breaking the speed of light article on howstuffworks.com

S

~~SciGirl~~

Guest
I just read that article and decided to find more information on google
and found this group... I am 14 years old (yes, I do understand quantum
physics, relativity, and some of the uncertainty principle; I'm
obsessed with science). After reading the article "How Time Travel Will
Work" a few days ago, I was thinking and figured that the only thing
that would ever be able to travel beyond the speed of light without
being destroyed is light itself. Then today I read about that
experiment, and it supports what I thought. I do think it is possible
for light to travel faster than its own speed, and if this didn't occur
in the cesium-filled container it could occur in space, if wormholes
exist. There also is a logical explanation for why the light appeared
to exit the container before it entered. I found it searching Google.
If you think about it enough, you realize there cannot be a set speed
that nothing can travel beyond
 
Here it is, I located it again.

"In Wang's experiment, a pulse of light passed through a small
chamber filled with atoms of elemental cesium. A light beam traveling
through such a medium has two different velocities - a velocity for
the individual light waves in the beam and a group velocity for the
entire beam. Oddly, some light waves in the beam can actually travel
backward for miniscule amounts of time, creating a sort of "tail"
behind forward-moving waves. As such, a light wave and its tail can
leave the gas cavity at different times, creating the effect that the
light beam has left the cavity before it's even entered."
 
"~~SciGirl~~" <palmtree117@juno.com> wrote:

Here it is, I located it again.

"In Wang's experiment, a pulse of light passed through a small
chamber filled with atoms of elemental cesium. A light beam traveling
through such a medium has two different velocities - a velocity for
the individual light waves in the beam and a group velocity for the
entire beam. Oddly, some light waves in the beam can actually travel
backward for miniscule amounts of time, creating a sort of "tail"
behind forward-moving waves. As such, a light wave and its tail can
leave the gas cavity at different times, creating the effect that the
light beam has left the cavity before it's even entered."
Click to expand...
This sounds a lot like the electrical effects observed by our friend
Mathew Orman during his FTL dream.

--
Reply to nico@nctdevpuntnl (punt=.)
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If you think about it enough, you realize there cannot be a set speed
that nothing can travel beyond
Click to expand...
You can realize anything but that does not mean that the physical universe
will ever cooperate with your musings.
 
Nico Coesel wrote...
This sounds a lot like the electrical effects observed by our
friend Mathew Orman during his FTL dream.
Click to expand...
No, actually quite different.


--
Thanks,
- Win
 
Mathew Orman, FTL dream? I must have missed something. Yes, I suppose
its true that "You can realize anything but that does not mean that the
physical universe will ever cooperate with your musings." After all, it
was considered common knowledge that a cause must always precede an
effect, yet it is believed the light left the tube before it entered.

All please note: I am only 14 and am one year ahead in math, the most I
know is basic algebra, so don't try to tell me anything with a lot of
equations as I will probably be unable to comprehend it. The one part
of all this I cannot yet understand is the math. No calculus, please.
 
As John Larkin said... "Same sort of thing, altering the shape of a
pulse and thinking that makes it go faster. Optically, an oscillatory
burst can appear to
exceed C if you sort of stand back and squint, but no photons are going
faster than C."

You can never be positive. If you cannot measure the position and
velocity of the photons simultaneously, how can you be sure they are
not going faster than c? Nobody can really measure the speed of the
particles as they exited the container, because you'd need to specify
the position defined as "exiting the container." This could disprove
the experiment, but it could also disprove the arguments of everyone
who does not believe the photons moved faster than c.
 
As John Larkin said... "Same sort of thing, altering the shape of a
pulse and thinking that makes it go faster. Optically, an oscillatory
burst can appear to
exceed C if you sort of stand back and squint, but no photons are going
faster than C."

You can never be positive. If you cannot measure the position and
velocity of the photons simultaneously, how can you be sure they are
not going faster than c? Nobody can really measure the speed of the
particles as they exited the container, because you'd need to specify
the position defined as "exiting the container." This could disprove
the experiment, but it could also disprove the arguments of everyone
who does not believe the photons moved faster than c.
 
~~SciGirl~~ wrote:
If you think about it enough, you realize there cannot be
a set speed that nothing can travel beyond
Click to expand...
Unfortunately for us, we naturally think in terms of linear
cubic space (Euclidian space in three dimensions). No matter
how much you think that way, it's impossible to visualise
an absolute speed limit - so you're right there.

The speed limit actually does exist however, because space
is curved and time dilates - the simple Euclidian model of
space is wrong. "Space tells matter how to move, and matter
tells space how to bend".
 
~~SciGirl~~ wrote:
As John Larkin said... "Same sort of thing, altering the shape of a
pulse and thinking that makes it go faster. Optically, an oscillatory
burst can appear to
exceed C if you sort of stand back and squint, but no photons are going
faster than C."

You can never be positive. If you cannot measure the position and
velocity of the photons simultaneously, how can you be sure they are
not going faster than c? Nobody can really measure the speed of the
particles as they exited the container, because you'd need to specify
the position defined as "exiting the container." This could disprove
the experiment, but it could also disprove the arguments of everyone
who does not believe the photons moved faster than c.
Click to expand...
Einstein's theory of Special Relativity prevents anything with mass or
information from travelling faster than light. It is possible that one
day this theory will be proved wrong, but it has been validated by many
experiments over the last 100 years. The FAQ on Wang's webpage states
that his experiment does NOT contradict current theory, and cannot be
used to send information faster than light. See:

http://www.neci.nj.nec.com/homepages/lwan/faq.htm

For a very good demonstration of how light can appear to travel faster
than light have a look at the Java applet in the link below:

http://gregegan.customer.netspace.net.au/APPLETS/20/20.html

The Java applet also shows what happens if you try to send information
by modulating the beam.

There is some more information on superluminal phenomena here:

http://scienceworld.wolfram.com/physics/Superluminal.html

Gareth.

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To reply to me directly:

Replace privacy.net with: totalise DOT co DOT uk and replace me with
gareth.harris
 
Ben Bradley wrote...
SciGirl wrote:

Mathew Orman, FTL dream? I must have missed something.

Short story, he was a guy here telling about his cables he tried to
sell on ebay for an outrageous price, that he claimed could transmit
a signal faster than the speed of light.
Click to expand...
Yes, he offered the original laboratory cable at a high price, as a
sort of historical valuable artifact, but at about the same time he
also offered a student cable for $10, IIRC. There were no bidders.


--
Thanks,
- Win
 
In article <pan.2005.02.05.03.23.48.430568@att.bizzzz>,
keith <krw@att.bizzzz> wrote:
[...]
I designed a logic level convert circuit once that I spec'd with a
negative delay, at least until someone read it. I was *forced* to do
rise-times from 20-80 and delays from 50-50. The threshold wasn't at 50,
so until I showed the PHBs how stupid their requirements were, it had a
negative delay. ...and no, no electrons were hurt in testing the circuit.
Click to expand...
I actually got a spec from some fairly smart people that said that one
pulse had to be produced before the other. The later pulse was called the
"trigger" and was supposed to be the external input to the circuit.

What they really wanted was a circuit that made two pulses that partly
overlapped. They didn't really want to have to provide the "trigger"
input.

--
--
kensmith@rahul.net forging knowledge
 
In article <36jnsiF52nelrU1@individual.net>, Gareth <me@privacy.net> wrote:
[...]
Einstein's theory of Special Relativity prevents anything with mass or
information from travelling faster than light.
Click to expand...
Actually it prevents anything that is not already FTL from getting there.
If something is FTL it can't slow down and has weird backwards physics.


You can get what appears to be FTL motion by projecting a image onto a far
away screen and rotating the projector. Since photon etc don't wear dog
tags, you can get some funny measurements if you aren't careful.




--
--
kensmith@rahul.net forging knowledge
 
Ok, I found online somewhere that E = mc^2 has been revised to E =
mc2/mc^2 - 1. Is this true or is it just some bogus thing?

Also, say wormholes existed and you traveled through one. There would
be hyperspace around you, and so you would age quickly. Wouldn't you be
dead before you exited?

To whoever said calculus is easy... it's more than just rate of change,
isn't it? We learned that in Algebra 1!
 
This is a question I have had since reading about Maxwell's
equations... in each one of them, there is this upside-down triangle
symbol that looks just like the delta triangle flipped over. What is
this symbol and what does it mean???

I took a quantum physics test on allthetests.com (to find it just type
"quantum" in the search box, there is only one) and I scored 8 out of
12.
 
"14 = 9th grade? Algebra, sounds about right. You're doing well. Keep
up
the interest."

Actually, 8th grade, but in 9th grade math. Still in 8th grade science,
but will be working on a research project a couple days a week instead
of class because class got too easy for me and I was bored to death.
They're doing convection, conduction, and radiation. It's like sitting
in a chair for an hour listening to a repetitive explanation of why one
plus one equals two.
 
"~~SciGirl~~" <palmtree117@juno.com> wrote:

Mathew Orman, FTL dream? I must have missed something. Yes, I suppose
its true that "You can realize anything but that does not mean that the
physical universe will ever cooperate with your musings." After all, it
was considered common knowledge that a cause must always precede an
effect, yet it is believed the light left the tube before it entered.
Click to expand...
A couple of months ago Mathew Orman posted messages about an
expirement he did and he thought he had discovered a way to make an
electrical signal travel through a cable faster than light. In reality
he made a mistake while doing his measurements which he could have
seen himself if he knew something (more) about transmission of signals
in cables.

--
Reply to nico@nctdevpuntnl (punt=.)
Bedrijven en winkels vindt U op www.adresboekje.nl
 
Just for the record... I intend to be a meteorologist when I grow up,
not a physicist.
 
I find all this interesting, but I just enjoy meteorology more. This is
a little too abstract for me.
 
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