[plt-scheme] Re: threads and multicores

I started teaching a simple implementation of uniprocessor threads 
(adapted from Reppy) in class today, and a student asked afterwards: "If 
I use MzScheme threads, can I get computations to run on different cores 
in my dual-core processor?" I said that I didn't know but that the 
answer was almost certainly no. Can I get a definitive ruling? Assuming 
my answer is correct, does anyone know how something like this can be 
accomplished? He's running Windows and Linux, but I'd be interested in 
the answer for OS X as well. Many thanks. --PR