Tag Archives: universe

Alien life over eons of time

I’m listening to a book where the earth is invaded then the aliens that defended earth start recruiting our troops to fight in low level intergalactic wars. This book got me thinking about the chances of meeting aliens and I thought about how time is the major factor preventing this.

I’m not just thinking about how any intelligent life form would likely be hundreds or thousands of light years away. I’m thinking about time since the universe began. The universe is about 13.5 billion years old. Earth is about 4.5 billion years old. The earth has missed 2/3rds of all existence. Even then Homo Sapiens have only been around for 200,000 years or 0.0044% of the earth’s existence. And we’ve had just over 100 years of radio transmissions, that’s about 0.0000022% of the earth’s existence. (That’s 0.00000074% of the existence of the universe,)

Now when you look at 100 years over the span of the life of the universe, it becomes evident that entire civilizations could have survived for 5 thousands years and could have died off 5,000 or 50,000 or 500,000 or 5 million, or 50 million, or 500 million, or 5 billion years ago, great distances from us, and we’d never know.

Let’s say intelligent life is abundant in the universe, giving us a great opportunity to meet aliens. And let’s say that life didn’t start for the first 3.5 billion years of universe development. That still leaves 10 billion years of inelegant life. There could be 1,000 civilizations that existed and died and each one could have missed the birth of another civilization by a million years.

Let’s face it, we are developing technologies that make it unlikely that we will survive another 2,000 years. In less than 100 years high school students will have the technological know how, and the tools, to build a deadly virus or a deadly bomb that could set our civilization back hundreds of years. I give humanity a 50/50 chance of getting through the next 200 years.

I’m willing to bet that even if there were thousands of intelligent civilizations across the universe most space travel ready civilizations wouldn’t make it to 2,000 years. So forgetting the vast expanse of the Milky Way and the universe beyond that, it’s highly unlikely that any close enough for contact aliens are even around now… They are probably either long destroyed, or they are in their version of the dinosaur age, still millions of years from developing to where we are, much less to the point of light speed travel.

So following this train of thought, it’s likely that intelligent life is/has been abundant in the universe, and yet we are very much alone.

Beyond space and time

Part 1 – Time travel

When people imagine time travel, they often don’t realize that they are also talking about space travel as well.

How Fast Is the Earth Rotating on Its Axis?

The Earth rotates on its axis once each day. Because the circumference of the Earth at the equator is 24,901.55 miles, a spot on the equator rotates at approximately 1,037.5646 miles per hour (1,037.5646 times 24 equals 24,901.55), or 1,669.8 km/h.

At the North Pole (90 degrees north) and South Pole (90 degrees south), the speed is effectively zero because that spot rotates once in 24 hours, at a very, very slow speed. (Source)

In addition to this rotation, the earth is hurling around the sun at 30km (19 miles) per second! And, our sun isn’t stationary in the galaxy, it travels 792,000 km (483,000 miles) per hour (and still takes 230 million years to complete a rotation).

These numbers are mind boggling. Now, going back to the idea of a time machine, if I was able to go back in time to only 5 years ago, the earth that existed back then was millions of kilometres away from where the earth is now. I’d have to travel through time and space.

Part 2 – The light of the stars

When we look at the stars, we only see their history. The closest star, our sun, is not where we see it, it is where the sun was 8 minutes ago, because that’s how long it took the light to reach us. For stars that are light years away, they could already have gone super nova, and wiped out their solar system, and generations later our ancestors will still see that star, not knowing it no longer exists. We are literally looking back in time when we look out into space.

Part 3 – the edge of the universe

A concept I can’t wrap my head around is what’s beyond the edge of the universe? And if you have an answer for me, what’s beyond that? This to me is the definition of infinite… the idea that no matter how far away something is, there has to be something still farther away.

If you had a string that was infinitely long and you cut it in half, you’d have two strings that are infinitely long. Think about that for a while… then try to forget it. 😜

Why should we believe that our universe is the only universe? Could there be multiple universes in the empty void beyond our own? Could our entire universe be an atom in a massive other universe? What secrets do the edge of our universe hold? We will never know because it takes too much time for the light way out there to reach us.

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These are 3 ideas about space and time that peak my curiosity and make me marvel at life, the universe, and everything… while we hurl through space on an insignificant rock around an insignificant sun, in an insignificant galaxy… thinking thoughts that significantly challenge my intellectual understanding.