When the Earth Was Purple

Ollabelle writes "It's always been a bit of a mystery why plants absorb red and blue light, reflecting green, when the sun emits the peak energy of the visible spectrum in the green. A new theory offers one possible answer: that the first chlorophyll-utilizing microbes evolved to exploit the red-and-blue light that older green-absorbing microbes didn't use, eventually out-competing them through greater efficiency and the rise of oxygen."

Re:Plants on other planets

[smilindog2000]

I agree. I sometimes wonder if there could even be upside-down life under us, at the interface of liquid vs solid rock. What would such life forms think the universe was like? Too bad there's no such evidence in lava-rock :-)

Re:Plants on other planets

[rucs_hack]

I can't understand people who think that to find life on other planets we have to look for conditions similar to Earth. All of the hubbub over liquid water seems so silly to me. We have *no idea* what life on other planets might be like. I think that the only thing to look for is patterns which we don't believe could occur in nature, suggesting that the anti-entropy force of life might be present.

That idea comes from the time before we started realising that the nutty Gia concept (of the earth as a living entity) was actually a hypothesis with more than a little proof to back it up. I'd go so far as to say it's a theory.

Thing is, no matter how far down we drill, we still find life, and no matter how cold or hot or dangerous (to us) an environ we find, there is always life there.

It's taken a long time for this realisation to permeate through the wider scientific community, and it's a long way from becoming accepted fact for the general public.

Anyway, I'm kind of a skeptic already, I don't think that looking for life outside our galaxy is particularly interesting or useful anyway, considering that the nearest life would be millions of years away by interstellar travel. Even if it's out there, we'll never meet it or communicate with it.

Given how many planets exist in our galaxy that are already inconceivably far away, including this new wet planet just 20 light years away (or 4 billion years travel time away at current technology levels that are capable of carrying people), you're right, inter galactic travel is something we shouldn't waste time thinking about.

Even if we did manage to find a way to do it, we could do little more then explore the minutest fraction of another galaxy. It would be pointless for all but a minority of pioneers willing to take the risk.

The problem with travel methods that let you go huge distances (wormholes, whatever, jolly fast stuff anyhow) is that they miss all the stuff between you and your destination. That is not the way true exploration works, likely we'd miss lots of interesting things.

Re:Plants on other planets

[rackrent]

It would be silly to exclude conditions not similar to Earth alltogether, but it is definitely reasonable to focus on conditions that are similar

While I agree it's arrogant presumption to assume that all "life" must rely on liquid water and similar to life on earth...it's all that we know about and hence, all we have the skills on which to focus. So yes, I agree. We have a decent set of tools to look for life forms that resemble ours, and that's all we have in our toolbox at present. It's natural to continue in that vein until we discover more tools that scientists can use.

Re:Plants on other planets

[Bryan Ischo]

I think you're making my point for me. Why does life have to based on processes similar to our own, using chemicals similar to our own, at temperatures similar to Earth? Why can't some substance that is gaseous in Earth conditions be liquid in a colder planet's conditions, and combined with other substances which have different properties than they would on Earth under that planet's conditions, be able to support chemical structures and reactions of a different kind of life?

Sure, at Earth's temperatures and atmospheric pressures, along with who knows how many other Earth-specific variables, water works great for what it does. But why can't some other molecule in vastly different conditions serve the same purpose elsewhere?

Note that I have no idea what such a molecule might be or how it might work; but I don't think that Earth conditions are so unique that they'd be the only way for life to work.

Re:Plants on other planets

[Rob Kaper]

Sci-fi is a bit broader than just Star Trek, although it is true that for obvious purposes humanoids are the primary choice of alien lifeform in most productions. Maybe that's one reason I liked Farscape so much, compared to other shows it definitely had a high amount of non-humanoid species.

Re:Plants on other planets

[mshurpik]

>This process of atmosphere glows is responsible for the massive bloom of life in the arctic regions of the earth.

Lol?

>The Temperate Latitudes....grows the most plant life.

Lol! Ever heard of Brazil?

I *pray* you're a troll, but somehow, I think you're a space scientist.

Re:Plants on other planets

[at_18]

Your idea of looking for non-natural patterns is interesting but note that it would very much limit search results to life so intelligent that like ourselves we would consider it above natural.

Non-natural patters wouldn't be some grid-shaped city. The basic non-natural pattern you can get is chemical non-equilibrium: if let alone, all the Earth oxygen would combine with some rocks and disappear. The presence of oxygen in the Earth atmosphere is a condition far from chemical equilibrium, and inequivocable proof that *something* keeps throwing the chemical balance out.

Re:Still fighting old battles

[maxume]

If you butchered your own meat once in a while, you would have an idea of what a bone was supposed to look like. If you then came across a really, really, big bone, you would construct a creature to match it in your mind. Isotopic dating continues to hold up well against the imaginations of historic humans.

Re:Plants on other planets

[Oligonicella]

"...that the nutty Gia concept (of the earth as a living entity) was actually a hypothesis with more than a little proof to back it up."

It's the 'acting like a single organism' thing that people don't grab. Me either. I just don't find that more than a little proof. Or any, for that matter. Kindly cite.

Re:Plants on other planets

[Atzanteol]

I can't understand people who think that to find life on other planets we have to look for conditions similar to Earth.

I don't think it's that difficult to understand. After all, we *know* that an "Earth-like planet" can sustain life (we have one great example). Why not look for similar planets to see if they do as well? As far as we know it's our best bet. There are a lot of planets to be found, you need to narrow the search somehow...

Re:Plants on other planets

[number1scatterbrain]

Hey, have you read Thomas Gold's book, THE DEEP BIOSPHERE? He believed that there are micro-organisms; just as you've described, living all through the Earth's crust, that excrete hydrocarbons and thus are the source of natural gas and petroleum. Thus there never was or will be "peak oil"; we'll never run out of "fossil" fuels because they're always being replenished.

Re:Plants on other planets

[MobyDisk]

They may become intelligent, that doesn't make them alive.

Trust me dude, if I find a planet of intelligent robots out there, nobody is going to be like "meh, they aren't alive, no sense in talking to them" :-) Besides, they might think the same thing about us. [netfunny.com]

And concentrations of those elements are so low in the universe, that they'd need to be mined by other life forms first.

Good point, they are all higher-up on the periodic table. Sounds like that makes a really good search criteria then.

Re:Still fighting old battles

[teknopagan]

Trying to combine the two (creation of a simple state that eventually evolved into a complex state) only places limits on God based on our human perceptions and expectations.

How do you figure that? Look around at the rest of nature. Everything changes, constantly - everything from a copse of trees to the Sahara Desert will change size, shape and local climate, albeit quite slowly. When an organism's environment changes, the organism must change with it, leave, or die out.

I don't understand why so many people insist that creationism and evolution are mutually exclusive. Who's to say that Deity didn't create everything in such a way that it would change over time? That doesn't mean that creation is imperfect (which appears to be creationists' biggest problem with evolution). It just means that everything is functioning as intended by the creator. I would think that in a system where the environment is able to change, an intelligent designer would in fact make it so the organisms within that system are able to adapt with those changes.

Gee, that was tough.

There is a logical reason, captain

[LunaticTippy]

They're filming these on a studio lot. There are tons of idle cowboy, nazi, ancient greek, etc. costumes and sets available. It's an obvious cost-saving move. Not to mention it taxes the writer's brain a lot less to rip off these plotlines.

That's part of why I loved Star Trek. Where else could you see all the different genre prope in the same series?

Color theory 101

[Pfhorrest]

Red and green aren't complementary colors in the light spectrum, they're both primary colors.

Red and green aren't complementary colors *period*. The Red-Yellow-Blue spectrum still taught to children and art students is simply incorrect, and the mixing of different ratios of "complementary" colors to get black is just a hack atop a poorly designed system. (And I say this as someone with an art degree, so don't think I'm bashing on art students here).

The additive primaries ("in the light spectrum" as you said) are red, green, and blue.

The subtractive primaries (as useful in inks and other pigments) are cyan, magenta, and yellow. This is what they ought to use in art classes.

The additive secondaries are the subtractive primaries, and vice versa; the two spectra are complementary. (As an additive primary is light of a frequency which stimulates only one of the cone types in the human eye, and a subtractive primary is something which absorbs only one such frequency range and reflects the rest).

Thus, the complement of red is not green, but cyan, which is a sort of blue-green. Interestingly enough, some of the earliest and most prevalent photosynthetic life forms were the blue-green algae, also known as cyanobacteria.