Piqued #1: The Big Problem With Interstellar Travel Or Why You Will Never See Alpha Centauri In Person

Travelling through space to another star is called interstellar travel and I'll tell you one thing for sure: you will never do it.

But your great great grand kids might.


For countless millennia humanity has gazed at the stars in wonder. For most of that time we were pretty dumb and we thought the stars were gods or spirits or just holes in the sky. For a few hundred years we've known the stars were not just twinkling sky sprites, but probably actual places, separate from earth.

But it's only in the last century, and really only the last 50 years, that we've actually thought we could go to the stars. The problem is, even as science fiction and science reality have converged a little in space travel, we still don't have any way to get up there. I mean, we can get into space OK, but we can't really get to the stars.


Stars are very far away. The star nearest the earth is Alpha Centauri.

It's the one on the left. And it is roughly 4.2 light years away.

What does that even mean? Let's get some context:

The distance from New York to Sydney is 9,934 miles .
To Get to Alpha Centauri you would have to travel the distance from New York to Sydney 2,485,403,664 times.

The distance from the Earth to the Moon is 238,900 miles.
To get to Alpha Centauri you would have to travel the distance from the Earth to the Moon 103,348,681 times.

The distance from the Earth to the dwarf planet"formerly known as the Planet Pluto" is 4,660,283,941 miles. That's a huge number.
But to get to Alpha Centauri you would have to travel the distance from the Earth to Pluto 5,297 more times.

The point is, stars are super far away, even the closest one to us. Still, this wouldn't be an insurmountable problem if we had space ships fast enough to bridge the distance quickly. Only problem is, we don't.


Let's take a look at the fastest object humanity has ever produced.

This is the Helios 2 spacecraft. Nasa turned it into the fastest thing we've ever made with the help of gravity. (For more info on gravity and slingshot maneuvers go buy Kerbal Space Program and never leave your house again). As a result, Helios 2 got up to a speed of 61 miles per second.

You read that right: 61 miles per second. Try to take a moment and consider that figure. Think of a place that is 61 miles away from you right now. Now imagine moving so fast that you counted "1 Mississippi" and you were there. A bullet travels at half of a mile per second. 61 miles per second is a wacko number.

And yet... when it comes to interstellar travel, it just ain't that impressive. Let's extrapolate:
61 miles a second is
3687 miles a minute is
221,232 miles an hour is
5,309,568 miles a day is
1,932,682,752 miles a year
Which adds up to only 12,774 YEARS TO GET TO ALPHA CENTAURI!

You see the problem here? Helio 2 is the fastest human built object ever, and it would still take longer than all of recorded history to get the Helios 2 to Alpha Centauri.

And keep in mind, Helios 2 was tiny. It couldn't even carry people. It was just an observational spacecraft. Plus, it was totally non-functional by the time it got up to that speed. To get people to Alpha Centauri, you not only need to go jaw droppingly fast - faster than anything, ever, by a lot - but you also need to make a ship big enough to hold a bunch of people. Not to mention the food and water and air for those people, and maybe even those people's shit, because pooping in space isn't easy.

This is why interstellar travel is difficult beyond almost anything else our species might try to achieve. It is also why, I promise you, you will never visit Alpha Centauri in person.

And yet, as I said earlier, your great great grandkids might. To find out why, look for Piqued #2.

Image Sources: 1,2, 3

All other sources linked throughout.

"Piqued" is going to be a recurrent series where I explain fairly complicated things in fairly comprehensible and, hopefully, entertaining ways. I will get things wrong inevitably. When I do, yell at me and I will fix it.

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