Tuesday, November 27, 2007

if looks could kill

a little knowledge is a dangerous thing, so the saying goes, especially in the hands of headline-hungry popular science writers, who claimed this weekend that we're killing the universe merely by looking at it:

new scientist reports a worrying new variant as the cosmologists claim that astronomers may have provided evidence that the universe may ultimately decay by observing dark energy, a mysterious anti gravity force which is thought to be speeding up the expansion of the cosmos.

the claim was sensational enough to merit an immediate debunking, and a thumping solid enough to force the theory's authors into a hasty retreat. so i needn't go into a rebuttal here.

i just want to address a pet peeve of mine regarding the ongoing abuse of the observer effect, one the most misunderstood concepts of modern science:

in science, the term observer effect refers to changes that the act of observing will make on the phenomenon being observed. for example, for us to "see" an electron, a photon must first interact with it, and this interaction will change the path of that electron. it is also theoretically possible for other, less direct means of measurement to affect the electron; even if the electron is simply put into a position where observing it is possible, without actual observation taking place, it will still (theoretically) alter its position.

(that last bit deserves translation: interaction is not dependent on the observer — or in other words, the universe will go on working without you! doh!)

to illustrate, if the observer himself set the abovementioned photon in motion with the use of say, a flashlight, then we can say the observer effect is indeed at work in this instance. however, if that photon was set in motion by ambient radiation (i.e., from the sun), then there is no observer effect and the observer is merely the fortunate recipent of the largesse of his environs. lastly, that ambient radiation will continue to interact with objects whether or not an observer is present to witness the interaction.

the idea that a person can effect something by merely observing it has been found extremely appealing to folks attracted to new age metaphysics and paranormal phenomenon, such as karma and telekinesis or telepathy. it gives them a high-sounding and sufficiently mystifying scientific principle onto which to hang what is still charitably considered pseudoscience.

this appeal is misplaced because the term "observation" as misused by paranormalists is clearly synonymous with the ordinary use of our eyes, which are not flashlights, but only passive recipients of photons. in science the term "observation" has a clearly more restrictive use (note the quotation marks enclosing the term "see" in the definition above, indicating that we are not talking about ordinary sight).

for example, for us to "see" an electron, a photon must first interact with it ...

because scientists often use the term "observation" synonymously with the term "measurement", paranormalists have been able to cleverly substitute a passive everyday experience for a far more involved, specialized and active process. but the act of "observation", especially in the realm of quantum mechanics, which operates only on the subatomic scale, means anything but a passive occurrence, and involves — like almost every scientific endeavorthe direct manipulation of the objects being measured, using specialized devices like particle accelerators:

... a more mundane observer effect can be the result of instruments that by necessity alter the state of what they measure in some manner. for instance, in electronics, ammeters and voltmeters need to be connected to the circuit, and so by their very presence affect the current or the voltage they are measuring.

so not only does ordinary passive observation by itself not affect that which is observed, any effects that are observed by any means can be traced to strictly physical causes.

so all you swamis can stop looking at me funny now.

it's not working.

No comments: