universe. With 125 billion known galaxies with a 100 billion stars in e

• sytelus 6y ago
  It might still be that there is probably barely 1 advanced life form per galaxy. We know that organic molecules and related evolution requires air, water, temperature and stability that Earth like planets can afford. Unfortunately, to be Earth like planet, you don’t just need right distance from the star but abundance of water, minerals and so on. You must maintain magnetosphere otherwise water will be gone. You must have right moon otherwise axis will wobble with eradicate seasons. Even there life had been almost wiped out many times. There are half dozen human like species which were extinct and never panned out. All these goes on to show that even with 100B stars, you just need handful of probability to chope it down to one or so instances. The non-existence proof of ETI also means laws of physics are cruel and cannot be violated. There is almost 100% chance that advanced life forms exist in other galaxies, may be even billion year old. But no one has figured out how to travel faster than light.