FASTER THAN LIGHT TRAVEL NOW A FACT...

....over limited distances...
http://www.space.com/scienceastronomy/astronomy/light_speed_000530.html
Excerpt from the web page:
"The situation is somewhat similar for faster-than-light experiments to
date, Chiao said. The beams contain a mathematical entity, called modes
-- the patterns by which the waves hang together -- that outpace light.
But there is no physical entity that does so."
What the heck is a mode (a la mode?) and if its just a mathematical
entity how can it travel faster than light if it has no physical
existence - how can the patterns of the light outpace the light itself
and how/why are the two separate things? Is this "modality" some weird
kind of perception changes existence quantum phenomenon?
And, most importantly, does this mean I'll get back my 35mm SLR photos
from the processor before I take them? ;-)

Thebokehking

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

Find a way for the bus's (and its occupants') mass to be reduced to
zero and would you still get this "pancake compression" effect?
All this "tangentially" ;-) sounds very similar to Einstein's
postulation/imagination of what would it look like if a
person/hitchiker were riding on the end of a light beam with a
?flashlight, would all be darkness or would the light from the flash
light be traveling at twice the speed of light but only at the speed of
light from the hitchhiker already goign at the speed of light (by
riding at the end of the light beam)...


Thebokehking

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

But their is a tantalizing quirk that says 'maybe it
can be done' and people go nuts trying to exploit
it.
Back to the bus analogy: A bus goes at velocity V and the
people on the bus do 'the wave' at velocity W and so the
wave of standing people is traveling at W+V though no
'thing' is traveling faster than V.
If, when the bus passes you throw a package to the last
person on the bus and the person passes the package forward
then the package is indeed traveling faster than the bus
at velocity W+V.
This won't work with a physical bus at light speed because
the bus becomes - as we sense it - a 2d pancake when traveling
at light speed, which it can't anyway, and so hitting the
last person on the bus is impossible.
Light, as far as is known, travels in uncompressed wave
packets with a beginning and an end and a group of photons
travel in a larger wave also having a beginning and end.
But so far, and probably till the end of time, no one has
managed to send information that travels forward in a
wave packet of light and then sense it at the other end.
Definitely a late at night with a pitcher of beer topic.
All the above fast-and-loose with details etc., it won't get
you a pass on the Physics IV final.
--
Nicholas O. Lindan, Cleveland, Ohio
Darkroom Automation: F-Stop Timers, Enlarging Meters
http://www.nolindan.com/da/index.htm
n o lindan at ix dot netcom dot com


Nicholas O. Lindan

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

On 21 Nov 2006 00:21:07 -0800, "thebokehking" <thebokehking@yahoo.com>
wrote:
Imagine you have a flash gun set up 12 metres behind a translucent
screen. It's a high-speed flash gun and goes to full power instantly.
You're observing it from a long way away the other side of the screen
(so the time taken for light to reach you from any part of the screen
will be constant and can be ignored).
.-Y------------------
15m.-' |
.-' |9m You, a long way away-->
.-' |
Flash F-----12m----X------------------
'-. |
'-. | FX = 12m, FY = 15m, XY = 9m
15m'-. |
'-|
(Diagram will only work if viewed in a fixed-width font.)
40ns after the flash fires the front edge of the pulse of light has
traveled 12m and reaches X. From your point of view (and ignoring the
time taken for the light to travel from the screen to you) you will
see a bright point of light at X. The rest of the screen will be dark
because no light has reached those parts of the screen yet.
50ns after the flash fires the pulse has traveled 15m and reaches Y.
From your point of view you now see a circle of light of radius 9m
centred on X.
But Y is 9m away from X, so from your point of view that expanding
ring of light has moved from X to Y at an average speed of 9m/10ns
= 9x10^8 m/s, or 3 times the speed of light. Note, however, that
although you see the edge of the circle moving outwards at several
times the speed of light, no component of the system is moving any
faster than c. The point of first contact between the light and the
screen is moving across the screen from X to Y at an average speed
of 3c, but there's nothing physical moving across the screen from X
to Y at all. The photons themselves are moving from F towards X or Y
(and thence towards you) at c.
It's a similar situation with the flashlight beam. There is no "beam"
as such. If you sweep the flashlight beam across the same screen from
a sufficient distance the point at which the spot of light moves
across the screen can travel as fast as you like, but the individual
photons are still moving at no faster than c.
--
Matthew Winn
[If replying by mail remove the "r" from "urk"]


Matthew Winn

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

Huh? Didn't you just say...
"The angular rate of the beam is
You just said above that the tangential velocity of the beam can be
many-many times the speed of light, so something (tangential photons)
is/are going on faster than light here.
The photons are only travelling
I know/understand that. The beam of light/packets of photons are
traveling at a speed of c (speed of light) outwards, but this still
doesn't explain how the tangential parts of that beam (still packets of
photons) are able to travel many times faster than the speed of light.
Look, either something (ie. some part of the beam/the tangential
packets of photons in that beam) is travelling faster than the speed of
light or it isn't... Which is it
Good explanation, I now at least understand part of your explanation,
but here is where I take exception.. Imagine, just imagine if you were
able to rotate that sprinkler fast enough so that the tangential/outer
packets of/stream of water were able to travel twice the speed of light
(disregarding friction in air and the fact that the metal of the
sprinkler might melt because of friction and/or break apart under the
stress of such super speed) - wouldn't the water stream be traveling
angularly outward at the same rate as before, but, and here's the big
caveat, wouldn't the tangential packets of water _within_ the angular
projection of water be traveling/spinning around the angular/radial
axis at 2c within that 1c angular stream?
Another way to look at it...
Imagine a car loses control and skids off an embankment at 50mph, it s
speed is 50mph in angular velocity, _however_ as it is flying through
the air it is rolling (imagine a spit over a Bar-B-Q) at twice the
speed of light (again minus friction in air/other physical limitations
normally experienced).
You get my point?
In both examples, whether careening car or photons the angular speed is
at (or in the car's case), or below the speed of light, so no "speed
limit" is violated whether state law (assuming the speed limit is
either 55mph or 65mph) or Einsteinian "law". However, the tangential
velocity (in the car's case, the speed at which it rolls) _does_
violate the speed of light. So I'm still asking, even in special
situations like tangential movement of a packet of photons or a car
rolling, _how is this possible_? Is the speed of light limit only
applicable to angular velocity and not other forms of velocity (ie.
tangential velocity)? Both are just "speed"/movement/velocity, so what
goes for one direction (angular movement) should logically apply to
speed/movement (tangential movement) in another direction as well.
....Unless the speed of light is more a "suggestion" than a "law". Then
al sorts of weird thing happens past the speed of light and effects
precede causality and (backwards) time travel (at least) becomes more
than a wish but an established fact.
Again, forget about wavelengths/frequencies and think just packets of
balls/photons, as mentioned in my first requoting of you...
"The angular rate of the beam is
so aren't the tangential particles/packets of photons/balls _within_
the beam of light still traveling at more than the speed of light
_tangentially_ even though the light beam itself is traveling ahead
angularly at the speed of light?
I appreciate your time/explanations, Alan, I'm just trying to get
closer to the truth, whatever that may be...


Thebokehking

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

No, only the angular rate of the beam. The photons are only travelling
in the direction they were sent: outward (at c) "radially"
The "beam" is really just how we say a contiuous stream of light, but it
is nothing but "particles" (photons) going in one direction.
Think of it as a stream of water and you turn very quickly. The water
speed never changes but a child running could not keep up with the
tangential speed (far enough out). Double the distance, double the
tangential rate (but the water is still travelling outward at a constant
speed (ignoring frictional losses).
Nope. Just the _beam_ rate at some point far enough off... not the
speed of the particles.
Cheers,
Alan
--
-- r.p.e.35mm user resource: http://www.aliasimages.com/rpe35mmur.htm
-- r.p.d.slr-systems: http://www.aliasimages.com/rpdslrsysur.htm
-- [SI] gallery & rulz: http://www.pbase.com/shootin
-- e-meil: Remove FreeLunch.


Alan Browne

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

I just did. You need to go back and re-read it yourself.
The "mode" is light traveling
That only refers to a quote nearer the top of the page which is:
""It's very counterintuitive, but under certain circumstances you can
have light travel in a vacuum in a mode which is faster than light,"
said Raymond Chiao, a physics professor at the University of California
at Berkeley."
And you've got the quotation all garbled.
The quotation is fine, and was copied and pasted v-e-r-b-a-t-i-m, what
_is_ garbled is your understanding of the quote, possibly in reference
to modes as the top of the article mentions a vacuum mode and the
bottom of the article mentions the mode as a mathematical entity:
"The beams contain a mathematical entity, called modes -- the patterns
by which the waves hang together -- that outpace light. But there is no
physical entity that does so."
Both talk about modes but one refers to the medium of empty space and
the other refers to modes as "patterns by which the waves hang
together". Understand?
I know, hence my original posts' saying, if I may quote myself:
"...over limited distances..."
and DID NOT carry any
Actually, all we know is that the scientist who conducted that mirror
experiment to test for faster than light travel didn't _claim_ it
carried a signal, that's not to say it couldn't, wouldn't, didn't -
only that they did_n't_ make the claim that it did.
So, after very clearly explaining this, again, I will re-iterate the
question, in the hopes that now everything I quoted and said/asked is
clear...
"What the heck is a mode (a la mode?) and if its just a mathematical
Please note that the "modality" I refer to in my questions above is not
"mode" as in the medium light travels through, ie. a vacuum, but the
mathematical entity of the way patterns of lights hang together. How
can the patterns of light outpace the light beam/photons themselves,
and whether on not they can or can't carry a signal, how can these
patterns have no existence? If they have no existence than they (the
patterns themselves) can have no measurable speed/velocity and hence
can't be measured traveling faster than light or green jello for that
matter! ;-)


Thebokehking

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

You need to go back and re-read it. The "mode" is light traveling
through a vacuum. And you've got the quotation all garbled.
It only worked over a distance of about 1 meter and DID NOT carry any
signal.


Pudentame

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

I am confused, are you saying its all semantics and that the target is
somehow being moved ?closer to the photons to make it appear those
photons are travelling faster than light -- something like moving the
finish line tape/mark to get a faster runner's track time/speed?
LOL
Well, now I _finally_ understand how a packet of particles (say that 10
times faster than the speed of light ;-)) can _appear_ to travel faster
than light. Thanks for the link. But what I don't understand is...
"In a forthcoming article in the journal Nature, Dr. Lijun Wang and
colleagues of NEC at Princeton will detail an experiment in which they
accelerated light pulses to AT LEAST THREE HUNDRED TIMES c!
Furthermore, Italian scientists at the National Research Council say
they have pushed microwaves to 1.25c!"
Is this more semantics/trickery or can I expect my microwavable pop
corn to blast out of the bag at "Warp speed, Mr. Sulu!"? ;-)
One time I got real sick and regurdgitated at warp factor 6 but we
won't get into that here -- somewhere there are Einsteinian physicists
with my egg sandwhich on their faces ;-) LOL
Beyond the speed of light mass and weight start going down so by the
time you hit warp factor two you are slimmed down to the point of
becoming a weightless point, or, as, we like to put it in scientific
terms -- "America's Top Model" -- or should that be "America's Top
Modal" ;-) Past warp four you get a reversal yet again and you go from
a point back to "infinite ass" in which case you get "America's Top
Couch Potato" ;-)


Thebokehking

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

"thebokehking" <thebokehking@yahoo.com> wrote in
Not at all, and in fact, it's sophistry.
We tend to think of a beam of light, such as the aforementioned
spolight, as a constant, almost a solid. However, it's really a stream of
photons progressing at their own pace.
Realigning a very long beam, as in the comparative description in
the article (though it was unclear whether the reporter or the scientist
made this comparison) simply means that you have changed the target of
the photons faster than they could travel between the targets on their
own. But while you aimed at a new target before the photons had reached
the old one, they're still on their way.
So if that's the kind of thing they're actually talking about in
this article, I can't help thinking, "Whoopee shit."
I was wondering if the article was speaking of this, or a variation
of it: http://www.straightdope.com/mailbag/mphasevel.html
The mirror part doesn't sound like it, but the last part might be
related.
As it is, I'm not sure I really want light to go faster than light.
I have enough trouble with reaching infinite mass while trying to catch
it, I'm not going to like going beyond infinite mass.
- Al.
--
To reply, insert dash in address to match domain below
Online photo gallery at www.wading-in.net


Al Denelsbeck

Re: FASTER THAN LIGHT TRAVEL NOW A FACT...

How could anything that doesn't exist have an speed at all since there
is nothing there that can have any speed in the first place?
Have read the explanation and still don't understand. Give me gravity
any day, an apple falling on a head, now that's something I can
understand, LOL :-)


Thebokehking

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