Earth's Period of Habitability Is Nearly Over

xp65 writes "Scientists at this year's XXVIIth General Assembly of the International Astronomical Union in Rio de Janeiro, Brazil agree that we do not yet know how ubiquitous or how fragile life is, but that: 'The Earth's period of habitability is nearly over on a cosmological timescale. In a half to one billion years the Sun will start to be too luminous and warm for water to exist in liquid form on Earth, leading to a runaway greenhouse effect in less than 2 billion years.' Other surprising claims from this conference: that the Sun may not be the ideal kind of star to nurture life, and that the Earth may not be the ideal size."

Comments

Re:So we still have...

[superwiz]

The idea that technological advance is as inevitable as a law of nature is a fallacy. It usually relies on us getting lucky because somewhere an enabling technology or knowledge was discovered. The only reason Europe emerged from the dark ages is that crusades brought back the Arabic numbers, for example. Gauss once blamed Euclid's not introducing digital numbers and sticking with base-60 numbers of the Greeks for all of the Dark Ages. Roman numerals do not make multiplication table manageable by any accounts, either. Basically, once the enabling technology is stumbled upon, you get a bunch of people in different parts of the world exploring all of its implications. Until then, you pretty much hit stagnation point sooner or later. American Indians never discovered a wheel, by the way. Social forces ALWAYS play catch up with technological state of humanity. As long as we remain the same specie, that is. Moore's Law is already at its limit. The next step is two-prong: parallelism and hybrid (analog-digital) chips.

Possible answer to the Fermi paradox

[damburger]

From TFA:

âoeThe Sun does not seem like the perfect star for a system where life might arise. Although it is hard to argue with the Sunâ(TM)s âsuccessâ(TM) as it so far is the only star known to host a planet with life, our studies indicate that the ideal stars to support planets suitable for life for tens of billions of years may be a smaller slower burning âorange dwarfâ(TM) with a longer lifetime than the Sun â about 20-40 billion years. These stars, also called K stars, are stable stars with a habitable zone that remains in the same place for tens of billions of years. They are 10 times more numerous than the Sun, and may provide the best potential habitat for life in the long runâ. He continues: âoeOn the more speculative side we have also found indications that planets like Earth are also not necessarily the best suited for life to thrive. Planets two to three times more massive than the Earth, with a higher gravity, can retain the atmosphere better. They may have a larger liquid iron core giving a stronger magnetic field that protects against the early onslaught of cosmic rays. Furthermore, a larger planet cools more slowly and maintains its magnetic protection. This kind of planet may be more likely to harbour life. I would not trade though â you canâ(TM)t argue with successâ.

Maybe nobody has visited us because, from interstellar distances, Earth doesn't look like a place that could harbour life?

Re:Sooner than that...

[Bakkster]

Religon making sense, doesn't that destroy the need for faith?

Not necessarily. An airplane's principle of flight makes sense (air pressure difference provides lift), but you still need to have faith that it your specific plane will be fine and that the pilot is good. It also doesn't prevent people from not putting their faith in airplanes, regardless of them being an incredibly safe form of travel.

I'd liken religious faith to quantum mechanics. Quantum makes sense, but not according to our normal methods of understanding. It has different rules very different from classical mechanics (secular worldviews), but taken as a whole is consistent.

Re:Dang! Things were just getting fun

[Trails]

I'm in the same mindset as you.

Up here in Canada, the Green Party used to have a wiki for their policy that intended to foster debate. On one of their pages, they decried fission. I posted a comment (not an edit, a comment), asking, basically that if the looming problem is global warming, and the waste products of nuclear fission are manageable, how is replacing coal plants with nuclear plants a bad thing. My comment was deleted.

Kinda stunning.

There are elements of the Green movement that are irrational, all you have to say is "we must/mustn't do X because it's good/bad for the environment", I consider myself a Green, and I find this behaviour abhorrent. While GP paints with too broad a stroke, imo, the colour is just right.

Re:Dang! Things were just getting fun

[Abjifyicious]

Do you even know how much waste you're talking about? Imagine a cylinder 10mm in diameter. A 5mm slice of that cylinder will supply your energy needs for a year.

Do *you* even know how much waste *you* are talking about? The US alone has accumulated over 60,000 metric tons of nuclear waste from fission reactors. Your figure of a 5mm by 10mm cylinder per year of waste is ridiculous.

Yes, of course coal releases more radioactive material into the atmosphere. Since we have to store the nuclear waste, *none* of it ends up in the atmosphere.

Now I'm not saying coal is good, or that nuclear isn't necessarily worth it...but if you want to advocate nuclear power, then stop damaging its credibility with arguments like these.

Re:Dang! Things were just getting fun

[RabidMoose]

I don't understand why you seem to think having radioactivity released into the atmosphere is preferable to having it stored safely at a power plant.

As for waste, a large coal power plant (under full load) requires about 10,000 tons of coal per day. This doesn't include the energy needed to transport the coal to the plant (via a big ass train).

And that nuclear "waste" that we've got 60,000 metric tons of? Were it legal to actually build breeder reactors, we could use it to generate more power, and be left with hardly any radioactive waste in the end.