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?
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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 ...
In 1638, Galileo tried to determine the speed of light.
His method was quite simple. He and an assistant each had lamps which could be covered and uncovered at will. Galileo would uncover his lamp, and as soon as his assistant saw the light he would uncover his.
By measuring the elapsed time until Galileo saw his assistant’s light and knowing how far apart the lamps were, Galileo reasoned he should be able to determine the speed of the light.
His conclusion: “If not instantaneous, it is extraordinarily rapid”.
“And how can it behave like a wave and pass through a vacuum, when all other waves require a medium to propagate?”
Wrong! Electromagnetic waves do not require a medium through which to propagate. Radio, television, x-ray, light are different frequencies of electromagnetic fields which travel through a vacuum at 299,792,458 meters per second.
If you are traveling the speed of light in your car and turn on the headlights, do they light up anything? ;-)
Right. No one knows what light actually is.
Yes.
Light emanates from its source at the speed of light regardless of the relative speed of the source.
Deal with it.
Short answer: "So how does light travel? Basically, traveling at incredible speeds (299 792 458 m/s) and at different wavelengths, depending on its energy. It also behaves as both a wave and a particle, able to propagate through mediums (like air and water) as well as space. It has no mass, but can still be absorbed, reflected, or refracted if it comes in contact with a medium. And in the end, the only thing that can truly slow down or arrest the speed of light is gravity (i.e. a black hole)."
“And how can it behave like a wave and pass through a vacuum, when all other waves require a medium to propagate?” Um, maybe the ‘vacuum’ is not empty. Maybe the vacuum is an energy field (called the zero point field) and the wave propagates through the medium of the zero point field of energy. Perhaps there is an infinite field of point/moment loci through which the photon wave propagates.
Roger that! Just have to have a detector for the appropriate
frequency depending on the angle of the viewer.
Ooh, light is both a particle and a wave!
Ooh, scientists call it a 'boson'. Hope that helps!
Sheesh.
Here's a particularly egregious sentence that conveys absolutely no useful information:
"The development of Quantum Field Theory (QFT) was devised in the following decades to resolve much of the ambiguity around wave-particle duality."
Translation:
Scientists came up with a new theory that did something. Whoopee!
From it’s source, indefinitely, until absorbed by a medium.
The scientific explanation is that light travels fast because it bypasses the TSA.
I’m curious how all of this applies to the insufferable waiting before MDC Penn. Ave. gets fumigated.
The photon is always in the present of the moment it was emitted, crossing the Universe always in the present of its origin.
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...
Someone else has already referred to it, but everyone knows light swims about in a sea of aether.
If I go to put on a t-shirt that has no label, there is a 50-50 chance that I'll put it on correctly. However, I inevitably put it on backwards. 100 percent of the time. Knowing that, whatever way I think is correct, I reverse it. I still put it on backward 100 percent of the time.
This leads me to the conclusion that, prior to my putting the t-shirt on, there are two possible ways for it to be oriented. The act of putting it on collapses the wave front and presents only one possibility: the wrong one. Otherwise, I would have to at least occasionally put the damned thing on the right way.
You can also see it demonstrated using the Peanut Butter Principle. Toast a slice of bread and put peanut butter on one side. Then stand over your expensive carpet and drop the toast. Theoretically, there are two ways the toast can land: peanut butter side up or peanut butter side down. However, it will inevitably, ALWAYS land peanut butter side down. That's because, per Schroedinger, the possibility of it landing peanut butter side up exists only until it's dropped. Then, the wave front collapses and leaves only the possibility that it will fall in such a way as to cause the most damage: peanut butter side down.
Science You Can Use!
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