Tired light.
Mike van Scherrenburg
Pardon me, I'm not trying to be anal here, but what experimental evidence
or indications do we have that light does not get tired? Why can't some of
the perceived red shift be due to light getting tired? Current theory
certainly suggests that free photons conserve their energy with a lack of
interactions to change matters. But, theory has been in need of correction
before. Or perhaps there is some very weak degree of interaction in "free"
space?
So, what observations lead us to believe that there is no light getting
tired? The rock analogy seems unconvincing to me. Any mechanism that
affected light would be expected to affect the electromagnetic fields
keeping the rock together, but then, the rock's mass is much greater than
the mass equivalent of these fields keeping it together, so I would expect
the effect, if it even existed at all, to have a far less detectable effect
on a rock than it would on light itself.
Gregory Loren Hansen wrote in message
<6kdhib$1ls$1...@jetsam.uits.indiana.edu>...
>In article <356a0a00...@News.bigpond.com>, <May.B Nott> wrote:
>>Does light lose energy as it travels vast distances through space?
>
>No. Not unless it's struggling against gravity. If it's losing energy,
>that energy has to go somewhere.
>
>>If not, why not?
>
>Why should it? A chunk of rock doesn't lose energy as it travels through
>space, either. Unless it's losing gravity or passing through dust or
>something.
>--
>Stay alert! Trust no one! Keep your laser handy! The Computer is
>your Friend!
>
V-man
Ahoy!
Getting tired? Better put some ' around that sucker.
#1 Why and how would photons lose energy?
#2 Energy is quantized.
#3 Photons don't split.
#4 Kinetic energy or momentum doesn't change for no reason.
#5 interaction with space? Electromagnetic? Explain.
#6 Blue shifts have been observed.
In case you will tell me that the photons gain energy somehow, then I will
ask you this: then why is shifting star dependent? Some stars have red
shifted light and some blue shifted.
Here's an experiment:
Laser light of 660nm ready to fire going in one direction.
Your detector with power source going in opposite direction.
Fire the laser and have the data sent to homebase.
Moving them away is also possible.
Boink!
_____SIGNUTURE_______4R-I/O-MONO____________________________________
**If you want to know,**
**follow like an animal**
_____END SIGNUTURE___9C-I/O-XXXX____________________________________
David Campitelli
Mike van Scherrenburg wrote:
> Pardon me, I'm not trying to be anal here, but what experimental evidence
> or indications do we have that light does not get tired? Why can't some of
> the perceived red shift be due to light getting tired? Current theory
> certainly suggests that free photons conserve their energy with a lack of
> interactions to change matters. But, theory has been in need of correction
> before. Or perhaps there is some very weak degree of interaction in "free"
> space?
>
> So, what observations lead us to believe that there is no light getting
> tired? The rock analogy seems unconvincing to me. Any mechanism that
> affected light would be expected to affect the electromagnetic fields
> keeping the rock together, but then, the rock's mass is much greater than
> the mass equivalent of these fields keeping it together, so I would expect
> the effect, if it even existed at all, to have a far less detectable effect
> on a rock than it would on light itself.
Being anal retentive is not a problem in this context. It just means that
you are attempting a thorough explanation of your question. The problem is that
this is not a scientific question. It is not scientifically sound to go out
and ask questions like " why isn't the moon made out of green cheese?"
Using a negative line of reasoning is fine if we have evidence or behavior
that is not explainable by an existing theory, or if a new theory explains it
better.
What I fail to see is why should we investigate this? Your question in
itself is a good one and worth consideration, as a supposition "Does light lose
energy as it travels through space?"
The problem is that even though we haven't thought to investigate this
directly there are some conclusions we may come up with. Are we talking about
visible light or all photon transmission? If it is all photon transmission
there may also be reason to believe that different wavelengths of light would
be affected differently. If that is true how differently? Would radio waves be
retarded more or less? Then other questions arise. If I use a spectroscope to
split the light from our start and investigate its chemical components, measure
the difference in the wavelength of those emission spectra, then do a similar
test on a more distant star would the distance between similar emission spectra
be significantly different? Shouldn't they be if light gets "tired"? Especially
if it gets "tired" at different rates for different wavelengths.
So you see the question itself is difficult to explore directly but
indirectly there we should know enough about the world to at least find out if
it is worthwhile to investigate.
Dave
Gregory Loren Hansen
In article <6kdmco$1...@sjx-ixn6.ix.netcom.com>,
Mike van Scherrenburg <mik...@ix.netcom.com> wrote:
> Pardon me, I'm not trying to be anal here, but what experimental evidence
>or indications do we have that light does not get tired? Why can't some of
>the perceived red shift be due to light getting tired? Current theory
>certainly suggests that free photons conserve their energy with a lack of
>interactions to change matters. But, theory has been in need of correction
>before. Or perhaps there is some very weak degree of interaction in "free"
>space?
>
> So, what observations lead us to believe that there is no light getting
>tired? The rock analogy seems unconvincing to me. Any mechanism that
>affected light would be expected to affect the electromagnetic fields
>keeping the rock together, but then, the rock's mass is much greater than
>the mass equivalent of these fields keeping it together, so I would expect
>the effect, if it even existed at all, to have a far less detectable effect
>on a rock than it would on light itself.
>
>
>
><6kdhib$1ls$1...@jetsam.uits.indiana.edu>...
>>In article <356a0a00...@News.bigpond.com>, <May.B Nott> wrote:
>>>Does light lose energy as it travels vast distances through space?
>>
>>No. Not unless it's struggling against gravity. If it's losing energy,
>>that energy has to go somewhere.
>>
>>>If not, why not?
>>
>>Why should it? A chunk of rock doesn't lose energy as it travels through
>>space, either. Unless it's losing gravity or passing through dust or
>>something.
There's a considerable body of theory that says light doesn't get "tired",
theory that works very well in other applications. Also, as I mentioned,
if light gets "tired", it will have to be sloughing off energy, and that
energy has to go somewhere! We don't just find a little spring in a
photon that winds down, it would need to do something like decay into two
photons of lesser frequency but identical total energy. That would make
stars appear not only redder, but brighter as distance increases.
Why wouldn't a rock lose energy? Well, you can transform to the reference
frame of the rock. And then it would just be sitting there, doing
nothing. If it has no kinetic energy, then it has no kinetic energy to
lose. Noether explained it much better than I can, it has to do with
having no preferred reference frame.
There's also Occam's razor-- we have no reason to suspect light may get
"tired" in its journey, so let's just assume it doesn't.
I'm not aware of any experiments done to look for light pooping out. Why
do you think it should?
jo...@petcom.com
In article <6kfos0$pqc$1...@flotsam.uits.indiana.edu>,
glha...@copper.ucs.indiana.edu (Gregory Loren Hansen) wrote:
> There's also Occam's razor-- we have no reason to suspect light may get
> "tired" in its journey, so let's just assume it doesn't.
>
Start a swing swinging and quit pushing- it stops.
Start a car rolling and quit giving it gas- it stops.
Put a satellite in orbit - it decays.
We know that light interacts with gravity. There's
gravity everywhere. Nothing else we know of
doesn't get 'tired'.
I would say Occam's razor says we have every reason
to suspect light gets tired. We should assume it does.
Then what would redshift indicate?
John
-----== Posted via Deja News, The Leader in Internet Discussion ==-----
http://www.dejanews.com/ Now offering spam-free web-based newsreading
jo...@petcom.com
In article <6khat6$cul$1...@nnrp1.dejanews.com>,
jo...@petcom.com wrote:
>
> In article <6kfos0$pqc$1...@flotsam.uits.indiana.edu>,
> glha...@copper.ucs.indiana.edu (Gregory Loren Hansen) wrote:
>
> > There's also Occam's razor-- we have no reason to suspect light may get
> > "tired" in its journey, so let's just assume it doesn't.
> >
> Start a swing swinging and quit pushing- it stops.
> Start a car rolling and quit giving it gas- it stops.
> Put a satellite in orbit - it decays.
> We know that light interacts with gravity. There's
> gravity everywhere. Nothing else we know of
> doesn't get 'tired'.
> I would say Occam's razor says we have every reason
> to suspect light gets tired. We should assume it does.
> Then what would redshift indicate?
Without constant energy input from incoming gravity
and inertia atoms would get tired too.
Gregory Loren Hansen
In article <6khat6$cul$1...@nnrp1.dejanews.com>, <jo...@petcom.com> wrote:
>In article <6kfos0$pqc$1...@flotsam.uits.indiana.edu>,
> glha...@copper.ucs.indiana.edu (Gregory Loren Hansen) wrote:
>
>> There's also Occam's razor-- we have no reason to suspect light may get
>> "tired" in its journey, so let's just assume it doesn't.
>>
>Start a swing swinging and quit pushing- it stops.
Due to friction with the air and the chain, not a good model for an
elementary particle.
>Start a car rolling and quit giving it gas- it stops.
Due to friction. Not a good model for an elementary particle.
>Put a satellite in orbit - it decays.
Due to friction, with negligible contributions from other interactions.
Not a good model for an elementary particle.
>We know that light interacts with gravity. There's
>gravity everywhere.
You're thinking of redshifting. This is well explored and accounted for.
Light can also blueshift, getting more energetic. But gravity is a
conservative force-- if you approach a planet or something from a
distance, you get pulled forward and then pulled back for no net energy
change. But there could be a direction change.
>Nothing else we know of
>doesn't get 'tired'.
Does an electron ever lose its charge? Does an atom ever get tired of
hanging on to its electrons? Does a hot gas ever get tired of bouncing
molecules around and cool down, unless it passes that energy to another
system? Does your table get tired of standing up and slump down? Does
the Earth get tired of pulling things back to the surface?
k
Mike Philbin
Hey, john,
waddayarekkn?
gravity out + polarisation of propagation = light frequency detectable
by human eye?
gravity source bigger + polarisation of propagation = red shifted light?
ie red shift isn't showing expansion, just gravity strength?
black holes would be black because the extra gravity-red-shift would
take light beyond detectable range... don't we detect x-ray stream or
some such 'other' radiation off of a black hole (aka the heavy gravity
sources at the centres of galaxies)
idunno
?:|
Niels M. Møller
Hi, all !
I just had a little note for this discussion...
I'm not very well versed in general or special relativity, but I think
(as others, who have contributed to this discussion) it is a weird
non-intuitive fact, that when an object or even light is "accelerated"
to a constant velocity in empty space and not affected by any forces,
it will just keep on moving for ever (as even Newton stated). Isn't it
a bizarre thing, that an object containing energy (mass and speed)
will be transported through space "for free", but an object with lower
energy (no speed) will not be transported ? One should think, that
moving an object even in space would need some energy. In a way, I
feel, that the term "space" has really no significance, but force has
?!? Well, if the universe has no end (which is also extremely
incomprehensible to me...), then I see why everything has to be
relative and why space in a way has no significance. Well, I guess
I'll have to throw away my intuition and my experience from earth,
won't I?
Sometimes I wish relativity was never "invented", the world is much
harder "understanding" when you have to think in more than three
dimensions and from pieces of atoms and out into infinite space... ;-)
And I will never be good at this - I'll stick to standard physics...or
maybe I'll read an introduction to relativity in my summer holiday =).
/Greetings
Niels M. Møller, 1.g stud. art, Denmark
(niels_...@bigfoot.com)
Nathan Urban
> I'm not very well versed in general or special relativity, but I think
> (as others, who have contributed to this discussion) it is a weird
> non-intuitive fact, that when an object or even light is "accelerated"
> to a constant velocity in empty space and not affected by any forces,
> it will just keep on moving for ever (as even Newton stated).
That doesn't really seem all that weird when you realize that everything
that slows down is doing so out of friction.
> Isn't it a bizarre thing, that an object containing energy (mass and speed)
> will be transported through space "for free", but an object with lower
> energy (no speed) will not be transported ?
Energy and speed are relative! From the perspective of the thing being
"trasported through space `for free'", it has no kinetic energy and it's
not going anywhere!
> One should think, that moving an object even in space would need some energy.
That becomes downright counterintuitive when you start thinking of the
object in its own rest frame. You're saying that a force would be
necessary just to keep it sitting there.
> Sometimes I wish relativity was never "invented", the world is much
> harder "understanding" when you have to think in more than three
> dimensions and from pieces of atoms and out into infinite space... ;-)
Such is life. :)
(And note that all of your conceptual problems with relativity also
exist in the Galilean relativity of Newtonian mechanics..)
Paul Stowe
In <6kpa9r$cea$1...@crib.corepower.com> nur...@crib.corepower.com (Nathan
>
>> I'm not very well versed in general or special relativity, but I
>> think (as others, who have contributed to this discussion) it is a
>> weird non-intuitive fact, that when an object or even light is
>> "accelerated" to a constant velocity in empty space and not affected
>> by any forces, it will just keep on moving for ever (as even Newton
>> stated).
>
>That doesn't really seem all that weird when you realize that
>everything that slows down is doing so out of friction.
Here's the rub (pun intended), as Feynman was fond of pointing out,
friction is nothing more or less than EM field interactions of atoms.
>> Isn't it a bizarre thing, that an object containing energy (mass and
>> speed) will be transported through space "for free", but an object
>> with lower energy (no speed) will not be transported ?
>
>Energy and speed are relative! From the perspective of the thing
>being "trasported through space `for free'", it has no kinetic energy
>and it's not going anywhere!
>
>> One should think, that moving an object even in space would need
>> some energy.
>
>That becomes downright counterintuitive when you start thinking of the
>object in its own rest frame. You're saying that a force would be
>necessary just to keep it sitting there.
>
>> Sometimes I wish relativity was never "invented", the world is much
>> harder "understanding" when you have to think in more than three
>> dimensions and from pieces of atoms and out into infinite space...
;-)
>
>Such is life. :)
>
>(And note that all of your conceptual problems with relativity also
>exist in the Galilean relativity of Newtonian mechanics..)
Yes, because it is simply an artifact of perspective. But in Special
Relativity and Newtonian mechanics we can chose any fixed coordinate
system 'relative' and then measure all body's motion consistently with
it. But the choice is arbitrary, since it is 'we' who are the
observer, and for calculation of physical processes these, in the end,
are only relative to our frame of reference and souldn't be affected by
the choice of which one we chose. So, lets take you body in motion, if
we chose its center of mass as our coordinate system, it has no kinetic
energy of motion, but we've transferred this to the 'other' objects
that are moving relative to it and from our perspective, these change
position relative to us. There's still kinetic energy, but its now
transferred to the 'other' objects.
Paul Stowe
Fredrick toe Laer
Nathan Urban wrote:
>
> In article <356fe77...@news.cybercity.dk>, myt...@iname.com (Niels M. Møller) wrote:
>
> > I'm not very well versed in general or special relativity, but I think
> > (as others, who have contributed to this discussion) it is a weird
> > non-intuitive fact, that when an object or even light is "accelerated"
> > to a constant velocity in empty space and not affected by any forces,
> > it will just keep on moving for ever (as even Newton stated).
>
> That doesn't really seem all that weird when you realize that everything
> that slows down is doing so out of friction.
>
> > will be transported through space "for free", but an object with lower
> > energy (no speed) will not be transported ?
>
> Energy and speed are relative! From the perspective of the thing being
> "trasported through space `for free'", it has no kinetic energy and it's
> not going anywhere!
>
> > One should think, that moving an object even in space would need some energy.
>
> That becomes downright counterintuitive when you start thinking of the
> object in its own rest frame. You're saying that a force would be
> necessary just to keep it sitting there.
>
> > Sometimes I wish relativity was never "invented", the world is much
> > harder "understanding" when you have to think in more than three
> > dimensions and from pieces of atoms and out into infinite space... ;-)
>
> Such is life. :)
>
> (And note that all of your conceptual problems with relativity also
> exist in the Galilean relativity of Newtonian mechanics..)
hi,
also in reaction to Paul Stowe....
May i first state that 'empty space' is not at all empty, there are many
particles and there is even more EM-radiation. Then the question rises:
"Can light
be slowed down by light itself?". I mean that if light encounters
another 'ray' of light from an opposite direction, wil they travel
trough each other without effecting each others speed? I find that hard
to believe.
Referring to the title 'Tired Light', i think that it must be possible
for light to be slowed down.
I that case maybe we should change our teminology to max. light speed,
in stead of light speed.
And if their is such a thing as tired light, that could also be a
possible explanation why there are
stars that are older than the universe itself.
but than again maybe I'm wrong :)
please respond, i'm particulary interested in this one....
Fredrick toe Laer
Nathan Urban
> Then the question rises: "Can light
> be slowed down by light itself?". I mean that if light encounters
> another 'ray' of light from an opposite direction, wil they travel
> trough each other without effecting each others speed?
There is an amplitude for photon-photon interaction, but it's very
very small. So no, they don't really affect each other's speed much.
And light rays travelling through vacuum just don't interact that much
with other things, even over cosmological distances.
> Referring to the title 'Tired Light', i think that it must be possible
> for light to be slowed down.
Well, certainly light travelling through a medium can be slowed down.
> And if their is such a thing as tired light, that could also be a
> possible explanation why there are stars that are older than the universe
> itself.
There aren't; that's an old result which has since been superceded by
better data; see the Cosmology FAQ entry, "How can the oldest stars in
the Universe be older than the Universe?", at:
http://www.astro.ucla.edu/~wright/cosmology_faq.html#age
For anyone who might have missed it, you might also want to consult the
following from the Cosmology FAQ
http://www.astro.ucla.edu/~wright/stars_vs_cmb.html
http://www.astro.ucla.edu/~wright/tiredlit.htm
in regard to cosmological redshift and tired light.
[Note followups. I decided to take sci.physics out and replace it
with sci.astro.]
Fredrick toe Laer
As i recall Stephen Hawking stated that the only 'radiation' from a
Black Hole are the particles or anti-particles which didn't anihilate
with each other cause the other one fell in the Black Hole. So you have
particle A and anti-A they both travel in half a cirkel first away and
later towards each other. BUT when the particles are on their path one
of them is catched by the Black Hole so, there is a particle looking for
its counterpart
but then again maybe I'm wrong.......... ;)
Mike Philbin
Okay, avoiding the theoretical thing they call The Black Hole, do you
concur that higher gravity wells might propagate light of an altered red
shift?
Fredrick toe Laer
No, i was suggesting that one cannot detect any radiation other than the
described one, 'cause you would need a super light speed radiation, wich
(as far as we know) doesn't exist. for further explanation on the
radiation wich stephen Hawking described read his book 'A Brief History
of Time'
Fredrick
Mike Philbin
I guess what I am trying to say is this ...
You wouldn't need a superlightspeed radiation iff light is propagated AS
A FUNCTION OF the gravity wave (technical details notwithstanding) light
would still be propagated from a great gravity source like a black hole
or neutron star ...
We don't see the light because it is redshifted off the scale?
?:)
Fredrick toe Laer
I don't think light is redshifted of the scale, so that is why a black
hole is black.. I think that the speed of light is not sufficient to
escape from the black hole, and since light speed is the maximum, wich i
doubt, NOTHING else can escape from the black hole.... but what do you
mean by light being a function of the gravity wave???
?:) with a puzzled face
fred.
ps. you can also read the other discusion about tired light between
nathian and i, in wich we discuss if light speed is the max (and wich i
am losing cause no one has ever made a theory about it....!!@$#&^%)
Mike Philbin
Okay, aren't these two examples the same thing?
In both cases I am thinking of electric current applied acrross the
tungsten element in a lightbulb.
1) you overload a system, causing electron jumping ... it gives out a
photon sized item which travels off at c.
2) you overload a system, causing universal instability ... it spins the
resonance of its interacting parts equal to the frequency of light
carried out as the universe fills in the imbalance at c?
I am not talking about 'ether' (not at least as a universe magnitude
liquid) but I am talking about a sum total effect of all the universe's
resonating parts = gravity wave via constructive/destructive resonance
and debts to pay across the function.
In example (1) you need bits called photons. In example (2) nothing is
transported. Only the interaction between elements is illustrated by the
so-called em radiation in all its forms.
Why does it take place at c? Why is a proton that size? Why is the
electron radius that size? There are huge clues in here regarding the
structure and relevance of c ...
I probably need to say more but shouldn't.
Charles W. Shults III
Mike Philbin wrote:
>
> Hey, john,
>
> waddayarekkn?
>
> gravity out + polarisation of propagation = light frequency detectable
> by human eye?
>
> gravity source bigger + polarisation of propagation = red shifted light?
>
> ie red shift isn't showing expansion, just gravity strength?
It is true that any luminous body with appreciable gravity does
red-shift the light that leaves it. The whole universe undoubtably has
a gravity field, but since it appears to be isotropic, the force would
cancel in all directions. The gravity field in a hollow massive sphere
would be equal to zero to anyone inside. The universe exhibits five
different methods of red-shift that I'm aware of; one is due to its
expansion, and is uniform. See 2.37 deg K microwave background.
>
> black holes would be black because the extra gravity-red-shift would
> take light beyond detectable range...
Yes, the light loses so much energy that it has a wavelength of zero.
This means it doesn't exist. Alternatively, the space around the
black hole is so curved that a path out of it does not exist.
> don't we detect x-ray stream or
> some such 'other' radiation off of a black hole (aka the heavy gravity
> sources at the centres of galaxies)
This is called Hawking Radiation and it is due to the fact that an
energetic photon passing near a mass can become a particle/antiparticle
pair. In the case of black holes, electron/positron pairs can be
created, and they steal the energy from the black hole itself.
If one of the particles falls within the event horizon, it is lost and
the other particle remains. Often, however, the pair will annihilate
each other and a unique gamma ray signature is left, at .51 MeV and at
.34 MeV, due to the different decay mechanisms of this annihilation.
Cheers!
Chip Shults
Charles W. Shults III
Nathan Urban wrote:
> That doesn't really seem all that weird when you realize that everything
> that slows down is doing so out of friction.
Untrue. Would you call rocket propulsion friction? Only when
material
slows from being in contact with other material is friction the cause.
Throw something up- it slows and falls. This has little to do with
air friction; it's due to the acceleration from gravity. This works in
space, too. If you were on a tower a thousand kilometers tall and
dropped
something, it would indeed fall, even though you would be in vacuum.
Cheers!
Chip Shults
Nathan Urban
> Nathan Urban wrote:
> > That doesn't really seem all that weird when you realize that everything
> > that slows down is doing so out of friction.
> Untrue.
The context was of inertial motion; the original poster was saying
that it's odd that something can "keep going forever" at constant speed
without slowing down. This usually comes from an intuitive notion of
things "running down" over time, due to friction. Of course, you can
have non-friction (i.e., noninertial conservative) forces acting like
electromagnetic fields and such.
Mike Philbin
Charles W. Shults III wrote:
>
> It is true that any luminous body with appreciable gravity does
> red-shift the light that leaves it. The whole universe undoubtably has
> a gravity field, but since it appears to be isotropic, the force would
> cancel in all directions. The gravity field in a hollow massive sphere
> would be equal to zero to anyone inside.
This isotropism could be a factor in debunking the idea until you think
of the mechanism that creates light in the scheme where it is carried
along by 'gravity'.
The material universe has an all pervading gravity field but this field
is based on the sum total of atomic resonances in the universe
propagating an imaginary gravity field. Nature tries at all times to
attain equillibrium and settle debts. You only have to overload an
atomic system to cause a 'butterfly wing' effect to propagate through
the imaginary gravity field as it tries to reattain balance. This
happens only once in a radiating path; for each settled debt (photon).
As shown by the speed of light, this loophole reaction takes place at c;
its frequency makes it visible; the energy given to the strength of
source would dictate the light's red shift.
I dunno?
Luka Crnkovic
Think of light as a wave, and it will be easier to understand.
If a light wave meets another light wave it will be the same as when two
sound waves meet: they interfere. Your result will be that the light
will in some places be stronger (more energy;same speed) and in some
places weaker (less energy, same speed). The thing is that the velocity,
c, stays the same. This is valid for all EM radiation, not just light.
//Luka
>
> hi,
> also in reaction to Paul Stowe....
>
> May i first state that 'empty space' is not at all empty, there are many
> particles and there is even more EM-radiation. Then the question rises:
> "Can light
> be slowed down by light itself?". I mean that if light encounters
> another 'ray' of light from an opposite direction, wil they travel
> trough each other without effecting each others speed? I find that hard
> to believe.
> Referring to the title 'Tired Light', i think that it must be possible
> for light to be slowed down.
> I that case maybe we should change our teminology to max. light speed,
> in stead of light speed.
> And if their is such a thing as tired light, that could also be a
> possible explanation why there are
> stars that are older than the universe itself.
Tom C
If that were true, would you not expect to see both red-shifted, and
blue-shifted spectral lines from the same stellar object?
TC
Luka Crnkovic wrote in message <3587AEA3...@sw.seisy.abb.se>...
M.C.Harrison
Tom C wrote:
>
> If that were true, would you not expect to see both red-shifted, and
> blue-shifted spectral lines from the same stellar object?
Sure, although speed of the edges is fairly trivial and most of the
light comes from the main body of the star.
Bjorn
M.C.Harrison wrote in message
<358AA9...@spammers.of.the.world.unite.etc>...
>Tom C wrote:
>> If that were true, would you not expect to see both red-shifted, and
>> blue-shifted spectral lines from the same stellar object?
>
>Sure, although speed of the edges is fairly trivial and most of the
>light comes from the main body of the star.
Actually, you can observe that from those double-stars circulating each
other really fast. Dunno what the appropriate name for those systems are,
but you can use the relative doppler shift to measure the speed of rotation.
/Bjorn
Gregory Loren Hansen
In article <rOoi1.327$2c6.1...@newsgate.direct.ca>,
Tom C <col...@direct.ca> wrote:
> If that were true, would you not expect to see both red-shifted, and
>blue-shifted spectral lines from the same stellar object?
>
We do. Except it shows up as a broadening of the lines, since there are
many different atoms with many different velocities, both positive and
negative. The hotter the star gets, the broader the lines get.
--
"Don't just do something, stand there!" - Buddha
Lars Rosenberg
Luka Crnkovic wrote in message <3587AEA3...@sw.seisy.abb.se>...
>Think of light as a wave, and it will be easier to understand.
>If a light wave meets another light wave it will be the same as when two
>sound waves meet: they interfere. Your result will be that the light
>will in some places be stronger (more energy;same speed) and in some
>places weaker (less energy, same speed). The thing is that the velocity,
>c, stays the same. This is valid for all EM radiation, not just light.
>
This phenomen is used in every CD player. If the light wheren´t a laser
light in phase it would be impossible for the CD to read the information of
the discs. When the light hit´s a hole in the record it reflects out of
phase and the light is not seen by the detektor. if the lights hits a non
hole the light is reflected in phase and the light is seen by the detector.
I don´t quite remember if it was thehole or non hole that made a non signal.
It was more twelve years ago I took the course in the CD technolagy. The
average of lights returned sets the speed of the disc. This is why the disc
runs faster at the center and slower at the edge.
//Lars Rosenberg