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Has the Sun's color changed?



 
 
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  #11  
Old August 16th 03, 01:43 PM
G=EMC^2 Glazier
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Hi Painius The doppler effect for sound needs the vibration of air.
Space does not vibrate. Still there is a sameness (for sure) Coming and
going from the rest receiver creates in sound,and light
shorter(coming),and longer(going) wave lengths. It is the answer to how
photons waves change their length in space that my theory answers. It
also gives a structure to photon waves. Bert

  #12  
Old August 17th 03, 01:46 AM
Odysseus
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Painius wrote:

What i have not figured out yet is how we can make the seemingly
huge assumption that light waves will behave in this manner similar
to sound waves. Any ideas?

I don't think it's an assumption at all, but a consequence (or
prediction, if you like) of the fundamental theories concerned, like
Maxwell's. The effect is only roughly similar to that for sound,
mainly in that sound is a longitudinal pressure wave propagating
through a medium, while EM radiation is a transverse wave that needs
no medium for transmission -- or if there is such a "lumeniferous
ether" its properties are such that it always has the same velocity
as both the source and the receiver, rather hard to picture in the
general case!

Imagine two cars, A & B, facing each other on a highway; A is
sounding its horn and has its headlights on. If A and B are
approaching each other, each at 50 km/h, then B stops while A's speed
increases to 100 km/h, the sonic Doppler effect heard by B's driver
will change slightly, the pitch rising between the first and second
phases, but the (tiny) blue-shift he sees in the light emitted by A's
headlights will remain constant throughout, despite the change in
their 'absolute' speeds. If A were then to stop while B approaches at
100 km/h, the blue-shift of the headlights would still remain the
same to B's driver but he would hear the pitch of the horn becoming
even higher.

--
Odysseus
  #13  
Old August 19th 03, 04:10 AM
Babak Sehari
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I gave it a thought that my eye lens might be "yellowed". Then again, I
used to remember that the sun
looked like a tangstan light bulb. Today, the tangstan light bulb is the
same color as it used to be, but the
sun is whitter! Plus, I just had an eye exam 3 month ago, which showed my
eyes are in perfect health.

The models we have for the sun or any star, only takes into acoount the
gravty and heat generated by
nuclear energy. It does not take into account many other known and unkown
phenomena, such as electric
charging or magnetic forces present on that star. So we roughly know that
the sun will end up red and
large, but before it gets there it could go through many types of transiant
states not known to us. For eample a
simple model of earth suggest that it rotated around itself and around the
sun. However, we know the
earth is more complicated than that. For example shifting of continants,
earth's interaction with moon causing ebb
and flow of the occw\eans, its maganetic pole, its electric charge, its
balck body radiation as a function of the
atmospheric conditaion, etc.

In my opinion the only way to resolve this question is to make a careful
measurement. I have seen some papers
written for solar cells in the 70s and 80s that have measured the sun's
radiation spectrum. We could do another
measurement and compare the results. Further more, since the sun is very
important for us, we really should
monitor it more carefully. Of course, we can not do a thing about these
changes for forseeable future, but at least
we can plan to deal with it in the earth.

Regards,
Babak


"Bob Weber" wrote in message
news:al_Ya.102082$uu5.15119@sccrnsc04...
I had cataract surgery several years ago. With the new plastic lens,
suddenly white is white!

Bob

"David Knisely" wrote in message
...
No, the sun has not changed color significantly. It will become

somewhat
redder in the distant future, but not over the period of a lifetime. To

me,
it looks about the same as it did as a child, although the yellowing of

the
eye's lens over time may cause a change in the perception of the color.

Clear
skies to you.
--
David W. Knisely
Prairie Astronomy Club:
http://www.prairieastronomyclub.org
Hyde Memorial Observatory: http://www.hydeobservatory.info/

**********************************************
* Attend the 10th Annual NEBRASKA STAR PARTY *
* July 27-Aug. 1st, 2003, Merritt Reservoir *
* http://www.NebraskaStarParty.org *
**********************************************







  #14  
Old August 24th 03, 12:28 PM
Painius
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"Benoit Morrissette" wrote...
in message ...

"Painius" wrote:

"G=EMC^2 Glazier" wrote in message...
...

Ho Painius What reason is given for the photons waves getting shorter
coming towards us,and longer going away from us. I have an idea why this
is reality for light. Bert


Similar to the Doppler effect for sound, Bert . . .

. . .
What i have not figured out yet is how we can make the seemingly
huge assumption that light waves will behave in this manner similar
to sound waves. Any ideas?


Because waves behaves like waves...

In the beginning, Isaac proved that light travels as waves. Problem is that
Albert Einstein proved that light travels as photons. They cannot both be
right, no? Yes, they are, thanks to "mind boggling" quantum dynamic theory...
Sometimes, light behave like waves and other times it behave like photons, just
make sure you don't mix the two together at the same time!

BTW, i am not sure but i think it is Doppler who got the idea for light waves
and Fizeau who got it for sound waves.

Benoît Morrissette


Thanks, Benoît!

Actually, Christian Doppler (1803-1853) *did* get the idea...
for sound *and* for light, yet it was Armand Fizeau (1819 -
1896) who proved Christian Doppler's theory as it applied to
light waves. Here is the story in a nutshell from one of many
similar websites...

Christian Doppler:

The Austrian physicist who developed the famous "Doppler
Effect."

Christian Doppler was an Austrian physicist famous for
devising the "Doppler Effect." Doppler theorized that sound
waves from a moving source would be compressed or
expanded, or that the frequency would change.

The Doppler Effect was used to confirm the Universe was
expanding, also serving an important role in the world of
astronomy.

In 1842, Doppler made the equation about frequency and
relative movement of sound source and observer. Doppler
conducted a unique experiment to prove his theories. For
two days, Doppler had a train pull repeatedly at different
speeds a freight car with trumpeters playing on top of it.
He then had a musician capable of understanding the
differences in sounds record the height of the notes played
as the train moved closer or further away. This effect proved
Doppler's theory superbly. Doppler later tried to prove that
his theory also applied to light but was unable to fulfill his
goal.

Instead, another scientist, Fizeau, generalized Doppler's
work and discovered that the Doppler Effect also applied to
light. This discovery contributed greatly to proving the
Universe was expanding and allowed Doppler's work to
have an important influence on astronomical studies.

-------------------------------------------------------

Now, Benoît... just to say that Fizeau was right simply because
"waves behave like waves" doesn't seem to me to be enough
of an explanation. I like reading your articles because you
usually take the time to make things as clear as possible. So
could you explain how transverse radiation (light, etc.) waves
can be proved to behave just like longitudinal sound waves?

Especially in light of what Odysseus and Bert had to say?

Thanks in advance for your help!

happy days and...
starry starry nights!

--
A smidgeon of fear and a sprinkle of strife
And a whole lotta love till your cold...
Most everyone here wants to live a long life,
Ah! but nobody wants to get old.

Paine Ellsworth



  #15  
Old August 24th 03, 01:30 PM
G=EMC^2 Glazier
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Hi Painius Well sound waves,and water waves go together. It is
possible Newton,and Einstien were both right. It takes a particle to go
through space without a medium,and every particle carries a wave with
it. The similarity(sameness) about waves and cords(strings) are the
longer the cord the lower the note. I would think people that play the
harp would like the string theory. Bert

  #16  
Old August 24th 03, 01:56 PM
Benoit Morrissette
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On Sun, 24 Aug 2003 11:28:21 GMT, "Painius" wrote:

"Benoit Morrissette" wrote...
in message ...

"Painius" wrote:

"G=EMC^2 Glazier" wrote in message...
...

Ho Painius What reason is given for the photons waves getting shorter
coming towards us,and longer going away from us. I have an idea why this
is reality for light. Bert

Similar to the Doppler effect for sound, Bert . . .

. . .
What i have not figured out yet is how we can make the seemingly
huge assumption that light waves will behave in this manner similar
to sound waves. Any ideas?


Because waves behaves like waves...

In the beginning, Isaac proved that light travels as waves. Problem is that
Albert Einstein proved that light travels as photons. They cannot both be
right, no? Yes, they are, thanks to "mind boggling" quantum dynamic theory...
Sometimes, light behave like waves and other times it behave like photons, just
make sure you don't mix the two together at the same time!

BTW, i am not sure but i think it is Doppler who got the idea for light waves
and Fizeau who got it for sound waves.

Benoît Morrissette


Thanks, Benoît!

Actually, Christian Doppler (1803-1853) *did* get the idea...
for sound *and* for light, yet it was Armand Fizeau (1819 -
1896) who proved Christian Doppler's theory as it applied to
light waves. Here is the story in a nutshell from one of many
similar websites...

Christian Doppler:

The Austrian physicist who developed the famous "Doppler
Effect."

Christian Doppler was an Austrian physicist famous for
devising the "Doppler Effect." Doppler theorized that sound
waves from a moving source would be compressed or
expanded, or that the frequency would change.

The Doppler Effect was used to confirm the Universe was
expanding, also serving an important role in the world of
astronomy.

In 1842, Doppler made the equation about frequency and
relative movement of sound source and observer. Doppler
conducted a unique experiment to prove his theories. For
two days, Doppler had a train pull repeatedly at different
speeds a freight car with trumpeters playing on top of it.
He then had a musician capable of understanding the
differences in sounds record the height of the notes played
as the train moved closer or further away. This effect proved
Doppler's theory superbly. Doppler later tried to prove that
his theory also applied to light but was unable to fulfill his
goal.

Instead, another scientist, Fizeau, generalized Doppler's
work and discovered that the Doppler Effect also applied to
light. This discovery contributed greatly to proving the
Universe was expanding and allowed Doppler's work to
have an important influence on astronomical studies.

-------------------------------------------------------

Now, Benoît... just to say that Fizeau was right simply because
"waves behave like waves" doesn't seem to me to be enough
of an explanation. I like reading your articles because you
usually take the time to make things as clear as possible. So
could you explain how transverse radiation (light, etc.) waves
can be proved to behave just like longitudinal sound waves?

Especially in light of what Odysseus and Bert had to say?

Thanks in advance for your help!

happy days and...
starry starry nights!

Unfortunatly, i am not a quantum physicist so i cannot go further than "waves
behaves like waves"... maybe if we can find the original paper of Fizeau?

One thing i am sure of: we must always be very carefull when we talk about the
dual nature (wave-particle) of light because then we are talking about a
mathematical MODEL, not about light itself. We don't know what light is. No
ones knows. We will never knows. All what we have is a model that describes
adequately all the observations we have so far on the behaviour of light. As
new observations will come by, new models will be built.

We are currently on the verge a a new era in astrophysic: the discovery of dark
energy. Here we have observations that cannot be explained by ANY theory we
have so far. This is the case where a new model of gravitation will have to be
conceived. Some people says that Einstein is right, others says he is wrong.
The real scientist says: I do not know how gravitation works, but it works LIKE
this (so far).

Now, what do we do with dark energy? First, get more observations, a lot more!
Second, create a new model or modify an old one to describe these new
observations. An absolute must for this new model to be accepted by the
scientific community: it must not invalidate any previous observations! Just
like relativity: at low mass low speed, it gives exactly the same results than
newtonian law of gravitation.

Remember: a model do not explain how the universe works, it just describe it.

For the short answer: i cannot prove that transverse light waves behave like
longitudinal sound waves. I don't even know if waves exists really after all...
Benoît Morrissette
  #17  
Old August 24th 03, 02:33 PM
John Zinni
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"Benoit Morrissette" wrote in message
...

In the beginning, Isaac proved that light travels as waves.


"As indicated earlier, Newton and his followers argued vehmently with
Huygens and his followers over the nature of light. Newton subscribed to a
"corpuscular" theory, where he envisioned light as small compact bodies of
energy. Huygens focussed on the wave like nature and developed that theory."
http://www.chembio.uoguelph.ca/educm...las/newton.htm


  #18  
Old August 24th 03, 05:07 PM
Bill Sheppard
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Painius asked Benoit,
So could you explain how transverse
radiation (light, etc.) waves can be
proved to behave just like longitudinal
sound waves?


Well, police radar uses reflected/ Dopplered EM radiation to
measure speed. Whether a wave is transverse or longitudinal is a moot
point as far as its being stretched/ compressed by the Doppler effect.
oc

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  #19  
Old August 24th 03, 08:12 PM
Painius
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"Bill Sheppard" wrote in message...
...

Painius asked Benoit,

So could you explain how transverse
radiation (light, etc.) waves can be
proved to behave just like longitudinal
sound waves?


Well, police radar uses reflected/ Dopplered EM radiation to
measure speed. Whether a wave is transverse or longitudinal is a moot
point as far as its being stretched/ compressed by the Doppler effect.
oc

To reply by e-mail please use anti-spam address: oldcoot88atwebtv.net
Change 'at' to@


'Lo Bill --

I believe that police radar operates on a principle that
has to do with the "radar mile." I know a little about this
because i worked on TACANs in the military. It's a very
different principle than Doppler's effect, which does not
require wave reflections.

And it still does not explain how light waves coming
from light sources that are moving toward us are
scrunched together, or how such waves from sources
that are moving away from us are stretched apart.

Nor does it explain how this can be found by actually
measuring the shift of spectral lines toward the red or
blue end of the visual spectrum.

Morrissette's right... it would definitely help if someone
could come up with Fizeau's paper. I'll keep looking.

happy days and...
starry starry nights!

--
A smidgeon of fear and a sprinkle of strife
And a whole lotta love till your cold...
Most everyone here wants to live a long life,
Ah! but nobody wants to get old.

Paine Ellsworth



  #20  
Old August 25th 03, 03:19 AM
Bill Sheppard
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P.S. to Painius-
The 'radar mile' is simply the time it takes for a
pulse, propagating at c, to travel one mile (1.6 km) and return to the
receiver. It applies to all radars, not just the Doppler-based police
speed-trap units. A web search under 'radar mile' will turn up some good
hits.

To reply by e-mail please use anti-spam address: oldcoot88atwebtv.net
Change 'at' to@

 




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