A human life as a percentage of the lifespan of the universe
I've just joined the vast number of users on this site which I know will give me hours of endless fun. As a Dawkins 'disciple' and Douglas Adams fan I must admit that it is a great way to share our thoughts about Life, the Universe and Everything.
So, I thought I'd ask the audience a couple of questions that have been perplexing me lately.
I am trying to work out ( roughly speaking ) the following :
- If the Big Bang happened 13.7 billion years ago and the sun will burn out into a dwarf star in 5 billion years from now that's a total of nearly 20 billion years. The question is : if an average life of a human (I smoke and drink too much so I won't include myself !) is 80 years, What percentage of 20 billion is 80 ( I'm sorry, I'm really bad at mathematics ). I just need to know this so that the next time I marvel at the Milky Way I will know that I've had the honour of being part of it all in a tiny miniscule fraction kind of way.
Question 2 is a follow on from question 1. Here goes...
If there are 7 billion people on the planet now, how can I calculate (roughly again) how many homo sapiens have lived and died, and secondly (and, I know, more mathematically complex, how many will live til the sun burns out in 5 billion years' time?
Although I know this will make me feel insignificant (I'm happy about that) it will give me goosebumps when I'm looking at the stars again because I will at last know that ... in the lifetime of this universe I will be one of xxxx billion who have had the privilege to take part for, albeit, xxxx percentage of the whole span.