Sources: COSMIC COINCIDENCES by Gribben and Rees and Barrow and Tipler's THE COSMIC ANTHROPIC PRINCIPLE. (Chapter 6.3 in PRINCIPLE for the formula about the mass of the universe and the Big Bang's expansion.) Of course, if there are billions of galaxies, that increases the chance of intelligent life arising. I am specifically NOT implying there is anything special or favored about Earth, in this discussion.
Abraham Loeb of Harvard has recently suggested that the brief million-year period when the whole universe is a “habitable zone” might be an objection to the anthropic principle. But only a few isolated freakish pockets, nearest to the first supernovas MIGHT have enough of the heavier elements to create planets and/or complex life. And such life would freeze to death as the universe grew colder and colder, and we believe the first generation of stars were giant and very brief. Doesn't sound very promising. Jack O'Malley-James at the University of St. Andrews, UK, voiced several objections. (You can read more about it here.) Considering most experts consider that the earliest stars probably formed around the time the universe was 100 million years (see “The First Stars of the Universe” )….which if true, would mean NO higher elements at this time…well, it depends on your opinion on whether hydrogen and helium by themselves could make a working biochemistry. I personally rate it as pretty low.
However, mental note: ultra-old alien races (Guardians of the Universe, the Watchers, that sort of crowd) probably grew up in metal-poor worlds, and would probably poison themselves eating earthly foods, with trace elements of iron and other metals unlikely to be on their home planet. I bet there's a good science-fiction story in that, somewhere…
Well, that presupposes that creating intelligent life is the ONLY purpose to the cosmos---which might be a little sentiocentric (to coin a term) on our part. To say that one of the universe's aims is to create sentient life is far different from saying its the only purpose. To use an analogy I used in a later strip, an intelligent book in a library might think the entire house was made for it---never dreaming of kitchens, bathrooms, entertaintment centers, bedrooms, etc. Maybe the Creator likes the stark places too---the way we can enjoy the view on a desert.
I'm not sure that actually answered the question. Okay, so we *have* to have a universe this big and old. But if you're a creator setting the initial conditions to encourage life, why not stack the deck so we end up with a lot *more* life in all this space we had to have? Why not stack the rules to encourage a habitable planet in the goldilocks zone of every second solar system? (Incidentally, will the next phase of stellar evolution - 4th generation stars - be more or less well suited for life?)
I am enjoying your lecture series, as well as the new version of Cosmos that is on National Geographic channel, hosted by Neil Degrass Tyson. They talked about life last time. The original Cosmos, by Carl Sagan, is also an excellent source, but we have learned a lot in the 30+ years since then, thus needing new material.
alschroeder at 6:31AM, March 25, 2015
Well, that presupposes that creating intelligent life is the ONLY purpose to the cosmos---which might be a little sentiocentric (to coin a term) on our part. To say that one of the universe's aims is to create sentient life is far different from saying its the only purpose. To use an analogy I used in a later strip, an intelligent book in a library might think the entire house was made for it---never dreaming of kitchens, bathrooms, entertaintment centers, bedrooms, etc. Maybe the Creator likes the stark places too---the way we can enjoy the view on a desert.
irrevenant at 6:24AM, Sept. 16, 2014
I'm not sure that actually answered the question. Okay, so we *have* to have a universe this big and old. But if you're a creator setting the initial conditions to encourage life, why not stack the deck so we end up with a lot *more* life in all this space we had to have? Why not stack the rules to encourage a habitable planet in the goldilocks zone of every second solar system? (Incidentally, will the next phase of stellar evolution - 4th generation stars - be more or less well suited for life?)
alschroeder at 4:56AM, May 4, 2014
Thanks! And yes, we need more shows like Cosmos.
Nutster at 9:29AM, March 23, 2014
I am enjoying your lecture series, as well as the new version of Cosmos that is on National Geographic channel, hosted by Neil Degrass Tyson. They talked about life last time. The original Cosmos, by Carl Sagan, is also an excellent source, but we have learned a lot in the 30+ years since then, thus needing new material.