February 24, 2006
Some real (bizarre) constructive interference
Paul Kwiat’s group at UIUC is doing experiments in counterfactual computing, which use constructive interference (among other phenomena).
Kwiat explains that:
In a sense, it is the possibility that the algorithm could run which prevents the algorithm from running…
which sounds dangerously like post-modern jargon. Should we issue a Sokal alert? No, physics is just outrunning our ability to parody it (again).
Of course none of this is actually relevant to our project. Maybe we should be finding ways to use the internet for counterfactual computing…
Update: John Holbo at Crooked Timber has a somewhat more extreme reaction to this development…
Update: Wait, there’s more! Sean Carroll at Cosmic Variance explains it all in terms of salad, steak, and sleeping puppies (no, really! I told you physics was beyond parody). As a bonus he tells you all you need to know about quantum mechanics, and notes that “the rest is just some equations to make it look like science.”
Filed by Jed Harris at 11:38 am under Light
Is this really stranger than the law of relativity being, as discovered in 2003-5, based wholly on the Doppler effect? Or than Whitehead having been right about occasions of experience? Or than mathematics turning out to have no symbolic foundation? Or than C++ programs that pump out the sieve of Erasthones at compile time thanks to static templates? What is strange about chained Zeno? To those who’ve been paying attention, it’s just not strange at all. In the 19th century, John Keely was describing harmony and other musical concepts, quite relevant to wave interference patterns, as the basis of physical reality. He turns out to have been more right than those who wanted to believe Einstein and the particle theory. But it’s hardly a new belief. The link between cognition and communication and motion and Doppler was being well described by Russian scientists based on animal experiments in the 70s.
Reality is analog/wave, and therefore always allows for more than one valid digital/particle representation. Get used to it.