
The Connection Between Color and the Existence of Life - markgoldman
http://mitchkirby.com/2015/05/04/color-and-existence-of-life/
======
tehchromic
The article underscore the point that the complexities of our planet are
intricate, and particular.

Nowadays people seem to think that life must be common throughout the
universe, given the number of stars and planets, and etc. It seems to me that
the opposite could be the case, that life is extraordinarily rare.

As far as I know, we don't really know the likelihood of life emerging in our
own planetary conditions: given a billion earth like planets with roughly
equivalent atomic makeup, distance from sun, etc (assuming these are common,
which fact we don't know either), how often will life emerge? We can guess and
say "all the time!", but it could be an infinitesimal small amount.

Even moreso for different conditions than earth. Commonly people say "given a
liquid like water, and certain other factors", but we don't know if life will
emerge in any other conditions except our own. We have no proof whatsoever.

We also don't know how likely it is that life reaches our own point, of being
capable of pondering life around other stars, or capable of imagining travel
to them. There may be many, many extremely low probability events that must
occur, in the billions of years between life's genesis and our own existence.

In fact, there's a good likelihood that our own dreams of interstellar travel
will end in our extinction prior to our ever making the attempt. If that
happens, it will prove my point.

To me this general optimism towards life on other planets is vaguely
anthrocentric, like the belief that god is an old man, or that the universe
revolves around the sun.

As such it results in a tendency to underestimate our own fragility, and to
pay appropriate attention to the challenges of maintaining our own continued
existence on earth.

~~~
smeyer
I saw an interesting talk by Professor Richard Wrangham (disclosure: a
personal friend) of the Harvard Human Evolutionary Biology department that
addressed part of this once. He pointed out the open question of whether
substantial intelligence was an expected likely fallout of life evolving or a
rare occurrence that happened via a bunch of low probability events. He
concluded that it was more likely to be a reasonably common occurrence, based
on claiming that the intelligence of the most intelligent creature on Earth
through the fossil record has increased monotonically, even though they have
not shared a common evolutionary line. Meaning that at any given time the most
intelligent organism might be a primate or fish or whatever on distinct
evolutionary paths, but that the peak intelligence across the planet keeps
increasing.

~~~
lumpypua
Ehh, intelligence/nervous systems aren't the hard part. It's development of
the eukaryotic cell that's extremely chance.

Microbial life in no way entails higher life. It's only by the insanely chance
event of the eurkaryotic cell emerging that sophisticated multicellular life
became possible on earth. Even if life is common in the universe,
sophisticated multicellular life is extremely rare.

The selective pressures on bacterial life favors small size and rapid
reproduction, jettisoning any unnecessary genetic material.

Mitochondrial ancestors relieved those pressures in a couple ways. Once the
eukaryotic cell developed, multicellularity has evolved several times. All the
cool things (multicellularity, eyes, flight) have evolved independently a
bunch of times, and the eukaryote has happened only fucking once. Here's a
longer explanation:

[http://ronbarak.tumblr.com/post/25996121029/life-is-it-
inevi...](http://ronbarak.tumblr.com/post/25996121029/life-is-it-inevitable-
or-just-a-fluke-by-nick)

~~~
hyperpallium
Interesting! Another argument is that less complex life evolves more slowly -
and the eukaryotic cell developed at about the expected time. [massive
speculation of course but interesting]

[http://www.technologyreview.com/view/513781/moores-law-
and-t...](http://www.technologyreview.com/view/513781/moores-law-and-the-
origin-of-life/)

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lordnacho
I love the writing, it's very direct.

He may have just killed life on other planets. Or at least a fair proportion
of it, if you have to have a star that outputs mainly in the water-
transparent, ideal-for-photosynthesis spectrum.

Of course these evolutionary things seem to somehow fix themselves. Some other
chemical might be a more suited to light from a different star, or something
in the water may change its spectrum. Or simply a brighter/dimmer star might
jiggle things.

~~~
juandopazo
> He may have just killed life on other planets

Not so much. Here's a different article posted to HN recently: "Can life exist
on a planet without a star?", [http://aeon.co/magazine/science/can-life-exist-
on-a-planet-w...](http://aeon.co/magazine/science/can-life-exist-on-a-planet-
without-a-star/)

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darkerside
There's really just one pair of coincidences: the wavelength of light most
able to pass through water is that emitted by our sun. All the other
statements are effected by that. And if the sun emitted another wavelength of
light, perhaps another stable liquid would have emerged as the building block
for life. I think what this really infers is that life on other planets could
look more different from ours than we'd ever expect.

~~~
bweitzman
I was thinking the exact same thing. I would add that there is one more
coincidence which is that the Earth is covered in water.

~~~
bjt
One more coincidence: Unlike most substances, solid water (ice) floats rather
than sinking. If this were not true, many bodies of water would be solid
through most of their depth.

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MarcScott
These types of article always lead me to start pondering the strong and weak
anthropic principles again. At which point I have to give up on getting any
more work done as my mind goes chasing itself down the rabbit hole.

~~~
dzhiurgis
Which raises another interesting question - how does brain deal with infinite
loops?

~~~
qbrass
You either quit from boredom, something more important comes along, someone
intervenes, or you die from not eating or sleeping.

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mrfusion
I read somewhere, that at some point long in the past, the cosmic background
radiation was at a point where all points in the universe were 70 degrees (F).
And this is when life would have had the most likely chance to get started.

What do you guys think of this idea?

Edit: I meant to post this as a response to tehchromic's comment:
[https://news.ycombinator.com/item?id=9493736](https://news.ycombinator.com/item?id=9493736)
(sorry)

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corbet
So I hate to whine, but how is it that somebody writing about color puts out
gray-on-white text that's so hard to read? I'd expect them to know better...?

