Speed of light explination! plz

[ryan125]

Don't call me crazy <img src="/images/icons/smile.gif" /><br /><br />Most science I don't have a problem with, except for the speed of light. YES i know it has been proven again and again. But hopfuly you smarter people can explain for me.<br /><br />The compton effect according to wikipedia "is the decrease in energy (increase in wavelength) of an X-ray or gamma ray photon, when it interacts with matter." <br /><br />So lets take an experiment of measuring the speed of light + motion. All of these experiments involve mirrors. Reflectivity (as i've read) works when a photon is absorbed and then emitted out of the molecule. Yet the compton effect states that a photon may lose energy, if that is true why would sciencists think the speed of light would remain the same?<br /><br />Why can't it be that a photon is simply stable at a speed of C, It will remain above C until it reacts with matter. It releases some of the extra kinetic energy into the matter, then is emitted at C relative to the object that absorbed it.<br /><br />Red shifting and blue shifting. When the wave length of light is measured, we have some coincidences. When matter that is emitting light is moving towards and observer, there is a decrease in the wave length. When it is moving away there is an increase. Yet the length in nm is assuming that the light is moving at C. What if it is the actual speed of light that is increasing, which is being measured incorrectly as a decrease in wavelength.<br /><br />Gravity. I understand from Gravitational red and blue shifts as well as gravitational lensing that gravity has an effect on light. So first gravitational red shift, which is known to occur when the observer is farther away from a source of gravity. So lets say something emitts light close to the even horizon of a black hole, the light wave length decreases and "shifts to red". Now the opposite is true for blue shifting. Now if a photon is replaced with matter, we accept that the matter is speeding up

 

[kelvinzero]

I remember something about putting a mirror on the moon and bouncing a signal off it. It actually takes a substancial amount of time for the signal to go both ways... I forget. 2.4 seconds?<br /><br />So that is just one example where it would be very easy to demonstrate if red light moved more slowly than blue light.<br /><br />Here is an interesting link from 1946 where they used radiowaves (and where I got the 2.4 from)

 

[emperor_of_localgroup]

In compton effect a photon is deflected by an electron, just like a cue ball is deflected by another ball on a pool table. The photon loses energy in the process. In case of mirror, a photon is absorbed and re-emitted by an atom. This process is nicely explained in Bohr's hydrogen atom model when explaining spectrum, can be found in most college physics book. By absorbing a photon energy an electron goes into a higher orbit, then loses exactly the same amount of energy by emitting a photon when it falls back into the original lower orbit.<br /> <div class="Discussion_UserSignature"> <font size="2" color="#ff0000"><strong>Earth is Boring</strong></font> </div>

 

[kyle_baron]

<font color="yellow"><br />Don't call me crazy </font><br /><br />Ok, your not crazy. <img src="/images/icons/wink.gif" /><br /><font color="yellow"><br />Now gravitational lensing is proof that photons are effected by gravity. </font><br /><br />Not exactly. It would be more accurate to say that the space around the photon is affected by gravity. The photon is following the curved space, of the gravity in that field.<br /><font color="yellow"><br />Am i just stupid?</font><br /><br />Ahhhhhhh.... No! As a matter of fact, you know quite a bit more about light than I do. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p><font size="4"><strong></strong></font></p> </div>

 

[lost_shaman]

ryan125 : <font color="yellow">Why can't it be that a photon is simply stable at a speed of C, It will remain above C until it reacts with matter. It releases some of the extra kinetic energy into the matter, then is emitted at C relative to the object that absorbed it.</font><br /><br />Well that's very close to the basic concept. Light only travels at c in a vacuum.

 

[h2ouniverse]

In relativity theory, the time referential attached to the photon is such that there is no time flow for the photon. The photon does not age! It is in a steady state "as long as" not intercepted (i.e; on the segment of spacetime ending at the point (x, y, z, ct) of the interception in your referential. <br />So it cannot travel at more than c in your referential otherwise that would mean a reversed time in its referential.<br />And although reversal of causality is now considered in quantum physics, it is not in relativity theory...<br /><br />Best regards.<br /><br />

 

[h2ouniverse]

Emperor,<br /><br />About my post on the other thread, and kinetic energy expressed as a function of (omega.D/c)²: in the case of the massless photon, there is no spatial extension so D=0, t1 = 0 and homogenized time interval is multiplied by c/D i.e. infinite. That would be equivalent to a zero moment of inertia, and free ability to "rotate", i.e. no possibility to privilege a time direction. <br />This is consistent with the fact that in relativity theory, any massless object is timeless and so MUST appear as traveling at c to an observer.<br /><br />Note that whan one says speed of light is lower than c in non-vacuum, that is seen as equivalent to a non-zero massed photon. Actually to me this a rough modelling of the series of interactions between c-speeded timeless photons (in between particles) and the particles of the matter crossed. = /> See Tcherenkov effect: the actual speed is c but the excited matter emits (blue) photons.<br /><br />Best regards.

 

[ryan125]

"Not exactly. It would be more accurate to say that the space around the photon is affected by gravity. The photon is following the curved space, of the gravity in that field. "<br /><br />Thx! now that makes sense to me...sorta, I have a whole problem with the bending of space thing.

 

[ryan125]

"In relativity theory, the time referential attached to the photon is such that there is no time flow for the photon. The photon does not age! It is in a steady state "as long as" not intercepted (i.e; on the segment of spacetime ending at the point (x, y, z, ct) of the interception in your referential. <br />So it cannot travel at more than c in your referential otherwise that would mean a reversed time in its referential. <br />And although reversal of causality is now considered in quantum physics, it is not in relativity theory... "<br /><br />i think i understand the basics of what your saying, that something can't move backwards in time so photons are stuck at C. thx <img src="/images/icons/smile.gif" />

 

[lost_shaman]

H2Ouniverse : <font color="yellow">Note that whan one says speed of light is lower than c in non-vacuum, that is seen as equivalent to a non-zero massed photon. Actually to me this a rough modelling of the series of interactions between c-speeded timeless photons (in between particles) and the particles of the matter crossed.</font><br /><br />It really has to do with spacetime rather than the photon itself. You see matter has gravitational and magnetic fields that condense spacetime, so a photon traveling through a medium acts as if it has more spacetime to travel through to equal the same measurable distance traveled that a photon in a vacuum can be measured to travel in a given amount of time.<br /><br />Here's an analogy... Imagine two Cars both traveling at 60 m/p/h, and one Car (A) is traveling on a road that is a relatively straight line like this... <br />__________________________ A<br /><br />And the other Car (B) also traveling at 60 m/p/h is traveling on a road with curves that looks like this...<br /><br />VVVVVVVVVVVVVVVVVVVVVVVVVV B<br /><br />Car A is measured to reach the end of the road in a much shorter amount of time than Car B does, so if you only measure the linear distance traveled over time without consideration for the difference between the two roads you might wrongly conclude that Car B is much slower than Car A. When in fact both traveled at 60 m/p/h the entire time.<br /><br /> <br /><br />

 

[h2ouniverse]

LSh,<br />That is fine with me. A very interesting analogy (the bumpy road) ! The attribution of a mass to photon in non-vacuum middle looks strange and inconsistent to me. This being said, is the bumpy road an academic explanation? It is the first time I see it, and it suits me well. <br />Do you know a link where I could find more about propagation of light in matter (with relativity!), and about energy and momentum transfer when lights reflects on a surface (radiation pressure) ?<br /><br />Best regards.

 

[dragon04]

"Gravitational Lensing" does not imply that there is any change in the velocity of a photon AFAIK.<br /><br />It only implies that the light takes a more circuitous path to the observer.<br /><br />What I'm saying is that while a photon might be affected by gravity, that might only be an expression of it following the path of least resistance <b>around</b> a source of significant gravity.<br /><br />We see the same phenomenon all the time in fluid dynamics. We test the aerodynamics of airfoils or automobiles in wind tunnels.<br /><br />By that model, it seems to me that photons might follow paths "around" massive gravity objects, and be directed to converge at a "focal point" as a result.<br /><br />I know, I know. Why wouldn't the light simply be scattered if that was the case. My only (and uneducated) explanation would be that light adheres to the same properties and principles that smoke in a wind tunnel adheres to under a unique set of parameters.<br /><br />To me, this would be proof that the fabric and shape of space-time defines how photons must behave when interacting with immense relative gravity.<br /><br /><br /> <div class="Discussion_UserSignature"> <em>"2012.. Year of the Dragon!! Get on the Dragon Wagon!".</em> </div>

 

[pyoko]

Experiment: Flash a light out your window, and run down real fast, looking up at ones' own window as soon as you get downstairs. You can try this at home alone or with your friends or family. Fun time for anyone of any age.<br /><br />Experiment2: Put two mirrors facing each other, and light a candle in the middle. Take the candle away really fast, and watch, to everyones' amazement, what happens. I think you'll be pleasantly surprised! <div class="Discussion_UserSignature"> <p> </p><p> </p><p><span style="color:#ff9900" class="Apple-style-span">-pyoko</span> <span style="color:#333333" class="Apple-style-span">the</span> <span style="color:#339966" class="Apple-style-span">duck </span></p><p><span style="color:#339966" class="Apple-style-span"><span style="color:#808080;font-style:italic" class="Apple-style-span">It is by will alone I set my mind in motion.</span></span></p> </div>

 

[onesimple]

Light constant<br /><br />Constant speed of light simple logical nicely.<br /><br /><br />When spacecraft moves quickly forward, there hits faster and more for example Photons and like this vessel self opens / to explode denser energy waves forward. <br /><br />These forward opening energy waves get from their formating come photons to explode much energy forward and speed of the like this their slows. <br /><br /><br />Well, when vessel has stopped its speed exciting, it does not open backwards nowhere near so much energy as forward, because there comes to guarantee towards slower and less energy, whereby vessel also explode in other words opens behind the less energy, towards and like this to guarantee towards to the initially coming photons get towards base much easier than from their formating come photons. <br /><br /><br />Well what from this company? <br /><br /><br />To initially coming light moves in the proportion to with the same towards in the speed, base in that on the moment when it hits to the initially, get it from the front towards or guarantee towards, even though vessel self moves on the huge speed forward, whereby born image so that observer is able in position relationship to the environment and that light speed is always constant observer in the relationship. <br /><br />And this if what is from the logical, simple and beautiful.