July 2nd, 2008

red dice

50 reasons (NOT) to believe in god

I'm going to deviate from my one-a-day theme, and do the next five all at once, because they are all variations on the same theme from yesterday.

#16 Most of us are born with the five senses to detect our surroundings, which we're provided with.

#17 What/who knew that had Earth been set nearer to the sun, we would burn up?

#18 What/who knew that had Earth been set any further from the sun, we would freeze up?

#19 What/who knew that had Earth been built larger or smaller, its atmosphere would be one where it would not be possible for us to breathe?

#20 What/who knew that we require the oxygen of plants, just as plants require the carbon dioxide of us?


These really are all interesting questions, except for the obvious implication in the phrasing of the last four. These are all misapplications of the Anthropic Principle. Let me address each "proof" on the facts first and then address them all as a group.

With respect to #16, I would really like to ask our dear theist just why it is that five senses is somehow ideal. There is a ton of information out there that's available about our surroundings that we simply can't experience without technology. Bees sees ultraviolent radiation that we can't see. Why not? What about infrared? Why can't we just stick out our hands (which already sense heat in a rudimentary fashion) and "see" the heat signatures of the objects around us the way that night vision does? And why can't we see in the dark as well as cats? Don't we need to defend ourselves from nighttime predators? And what about our sense of smell? Why isn't it as good as a dog's? Or what about our hearing? Why can't we do echolocation just like bats or whales? Or what about sensing magnetic fields? Birds seem to navigate by sensing the Earth's magnetic field, why can't we? Or why can't we do even better? Why do we lose the senses we do have as we get older?

I could go on like that for a while, but I trust I've made my point. The five senses we have work okay, and we get enough information to get by, but the collection of them can hardly be said to be perfect. And there is plenty out there that we can't detect. It doesn't cease to be important because it isn't obvious to us. Ultraviolent is quite important to bees because they can see it. We should not be biased by our own perspective here. If we had three, six or eight senses, we would assume that they were somehow perfect and the rest superfluous as well.

We can address #17 and #18 together. While it's true that Earth is in what astronomers refer to as a habitable zone, it's not true to say that where we are is somehow perfect, in a Goldilocks kind of way. If we were closer to the sun, we would require less carbon dioxide to stay warm. If we were farther away, we would need a little more. Humans are also perfectly capable of adapting to a range of temperature conditions, as are plants. The current temperature range is hardly "ideal" in any real way either. And since we don't know exactly what set off Venus' runaway greenhouse effect, it's not to say that Earth at that location would necessarily have done the same thing, and likewise for Mars. Earth is larger, and at the location of Mars, we would certainly have an easier time hanging onto an atmosphere.

Which brings us to #19: there is absolutely no evidence for the claim inherent in this question. The atmosphere would hardly be toxic if it were thinner, or thicker. The fact that Mars and Venus are both predominantly CO2 is no reason to think that Earth at those positions would have evolved identically. And if life had evolved on such a planet, whatever life evolved there would have evolved to survive in the conditions that were present, or they would have died off.

As for #20, plants were here before us. CO2 was here before us. Plants evolved and emitted oxygen, and only after there was enough free oxygen could animals evolve to utilize it. The balance is maintained because if the plants died off, so would we. It's a very basic dynamical system.

Having addressed these all individually, the basic problem with all of them is that the theist is putting the cart before the horse. The theist is assuming that someone had humans specifically in mind when designing the Earth and therefore set the Earth up to service our particular needs in our current configuration. This is not, however, how things really came to be. Rather, the Earth evolved into it's present configuration and life, and subsequently humans, evolved up into the environment available to us. If there were a different environment, we would have evolved differently, perhaps into something entirely unrecognizable. And frankly, even with the Earth reset to into original configuration and let the "program" rerun, there is no guarantee we would evolve again... indeed, it's highly unlikely.

In summary: the world is not suited to us... we are suited to it.
taun we

50 reasons (NOT) to believe in god

#21 The concept that life came about through sheer chance is as absurd & improbable as a tornado blowing through a junk yard, consequently assembling a Boeing 747!

This is an old, old alleged refutation of evolution, and it unfortunately rests on a gross misunderstanding of how "chance" works in this process. What would be a better analogy?

Well, suppose that tornado blew through a junk yard and just by accident, happened to put a couple pieces together that worked. What if, the next time the tornado blew through, we could preserve those pieces? And only replace them if we accidentally came up with a configuration that worked better? Now that would be more like what evolution does.

Will this take a long time? You bet. And remember, that we aren't just building a 747, we are building all kinds of things in our tornado. A watch, and a light bulb, and a chair, and all the independent little things that make up the 747, and all kinds of other stuff. We may find that eventually we get that watch to work, and that it can now be incorporated into the 747 we are building, as well as work independently. And we aren't just doing this for just a year, or even in a thousand junkyards. We are doing this for billions of years and in trillions of junkyards. When you start talking about a number with 21 zeros after it, the chances of life ending up in our current configuration don't need to be very large, even incredibly improbable, to still end up with what we've got. And when you further figure that we aren't really aiming for a Boeing 747, but only something with equivalent capabilities (i.e. an Airbus model would be an acceptable alternative), it's even more likely to end up with something acceptable.

More than this, though, this "proof" has a similar problem to it that the previous several "proofs" did as well: and that's this idea of starting out with a goal, and then trying to arrange the universe to achieve that goal. But evolution has no goal. Evolution is only going with what works. Nothing more.

For more information on the numbers game being played with the argument, read Irreligion by John Allen Paulos. As a mathematician spends a considerable amount of time with it.