“Aliens can’t exist because we haven’t found them yet”. I never really believed that people were stupid enough to base an entire “logical” thought process on this “evidence” but apparently many people do. Well, here’s a pretty famous quote (paraphrased) that’s been used to refute this poorly thought out argument against extraterrestrial life:
It’s like taking a scoop out of the ocean with a cup and saying there are no such things as whales because there are none in my cup.
Neil deGrasse Tyson.
Humans have been leaking radio waves for 70 years now so our radio bubble is approximately 70 light years. Our galaxy has a diameter of around 110,000 light years. There are around 170 billion galaxies in the universe.
The top three elements in the human body are oxygen, carbon and hydrogen. The most abundant elements in the universe are hydrogen, helium, oxygen, neon, nitrogen and carbon. And that is assuming that alien life must be identical to human life, which is highly unlikely.
But wait, what about the Goldilocks zone? Well, I’ve heard this term tossed around quite a lot and it always ends up being misconstrued somehow. The “Goldilocks” loosely describes inhabitable planets/regions. The Goldilocks zone specifically denotes a distance from a star that is the perfect distance for liquid water to exist on a planet (not too far to be frozen and not too close to be evaporated). In our solar system, Earth and Mars are the only two planets within this zone.
What’s the significance? Well as far as we know, water is really the only thing necessary for life to exist. There are bacteria that can survive in 400,000 times our gravity, in ridiculously high and low temperatures, and can feed of poisonous elements like sulfur. Honestly, it wouldn’t surprise me if there’s life out there that doesn’t need water.
When they (Deguchi et. al.) spun E. coli up to the equivalent of 7,500 G’s (7,500 times the force of Earth gravity), however, they found that the microbe didn’t miss a beat. It grew and reproduced just fine.
But wait, let’s just assume water is a necessity. The Goldilocks zone isn’t even exclusive as the only place with liquid water. For example, it’s been theorised that Europa (the ice moon of Jupiter) could be hiding a vast ocean under its icy crust. How? The moon is outside the Goldilocks zone but its orbit around Jupiter is elliptical. This means that the gravitational pull on the moon is uneven. Essentially, it is being constantly contracted and expanded. This gives it the potential to heat up the ice at its core enough to form water. There could be an alien species living in that ocean, oblivious to the rest of the universe as it is unable to penetrate the icy shell of Europa.
There’s more. Let’s limit our search even further and only look at Goldilocks candidates. Those of you that have kept an eye on the news might recall a few Goldilocks planets being found. Here’s a fun picture showing their similarities to Earth:
If you think that’s impressive, wait ’til you hear this. The Kepler telescope and the NASA team behind it predict as many as 500 million planets in our galaxy fall into the habitable zone. And yes, that’s just our one, lonesome galaxy.
And the truth is, life is not as elusive as it’s often made out to be. If you remember my post on Panspermia you’ll recall that bacteria and amino acids are commonly found in the tails of comets.
Now I did mention the Curiosity rover, but in all honesty, there’s not much I can say right now. For those of you that missed it, Curiosity found evidence of organic compounds on Mars, including water. However, there’s still a possibility the data was contaminated by Earth compounds, so I’ll refrain from drawing any conclusions (as the NASA team hasn’t drawn any conclusions yet either). All I can say is that I look forward to great findings over the entire expedition by Curiosity, just as many in the science world are. And I wouldn’t be surprised by any positive results.
But I want to leave you all with something mind-boggling to think about. I’ll try my best, though the more informed of you may scoff.
You may be asking: Why haven’t we seen any signs of aliens? or Why haven’t any aliens contacted us? Well, think about the vastness of the universe. We aren’t even capable of staying in contact with any probes to leave our solar system, and those few probes presumably to have left our solar system haven taken almost half a century to get that far. Our technology is so limited that contacting alien life would be close to impossible. In fact, if you consider that our galaxy is 110,000 light years in diameter, you’ll quickly realise our limitations. If you abide by classic physics and take light speed as the maximum possible speed (and there’s no evidence to the contrary right now), that means that even the most infinitely advanced alien life would still take 110,000 years to cross our galaxy. It could be that life in the universe is not destined to ever meet, and that light speed is the great limiter placed on the entire universe. At the very least, NASA recognises a problem in fuel based propulsions – something I’ll do a post about later. Basically, we have no possible technology that could ever be sufficient to let us explore into our own galaxy, let alone the rest of the universe.
And finally, a thought inspired by another Neil deGrasse Tyson quote, as well as predictions by Stephen Hawking. Most likely, we are either infinitely more advanced than alien life and overlook its existence or do not recognise it as life (such as bacteria), or we are infinitely inferior to alien life, so they see us as nothing more than insects and ignore us. After all, when was the last time you stopped and had a conversation with a worm?