Re: Questions (Space)

Jonathan L Cunningham <spam@xxxxxxxxxxxxxxxxxxxx> wrote:
Sea Wasp <seawaspObvious@xxxxxxxxxxxxxxxxx> wrote:
Tina Hall wrote:

The light that travels has to be something. There's something that
first hits the cupboard, then my eye, for example. Or comes from a
distant star.

Energy.

[Tina, what I'm about to add is not a direct answer to your question.
It's a digression, commenting on something the people replying to you
said. Read it if you want, but don't get annoyed that it's not
answering your question, because it isn't supposed to.]

Ok. (That's a long way to say; "<digressing>".)

What you say is interesting, so I'll comment anyway.

It may be true that energy is travelling, but that's, at some level,
incidental. (And I know, or used to know, about Poynting vectors and
stuff like that: I'm making a more fundamental, possibly sfnal,
point.)

Analogy: if I throw steel ball-bearings at you, the ball-bearings are
travelling, and so is their kinetic energy, but the energyy transport
is incidental. It might help (and might not) to compare the situation
if I throw them at different speeds, or bearings made of different
stuff.

Well, that's the force stuff I couldn't follow in Physics. :) (Having
formulas and funny arrows dumped on me without explanation.) I've grown
to some vague idea of what's meant in the meantime, though. (Don't
explain! :) I can work with what I've got.)

The point is, that it's the little balls of metal that are the things
that move. If you think of light as made of photons, it is the
photons that move,

Photons would be something I can imagine even, but no one mentioned
them. (I would like to know more about how they come to be, though.)

the energy transport is incidental (because mass equals energy, like
Einstein said).

Here she just quacks. (Or in other words, I'll drop out here. For those
that don't know, the cat here was named Einstein for some reason. Not by
me. I'd have called her Scowl.)

For a wave motion, *nothing* moves from A to B. If you think of light
as an EM wave (instead of photons), then nothing physical moves.

Where's the problem in assuming that the photons create a wave when
measured (like you do with electrons)?

I just don't see the problem people say there is when trying to
reconcile the theories. There must be one; the folks dealing with this
sure know a lot more than I.

But the wave is just the intensity (rising and falling), no? They don't
wiggle around, travelling in a zig-zag. If it isn't 'more photons' and
'less photons' but 'stronger photons' and 'weaker photons' or something,
I don't see a problem, either.

But waves can still transport energy (compare ocean waves: you can
build wave power generators to extract energy from them, but the water
doesn't travel across the Atlantic: all the actual water particles
move in circles).

Should I imagine a star (sphere) of photons that (one 'shell' after the
other) raise their hands and wave at the next one (so to speak), the
movement 'rippling' outwards?

So since light is both particle and wave, it both travels and doesn't
travel. At this point, anyone whose head isn't hurting hasn't
understood the problem! :-)

You're right there. I don't understand the problem. :) (And my head
isn't hurting, yet.)

For some other examples of things that move without travelling: the
spot of light on an (old fashioned, cathode-ray tube) TV. The spot of
light "moves" across the screen, painting the picture. But actually,
nothing physical moves across the screen at all (there are electrons
travelling down the length of the tube and hitting the screen, but
that's different.)

Pfft. The paper isn't moving when I draw a line on it with a ballpen,
either. ;-P

Another example is a giant, light-years long, pair of scissors. It's
quite within the realm of possibility for them to cut a giant,
light-years wide, *** of paper faster than the speed of light. The
physical scissor-blades can't move faster than light, and neither can
any part of the paper, but the cutting-point can.

Hm. Say the scissors start at a quarter circle angle (90.), each point
gets to travel half that (45.).

That's (3.14/4 (diameter)) /2 compared to (diameter)/2. Which is
naturally smaller (3.14 : 4).

But the angle was chosen arbitrary, looking at my sciccors. If you
increase that... I guess the real formula would have to involve the
length of the cutting edge of the blades being equal to the cut that's
done, never mind the actual size of the paper (I don't see your paper
travelling, either).

But I've got enough of trying to picture that. :) How did we get to
faster than light, anyway?

<snip>

It's even possible to get light travelling faster than light

I heard about that. Not that I know how, just that someone did it some
years ago.

<snip>

--
Tina
WIP: Space: 1317 words
WISuspension: Seasons & Elements trilogy | Magic Earth series
Posted to Usenet newsgroup rec.arts.sf.composition.

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