Thursday, December 08, 2005

Science and the design hypothesis

In today's environment it's a topic every science blog has to mention, Intelligent Design.

Before we go to biology, where the battle is going on, lets look at my particular field, physics. I recently read an article at The Panda's Thumb called SETI vs ID which talks about the methods the people at SETI try to infer design. This brought up a memory of something one of my professors mentioned from when he was a grad student at MIT. This was when pulsars were first discovered. A call came in from the discoverer of pulsars about his (really his grad student's) discovery, and that they were calling it LGM-1 for little green men, thinking that it must be some alien civilization because it was sending out periodic pulses at times on the order of microseconds. My professor used this as a jumping off point to describe the technique of dimensional analysis, whereby the MIT people managed do decide in about 20 minutes that a spinning neutron star could cause the signal, but this is an example of the design hypothesis at work, and an (almost) legitimate invocation of it. Let us look more closely at it.

Why was the design hypothesis made in this case? Mostly because very exatly timed radio signals on astronomic scales occur very rarely in nature, pretty much only in pulsars (note that they do happen very often at small scales, such things as quartz and atomic clocks, but such things don't really scale up). So it was unlike anything ever seen before, but also it would seem to be something that would be useful to an intelligent life. Also note that the design hypothesis would require no changes to the known laws of physics. So why was this wrong? Simply put because it was unnecessary, it was found through calculation that spinning neutron stars could create the signal. The design hypothesis should only be used as a last resort, all else being equal the undesign hypothesis should succeed.

So let's reenter the battlefield of evolutionary biology, what lessons should we bring from this example?
  1. The design hypothesis can be legitimate
  2. It almost never is
  3. The design hypothesis should be put to extra scrutiny to meet with evidence because extraordinary claims require extraordinary evidence

Also I would like to note that ID usually invokes a form of the design hypothesis that is unscientific in that it invokes the supernatural (or at least technology so advanced as to be indistinguishable from the supernatural) to make it's claims. Anyways, ID falls down simply because it lacks evidence, and the data can be better explained using evolution, which is nice since we try to avoid the design hypothesis anyways.

Anyways, thanks for reading

1 comment:

Max said...

mmm... my first comment is an ID flame :)

actually there are many things that could be used as "the building blocks of life". RNA is thought to be possible to use as both structural and genetic portions of early replicators. Once DNA + proteins were used thpse would have pushed out the less efficient RNA life forms.

In any case, even if we don't understand the origens of life completely, that affects evolution not at all, once life begins evolutions begins to work, before then is another problem (though an interesting one, that is under current reasearch). Aboigenesis is altogether unrelated to evolution (though The Miller-Urey Experiemnt would seem to indicate that is at least feasable).

anyways, I've got to run to class so I might post something later...