Extraterrestrials Probably Haven't Found Us - Yet

kasparn writes "The Guardian today has a story about the Danish astrophysicist Rasmus Bjoerk, who recently conducted simulations on how long it will take to colonize the Milky Way. The basic idea is to send out probes in different directions (including various heights above the galactic plane). He estimates that it will take some 10 billion years to explore 4 % of the Milky Way. Since the age of the Universe is of the same order, his conclusion is that aliens can't have had time required to find us yet."

Comments

Based on poor assumptions

[BadERA]

Why 1/10th c? Why not 99% of c? Why not faster than c? Granted faster than light travel is nothing more than theory and dreams at this point, but this article makes the assumption that other civilizations have not progressed in the field of physics any faster nor further than we ourselves have, to date.

Re:Based on poor assumptions

[QuantumG]

Yeah, imagine a civilization that, having discovered enlightenment, actually embraced it and dedicated their industrial base to further it, instead of shuffling it off to the minor specialists who they then make beg for funding, typically by militarizing their research.

Re:Based on poor assumptions

[gobbo]

But the bad assumption remains: rocket technology. Like I said, who's to say they haven't gone further with physics, or pursued a different, or completely unthought-of (to us) means of travel?

No kidding. "If we put a thousand horses on a carriage, it still won't be fast enough to lift from the ground. But if we could discover the rumoured winged horse, we can do it."

Something tells me that we're a couple of paradigms away from comprehending galactic distances as attainable. Propellant propulsion systems are to interstellar travel what horses are to flight.

Duh

[Reality Master 101]

Sheesh, talk about "proof by lack of imagination." This is supposed to answer the Fermi Paradox?

You can't explore a galaxy with a handful of probes. 72 probes??? First of all, if you're going to do it that way, you'd create hundreds of thousands of probes, if not millions of probes (mass production would reduce the cost). Second, you still probably wouldn't do it that way. You'd wait until you had the technology to make self-replicating probes, and the galaxy could potentially be explored in thousands of years.

Not impressed by this guy's argument.

Re:Well, DUH!

[Ignorant Aardvark]

To be pedantic ... the absolute minimum time to explore the whole galaxy from Earth is about 80,000 light-years, because the farthest part of the galaxy is about 80,000 light-years away from us. Although to be even more pedantic, double that, because you can't really say you've explored until the information about what you've found has made it back to you.

So, yeah, you can't explore the galaxy in only a few thousand years.

It has been done already

[140Mandak262Jamuna]

The aliens knew they could not send out probes that carry enough energy to beam back the information. So they built generalized adaptive Turing machines, (a machine that can build itself) of incredibly small dimension. They created billions and billions of these machines and scattered them. These machines are so tiny, they get carried by the solar wind and other cosmic radiation.

One of these Turing machines reached Earth about 4 billion years ago. It first had to start by building very simple amino acids, then it graduated to proteins, then to RNA and then to DNA, and then these DNA machines built bodies around them and started using natural selection to evolve into more and more capable organisms. The final aim of these DNA structures is to build powerful radio beacons and send the information back to the original aliens who created these molecules and scattered them to the (solar) wind.

Re:That's assuming...

[Dr. Spork]

More puzzlingly, he assumes these probes can repair themselves for and keep running for billions of years, but they can't self-replicate. Really? If the probe can repair every potential internal probem on its own, the capacity to self-replicate should come almost for free.