Who are WE?

Who are WE?
We are humans and we are about 6 and a half billion humans on earth.

Who's Earth?

- around 4.54 billion years old.
- the first self-replicating molecule on Earth is estimated to have appear around 4 billion years ago
- surface: ~510million square km
- it's the third planet from the Sun and it's orbiting it at an average distance of 150 million kilometers.

Who is Sun?

- the Sun's mass is 98.6% of our solar system's mass.
- hydrogen is 74% of it's mass and 92% of the volume, the rest is mostly helium.
- the energy of the sun that disperse all the light is created by nuclear fusion (the hydrogen is transformed into helium)
- temperature at the surface is around 5500°C
- the Sun is more brighter then 85% of the other stars in the galaxy
- from it's light we perceive mostly the yellow color, but the blue spectrum is mostly seen as the reflection of the atmosphere and thus we see the blue sky, also as the degree of the light comes steeper we can see the red/orange light in the atmosphere at dusk and dawn.

Location:
- inner rim of the galaxy at around 24.800 light years from the center.
- the Sun orbits the center of the galaxy with 251km/s and 1 revolution is done in 225-250 million years.
- it takes 1400 years for the solar system to travel 1 light year.

Life cycle:
- 4.57 billion years old
- has around 10 billion years from birth until becomes a red giant (not enough mass for a supernova explosion)
- it will end up as a typical white dwarf (mostly carbon) in about 8-9 billion years from now.

Who's our galaxy?

- age is unknown but the oldest star identified is 13.2 billion years old.
- the Galactic thin disk is estimated to have been formed between 6.5 and 10.1 billion years ago
- current measurements suggest the Andromeda Galaxy (2.5 million years away) is approaching us at 100 to 140 kilometers per second and it will collide with Milky Way in 3 to 4 billion years from now --> kaboom or not kaboom? :)


There are between 200 and 400 BILLION stars in this galaxy.
There is a brute estimate of between 200 and 400 billion galaxies in a meta-galaxy
Can we go forward saying that there might be around 300 billion galaxies in the universe?

So there are "about" 30.000.000.000.000.000.000.000.000.000.000.000 stars out here... oh wait... did I say there are perhaps 100 trillion cells in your body? well... that's 30 billion of trillion of trillion less cells in your body then there might be stars in the universe...

Talking about a big ego:
Oh... if GOD created the universe... would he care about that bit of nothing growing on a small insignificant planet? If you would say 'yes' then I would say... man you really feel important!!!

And so I conclude: WE are nothing... we are really-really NOTHING... and we are all bound to disappear in less then 4 billion years unless we mass suicide before that.
Here's a nice song to go with this.

Have a good day and long life!