Living on a planet comes with certain advantages. Gravity, for instance. The only reason hot air rises on Earth is that colder, denser air will always fall to displace it upwards. On the International Space Station everyone has to sleep next to a fan or they end up being enveloped in a bubble of their exhaled carbon dioxide (or worse).
Perhaps this won’t be a problem for life forms that evolve in microgravity, since they might evolve to keep moving around all the time, even when sleeping – kind of like how sharks do in Earth’s oceans.
But then, life forms that might evolve in microgravity are unlikely to be metabolically dependent upon either atmospheric gases or oceans, since if you are going to have an atmosphere or an ocean of any appreciable density – you kind of need something like a planet to start with. Hmm…
So, can something interesting evolve in microgravity, in the the absence of a dense medium? Well, there’s Sir Fred Hoyle’s fictional Black Cloud – where something approximately 1 AU in diameter, with the mass of Jupiter and considerably less density than water still managed to be hyper-intelligent, despite the substantial impost placed on its speed of thought. I mean, that’s eight minutes travel time just to go hmm…
Our one and only data point about how intelligence might arise organically suggests an electrochemical basis, while the hypothesized Black Cloud required an electromagnetic basis. The latter is feasible in a brain with a density considerably lower than water, but you would need to transmit thoughts at the wavelength of X-rays to effectively move them through the dense organic tissues we are familiar with on Earth. On that basis, too much thinking really could give you cancer.
So, it seems plausible that intelligent, electrochemical thinkers generally evolve on planets – but we can still keep it open for some much bigger, though perhaps slower, electromagnetic thinkers to evolve in microgravity.
And there are reasons to envy an entity that can survive long term in microgravity and can manage a slow and steady journey between stars under its own propulsion system. For us high density thinkers, there’s a time limit on just how long you can enjoy the particular gravity well you happen to have evolved in. Habitable zones don’t stay habitable forever. Firstly, gravity wells have a habit of attracting devastating meteor or comet impacts – and for the longer term, your star is eventually going to die.
Probably, the smart thing to do first is to build a planetary defense system – noting the current population of dinosaurs on Earth is exactly zero. In the longer term, you would need to make a run for it – ideally taking as much of the surviving ecosystem with you as you can. You never know when some giant energy-sucking alien artifact is going to show up, wanting to talk to a whale.
Anyhow, it’s great that we are now in orbit on a regular basis. It’s a really good start.
This is an interesting article about a subject I’ve often considered. If you break down the fundamental processes by which human thought is believed to take place many will tell you it’s just a series of chemical reactions. Why then aren’t other equally intricate chemical reactions considered to be the basis for other forms of intelligent though?
Well written article.
Its interesting to note that humans are a symbiote of earths biota and human cells. (theres a great article about this on NewScientist atm: I, virus: Why you’re only half human )
So when a single human goes to space or another planet, some 300 distinct species of earth biota also travel with them.
I think given the right conditions in space. (adapting earth biota to symbiotic equilibrium in zero G) Rather then tin cans as spaceships. Could be the start of some interesting science and evolutionary catharsis.
We really should try making a Biome in space. Perhaps a large body of water with an selective ecosystem of microscopic alge and fauna that are left to (adapt) and be adapted to zero gravity.
We should get some squid up there as well. I propose that the (octopus) body design would be the most suitable to life in zero gravity. 🙂
Damian
So in space they have to sleep next to a fan… looks like the South Korean space program has received a major set back.
This topic needs a new title and possibly a better intro. My reaction halfway through the article was: WTF is this about?
The known universe looks positively organic when viewed through the right eyepiece? But why limit the speed of thought to that of light? Super-luminescence anyone? Or how about a quantum entanglement between the seventh and the eleventh dimensions?
“You never know when some giant energy-sucking alien artifact is going to show up”
Like the giant space amoeba from Star Trek? http://en.wikipedia.org/wiki/The_Immunity_Syndrome_%28Star_Trek:_The_Original_Series%29
OT related info: According to wiki “This episode makes one of the earliest references to black holes, a term that was coined by theoretical physicist John Wheeler, being first used in his public lecture Our Universe: the Known and Unknown on 29 December 1967.” The show originally aired Jan 19, 1968, less than a month after the lecture!
Damian – your suggestion reminded me of a short story I read years ago, about a gene-engineered intelligent squid that had been trained to pilot a space probe with just enough of a biosystem to keep her alive to the end of the mission. It’s a cautionary tale and at the same time, a triumphant one.
http://www.vondanmcintyre.com/squids/Baxter-Sheena5.html
The Star Trek reference is to the 4th movie (The Voyage Home) – but the connection to Immunity Syndrome is a good call. Thanks for reading.
I’ll have to agree with HAU, the article is a bit rambling.
A couple of nitpicks:
– Most Earth life forms don’t sleep. Sleep evolved, for still unknown reasons, exclusively in animals with nervous systems. Even nematodes, with just a handful of nervous cells, has been claimed to have a quiescent state.
But lower animals, plants, and of course the wast amount of prokaryote species have nothing like it. (Though of course they have biorhythms as well.)
Seems to me that having to move around all the time would make evolving sleep both unnecessary and difficult.
– Dinosaurs made it just fine to today. “in 1951 “Fisher, a British ornithologist, estimated there are more than 100 billion individual wild birds in the world,”” [Ask a Scientist. As a matter of fact, the number of bird species outnumber mammals 2:1 (~ 9 700 species against ~ 4 300). Not only are birds known to be surviving descendants of dinosaurs, cladistically they are (and were) dinosaurs.
Life has survived many mass extinctions until today, so is really robust. In all probability our species will go extinct, and/or possibly evolve into new species, before we have a chance to be wiped out by the odd event. 99.9 % of all species have gone extinct, many or most outside mass extinctions.
Oh, and maybe the last point is more than a nitpick, come to think of it. It seems to this layman that it has become really popular among biologists to refer to “non-avian dinosaurs”.
Personally, I enjoyed this article a lot. Makes a nice change to do a little musing with a writer. The HEADLINE-TEASER-FACTS-END news model can get a little dry sometimes. By the way, that’s not a UT complaint. It’s just… news.
You are quite right about the dinosaurs and the birds. You are also right about the resilience of life after an impact.
But perhaps the foreknowledge of risk negates the statistical inevitability of our doom. While the birds don’t seem to have learned anything from Chicxulub, we don’t have to follow their example.
Thanks ‘khyron’ for the link.
http://www.vondanmcintyre.com/squids/Baxter-Sheena5.html
Thats a great story. Stephen Baxter is one of my favorite authors. While the story is a parable of sorts, the idea behind a Biome in space that is Aquatic is a very interesting one to me. Take a Body of liquid water in space, pressurize it and you also get an atmosphere. We happen to have evolved in the GAS form of water. But when thinking about liquids in space, you can have water in all 4 states, Solid, Liquid, Gas and Plasma.
Finding a (workable) balance between these states is the key to a self sustaining Biome.
Thoroughly sprinkled with life of course.
Stephen Baxters story is a great anagram for us. IF we were up there living, and depending on our own ingenuity to better our living conditions humans would find the solutions.
Damian
Sleep has evolved as a period of rest and repair for most tissue in an animals body. Even parts of your brain require rest/repair time. Do you ever wonder why you have no sense of logic in your dreams?
Without a down time for repairing itself, a species isn’t going to evolve to be too complex. Species without this have a very short lifespan… typically averaging about 45-90 days. Some much shorter, some a bit longer.
These things might be possible only if there is some force, maybe gravity, which keeps the cloud within some volume, and some other process which keeps it from collapsing to far.
In such loose speculations, maybe dark matter clouds or galactic halos are some form of life. Not that I think this is at all likely, but maybe it is not impossible.
LC