Goal: To understand life in our universe. Objectives: To understand the Basic building blocks for life in general To learn about What type of stars and planets to look for if we want to find life To understand How to find these planets To examine The search for intelligent life To learn about The Drake equation

Intelligent life There is an agency that is searching for intelligent life: SETI (Search for Extra Terrestrial Intelligence).

What does SETI look for? SETI scours the radio section of the electromagnetic spectrum. SETI tries to find signals that could not occur naturally. Some examples include beamed transmission, repeated patterns, very narrow band emission, or anything else that can only be created intentionally by an alien civilization.

How far away will life be? Do figure this one out we will use what is called the Drake Equation. The Drake Equation is just a giant unit conversion basically… There are a few forms to it. We will be examining an offshoot here…

How many stars are in the Milky Way galaxy? About 400 billion

What fraction of those are like our sun? B) 10% C) 1% D) 0.1% E) 0.01%

What fraction of those have planets? B) 10% C) 1% D) 0.1% E) 0.01%

What fraction of those have planets or moons like our Earth in a region where you can have life (in general)? A) 100% B) 10% C) 1% D) 0.1% E) 0.01%

How many Earth’s do you get per system? Our solar system has 3 planets in the “habitable zone”

What fraction of those have actually develop life? B) 10% C) 1% D) 0.1% E) 0.01%

What fraction of those have develop intelligent life? B) 10% C) 1% D) 0.1% E) 0.01%

What fraction of their planet’s life will there be intelligent life on that planet?

So, we have a number of expected civilizations! But how far are they from us? Lets take the radius of our galaxy (50,000 light years across) and divide by the expected # of civilizations. Now, if we travel at 10% the speed of light when do we get there?

Light speed! Instead of going there, lets just communicate (if we can figure out how to do this and we both have a wish to). How long will it take us to get a response?

Universe Remember there are about 100 billion spiral galaxies in the observable universe! It would be very unlucky, a great shame, and a big waste of space if we truly were alone in the universe. Will we find life – probably (and maybe within our own solar system too) – and maybe within our lifetimes! Intelligent life? Well, we shall see.

Conclusion We have estimated the # of intelligent civilizations in our galaxy. Sadly, getting from place to place is really hard (after all as we found at the start of the semester, the distances between stars is really big).