I have been asked on at least twenty occasions about life in the universe. I think everyone thinks that there is life like trees and animals but something really strange happens when an actual living, breathing, intelligent "person" from another planet is brought into the mix. Some people go bonkers, some are fully accepting and others just don't believe a single thing. The responses will vary,
"There can't be other civilizations in the universe, we are just perfection",
"Life is way too difficult to start, it can't possibly happen anywhere else", and
"Life is absolutely everywhere, most of the solar systems in the universe have started with intelligent life."
I come down on the side of every solar system starting with the seeds of life. The creation of a star is a very violent event and planets that form through this mass mayhem are bombarded with rocks, comets, solar radiation, boiling and freezing temperatures. Through all of this, microbes grow, amoeba multiply, algae blooms and plants start to grow. It just happens, moreso when the planet is at a temperature that allows water to exist in a liquid state. Life also finds other ways to grow in the most inhospitable places. Life is likely to exist in every environment, every single one. Intelligent life, then again, is slightly more difficult to pull off.
Nearly every planet in a warm orbit (liquid water on the surface and some type of air) has the tools to create multiple levels of life. How long that planet stays in one piece and doesn't face terrible cataclysms is the real question. How likely is that to happen? How many planets could there be in the universe? How many galaxies, burned out stars, stars like our star or newly formed stars were ever available to create a civilization? The short answer is lots, lots and lots, as a matter of fact this number may be so large that it is beyond our comprehension. Who said that a civilization must breathe Oxygen and Nitrogen and use Carbon as the basis for building life? There are 118 elements so far in the Periodic Table of the Elements, we still have no idea if they are all at play in the game of life.
Frank Drake (the Drake Equation) theorized a formula where likely percentages of warm planets can be imagined, put into this formula and it would generate a likely number of inhabited planets in a galaxy. In most scenarios, this number turned out to be in the millions and that is just for the Milky Way alone. What does this look like in the totality of our universe? Let's do some math and discuss some scenarios.
* There are between 200,000,000,000 and 400,000,000,000 stars in our galaxy
* There are likely 2,000,000,000,000 galaxies in the visible universe
* This does not include that which we cannot see - the universe is older than we thought
* That makes 800,000,000,000,000,000,000,000 stars in the visible universe
* If you made up a name for each star (one per second),
* It would take 3,000,000,000,000,000 years to complete this task
* The likely number of civilizations in the universe would eclipse 1,000,000,000,000,000
In the past 150 years, our planet has advanced from horseback to space travel. The civilization that we call human seems to be about 7,000 years old since its last apocalyptic near-extinction event. The universe is 2 million times older than us humans. What would an advanced civilization look like if they were spared catastrophe? How far would they have advanced in that time frame? What could we accomplish in the next thousand years, million years or billion years? Getting to us through all of the trillions of miles would be very simple for them. In a million years we could probably return the favor, no matter where they were.
Look up and pay attention to your place in space. It is trying to tell you something! Still think we are alone?