I thought so!

Several years ago a friend suggested I read Rare Earth: Why Complex Life is Uncommon in the Universe. I read the book but was pretty annoyed at it. Among other things that I thought were faulty one of the claims was that a low radiation environment was required for life. I was skeptical. Sure, all life as we know it is damaged by radiation but that doesn’t mean that some life form couldn’t evolve that actually required radiation, right? Wouldn’t intelligent life from that evolutionary chain conclude the earth would be lifeless because the lack of radiation required for certain of their life processes didn’t exist?

It turns out we now have life on earth that flourish in a high radiation environment. You can thank the Chernobyl disaster for that.


9 thoughts on “I thought so!

    • That was the argument I used with my friend. He just claimed there was no beneficial levels of radiation as opposed to a beneficial range of temperatures.

  1. I’ve had similar arguments in the past regarding levels of radiation & I always point out the Oxygen is one of the harshest molecules in the universe. It destroys most metals, ruins medicines, foods, etc. Yet most of the dominant life forms here require it to exist. That may not be the case elsewhere.

    • That mechanism is different from the argument I would make. In the Radiation Hormesis hypothesis the radiation increases immunity and/or perhaps some other benefits.

      I hypothesize that a life form could exist that the hard radiation is a primary energy source. Sort of like the light from our sun is a primary energy source for plants. All life on our planet depends upon the sun(light). All life on some other planet may depend upon gamma radiation.

      • So instead of light hitting a chloroplast and providing the energy for water and CO2 to become a sugar, you have radiation striking a “radioplast” to kick some electrons into higher energy states causing a chain of reactions to cause “stuff” to get converted into sugar (or alcohol, or something like that). Possibly. But I suspect that it can’t be more than a secondary energy source, or perhaps one of several in a cell, so that when radiation falls it can still live on chemical or photosynthesis as an energy source.

  2. Good arguments…I usually just respond that to assume that we’re the only planet with life, and therefore the only “intelligence” in the whole entire universe, is the absolute height of egotistical thinking. Our forays into interstellar space has only just begun, and we’ve even given up on visiting other planetary bodies. We’re content to splash at the waterline of the interstellar zero-entry pool, stare myopically at a foreign body hundreds of light years away through crude telescopes and measure and guess, and then preen that we’re so advanced?!? Its like the 98-pound geek sitting at the high-tide line on the beach, taking off his inch-thick glasses, and exclaiming that there must be nobody else on the beach since he can’t see them, only vague blurs at close range, completely missing the butt-floss bikinis all around.

    Poor analogy, but I now have this incredible urge to go visit the beach.

  3. At least on our planet, radiation is at least one driver for mutation – assuming that natural selection may operate on some level in other environments, wouldn’t it select for organisms that better-tolerated, or perhaps thrived, on radiation?

    Also, it seems, there may have been embedded in that Rare Earth hypothesis the notion that the level of radiation in a given environment is steady state. That’s a big assumption. Stars follow a fairly predictable sequence – what may start as a low-radiation situation may well ramp up over the years, causing and selecting for mutations that are radiation-tolerant.

  4. “Why Complex Life is Uncommon in the Universe.”

    Yeah, my first thought at reading that title is; “First we’d have to establish that complex life is uncommon in the universe, which we haven’t.”

    It’s like the typical Progressive argument that starts with an unsupportable premise and then proceeds as though it were an obvious given. You’re not supposed to notice.

    We’re not even 100% sure that complex life is uncommon in our own solar system, yet. What’s with this universe talk?

    Complex life may or may not be common or uncommon, so what is the point in arguing from the position that is one or the other? The best we could do at the moment would be to say something like, “IF life is common (or uncommon) in the universe, then I propose that such and such would be the “reason” for it…” I’m not convinced that “reason” would have a lot to do with such an argument.

    Oh; I have an idea to throw out there regarding the notion that God created this whole universe, with billions of galaxies (that we can see) with billions of stars in each galaxy, all just for Mankind, all just for us here on Earth. Why would all that out there need to exist then?

    Heh– How about for the purpose of plausible deniability? I mean, if this one solar system were all that existed, then it would be a little too obvious, or certainly a bit less deniable, wouldn’t it?

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