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the speed of light = 299 792 458 m / s???????

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posted on Jun, 24 2012 @ 06:52 AM
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Originally posted by Vandettas
reply to post by DaveNorris
 

Einstiens Big Idea

This might be the most clearly stated, simplest explanation of this phenomenon I've ever seen. Good find.




posted on Jun, 24 2012 @ 07:13 AM
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Originally posted by zilebeliveunknown
reply to post by Phage
 

I know that c is constant in vacuum, but in your opinion, why it is constant in generally, when light travels at a different speed in different materials?

Light seems to slow down in a medium because it encounters atoms of the material it is moving through and, in extremely simple terms, has to "deal with" moving through the lattice of these atoms before being re-emitted on the other side. This causes a delay in the apparent speed of the photon. The speed of light doesn't really change, but the interaction of the photon with the material makes it seem that way in its aggregate effect once it has passed through the medium. Different mediums will delay the photon for different lengths of time. If you could observe an individual photon moving through glass, water or air, it would never actually slow down, but it might interact with an atom, get briefly delayed before moving on again at the speed of light:

www.physicsforums.com...

Edit: Oh, I didn't see you explained it dxdydz, missed it going through the thread.
edit on 6/24/2012 by LifeInDeath because: (no reason given)



posted on Jun, 24 2012 @ 07:36 AM
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Originally posted by vister74
reply to post by jiggerj
 


i thought light speed was 186,000 miles per second?


Ummmmm, well...sure, if you wanna talk about THIS universe.


When I googled it to make sure of the speed I typed in 'speed of light is 164,000' and I got Nautical Miles per second. Ah well.



posted on Jun, 24 2012 @ 08:23 AM
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reply to post by jiggerj
 


yeah no worries, im not here to compare brain pans! i just thought i read somewhere that the speed of light was 186,000 miles a second



posted on Jun, 24 2012 @ 09:32 AM
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Originally posted by vister74
reply to post by jiggerj
 


yeah no worries, im not here to compare brain pans! i just thought i read somewhere that the speed of light was 186,000 miles a second


Yes, the speed of light is 186 282.397 miles per second, but when measured in meters per second, it is 299792,458 rounded off to 3.00 x 10^8 m/s. Units are the key

A mile is much further than a meter. A meter is very close to the size of a yardstick, there are 1760 yards in a mile or approximately 1609 meters in a mile.
The US is obsessed with remaining with the English system of measurement as opposed to the metric system which is used world wide.



posted on Jun, 24 2012 @ 09:37 AM
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Originally posted by PurpleChiten

Originally posted by vister74
reply to post by jiggerj
 


yeah no worries, im not here to compare brain pans! i just thought i read somewhere that the speed of light was 186,000 miles a second


Yes, the speed of light is 186 282.397 miles per second, but when measured in meters per second, it is 299792,458 rounded off to 3.00 x 10^8 m/s. Units are the key

A mile is much further than a meter. A meter is very close to the size of a yardstick, there are 1760 yards in a mile or approximately 1609 meters in a mile.
The US is obsessed with remaining with the English system of measurement as opposed to the metric system which is used world wide.


Ehhhh, we're slowly coming around. Though I have NO idea why we started with non-metric in the first place????



posted on Jun, 24 2012 @ 09:43 AM
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Originally posted by jiggerj

Originally posted by PurpleChiten

Originally posted by vister74
reply to post by jiggerj
 


yeah no worries, im not here to compare brain pans! i just thought i read somewhere that the speed of light was 186,000 miles a second


Yes, the speed of light is 186 282.397 miles per second, but when measured in meters per second, it is 299792,458 rounded off to 3.00 x 10^8 m/s. Units are the key

A mile is much further than a meter. A meter is very close to the size of a yardstick, there are 1760 yards in a mile or approximately 1609 meters in a mile.
The US is obsessed with remaining with the English system of measurement as opposed to the metric system which is used world wide.


Ehhhh, we're slowly coming around. Though I have NO idea why we started with non-metric in the first place????


The metric system wasn't formalized until 1799 and the US had already passed it's "revolutionary phase", lost a lot of lives and just weren't ready to tackle it again



posted on Jun, 24 2012 @ 10:22 AM
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and from wikipedia
"
299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant
"

so the metric system has changed and fixed to fit the speed of light.



posted on Jun, 26 2012 @ 10:05 AM
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I think a lot of members on here have pondered that question before, but i have always wondered, if nothing can escape a black hole, not even light, and light is the fastest known thing in the universe, then how is radiation detected jetting out of black holes if nothing can escape not even light, and light is fastest? or this one ....that if the universe is expanding at the speed of light, then surely it is travelling at twicee the speed of light, or better still, growing at twice the speed of light as it is simultaneously expanding in both directions at the speed of light? its things like this i love to think about, like where is the universe expanding in to? and what came first, the chicken or the egg? and where was this so called "super atom" hanging or situated that all matter came from when the big bang happened?



posted on Jun, 27 2012 @ 04:13 AM
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GR states that nothing can break the speed barrier, I beg to differ..... I already know how to make something go over 4 times faster than light...



posted on Jun, 27 2012 @ 05:43 AM
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reply to post by DARREN1976
 


Actually, it states that nothing can accelerate to the speed of light. So go on then, explain how you know to make something go "over 4 times faster than light".



posted on Jun, 27 2012 @ 07:42 AM
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Originally posted by john_bmth
reply to post by DARREN1976
 


Actually, it states that nothing can accelerate to the speed of light. So go on then, explain how you know to make something go "over 4 times faster than light".


Well, (are ou ready for this?) wait until the moon is on the horizon, then spin round once, the moon will then be travelling around your head at over 4 x the speed of light!!



posted on Jun, 27 2012 @ 08:33 AM
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if you are in a ship traveling at light speed
and shine a light behind you.
will the light just stop?

if you shine a light ahead of you
do you run in to it?

what IS light?



posted on Jun, 27 2012 @ 01:27 PM
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Space can expand faster than light but the matter and energy residing in the space cannot go faster than the speed of light. It's hard to imagine but this is what scientists say.
So when you read about stars moving away from us faster than light they are really being carried faster than light by the expanding space in which they reside. But not really see the analogy below.

Imagine living on the surface of a balloon. Now move along the balloon at almost the speed of light while the balloon is inflating quickly. Your are constrained by the speed of light on the balloons surface but to an outsider it looks like can move faster than light due to the inflation.

The universe is the balloons surface. We live on the surface.

This is also a good example of how every galaxy can be moving away from every other galaxy. Put the galaxies on the surface of the balloon. Now inflate the balloon. They all move away from on another.



posted on Jun, 27 2012 @ 01:38 PM
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Originally posted by randomname
what if einstein lied.


He did. Just not about that, so much.



he says nothing can travel faster than light because it would need infinite energy. what if this is just a lie.


It sure seems to fit the numbers you get from particle accelerators.



what if we found an infinite power source. then one half of the problem is solved.


Other than there's not one, the infinite heat dissipation from your infinite energy drive would return the universe to its primordial state.



in space, an object has essentially zero mass. you can "lift" up an elephant as easily as a pen.

you weigh just as much as a light wave in the vacuum space. so "mass" in the sense of the power to move an object is irrelevant.


You are confusing weight with mass. They are not the same.



side note. how does a flashlight work. a duracell battery is hardly an infinite power source, yet it is able to power light waves to 299792458 m/s.


That would be because photons have no rest mass. In space, astronaut Joe Snuffy still has his 160 pounds of mass, but he's in free fall.

Mass != weight. Weight is proportional to mass in a gravitic field. But when you're drifting about in interplanetary space where it's "flat", you still have mass.

Now, the question is, would you have mass in an empty universe where you were the only matter. There's the ticket.



posted on Jun, 27 2012 @ 01:48 PM
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I would like to add that in space because you still have "mass" you have momentum as well. So if you were at rest and did a pushup in space you would still need to accelerate your mass which takes force and muscle. Now the pushup would be easier than on earth because you don't have the force of gravity pulling down on you.

On earth
Fy - Fg = ma - mg,
where Fy= force of you pushing up, Fg = force of gravity, m =mass, a = acceleration, g = 9.8 meters/second^2 the acceleration of gravity.

In space Fy = ma

and! Fg = mg = your weight!

hopefully I got all that correct.



posted on Jun, 27 2012 @ 01:49 PM
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Originally posted by dxdydz

Think of it this way. What really happens when light travels through a medium? An atom absorbs the photon causing an electron to move to a higher energy orbit. Eventually the electron moves back to its lower energy orbit and the atom emits the photon. This takes time. The light still travels a constant C between the atoms. It's the absorption and emission that makes it appear to travel slower.


Not so much. The electron can only make transitions between orbitals with very constrained energy levels. It takes the right color photon, in other words. Also, the re-emission is not correlated in phase or direction - if an electron happens to find a photon it "likes" and makes a transition to a higher orbital, when it transitions back (talking spontaneous, not stimulated here) it will reemerge in any direction it likes.

The pickiness of which photons are captured and which are emitted is the basis of spectroscopy.

What is actually happening has to do with plasmon behavior, imho.



posted on Jun, 27 2012 @ 01:55 PM
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reply to post by Bedlam
 


Yeah in a later post I added scattering as well.

"the incident electromagnetic wave on a molecule excites the charges to oscillate and radiate secondary electromagnetic waves... The Superposition of the secondary waves give the total elastically scattered field.
That is scattering. There is also absorption. If the absolute temperature of the particle differs from zero, electron transitions from a higher to lower energy level cause thermal emission of electromagnetic energy at specific frequencies"

I'll have to read up on plasmons.



posted on Jun, 27 2012 @ 02:08 PM
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Originally posted by dxdydz
reply to post by Bedlam
 


Yeah in a later post I added scattering as well.

"the incident electromagnetic wave on a molecule excites the charges to oscillate and radiate secondary electromagnetic waves... The Superposition of the secondary waves give the total elastically scattered field.
That is scattering. There is also absorption. If the absolute temperature of the particle differs from zero, electron transitions from a higher to lower energy level cause thermal emission of electromagnetic energy at specific frequencies"

I'll have to read up on plasmons.


The description of scattering is pretty much it - the plasmon cloud is the group of electrons as a whole - when the photon goes past, the electrons shift about in a slower wave which appears to delay the photon.

In a bigger sense, you can diddle a larger group of free electrons to do the same to an incident EM wave - say a radar beam - and either scatter, re-radiate it at a wrong frequency, or couple the energy of the wave into something purely dissipative.

Now, something to consider.

The interaction with the plasmon clouds of matter appears to increase the relative permeability and permittivity of space - which represent, (sort of - not trying for a physics defn here) the amount of difficulty with which electric and magnetic fields push through space. However, when all matter is removed and only vacuum remains, the relative permeability and permittivity of space is not zero - it still has a value (1). That value is also what gives you the value for "c" - as these two values set the speed for c in a medium.

If matter increases these values, and no matter doesn't decrease it to zero, what's going on? What's interacting? Why aren't the values for them zero in empty space? If you have an engineered plasmon cloud with relative permittivity less than 1, does light go faster? What about a metamaterial with negative permeability? Can you arrange for free space to have different values for these constants?



posted on Jun, 27 2012 @ 02:31 PM
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From what I understand the virtual particles in the vacuum give rise to the permeability of the vacuum. I believe I read that somewhere. Probably wikipedia.

Also, very interesting that charge of electrons is actually modified by this vacuum energy. What we actually measure and observe as the charge of electrons is actually not the fundamental value.

One more thing. It is hypothesized that the intrinsic angular momentum of the electron is caused by the vacuum energy. There is actually a german term for this Zitterbewegung.

From wikipedia :

Zitterbewegung (English: "trembling motion", from German) is a theoretical rapid motion of elementary particles, in particular electrons, that obey the Dirac equation. The existence of such motion was first proposed by Erwin Schrödinger in 1930 as a result of his analysis of the wave packet solutions of the Dirac equation for relativistic electrons in free space, in which an interference between positive and negative energy states produces what appears to be a fluctuation (at the speed of light) of the position of an electron around the median, with a circular frequency of 2 m c^2 / hbar ,!, or approximately 1.6×1021 Hz.
edit on 27-6-2012 by dxdydz because: Changed theorized to hypothesised.



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