'Humans will make contact with aliens within two decades,' say astronomers

Of course, this would be SETI astronomers.

Here's the story => dailymail.co.uk

Although I'm not as optimistic as them, I still think SETI does valuable research. I think the odds of contacting an alien civilization are very small, but if we don't look they're zero. I believe the payoff of such a discovery would be a tremendous push towards changing the petty world view that so many of us have.

The key to how likely you think it is to find intelligent life depends upon the values you stick into the now famous Drake equation (invented by the first SETI researcher of course).

N = R^* f_p n_e f_l f_i f_c L
It calculates the number of communicating, intelligent, species in the galaxy. The equation seems to carry a lot of weight with folks simply because its math. Math can't be wrong, can it? Well, the math can't be wrong but that doesn't necessarily mean that the number it calculates as any connection to reality.

Here are what each variable stands for.

R^*: The number of stars in the Milky Way galaxy.

f_p: Fractions of stars with planets around them.

n_e: Number of planets per star system capable of supporting life.

f_l: Fraction of those planets where life arises.

f_i: The fraction of the above planets on which intelligent life evolved.

f_c: The fraction of those civilizations that develop the means to communicate over distance.

L: The length of time these civilizations last for.

Obviously, most of these numbers would be highly speculative, but what Drake argued was that even conservative numbers produce tens of thousands of such civilizations. Well, since his time what were considered to be conservative numbers by Drake have turned out to still to large. Do a bit Googling and you can find conservative numbers that have this coming out to be less then ten. The galaxy is a far less hospitable place then we thought half a century ago.

But I'm not going to even bother with that. There's plenty of evidence that Drake's equation is obsolete anyway. One of the biggest factors it doesn't take into account is that the universe his hardly static and is continuing to evolve as well. The universe 5 billion years ago (when our solar system came into existence) is not the same as the universe now.

Here's a good article that provide a counter-point to SETI and the Drake equation.

The Drake Equation is Obsolete

Mike