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How Does Light Travel?
universetoday.com ^ | 19 May , 2016 by | Matt Williams

Posted on 05/19/2016 1:06:30 PM PDT by BenLurkin

Ever since Democritus... argued that all of existence was made up of tiny indivisible atoms, scientists have been speculating as to the true nature of light. Whereas scientists ventured back and forth between the notion that light was a particle or a wave until the modern, the 20th century led to breakthroughs that showed that it behaves as both.

These included the discovery of the electron, the development of quantum theory, and Einstein’s Theory of Relativity. However, there remains many fascinating and unanswered questions when it comes to light, many of which arise from its dual nature. For instance, how is it that light can be apparently without mass, but still behave as a particle? And how can it behave like a wave and pass through a vacuum, when all other waves require a medium to propagate?

...

By the late 19th century, James Clerk Maxwell proposed that light was an electromagnetic wave, and devised several equations (known as Maxwell’s equations) to describe how electric and magnetic fields are generated and altered by each other and by charges and currents. By conducting measurements of different types of radiation (magnetic fields, ultraviolet and infrared radiation), he was able to calculate the speed of light in a vacuum (represented as c).

In 1905, Albert Einstein published “On the Electrodynamics of Moving Bodies”, in which he advanced one of his most famous theories and overturned centuries of accepted notions and orthodoxies. In his paper, he postulated that the speed of light was the same in all inertial reference frames, regardless of the motion of the light source or the position of the observer.

(Excerpt) Read more at universetoday.com ...


TOPICS: Science
KEYWORDS: light; stringtheory
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To: All

Is my previous post correct??? Or does the light disappear immediately when it goes away no matter the distance???


41 posted on 05/19/2016 1:43:17 PM PDT by JBW1949 (I'm really PC....PATRIOTICALLY CORRECT!!!!)
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To: IronJack

All I know is that whoever got the bright idea to stop using sewn in tags for t-shirts has obviously never had to get dressed in the dark.


42 posted on 05/19/2016 1:45:50 PM PDT by BenLurkin (The above is not a statement of fact. It is either satire or opinion. Or both.)
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To: JBW1949
Here’s the thing...If you look up into the night sky, that faraway star you are seeing the light of may not even be a star anymore...it won’t be where you are looking anyway...If the star is 1,000,000 light years away, that light you are seeing is 1,000,000 years old...

When I read that I started to cry...it's so profound...

43 posted on 05/19/2016 1:47:09 PM PDT by JusPasenThru (it is tragic that Americans have lost the ability to become outraged over the behavior of Democrats.)
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To: BenLurkin
How Does Light Travel?

Pretty damn quick, as I understand it.

44 posted on 05/19/2016 1:47:59 PM PDT by OldSmaj (Voting for Hillary because she is a woman is like eating a turd because it looks like a Baby Ruth.)
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To: BenLurkin
But....But....
The real question is.....
How fast (or slow) does 'dark' travel??
45 posted on 05/19/2016 1:49:56 PM PDT by Fiddlstix (Warning! This Is A Subliminal Tagline! Read it at your own risk!(Presented by TagLines R US))
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To: Techster

“when all other waves “

...referring to mechanical waves e.g, sound, water, earthquake.


46 posted on 05/19/2016 1:51:30 PM PDT by fruser1
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To: r_barton
If you are traveling the speed of light in your car and turn on the headlights, do they light up anything? ;-)

I don't know, but I do know that the speed of light is even faster than my kids opening the refrigerator door...

47 posted on 05/19/2016 1:52:54 PM PDT by Quality_Not_Quantity (Democrat Drinking Game - Every time they mention a new social program, chug someone else's beer.)
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To: BenLurkin
Some prefer to travel heavy.


48 posted on 05/19/2016 1:57:42 PM PDT by fruser1
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To: BenLurkin
If you figure it out....is this a way to tax it?

If everyone traveled light, there would be no need for the TSA lines


49 posted on 05/19/2016 1:58:26 PM PDT by Daffynition ("We have the fight of our lives coming up to save our nation!" ~ Jim Robinson)
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To: JusPasenThru

LOL...I’m so glad I brought you so much “profoundness”...:o)


50 posted on 05/19/2016 1:58:55 PM PDT by JBW1949 (I'm really PC....PATRIOTICALLY CORRECT!!!!)
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To: BenLurkin

Dark Helmet says it can be exceeded by ludicrous speed.


51 posted on 05/19/2016 1:59:00 PM PDT by BigEdLB (Take it Easy, Chuck. I'm Not Taking it Back -- Donald Trump)
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To: r_barton
"If you are traveling the speed of light in your car and turn on the headlights, do they light up anything?"

Only if you tap the brakes.

52 posted on 05/19/2016 1:59:00 PM PDT by Godebert (CRUZ: Born in a foreign land to a foreign father.)
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To: PJBankard
You rang?


53 posted on 05/19/2016 2:01:48 PM PDT by Daffynition ("We have the fight of our lives coming up to save our nation!" ~ Jim Robinson)
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To: Attention Surplus Disorder

Through the aether?


54 posted on 05/19/2016 2:06:22 PM PDT by Little Ray (NOTHING THAT SOMEONE ELSE HAS TO PAY FOR IS A RIGHT.)
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To: BenLurkin

Wavicles. Sometimes with group velocity


55 posted on 05/19/2016 2:08:11 PM PDT by Nifster (I see puppy dogs in the clouds)
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To: BenLurkin

Did you not basic physics?


56 posted on 05/19/2016 2:08:46 PM PDT by Nifster (I see puppy dogs in the clouds)
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To: JusPasenThru

It is. The speed of light, though swift for us, is no match for the vastness of space. Even our own galaxy, which is something like 100,000 light years across, the light starting out from the opposite rim when Christ was born would be only 1/50th of the way across by now. And that’s just in the local neighborhood. Imagine what it is like between galaxies.


57 posted on 05/19/2016 2:15:07 PM PDT by chimera
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To: fruser1

Richard Boone - much better as the bad guy as in the movie “Hombre”.


58 posted on 05/19/2016 2:20:07 PM PDT by Jim W N
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To: BenLurkin

With a background in electromagnetism, I agree with the ‘both - particle and wave - and with no mass ‘club’.

Electromagnetism uses ‘speed of light = C’ in many of its various formulae, including signal propagation and reception for communications and object tracking.


59 posted on 05/19/2016 2:21:18 PM PDT by Terry L Smith
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To: BenLurkin
Question: How does light travel?

Answer: Lightly.

60 posted on 05/19/2016 2:21:48 PM PDT by AEMILIUS PAULUS
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