Alien Contact

All of this information will be exciting, yes, but what would really knock our hosiery off is to know what the aliens are saying. That requires additional work beyond detection. To make them more sensitive, the SETI receivers add up the incoming radio waves over fixed period – the time constant – which is typically a second or so. As a result, any variations in the signal that are faster than once per second are smoothed out and lost. A terrestrial TV signal, for example, varies about five million times per second, so if your home set were to have a one-second time constant, you’d find the telly a bore (or perhaps I should say, more of a bore). The screen would be a slowly changing, gray wash of light.

Simply shortening the receivers’ time constant isn’t the trick, however. That just weakens the signal and makes it noisier. What we need is to boost the signal first, so we can still detect it even with a shorter time constant. In practice, that means SETI researchers will have to build far larger telescopes than they have today - perhaps ten thousand times larger. That’s currently a financial impossibility, but if an alien signal is detected I fully expect that the money will be found to construct this super-instrument.

Suppose it happens. Suppose that we have not only tuned in to ET’s broadcast, but we are happily downloading the bits that constitute the message. These bits will be recorded and distributed for analysis. After years of work, either we will succeed in figuring them out, or we won’t.

It’s probably realistic to assume that we will comprehend the aliens only if they are broadcasting deliberately, trying to communicate with other worlds. They could be engaged in altruistic efforts either to enlighten their neighbors or simply get in touch with young, technological societies such as our own. In that case they’ll devise a message that can be decoded fairly straightforwardly.

Since it’s overwhelmingly likely that any civilization we detect will be technologically far older than our own, the message would be of great interest. The aliens could allow us to short-circuit thousands of years of research into physics, astronomy, and chemistry, and tunnel our way into a far more sophisticated future. This could be compared to the rediscovery of classical science during the Renaissance, but would be of much greater magnitude. (Mind you, this windfall of knowledge will impose certain burdens. Scientists, for example, will suddenly be confronted with answers to research problems that have consumed their entire careers. These earthly scientists may not be entirely gratified to yield their chance for a Nobel Prize to the aliens!)

Department of Education, Mexico A Mayan Codex - a cryptological puzzle from the past

Such a sudden discovery of knowledge is possible, and it’s an exciting thought. But it’s also conceivable – and I personally think more probable – that the message will be difficult and perhaps impossible to decode. Imagine if the classical Greeks were given the bits belched out by a modern telecommunications satellite. The Greeks were not dumb, but they wouldn’t get very far in understanding this torrent of information.