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Are We Alone In the Universe? Not Likely, According To Math (cnet.com)
An anonymous reader writes: An equation, which calculates the probability of the evolution of other technological civilizations, has found that it's wildly unlikely we're the only time advanced society in the universe. Adam Frank from the University of Rochester and Woodruff Sullivan from the University of Washington base their new equation on the Drake equation, used for calculating the probability of extraterrestrial civilisation, written by astronomer and astrophysicist Frank Drake in 1961. The scientists also take into account Kepler, which suggests that one in five stars have planets in the habitable zone. Frank and Sullivan calculated that human civilisation is only unique if the odds of a civilisation developing on a habitable planet are less than one in 10 billion trillion. "One in 10 billion trillion is incredibly small. To me, this implies that other intelligent, technology producing species very likely have evolved before us," Frank said. Frank said: "Of course, we have no idea how likely it is that an intelligent technological species will evolve on a given habitable planet. But using our method we can tell exactly how low that probability would have to be for us to be the ONLY civilization the Universe has produced. We call that the pessimism line. If the actual probability is greater than the pessimism line, then a technological species and civilization has likely happened before."
One may argue that we are outside the norm for life on Earth; although i'd argue that there are enough other species that show some degree of sentience; members of genus Corvus, the other great apes, cetaceans, and even elephants, that I'd argue that we are more the most extreme example of a phenomenon found in several lineages, in particular in mammals (though genus Corvus are birds). The differences are more degree. Obviously that matters, because there are no chimps building skyscrapers or writing posts on Slashdot, but it also means that our cognitive abilities are firmly entrenched in evolutionary processes.
There's no reason to imagine that if Earth alone can produce two or three lineages of animals capable of some degree of sentience that there aren't millions of worlds in the vastness of the Universe that haven't produced similar organisms.
The world's burning. Moped Jesus spotted on I50. Details at 11.
It's also wildly unlikely that I got these numbers out of /dev/random (base64 encoded):
a2yIbR 06VMDu f3WkRu mCTMwT S/1sTr 5MC+JF VIAYQo El1/dj WPL+JL HNUZSZ 0yTnsd UDstFc SwIQcZRCTZ MXVO1o cqvrbG vn1TF4 qKhdL4 mBsdiI BxZ4Sx 9P+Pcj zto/bY w9+afI +JNUfu XpETQK 2k7dWFBSqC phnTUe y9cRsQ LfPeAX +sUA+n IB5xD7 fnJlF8 SwfMyE K3wuJb PfCKSc yjDkBk 8zXqnr AbDcwdVvMf GofKC4 fnbv6x j81Wyp ip3Zym Dva50x kRAFHB Z2PD+r e6PewB Jwg2NW rrSRf8 vKyRRe 1d4nTKRIYe NhFD2x mcudTw ybhJX/ BenFJD m+Z4JK xk86DT v71laB wywDf7 xhGVBh dLeILX pPDpoH OJV9jsziLY r6FpU1 5U0/0Q xRlv72 XYCbeY cUKvrS pkTgvp NqOhQi KBRxEc +tpS6D 31XcM/ skM9s1 t+gkTTQYpw FT6Q37 r5pdhq P/bENf Nfq4wA p17TnV +Iqz1Q FlmocM YQtp3l N7aopC t//jtL OkbO9r OdUMwq/Yak aySm9L U5IwSJ Lca1gs kUAgyh GNk099 eu9GgC d10kWL EMoX6D lA6bdY 7AYESp nA7hT6 ChZOraHk3+ a7sZDT GElTZI 4sSflA 1ccbmi B9V4HR BieFj4 G0F8qg Gy7ugw BP4DQ0 G8IyJ8 OZprIx 029GlmXibT rWQMgk 3D/EsS 9Jqu4m kcNDdB jij85G HXU/dr uG9eXD 73FtnX MoXBsq cjccXR oDhZxN DnubE+7vhS xR/Gxg L/FmN7 Q/hilg SBiZNw UeMz5M 1CLLag Mp+Lae TNRsbk YryRuv IFck/+ KO2yH8 y9GqQyK90c WoCTQF Yb04UQ OmPHCt ZELs2C HZaE/x 8uaUoO 7tBA0I Um57tZ RZ1gVK pSD4zN hRIPyJ I6efcIC1an JkQnuV 1vdtXr QDzXv3 8gLeK1 yGiBga KOJOBr aIjeBF S39M4L G3sZ2L wGutBe fVyWF2 Z7UOzh2yny IUQ/bS gt0fMM V1+GWE r1f+zh f5QKnL rDMIPi ENg10n SsRQ+E gl5ims 0gEvxc ZuNTgi vN9v6s1EgL wEAMJW IN4dJO fjanbL lro2fS CI4dwG UWqGV2 SOXH6o 8Gs0rM KaiNkb ny4GXQ ZzcBq2 QaJYgrnHM3 I4EhgD VEpPoU djY9hb kGuSDt Pth+9R xqqxxy 6NUlDk sHUiXh 8lq+B0 QLPVNt SaF6Wc BICSPupiCP n8QoEY ZKKK1X qN5qoB qkOtTt 77bbiH xqUC80 eOPdS0 RBsMNL e/AlKL NUmspv KjDzba bnPZtF9BH0 I9yTXr YjMn5K hSRjKD qy+SoL E8xT8Z ZgY1rA ==
The chance was in face 1 in 2^8000, or if you prefer 1 in 1.7E+2048. We could run this universe over many bilions of times and no one would get those numbers again, so treasure them!
So, as you can tell that event above is very unlikely. However, the chance of me getting 1000 numbers out of /dev/random is very close to 1. I'd expect it to fail very much under 1 in a billion times.
In other words, just because a specific event is unlikely (me getting those digits/this type of life evolving) doesn't mean that getting AN event from the class (e.g. some digits from /dev/random or some type of life evolving) is nearly so unlikely.
SJW n. One who posts facts.
Who are WE to determine that life has to be like US.
Well, obviously that's silly, however...
Why assume life out there would be carbon based, breath, and require water?
Because we don't know any better. It's likely that carbon is important. There are several reasons for this. First, it forms stable, complex molecules over a wide range of temperatures. Silicon does to some extent, though the upper limit on the temperature is much lower. Boron also formes long complex molecules readily. There might be options with some metals too.
However abundance is also key. Boron is not formed in stellar nucleosynthesis un significant quantities unlike silicon and carbon, so it is very rare. This is a downside for life, since some non living process would have to concentrate it first.
The next problem is solvents. Likely solvents are hydrocarbons, ammonia, water, sulphuric acid and possibly liquid or supercritical gasses like nitrogen or hydrogen. We know those do exist out there in space. More exotic solvents may well depend on a large quantities of large molecules being formed (unlikely) or concentration of rare elements (also unlikely).
Those solvents will affect what chemistries are possible and what the base molecules are.
Now, the thing with carbon is that it comes in a variety of forms ready made. There's plenty of methane around the solar system, and the interaction with UV makes various other molecules too. However, silicon just doesn't seem to do that which puts it at a disadvantage. Likewise, CO2 is a nice gas which can spread itself around, unlike SiO2 which is rather more rooted to the ground.
So, while there might be non carbon forms of life, the other elements are at a severe disadvantage.
As for solvents, yeah I can see other ones could work. There's a few choices.
SJW n. One who posts facts.
Let me amend that. There are not a lot of chimps posting on /.
No, mostly they moderate.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"