View Full Version : Less Than 1% of Exoplanet Systems Have Intelligent Life, Researchers Say

2013-Feb-08, 02:40 AM
Recent findings say that Earth-like exoplanets could be all around us in our cosmic neighborhood. But how many would be home to intelligent life? A new study estimates that fewer than 1% of transiting exoplanet systems host civilizations technologically advanced enough to send out radio transmissions that could be detected by our current SETI searches. [...]

More... (http://www.universetoday.com/99812/less-than-1-of-exoplanet-systems-have-intelligent-life-researchers-say/)

2013-Feb-08, 03:30 AM
Hmmm. Actually, the report abstract doesn't say that, it says:

We estimate that fewer than ~1% of transiting exoplanet systems host technological civilizations that are radio loud in narrow-band emission between 1-2 GHz at an equivalent isotropically radiated power (EIRP) of ~1.5 x 10^21 erg s^-1
That is VERY, VERY different to asking "how many would be home to intelligent life". Badly worded title and article, imnsho.

I would suggest that trying to meaningfully guess the ratio of those potential intelligent civilisations that are 'radio loud' in that band, versus those that aren't, is impossible. Just as a trivial point, how long have *we* been loud in that band, versus the time we could be said to be intelligent?

2013-Feb-09, 03:36 AM
The 1% estimate miraculously appears in the report, which offers absolutely no justification for it, whatsoever. It is thus a pure fabrication, (and a wishful one, at that).

The actual result from the experiment was:

No signals of extraterrestrial origin were found.QED .. end of story.

Also noteworthy, is that SETI is entirely dependent on technological developments coming from other totally unrelated research ventures:

The exponential growth in semiconductor technology over the last decades has been an incredible boon to SETI experiments, allowing orders of magnitude improvements in spectral coverage. Within the next decade, we will have the ability to examine significantly larger portions of the electromagnetic spectrum, including instantaneous analysis of the entire 10 GHz of the terrestrial microwave window. In addition to radio searches, new technology will extend SETI into regions of the electromagnetic spectrum never before observed with high sensitivity (Siemion et al. 2011). Extending searches to encompass much larger classes of signals is crucial to producing robust and meaningful limits.In other words, SETI is a user of this technology .. not a developer of it.

2013-Feb-09, 04:43 AM
A good example of 99.42 % of statistics are made up on the spot.
I'll guess Earth is only that loud in that band and in ETs direction a few seconds per year, if that often. Worse ET = extraterestrials probably can't distingush the multplexed data we are transmitting from galactic noise, especially if we are using spread spectrum modulation.
I suggest we use spread spectrum modulation whenever practical to reduce the probability of a visit from ET. Neil

2013-Feb-09, 06:20 AM
Directed searches for this, stand no better chance than pure luck.

That is not a reason to not look.

It is a reason to not lose focus on the insignificance speculation plays in empirical testing.
(Which, paradoxically, is completely the opposite in the case of faith-based searches).

It is also a reason to not lose focus on local exploration as being the only way uncertainties can be systematically eliminated ... (which is totally not dependent on speculative ideas about the behaviours, or nature of ETs).