Warp wrote:
 >   These "quants" behave oddly. Sometimes they behave like particles,
 > sometimes they behave like waves, and sometimes they behave like both
 > at the same time.

Actually, you might be confused because you're not being precise enough.

The way I think you want to think about it is this:

"Sometimes they behave like particles" means "in some experiments, we 
get results whose mathematical formulation is isomorphic to the 
whatever-they-ares being particles."

"Sometimes they behave like waves" means "in other experiments, we get 
results whose mathematical formulation is isomorphic to the the behavior 
of waves."

In particular, the times you see "behavior like waves" is when you stop 
*measuring* "does it behave like a particle?"  The times you see 
"behavior like a particle" is when you stop *measuring* whether it 
behaves like waves. But in each case, you're explicitly excluding some 
of the behavior and not too unsurprisingly seeing the other behavior.

In other words, when you do the math, sometimes the results you get for 
electrons are the same results as those you get for waves. That doesn't 
mean electrons *are* waves, any more than it means that light behaving 
like a wave needs a medium to "wave" in order to travel.

Sort of like a PRNG. Some experiments you do, it looks random. That 
doesn't mean it's random. It just means you haven't seen the real thing, 
and you haven't measured whether it's deterministic or not. But every 
time you *do* measure whether it's deterministic, it looks like it is.
Every time you take a (good) PRNG and measure its statistical 
properties, it looks random. Every time you start a (good) PRNG from the 
same seed, you get the same values. That doesn't mean sometimes the PRNG 
is deterministic and sometimes it isn't.

Sort of like General Relativity. You can predict which way a satellite 
in outer space will go by assuming gravity is a force like muscular 
exertion is a force. That doesn't mean gravity *is* a force - it just 
has the same equations (modulo Lorenz contraction, of course).

 > Different measurements of the exact same quant can
 > show wildly different behavior in this respect.

"Exact same"? I didn't know you could tell electrons apart.

 > (One experiment will
 > clearly show that light behaves like a wave and not like a stream of
 > particles, while another experiment will show the exact opposite.)

Yes. That doesn't mean sometimes it *is* a wave and sometimes it *is* a 
particle. It means that sometimes the particle behaves in a way that can 
be predicted with the same mathematical formulas that predict the 
behavior of waves.

Plus, as I understand it, light as such doesn't have a specific 
"frequency". The light source does, but not the photons themselves. But 
I'll admit I'm probably very confused on this one. I.e., a photon isn't 
"waving" as such while it travels, but you can tell frequency by looking 
at the probability vectors of photons over time coming out of a source. 
If there's anyone who can actually explain that better to a layman, I'd 
love to hear it. :-)

Note that a single electron does *not* interfere with itself in the same 
way a wave does. If it did, it would cancel itself out sometimes, and 
that doesn't happen. You can set up a detector behind the two slits 
that's too imprecise to tell you *which* slit the electron went through, 
but can tell you it went through, and the two sets of detectors will 
count approximately the same number of events. Hence, electrons don't 
interfere with themselves in a wave-like manner. They just change the 
probabilities of where they'll land, and the formula for that is the 
same as the formula for a wave, and for the same reason - they're both 
multiplications (and hence convolutions) of cyclic 2-dimensional values.




(Oh, and as for "half the charge of an electron", the one that boggles 
my mind is spin-2 particles. A particle that's not symmetric when you 
turn it 360 degrees, but is when you turn it 720?)

-- 
   Darren New / San Diego, CA, USA (PST)
     "That's pretty. Where's that?"
          "It's the Age of Channelwood."
     "We should go there on vacation some time."

Post a reply to this message