Hawking answers cosmic question: 'Are we alone?'

[Coolhand]

Thats an interesting theory, but one thats been around for a very long time, called 'Ancient astronaut theory', it postulates that previous civilisations, Atlantis and an ancient indian civilisation (who flew around in mercury powered(?) flying machines called 'vimanas') could have possibly explored our solar system before us. Erich von Däniken wrote some popular books on it in the 70's - Chariots of the gods, and another one i think about the bermuda triangle. Some of this is meant to be backed up in ancient indian texts. There's even meant to be evidence of an ancient nuclear war between these civilisations like radioactive skeletons being dug up or something!

It's certainly possible that we could wipe ourselves out or become victims to some event and our relics would be rediscovered... so i guess there is some possibility that this happened in the past. Seems to be a distinct lack of hard evidence for it though

 

[ar81]

Indigenous city in Mexico was bigger than Rome and it was the biggest known metropoli of the world until it was gone. Romans had buildings that will last longer than ours.

Egyptians claimed to have won a war against Hitites, but recent findings show that Hitites won.

So if you ask me, I could not discard anything when studying history.

 

[Eagle]

I wouldn't hold out much hope for ancient astronauts... But I do have a feeling that manned flight (among other 'modern' inventions) has been around longer than we may think. Manned kites are mentioned by Sun Tzu. Hot air balloon technology was also known to the Ancient Chinese, but there's no known evidence of them being manned.

There was also a mechanical astronomical calculator recovered from an ancient shipwreck in the Mediterranean.

My only point, is that ancient peoples were not dumb. They probably knew a lot more than what we give them credit for.

____

On the point of extraterrestrial life. Our detection ability is quite bad. We might notice if some warring civilization started blowing up several nearby stars. Or possibly if they broadcast interstellar digital radio to stars further away than us. There may also be something to be said about the level of technology intelligent life will be at...

...Maybe Star Trek was on to something when they kept landing in Ancient Rome...