Let’s start by clarifying something.

There is a distinction to be made between UFO’s and the idea that there might be life elsewhere in the Universe. By UFO’s I’m referring to the popular myth of little green men who turn up in flying saucers, making crop circles and probing particularly attractive farmers. Aliens who supposedly have (and continue to) visit Earth, with their existence covered up by the government. There are a myriad of reasons to be skeptical of this belief – yet I think only one is needed.

Interestingly, this one reason against UFO’s does point towards life elsewhere in the universe. So what is this reason?

Space is Big.  Space is mind-bogglingly big.

It is impossible to grasp quite how big of a space, space is.

To scale, if the Earth were the size of a classroom globe, the Moon would be 30 feet away, Mars a mile away. And those are only our nearest neighbours. The Voyager craft, 2 space probes launched by NASA in the 70s, are some of the fastest man made objects ever, travelling at around 17km/s. That is very fast (for comparison Concorde’s top speed was only around 0.6km/s). However despite this immense speed and the fact that they have been travelling for nearly 40 years, they have still only just reached the edge of the Solar System. In space terms this is just stepping out of your front door!

600px-Solar_System_scaled_to_a_football_field
The Solar System to scale on a football field.

The nearest star to us is named Proxima Centauri. It is 4.2 light years away. So if were we travelling at the speed of light it would take us 4 years to get there (though interestingly it would take less time for the astronauts on board due to special relativity – a post for another time maybe!). However our current speeds are woefully short of such velocities; the Voyager craft travel at just 0.00006% of the speed of light. Travelling at those speeds it would take around 75,000 years to reach Proxima Centauri.  And that is just to the nearest star – that’s the cosmic equivalent of going to visit your neighbour!

Our galaxy, the Milky Way, is some 100,000 light years across. This is an immense distance.

Consider that you have been alive for only 10’s of years, that the entirety of recorded human history is roughly only 4,000 years old, and then imagine travelling in a rocket ship for 100,000 years. Now imagine you’re an advanced alien civilisation. We’ll be as kind to the UFO theorists as possible and allow this advanced civilisation to have ships that can carry passengers at 99% of the speed of light (around 20,000 times faster than our unmanned probes). Now suppose that your civilisation has spent tens of thousands of years making advances in science and technology, set up a long term space program spending huge quantities of alien money, to produce a starship that can travel at 99% of the speed of light.

You then use this zenith of engineering, this marvel of science and travel for 100,000 years just to secretly scare some farmers on a small planet in the outer reaches of the Milky Way?

This makes zero sense.

And thats just for aliens that would be in our own galaxy! The nearest galaxy to us is Andromeda, which is 2.5 million light years away! Do UFO conspiracies think that aliens are travelling for 2.5 million years just to come and probe them, or are they more conservative and say, “No! No! Don’t be silly – only UFOs from our galaxy!

The Andromeda Galaxy.
The Andromeda Galaxy.

The astrophysicist Neil deGrasse Tyson has a good little thought experiment that I shall reiterate for you here.

When you walk past a worm, does the worm have any notion that you exist? Any idea of how great you are compared to it? Can the worm even conceive of a being like yourself? Do you stop to consider the worm, give it your time and attention?  Of course not.    You walk straight on past the worm and don’t give it a seconds thought.

Any civilisation that was capable of traversing these immense distances would have to be as great compared to us as we are compared to a worm. So, he argues (somewhat ironically) that alien beings are far more likely just pass us by, and not give us any thought, and we might not even be able to comprehend their existence should they choose to say hello.

However, the same reason that argues against UFO’s, is also one that argues FOR the possibility (or probability) of alien life. In science, there is something known as the Cosmological Principle which states that there is nothing particularly special about our current position in the universe. Therefore, given that life has arisen here on this planet, and there is nothing special about here, it seems likely that life has arisen elsewhere. The huge size of the universe brings with it huge numbers of galaxies, star systems, planets. Even if the chance that life was elsewhere in the universe was only 1%, that would still give us a billion or so planets with advanced civilisations on!

However, in a final cruel irony the size of space kicks in again.

Due to the huge distances involved, the universe could have a billion civilisations, yet the chance of any two of these civilisations ever meeting is, very sadly, practically nil.

 

This article was contributed by Tom Kimpson from TomKimpson.com.