As an astrophysicist I fly a lot. Mainly to telescopes, conferences and workshops.
And while I’ve learnt that life is not transformed into one of unparallelled joy by becoming a Gold frequent flyer, it does mean I’ve watched a lot of aeroplane movies and TV shows.
On a recent trip I was browsing through the documentary section and was delighted to see a show in which a vet – self-described “man of science” – takes on his poor mother’s beliefs that we are frequently visited by aliens, in the documentary My Mum talks to Aliens.
Mary, the vet’s mum, is apparently Australia’s leading authority on everything to do with aliens, and her poor son agrees to accompany her to various meetings and interviews to put her evidence to the test.
Sadly, about half way through the documentary, our vet starts to realise that humiliating his mother in a national documentary is not any fun, and the show didn’t pursue the alien jugular (should they possess one) in quite the way I was hoping. Worse, our poor vet starts to lose his nerve, even when he starts having to listen to tales of human-alien sexual encounters.
Fortunately, since Mary is not my mum I don’t have to hold back.
Moore’s Law and astronomy
There’s a very compelling reason why we aren’t regularly visited by aliens.
In astronomy, as in our everyday lives, technology is on the march. In fact, as with computers, every few years new telescopes and their instruments get twice as powerful.
This exponential growth in technological capacity means that a PhD student can often perform more science during his or her thesis than their supervisor has in their entire career - which can be embarrassing.
But this exponential growth has transformed our knowledge of the universe as our detectors and telescopes continue to get better and better.
Astronomical discoveries of things such as supernovae, pulsars, quasars, extra-solar planets and supermassive black holes have all grown exponentially since the first few were uncovered by now-primitive instruments.
In my own research field the first pulsar (a regularly repeating series of radio pulses from a neutron star) was discovered in 1967. Initially it was seriously postulated to be an alien beacon.
Within a few weeks they realised it wasn’t aliens when three other pulsars were found in very different regions of the galaxy.
Technology advanced and, within ten years, there were about 100 pulsars known. By the mid 1980s a few hundred. Now they number well over 2,000.
Some pseudo-random combination of bigger telescopes, better detectors, more scientists and more powerful computers has led to exponential growth in pulsar numbers for more than 40 years.
Indeed pulsar astronomers are equipped with some of the best alien-detecting equipment on the planet, but so far its pulsars > 2000, aliens nil.
This exponential growth in numbers is mirrored in almost all domains of astronomy, and conversely, whenever a “false positive” discovery occurs, it is soon revealed as such by the lack of any other examples as newer, more sensitive telescopes come online.
The rise of the digital camera
Now, despite hundreds of claimed sightings of unidentified flying objects (UFOs) by the late 20th century, there has never been any particularly convincing photographic evidence.
Which, when none of us carried around cameras, could be perhaps forgiven.
But since the turn of the century the number of high-quality digital cameras coming into existence has been staggering.
More than two billion digital camera phones now roam the planet and almost 100 billion photos a year are going onto Facebook alone.
The world has become one enormous alien detector courtesy of more than two billion “observers” all armed with a portable alien detector (their phone)!
And yet, despite all the people who have previously claimed to have witnessed alien visitation, none of these new cameras has managed to snap a picture of an alien in any detail.
Nor have any of the giant telescopes, with their astonishingly sensitive detectors.
Not by anyone. For every grainy UFO photo from the mid-20th century we should now be seeing hundreds of high quality close-ups.
But we don’t.
Sorry Mary. You might be on a quest to teach us the truth about alien visitation, but it’s going to take more than your mate the builder passing a polygraph about experiencing a “six-hour erection after having sex with a beautifully-proportioned blonde alien that he bit the nipple from” to convince me aliens frequent our planet, or indeed our bedrooms!
Thanks to Bruce Elmegreen (IBM) for his amazing insight into the consequences of Moore’s Law for Astronomy PhDs compared to that of their supervisors.