If you're interested in any way about space, evolution and the possibilities of life beyond Earth then you'll probably find the Fermi Paradox fascinating. I've just come across this myself, and whilst I've previously pondered various things the following article is very well written and gives some perspective on current theories surrounding the how's and why's.
The general premise is that there are estimated billions of sun like stars in the galaxy along with planets sometimes billions of years older than Earth. If the Earth is typical, then by odds alone there should be thousands of potential advanced civilisations out there. So where is everyone?
It's a long article, so be prepared to lose a good half hour:
http://waitbutwhy.com/2014/05/fermi-paradox.html?doing_wp_cron=1416993671.2402648925781250000000
Comments
I think there absolutely must be other life out there so it's a fascinating question.
What a good post. I'll tuck into that in a bit. Most of the stuff I have been reading recently is around the universe starting from nothing in quantum fluctuations. If at the quantum level, particles (dark matter) can pop in and out of existence, then why couldn't a whole universe too.
I'm always frustrated though because I lose the trail of thought when people discuss the curvature of space time. I have to re-read and go over this concept because being a person who lives in a dimension where space and time as a concept impact on my/our very existence, it is hard to step outside yourself and think about space time as a by product of our dimension.
Also, when they talk about looking at the moon and seeing it as it were 2 seconds ago, the Sun 8 minutes, the nearest galaxy 1000 years ago. We're not wired to comprehend that in the first instance.
It will also impact upon the 'are we alone' question. Intelligent life (if it exists) will be looking at earth as it was xxx amount of years ago. Also things like Gaia the SDSS are only ever imaging a portion of our universe at a given time. Who knows what else we haven't discovered yet/missed.
This is a great age for astronomy, I just fear that if we are living in an ever expanding universe, the goal posts are constantly being moved or even hidden
@ValleyGary you might like this one mate http://www.bbc.com/earth/story/20141106-why-does-anything-exist-at-all?ocid=twert
Are they out there? Almost certainly yes. Would they have the means to travel that far? (assuming the speed of light is a limiting factor) - almost certainly not - it would just take too long.
Millwall fans developed 2 billion years ago.
I bet they kicked off with the multi cellular organisms a billion years later, coming here knicking our jobs and amoebas.
http://www.distancetomars.com/
Say you lived in flatland - where there were only two dimensions (width and height - no depth). Any visitor to your land that was from three dimensional space would appear to instantly materialise, get wider, then narrower, then disappear as they passed through your dimension.
That's what it would be like if we saw visitors from another dimension pass through ours. We wouldn't be able to comprehend it because the whole concept makes no sense to our three dimensional brains
I think it was on Brian Cox's latest series he mentioned the theory that there are many planets out there that have the possibility to sustain life, but when you look at what ours has gone through and what we as humans have gone through to be here today the chances are so remote that basically we are the only ones just that we are ridiculously lucky that we are here at all.
I could have got that completely wrong but it sort of made sense to me.
This is quite possible IMO bob, given everything I have been reading about various developments recently. You might also like this article I came across the other day. It's in reference to your point above about anyone looking at us from any point of the galaxy seeing us as we were 100,000 years ago.
http://blogs.scientificamerican.com/observations/2014/12/03/worlds-oldest-engraving-upends-theory-of-homo-sapiens-uniqueness/