| Topic: |
Science > Physics |
| User: |
"Timothy Law" |
| Date: |
23 Jan 2005 08:16:29 PM |
| Object: |
what is faster than light? |
Hi, is there anything faster than light? Serious answers please.
Thank you.
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| User: "Franz Heymann" |
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| Title: Re: what is faster than light? |
26 Jan 2005 03:47:33 AM |
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"greywolf42" <mingstb@marssim-ss.com> wrote in message
news:0jwJd.5716$VA5.646@fe07.usenetserver.com...
Franz Heymann <notfranz.heymann@btopenworld.com> wrote in message
news:ct4ris$nn7$1@hercules.btinternet.com...
"greywolf42" <mingstb@marssim-ss.com> wrote in message
news:JReJd.49$VA5.37@fe07.usenetserver.com...
greywolf42 <mingstb@marssim-ss.com> wrote in message
news:lWaJd.3430$rc4.3127@fe07.usenetserver.com...
Timothy Law <timlaw@gamebox.netNETNETNET> wrote in message
news:1UYId.8659$rp1.7277@newsread3.news.atl.earthlink.net...
Hi, is there anything faster than light? Serious answers
please.
Thank you.
Electrons and UV photons have both been repeatably (and
repeatedly)
measured to move at 1.7 times the speed of light -- when
tunneling.
These are direct measurements, and not simply a "phase
velocity"
problem.
And the results are all vetted and peer reviewed. They are
simply
ignored
by theorists.
Whups! Meant to go back and put in reference links. But I got
sidetracked
by Tom R's new missive. Here are two links on the issue, with
prior
discussion and references.
http://groups-beta.google.com/group/sci.physics.relativity/msg/cf6f4e4fc7d37
d47
http://groups-beta.google.com/group/sci.physics.relativity/msg/2ce217e7d64dc
0d7
References to newsgroup threads are overwhelmingly likely to lead
to
horse dung, so these two don't count in my book.
[snip]
If you won't look, your ignorance is incurable. The vetted refs are
contained within the links.
I am unlikely to learn anything worth knowing from references to ng
threads provided by known kooks.
Franz
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| User: "greywolf42" |
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| Title: Re: what is faster than light? |
28 Jan 2005 04:21:04 PM |
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Franz Heymann <notfranz.heymann@btopenworld.com> wrote in message
news:ct7ovk$d0l$5@sparta.btinternet.com...
"greywolf42" <mingstb@marssim-ss.com> wrote in message
news:0jwJd.5716$VA5.646@fe07.usenetserver.com...
Franz Heymann <notfranz.heymann@btopenworld.com> wrote in message
news:ct4ris$nn7$1@hercules.btinternet.com...
Whups! Meant to go back and put in reference links. But I got
sidetracked by Tom R's new missive. Here are two links on
the issue, with prior discussion and references.
http://groups-beta.google.com/group/sci.physics.relativity/msg/cf6f4e4fc7d37
d47
http://groups-beta.google.com/group/sci.physics.relativity/msg/2ce217e7d64dc
0d7
References to newsgroup threads are overwhelmingly likely to lead
to horse dung, so these two don't count in my book.
[snip]
If you won't look, your ignorance is incurable. The vetted refs are
contained within the links.
I am unlikely to learn anything worth knowing from references to ng
threads provided by known kooks.
Obviously, you can't learn from reading, either. Bye in this thread.
greywolf42
ubi dubium ibi libertas
{remove planet for e-mail}
.
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| User: "Franz Heymann" |
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| Title: Re: what is faster than light? |
29 Jan 2005 05:11:10 AM |
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"greywolf42" <mingstb@marssim-ss.com> wrote in message
news:kVyKd.6785$VA5.102@fe07.usenetserver.com...
Franz Heymann <notfranz.heymann@btopenworld.com> wrote in message
news:ct7ovk$d0l$5@sparta.btinternet.com...
"greywolf42" <mingstb@marssim-ss.com> wrote in message
news:0jwJd.5716$VA5.646@fe07.usenetserver.com...
Franz Heymann <notfranz.heymann@btopenworld.com> wrote in
message
news:ct4ris$nn7$1@hercules.btinternet.com...
Whups! Meant to go back and put in reference links. But I
got
sidetracked by Tom R's new missive. Here are two links on
the issue, with prior discussion and references.
http://groups-beta.google.com/group/sci.physics.relativity/msg/cf6f4e4fc7d37
d47
http://groups-beta.google.com/group/sci.physics.relativity/msg/2ce217e7d64dc
0d7
References to newsgroup threads are overwhelmingly likely to
lead
to horse dung, so these two don't count in my book.
[snip]
If you won't look, your ignorance is incurable. The vetted refs
are
contained within the links.
I am unlikely to learn anything worth knowing from references to
ng
threads provided by known kooks.
Obviously, you can't learn from reading, either. Bye in this
thread.
Your standard cop-out
Franz
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| User: "Randy Poe" |
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| Title: Re: what is faster than light? |
24 Jan 2005 12:22:59 PM |
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greywolf42 wrote:
Timothy Law <timlaw@gamebox.netNETNETNET> wrote in message
news:1UYId.8659$rp1.7277@newsread3.news.atl.earthlink.net...
Hi, is there anything faster than light? Serious answers please.
Thank you.
Electrons and UV photons have both been repeatably (and repeatedly)
measured
to move at 1.7 times the speed of light -- when tunneling. These are
direct
measurements, and not simply a "phase velocity" problem. And the
results
are all vetted and peer reviewed. They are simply ignored by
theorists.
It's discussed in the Relativity FAQ. I don't see
how that counts as "being ignored".
http://www.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SpeedOfLight/FTL.html
(See item 11).
- Randy
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| User: "greywolf42" |
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| Title: Re: what is faster than light? |
24 Jan 2005 04:42:48 PM |
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Randy Poe <poespam-trap@yahoo.com> wrote in message
news:1106590979.938599.310030@z14g2000cwz.googlegroups.com...
greywolf42 wrote:
Timothy Law <timlaw@gamebox.netNETNETNET> wrote in message
news:1UYId.8659$rp1.7277@newsread3.news.atl.earthlink.net...
Hi, is there anything faster than light? Serious answers please.
Thank you.
photons have both been repeatably (and repeatedly) measured
to move at 1.7 times the speed of light -- when tunneling. These are
direct measurements, and not simply a "phase velocity" problem. And the
results are all vetted and peer reviewed. They are simply ignored by
theorists.
It's discussed in the Relativity FAQ. I don't see
how that counts as "being ignored".
http://www.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SpeedOfLight/FTL.ht
ml
(See item 11).
Sure it's ignored. Look at your own reference. The FAQ has the following
claim:
"Quantum Tunnelling is the quantum mechanical effect which permits a
particle to escape through a barrier when it does not have enough energy to
do so classically. You can do a calculation of the time it takes a particle
to tunnel through. The answer you get can come out less than the time it
takes light to cover the distance at speed c. ... ref:T. E. Hartman, J.
Appl. Phys. 33, 3427 (1962)."
And the FAQ "reasoning" that this can't happen is:
"The answer must surely be 'No!' otherwise our understanding of QED is very
suspect."
In other words, experiments must be ignored, otherwise our theory (QED) is
wrong. In addition, the FAQ mentions only one set of experiments (though
several are commonly known):
"Yet a group of physicists have performed experiments which seem to suggest
that FTL communication by quantum tunneling is possible. They claim to have
transmitted Mozart's 40th Symphony through a barrier 11.4cm wide at a speed
of 4.7c."
So, the FAQ simply ignores most experiments. Choosing the one it can best
malign through innuendo. The FAQ then expounds upon why the experiment
should be ignored:
"Their interpretation is, of course, very controversial. Most physicists
say this is a quantum effect where no information can actually be passed at
FTL speeds because of the Heisenberg uncertainty principle. If the effect
is real it is difficult to see why it should not be possible to transmit
signals into the past by placing the apparatus in a fast moving frame of
reference."
In short, because theory says this experiment can't be true, we are going to
ignore it:
"The likely conclusion is that there is no real FTL communication taking
place and that the effect is another manifestation of the Heisenberg
uncertainty principle."
See also:
http://groups-beta.google.com/group/sci.physics.relativity/msg/2ce217e7d64dc
0d7
--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}
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| User: "Uncle Al" |
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| Title: Re: what is faster than light? |
24 Jan 2005 02:57:25 PM |
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Randy Poe wrote:
greywolf42 wrote:
Timothy Law <timlaw@gamebox.netNETNETNET> wrote in message
news:1UYId.8659$rp1.7277@newsread3.news.atl.earthlink.net...
Hi, is there anything faster than light? Serious answers please.
Thank you.
Electrons and UV photons have both been repeatably (and repeatedly)
measured
to move at 1.7 times the speed of light -- when tunneling. These are
direct
measurements, and not simply a "phase velocity" problem. And the
results
are all vetted and peer reviewed. They are simply ignored by
theorists.
It's discussed in the Relativity FAQ. I don't see
how that counts as "being ignored".
http://www.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SpeedOfLight/FTL.html
(See item 11).
A crackpot only believes his voices. It is a safe, small, smelly
existence. Consider Jack Sarfatti. He has over the yeasrs posted
thousands of pages of "erudition" yet not a single line of his spew
has ever been reduced to practice. Perhaps that obtains because
everything he has proposed is crap.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
.
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| User: "greywolf42" |
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| Title: Re: what is faster than light? |
24 Jan 2005 04:42:47 PM |
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Uncle Al <UncleAl0@hate.spam.net> wrote in message
news:41F56135.3B3984B1@hate.spam.net...
Randy Poe wrote:
greywolf42 wrote:
Timothy Law <timlaw@gamebox.netNETNETNET> wrote in message
news:1UYId.8659$rp1.7277@newsread3.news.atl.earthlink.net...
Hi, is there anything faster than light? Serious answers please.
Thank you.
Electrons and UV photons have both been repeatably (and repeatedly)
measured
to move at 1.7 times the speed of light -- when tunneling. These are
direct
measurements, and not simply a "phase velocity" problem. And the
results
are all vetted and peer reviewed. They are simply ignored by
theorists.
It's discussed in the Relativity FAQ. I don't see
how that counts as "being ignored".
http://www.physics.adelaide.edu.au/~dkoks/Faq/Relativity/SpeedOfLight/FTL.ht
ml
(See item 11).
A crackpot only believes his voices. It is a safe, small, smelly
existence. Consider Jack Sarfatti. He has over the yeasrs posted
thousands of pages of "erudition" yet not a single line of his spew
has ever been reduced to practice. Perhaps that obtains because
everything he has proposed is crap.
Zero content, ad hominem cowardice.
Bye, Al
--
greywolf42
ubi dubium ibi libertas
{remove planet for return e-mail}
.
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| User: "Uncle Al" |
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| Title: Re: what is faster than light? |
24 Jan 2005 11:11:13 AM |
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Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Thank you.
Look up phase and group velocities. The only lightspeed constraints -
as with thermodynamics, absolute zero, and negative kelvin temps for
population inversions - are
1) Non-zero rest mass may not propagate at lightspeed (division by
zero), and
2) Information may not propagate FTL (or causality is violated).
In principle one could toss a Windows manual FTL with a strategem
analogous to that used for obtaining negative kelvin temps. The
empirical doing of the former is left as an exercise for the alert
reader.
Einstein-Podolsky-Rosen experiments collapse entangled wavefunctions
into consistent observables *instantaneously* across arbitrarily large
distances. No information is transferred. Won't even give you FTL
Morse code.
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/qz.pdf
.
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| User: "G=EMC^2 Glazier" |
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| Title: Re: what is faster than light? |
24 Jan 2005 01:51:21 PM |
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Hi Tim Possibly the graviton in the Quantum gravity realm. Possibly
space expansion in the macro realm in regards to our inflating universe
horizon. Possibly in Guth's inflation of the BB in he first
trillionth of an second of the BB where it moved out many billions of
years in the very small part of a second.Possibly the Kaon particle does
not obey SR. I have a thought experiment that is faster than"c" Bert
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| User: "tj Frazir" |
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| Title: Re: what is faster than light? |
24 Jan 2005 05:38:10 PM |
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Try going faster than light will result in a change of direction .
No photon can go faster than light C.
A rize and fall is conducted by energy at the rate energy reacts with
energy.
nothing can go faster than energy reacts or slower than energy reacts.
More energy wount go faster or slower it will just change directions
more.
Boath the sender and observer see light at C no matter their motion
the rate they will see a photon is C.
The wave lenth X the frenquency is allways C.
The harder you push against it the taller te wave gets.
But the speed of the wavical is C.
Re: Survey of Minds
Group: sci.physics Date: Mon, Jan 24, 2005, 12:40pm From:
GravityPhysics@webtv.net (tj=A0Frazir)
ALL things fall the same speed.
=A0=A01 pound falls the same 6 pounds falls on the ame angle of energy
slope
=A0=A0The stronger slope is not a faster fall. (( bust a pice of a
magnet off and place the 1/6 of a magnet on a
table as a steel plate passes over , the 1/6 magnet jumps up at the same
speed the hole magnet does.
=A0=A0Gravity is not a magnet.
But notice the stronger magnet is just a larger pice of the same.
=A0=A0=A0=A0=A0=A0=A0=A0=A0=A0Each atom is a pice of the mass and its
strenth is the same no matter what mass its part of...like a pice of a
magnet.
=A0=A0The displacment rrate of each pice of the magnet is the same ,,
even
if it wieghs less.
=A0=A0=A0=A0((((((Evrything falls the same speed ,,because evry atom
changes mass in the field at the same rate
))))))))))))))))))))))))))))))))))))
=A0=A0now that statement aplys to gravity and EMF.
Re: Survey of Minds
Group: sci.physics Date: Sun, Jan 23, 2005, 9:17pm From:
GravityPhysics@webtv.net (tj=A0Frazir)
In any energy slope mass will be displaced at the rate it can change
mass.
=A0=A0The rate an atom can change mass is fixed. as an atom is an energy
slope has more mass on 1/2 the atom than the other.
=A0=A0. >>>> but kenetic energy is mass in motion. As the atom is in
motion it takes up more space per time unit. 1/2 the atom has a larger
LOW as it takes up more space per time unit. The sum of the low is mass.
<<<<
An atom in motion threw energy as it expands is taking up more space as
it moves . Eliminating space ahead and leaving a low behind.,<<<<<
=A0=A0=A0=A0As an atom moves threw one time frame
=A0=A0the streak it leaves in time will afect how much mass is on each
side of the atom and a gain in mass is pushing te other 1/2 of atom .
=A0=A0the distortion or drag of an atom in motion is a low and part of
the sum of te atoms mass.
kenetic energy is related to gravity as they boath deal with the rate an
atom changes mass. <<<<<<
=A0=A0=A0=A0=A0The speed of fall is fixed.
The reason the rock hits the moon instead of the moon and rock moving
twards each other
=A0=A0is kenetic energy .
=A0=A0The energy slope at the serface of the moon is 90 deg . On the
earth
its 90 deg.
=A0=A0a rock falls the same speed on the moon . It wieghs 1/6 but falls
the same speed.
=A0=A0nasa has it wrong.
.
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| User: "Morituri-|-Max" |
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| Title: Re: what is faster than light? |
24 Jan 2005 12:44:38 AM |
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Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Seriously, no.
.
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| User: "Franz Heymann" |
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| Title: Re: what is faster than light? |
24 Jan 2005 02:56:57 AM |
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"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
There are also certain wavelength ranges in which X rays have a phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
Franz
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| User: "Duckynot" |
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| Title: Re: what is faster than light? |
24 Jan 2005 09:59:31 AM |
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"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:ct2d8o$7en$2@hercules.btinternet.com...
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
no, it exceeds the velocity of the EM wave in the wave guide, also you
cannot measure the faster than light phase velocity.
There are also certain wavelength ranges in which X rays have a phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
Franz
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| User: "Franz Heymann" |
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| Title: Re: what is faster than light? |
24 Jan 2005 04:05:15 PM |
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"Duckynot" <nospam@nospam.com> wrote in message
news:35kkahF4ljti2U1@individual.net...
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:ct2d8o$7en$2@hercules.btinternet.com...
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers
please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
no, it exceeds the velocity of the EM wave in the wave guide, also
you
cannot measure the faster than light phase velocity.
I am afraid you are wrong.
How can an EM wave speed exceed the speed of the same EM wave?
In an empty waveguide carrying a wave with a longitudinal component of
either E or H, the phase speed is always larger than c, the speed of
EM waves in free space.
It is in fact quite easy to measure this phase speed. All you need to
do is to put a reflecting surface at the far end to set up a standing
wave and measure the wavelength in the guide. By knowing that and the
frequency, the phase speed can be deduced.
There are also certain wavelength ranges in which X rays have a
phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
Franz
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| User: "Noone Home" |
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| Title: Re: what is faster than light? |
24 Jan 2005 08:05:34 PM |
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"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:ct3req$87f$3@hercules.btinternet.com...
"Duckynot" <nospam@nospam.com> wrote in message
news:35kkahF4ljti2U1@individual.net...
"Franz Heymann" <notfranz.heymann@btopenworld.com> wrote in message
news:ct2d8o$7en$2@hercules.btinternet.com...
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers
please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
no, it exceeds the velocity of the EM wave in the wave guide, also
you
cannot measure the faster than light phase velocity.
I am afraid you are wrong.
How can an EM wave speed exceed the speed of the same EM wave?
In an empty waveguide carrying a wave with a longitudinal component of
either E or H, the phase speed is always larger than c, the speed of
EM waves in free space.
But the speed of EM in the waveguide is slower than freespace. It is 80% to
90% c
It is in fact quite easy to measure this phase speed. All you need to
do is to put a reflecting surface at the far end to set up a standing
wave and measure the wavelength in the guide. By knowing that and the
frequency, the phase speed can be deduced.
It is calculated, not measured.
There are also certain wavelength ranges in which X rays have a
phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
Franz
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| User: "Steven Gray" |
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| Title: Re: what is faster than light? |
26 Jan 2005 07:50:59 PM |
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"Noone Home" <nospam@nospam.com> wrote in
news:35lnqkF4m68nnU1@individual.net:
I am afraid you are wrong.
How can an EM wave speed exceed the speed of the same EM wave?
In an empty waveguide carrying a wave with a longitudinal component of
either E or H, the phase speed is always larger than c, the speed of
EM waves in free space.
But the speed of EM in the waveguide is slower than freespace. It is
80% to 90% c
What do you mean by "the speed of EM"?? The group velocity times the phase
velocity is (c/sqrt(epsilon sub r))^2. If the relative dielectric constant
is 1, then Vg*Vp=c^2. The 80% to 90% to which you refer is presumably for
a dielectric filled waveguide.
It is in fact quite easy to measure this phase speed. All you need to
do is to put a reflecting surface at the far end to set up a standing
wave and measure the wavelength in the guide. By knowing that and the
frequency, the phase speed can be deduced.
It is calculated, not measured.
That's a distinction without a difference. The calculation is based on
measured parameters.
--
Steve Gray
sgray2@cfl.rr.com
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| User: "Franz Heymann" |
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| Title: Re: what is faster than light? |
27 Jan 2005 03:02:20 AM |
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"Noone Home" <nospam@nospam.com> wrote in
news:35lnqkF4m68nnU1@individual.net:
I am afraid you are wrong.
How can an EM wave speed exceed the speed of the same EM wave?
In an empty waveguide carrying a wave with a longitudinal component
of
either E or H, the phase speed is always larger than c, the speed
of
EM waves in free space.
But the speed of EM in the waveguide is slower than freespace. It
is
80% to 90% c
The phase velocity in any wave which has a longitudinal component of
either E or H has a phase velocity which exceeds c. Such a wave is
always dispersive and consequently has a group velocity which differs
from its phase velocity. The group velocity of such a wave is always
less than c.
It is in fact quite easy to measure this phase speed. All you need
to
do is to put a reflecting surface at the far end to set up a
standing
wave and measure the wavelength in the guide. By knowing that and
the
frequency, the phase speed can be deduced.
It is calculated, not measured.
No. It is measured routinely in any laboratory in which waveguides
are in use. I have measured it myself. Many times.
Franz
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| User: "tj Frazir" |
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| Title: Re: what is faster than light? |
24 Jan 2005 08:50:24 PM |
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The fused filiment in a light bulb .
It blew befor the light came on.
Re: Survey of Minds
Group: sci.physics Date: Sun, Jan 23, 2005, 9:17pm From:
GravityPhysics@webtv.net (tj=A0Frazir)
In any energy slope mass will be displaced at the rate it can change
mass.
=A0=A0The rate an atom can change mass is fixed. as an atom is an energy
slope has more mass on 1/2 the atom than the
other.
=A0=A0. >>>> but kenetic energy is mass in motion. As the atom is in
motion it takes up more space per time unit. 1/2 the atom has a larger
LOW as it takes up more space per time unit.
The sum of the low is mass. <<<<
An atom in motion threw energy as it expands is taking up more space as
it moves . Eliminating space ahead and leaving a low behind.,<<<<<
=A0=A0=A0=A0As an atom moves threw one time frame
=A0=A0the streak it leaves in time will afect how much mass is on each
side of the atom and a gain in mass is pushing te other 1/2 of atom .
=A0=A0the distortion or drag of an atom in motion is a low and part of
the sum of te atoms mass.
kenetic energy is related to gravity as they boath deal with the
rate an atom changes mass. <<<<<<
=A0=A0=A0=A0=A0The speed of fall is fixed.
The reason the rock hits the moon instead of the moon and rock moving
twards each other
=A0=A0is kenetic energy .
=A0=A0The energy slope at the serface of the moon is 90 deg . On the
earth
its 90 deg.
=A0=A0a rock falls the same speed on the moon . It wieghs 1/6 but falls
the same speed.
=A0=A0nasa has it wrong.
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| User: "Steven Gray" |
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| Title: Re: what is faster than light? |
25 Jan 2005 06:51:26 PM |
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"Duckynot" <nospam@nospam.com> wrote in news:35kkahF4ljti2U1
@individual.net:
The phase velocity of a wave in a waveguide exceeds that of light.
no, it exceeds the velocity of the EM wave in the wave guide, also you
cannot measure the faster than light phase velocity.
Sure you can. Use a slotted waveguide. Probe the field at two points
separated by a measured distance along the centerline of the guide.
Measure the time difference between zero voltage crossings of the E field
at the two points.
--
Steve Gray
sgray2@cfl.rr.com
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| User: "Morituri-|-Max" |
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| Title: Re: what is faster than light? |
24 Jan 2005 07:14:51 AM |
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Franz Heymann wrote:
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
There are also certain wavelength ranges in which X rays have a phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
I was answering in the spirit of his question, which I interpreted to mean
things more basic than waves or wavelengths.. heh..
thankee information tho.
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| User: "Creighton Hogg" |
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| Title: Re: what is faster than light? |
24 Jan 2005 07:30:43 AM |
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On Mon, 24 Jan 2005, Franz Heymann wrote:
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
There are also certain wavelength ranges in which X rays have a phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
Okay, so even though these x-rays would have a phase velocity greater than
c, the total information propagation speed is still less than c, right?
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| User: "Franz Heymann" |
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| Title: Re: what is faster than light? |
24 Jan 2005 04:05:13 PM |
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"Creighton Hogg" <wchogg@hep.wisc.edu> wrote in message
news:Pine.LNX.4.44.0501240729590.12764-100000@dill.hep.wisc.edu...
On Mon, 24 Jan 2005, Franz Heymann wrote:
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers
please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
There are also certain wavelength ranges in which X rays have a
phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
Okay, so even though these x-rays would have a phase velocity
greater than
c, the total information propagation speed is still less than c,
right?
Certainly. The far UV and Xray wavelengths involved lie in the
neighbourhood of absorption bands, which makes them dispersive. The
group velocities are always less than c.
The group velocities in the waveguide modes are also alway less than c
Franz
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| User: "Greysky" |
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| Title: Re: what is faster than light? |
24 Jan 2005 08:41:39 AM |
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"Creighton Hogg" <wchogg@hep.wisc.edu> wrote in message
news:Pine.LNX.4.44.0501240729590.12764-100000@dill.hep.wisc.edu...
On Mon, 24 Jan 2005, Franz Heymann wrote:
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
There are also certain wavelength ranges in which X rays have a phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
Okay, so even though these x-rays would have a phase velocity greater than
c, the total information propagation speed is still less than c, right?
Yes. Remember, for any complex system meaningful information can not move
faster than the propagation speed of the disturbance that carries it.
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| User: "Franz Heymann" |
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| Title: Re: what is faster than light? |
24 Jan 2005 04:05:14 PM |
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"Greysky" <greyskynospam@sbcglobal.net> wrote in message
news:DO7Jd.14431$wZ2.1328@newssvr13.news.prodigy.com...
"Creighton Hogg" <wchogg@hep.wisc.edu> wrote in message
news:Pine.LNX.4.44.0501240729590.12764-100000@dill.hep.wisc.edu...
On Mon, 24 Jan 2005, Franz Heymann wrote:
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers
please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of
light.
There are also certain wavelength ranges in which X rays have a
phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
Okay, so even though these x-rays would have a phase velocity
greater than
c, the total information propagation speed is still less than c,
right?
Yes. Remember, for any complex system meaningful information can not
move
faster than the propagation speed of the disturbance that carries
it.
The propagation speed of a surface of constant phase of a sinusoidal
wave (for example the wave peaks) can in fact propagate at speeds in
excess of c if the wave is dispersive. In such a case, there is a
second type of speed, which is that at which an envelope of a
modulated wave propagates. That is called the group speed, and it is
that speed which is always less than c.
Franz
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| User: "Timo Nieminen" |
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| Title: Re: what is faster than light? |
24 Jan 2005 04:10:03 PM |
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On Mon, 24 Jan 2005, Franz Heymann wrote:
"Morituri-|-Max" <newage@sendarico.net> wrote in message
news:qP0Jd.58751$Ta2.1162@fe2.texas.rr.com...
Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Seriously, no.
More seriously, Yes.
The phase velocity of a wave in a waveguide exceeds that of light.
There are also certain wavelength ranges in which X rays have a phase
velocity larger than c. This shows up as instances in whichthe
refractive index is less than 1.
And then there are the cases where the group velocity of light pulses can
be > c. Lossy and gainy media, with just the right dispersion, by and
large.
--
Timo Nieminen - Home page: http://www.physics.uq.edu.au/people/nieminen/
Shrine to Spirits: http://www.users.bigpond.com/timo_nieminen/spirits.html
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| User: "Sam Wormley" |
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| Title: Re: what is faster than light? |
24 Jan 2005 08:15:02 AM |
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Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Thank you.
Not arbitrary information
Not measured velocity of matter
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| User: "robert j. kolker" |
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| Title: Re: what is faster than light? |
23 Jan 2005 08:20:57 PM |
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Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Thank you.
Faster than light in vacuo? There is no known object or process that
moves at greater than light speed in vavuo. If you find something
faster, will you tell us about it?
Bob Kolker
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| User: "Paul Cardinale" |
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| Title: Re: what is faster than light? |
24 Jan 2005 01:36:40 PM |
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Timothy Law wrote:
Hi, is there anything faster than light? Serious answers please.
Thank you.
The speed limit applies to matter, energy, and information as viewed
from an inertial frame of reference. Anything that can move without
carrying matter, energy, or information has no speed limit. Examples
are: A laser spot, a projected image, a shadow, the propagation of a
cut.
Paul Cardinale
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| User: "robert j. kolker" |
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| Title: Re: what is faster than light? |
24 Jan 2005 01:43:55 PM |
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Paul Cardinale wrote:
The speed limit applies to matter, energy, and information as viewed
from an inertial frame of reference. Anything that can move without
carrying matter, energy, or information has no speed limit. Examples
are: A laser spot, a projected image, a shadow, the propagation of a
cut.
Is the spot really traveling? Or are we seeing a reflection here then
there? When a lot spot moves or seems to move what is really moving?
Bob Kolker
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| User: "robert j. kolker" |
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| Title: Re: what is faster than light? |
24 Jan 2005 01:44:41 PM |
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robert j. kolker wrote:
Is the spot really traveling? Or are we seeing a reflection here then
there? When a lot
Make that light spot. Thank you.
spot moves or seems to move what is really moving?
Bob Kolker
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