My Thoughts on the Fermi Paradox

Enrico Fermi famously asked why, if our galaxy really does contain other intelligent, technologically capable species, we haven't seen any trace of them. Against the great age of the galaxy, the time required for a civilisation to explore every single star system in it is relatively small, so we should have encountered a probe or something by now. That we haven't would imply that in fact intelligent life is not very common.

Speaking personally, I would very much like there to be intelligent extra-terrestrial life. I largely grew up on Science Fiction, so the possibility of humanity one day making contacts with aliens featured highly in my formative years. Ironically, I automatically assumed that ET would be friendly towards Humanity, despite this rarely being the case in SF films and books.

To rebut the Fermi Paradox I used to reason that ET would very likely be thousands or even millions of years more advanced than us, and so would have little interest in making contact with a such primitive species as we would seem to them. Indeed, they might not even recognise us as being intelligent enough to be contactable. A second line of defence was that perhaps we have observed evidence of them, but have wrongly constructed naturalistic theories to explain the evidence.

Recently a third possibility has occurred to me. I wonder if we're being a bit parochial in our assumptions about what an advanced civilisation would do. Sure, it seems natural to us that they would expand out from star system to star system, building that Galactic Empire I used to read about, but maybe your needs and aspirations change as your civilisation advances. When our culture looks into the future we typically have a time frame of no more than a few decades. Many of our politicians seem to look little further than the next election, so that's probably not surprising. I'd hope, though, that this would change eventually. A sufficiently advanced culture might conquer problems like ageing and death, and start to think on a far longer scale. When your potential lifespan might be measured in millions of years, and remote possibilities morph into inevitabilities, you might become rather risk-averse. Galaxies contain supernovas, wandering planets, and who knows what other perils. Sure, their advanced technology might allow them to, say, relocate away from a star that would one day explode, or maybe even dismantle the star to stop it going off at all. But an easier solution might be just to leave the stars behind.

I wonder now if the missing alien civilisations aren't to be found in intergalactic space, millions of light years from anything that could harm them. According to David Deutsch in his book The Beginnings of Infinity (an excellent book, by the way), the density of matter is thin indeed out there, but a volume the size of the Solar System would still contain over a billion tonnes of matter, mostly Hydrogen. A sufficiently advanced civilisation, perhaps one that has moved from organic lifeforms to some form of miniaturised cyber-existence, might manage quite well.

'Might' seems to be the operative word in this post, so I'll permit myself to finish with another piece of even wilder speculation. Maybe a sufficiently advanced civilisation gets the option of abandoning ordinary matter completely, and migrates to dark matter. Then passing threats can be ignored as they'll just pass straight through you.

Additional: maybe this is how you'd do it.

Living in a Simulation - Some Thoughts from Within

It was about 2007 when I first encountered Professor Nick Bostrom's Simulation Argument.

You are well advised to read the original argument rather than my digested version of it, but basically it suggests that, providing it is possible to create a conscious entity in a computer simulation, and if humanity ever achieves the technological ability to run such simulations, and if humanity chooses to, then the overwhelming likelihood is that you are a conscious entity in a computer simulation.

The first condition is still a big IF. However, the second one possibly only involves humanity and our technology continuing on their current path for another few decades. The third condition I would argue is almost a certainty.

Ever since I first met this idea it has intrigued me. If it could be shown to be true, how should that affect the way I live my life? Should I try to be more interesting and entertaining, to decrease the risk of being edited out? Should I try to make contact with my programming overlords?

And might there be a way of working out for sure that our universe was really inside a computer program?

Putting myself in the place of the simulation designers, but using the computer technology available to me today, I tried to imagine what constraints or short cuts might be evident to the inhabitants of my creation, and these three points occurred to me.

1. The constraints of working in a digital computer would mean it was easier if there was a minimum possible size for such quantities like length, time, etc.
2. Likewise, it would be nice if it was possible to average the effects of the basic components of the universe, so that a wall, say, could be treated as a surface without needing to calculate the movements of all its component particles.
3. There would be a largest possible number.

Now as it happens, Quantum Mechanics says that there is a smallest possible value for time and length: the Planck time and Planck length, respectively. They are very, very small: the Plank time is 5.4 x 10^-44 seconds, and the Plank length is a mere 1.6 x 10^-35 meters. Nevertheless, this feature of the Universe is not intuitive.

And the properties of large objects can be calculated without having to consider all their component particles, which is one of the reasons we could do Physics before the particles were discovered.

The maximum number idea was a non-starter though, as everyone knows about infinity, and some people even know about the many different infinities. It was while hoping to learn more about the fascinating world of transfinite numbers that I recently watched the BBC program To Infinity and Beyond. In the middle of a series of interviews with mathematicians, I almost fell off my chair when one Dr Doron Zeilberger said that he didn't believe in infinity. No, he thinks that if you keep counting indefinitely, you eventually reach a maximum number, after which you get back to zero. The maximum number would be very, very big, but he believes it does exist. I don't know if he is alone in this view, but the fact that any serious mathematician could hold it I find very intriguing.

If Bostrom's Simulation Argument is valid, then its discovery must surely be a landmark in the running of a simulation, perhaps hastening the point when the simulation ceases to be of interest to its creators. I would guess that the 'turn off the program' point is when the bulk of humanity's behaviour becomes influenced by the knowledge of the true reality. If so, publicly speculating on the Simulation Argument might not be quite the good idea it seemed when I started this blog post.

For which I apologise; although if it makes me more interesting...

How We Know that Precognition Doesn't Exist

Although in my youth I was quite sympathetic towards the possibility of ESP, the continued lack of consistent evidence turned me away from it. That, plus the realisation that, if phenomena such as telepathy were possible, they would confer a huge survival advantage on any creature possessing, so natural selection would ensure that they were as widespread as, say, the sense of smell.

In the case of precognition, the ability to see the future, there is an even better argument against its existence. Many countries around the world hold lotteries, in which the participants have to guess which numbers are going to turn up in a draw. If precognition was a real power, even one that was only held by a small percentage of humanity, and then not even very reliably, still the effect would be visible in lottery results.

The lottery organisations would be the first to notice that more people were winning than chance would allow. Rollovers would be almost unheard of, and jackpots would routinely be shared between many winners. In the UK, guessing just three numbers out of six gets you a £10 prize.Even someone whose precognitive powers were only right half the time should be able to scoop up prizes week after week.

None of this happens. Unless it goes hand in hand with a profound aversion to gambling, I think it's reasonable to conclude that precognition does not exist.