Science: Math edition

Hello scientists!

Again, I'm sorry for not posting in a while. At home we've had many technical difficulties. At any rate, here's the post you've been waiting for.

Science and math go hand in hand most of the time, but especially in today's blog entry. We're going to talk about aliens! However, we can't just shout out that they exist because of blurry photographs or UFO sightings. We can use an equation to find out the probabibilty that they exist in the galaxy.

The mentioned equation is called the Drake equation, and it goes something like this:

There are a lot of variables here, as there should be. After all, finding extraterrestials is not an easy task. Here's a key:

N=the number of civilizations that we can communicate with by radio*

R*=the average rate of star rate formation in the galaxy

fp=the fraction of stars in our galaxies that have planets

ne=the fraction of those planets that can support life

fl=the fraction of life-supporting planets that actually have life**

fi=the fraction of life-containing planets that have intelligent life

fc=the fraction of those civilizations that release clues of its existence into space (such as radio waves)

L=the length of time those signals last

Once you figure out all those variables, you multiply them all together. Their product is the probability of other intelligent life in our galaxy.

So, what are these values? Let's start with R. There is usually about 1 star formed per year in the Milky Way, although this is sometimes considered on the conservative side.

fp is next. Out of 100 average stars, 20-50 will have planets. This means that fp is between .2-.5 .

ne is actually higher than what you expect, or at least higher than what I expected. Every star that has planets usually have between 1-5 planets that can support life, so ne is 1-5.

After this, scientists view the Drake equation as not very useful. After all, we don't know if there is alien life, so we can't figure out fl or any of the variables after that. They are also very hard to estimate. However, scientists have figured that if a planet can support life, life will somehow begin there. Therefore fl is 100%, or 1.

Scientists also assume that this life will evolve into intelligent life if given enough time, so fi is also 100%, or 1.

Interstellar communication is not an easy feat, however, so 100 given intelligent civilizations will probably have 10-20 that communicate through space. This means that fc is 10-20%, or .1-.2 .

Lastly, there is L. It is assumed that from the start of the civilization's communication, it will continue to communicate through space until it becomes extinct. This a large range. It's existence will probably occur anywhere from 1,000 to 100 million years after they begin to communicate. This means that L is 1,000 - 100,000,000.

Although some of them are estimates, we still have our numbers! Let's plug them into our equation.

Multiplying the lowest numbers possible, the equation tells us that we are the only ones in the galaxy, and probably the only ones in the observable universe.

However, the highest possible numbers provide a more optimistic answer. It states that are 36.4 million other civilizations in the galaxy! So yes, we come to the incredibly satisfying answer of there being 0 to 36,400,000 other species in the galaxy. Doesn't exactly improve our knowledge. Oh well.

Thanks for reading! Make sure to comment below! Next time, I'll introduce you to a new tradition for the blog, so stay tuned!

Until next time,

Ben's jamin'

Benjamin

P.S. Make sure you check out John's math blog at http://johncooksmathblog.blogspot.com.

*We have to communicate with these civilizations. If we can't, it doesn't matter if they exist or not.

**Just because planets can have life doesn't mean it has to.