Is the speed of light contant?
Also, if the speed of light is not constant, what does this mean in our universe? How would this affect our views of science?
some anomalies which might back up the claim that the speed of light is slowing down:
quantized red-shift observations from other galaxies,
measured changes in atomic masses over time,
measured changes in Planck’s Constant over time,
and differences between time as measured by the atomic clock, and time as measured by the orbits of the planets in our solar system.
Also, some historical recordings of the speed of light:
In 1738: 303,320 +/- 310 km/second
In 1861: 300,050 +/- 60 km/second
In 1877: 299,921 +/- 13 km/second
In 2004: 299,792 km/second (accepted constant)
We are getting more and more accurate, but why was it always an overestimate?
Light does continue, which makes it constant. Yet, light also changes in different settings. Light is slowed down in transparent media such as air, water and glass. This was discovered by Jean Focault in 1850.
According to standard modern physical theory, all electromagnetic radiation, including visible light, propagates (or moves) at a constant speed.
(1) General relativity is capable of predicting and explaining phenomena that have been experimentally verified to 9 decimal digits, making it the most accurate scientific model to date. This explains its general acceptance - practically all scientists consider relativity to be “true”.
(2) General relativity is based on the notion that the speed of light in a vacuum is constant.
(3) So if it isn’t constant, then the most successful theory of all time must be either wrong or seriously incomplete.
i love the idea that things are radically changing and the effects are invisible if you only look for 50-100 years. so we could have been looking at a slow moving thing for the past century and we call it static because we dont know any better.
whats quantized mean? and is the change in mass certain or possibly caused by error?
“Quantized” means split up into discrete, indivisible parts - “quantum” mechanics deals with “quanta” of energy - the electron leaps from a lower (p) to a higher (q) energy state when it absorbs a photon, without passing through any state between p and q. (Edit - basically “quant-” means “count” - think of it like a numberline that has only integers, the electron cannot be at 1.49575, only at 1 or 2.)
I have heard via conversation (but have not actually read) that now some believe that spacetime itself may be quantized - which we may as well describe as pixelated in the case of three-dimensional locations. Anyone have comments or links on this?
Mabey the reason the universe is expanding FASTER is because the LOGIC that binds what we percieve as an immutable (micro atomic forces) are also changing and shifting. Therfore on the edges of the universe perhaps electrons become slightly more negative… or protons become slightly more positive.
Thus the universe is constantly shifting… and therefore even light shifts (it’s charactor) as the logic that confinds and releases light - shifts…
The reason it is not likely that physical constants change willy-nilly is because there aren’t many combinations of constants that wiull produce a stable universe. even small perturbations (such as a decrease in electron or proton charge) would have tremendous consequences over time, which so far our observations have not shown. Our best theories at this point is that the physical constants are exactly that.
If you can devise a theory in mathematical terms that explains the universes phenomena better (i.e. makes more accurate predictions than than QED and general relativity), then you’d have a point.
Been thinking about this since I read some quantum physics stuff…
Within one’s frame of reference light is allways c. So regardless of your velocity light is allways c. How is that?
I’m starting to think speed doesn’t mean what we think it means on a micro scale. Mabey SPEED of light refers to the maximum change (exchange of energy) the universe can undergo at any given point or frame of reference. Make sense?
Light is what makes up atoms. Because atoms have positive, and negative charges. And electricity is made of light. I just believe speed of light is always constant, but sometimes manipulated to change speeds for certain entity’s.
For example psychics. Whose brain waves are obviously different. But still brain waves. Most likely just manipulated the speed of light, to activate certain things in the brain, but still constant the light is for that part of the brain.
Speed of light can change, as long as theres a set of it moving at the same speed. Example…
A-A-A-A b-b-b A-A-A-A-A
Like black, and white light. Both classified as lights, but do both do the same thing exactly??
If you keep thinking like that and follow it to it’s logical conclusion you will end up with Einsteins special theory of relativity; The speed of light doesn’t change, so a photon p1 shot from a photon p2 must reach a given destination at the same time as photon p2 ??? The only possiblility is that time/space is somehow ‘dynamic’. As I understand it that’s (very) basically it.
goldy, A list of factual and conceptual errors in your post:
electricity is not made of light. Light is an electromagnetic wave/particle duality, having an oscillating electric and magnetic field. Electricity is a flow of charge (e-) or charge carrying particles.
psychics are phonies
3)brain waves do not carry thought. Electrical signals in the brain travel across neurons, which along with other chemical singals move information in the brain.
ok, the last half of your post makes no sense at all. I have no idea what you are trying to say with you A-b-A example, but i’m guessing from the rest of your post it’s likely wrong.
black light is a common term for ultraviolet, which isn’t really black at all, it’s just a shorter wavelength than our eyes can see (100-400nm). White light is a mix of light roughly 400nm to 700nm in wavelength. The only difference between the two is the wavelength, and it is the wavelength of light that makes them interact with matter in different ways. ALL EM radiation travels at c (through vacuum).
I don’t think the original post is questioning whether or not the speed of light is constant with respect to the speed of the observer, what it’s asking it whether or not the speed of light is constant with respect to the age of the universe. Now, I don’t know much about the theory (please correct me if I’m wrong), but I imagine that c could very well be changing in this respect without an impact on at least the observable consequences of relativity theory.
Why does the line have to be straight? Surely we could fit a “negative power” type curve to the data as well, so that the speed of light would have been near-infinite at the start of the universe, and tends towards nought or some finite value as time goes on? Wouldn’t this make sense?
for the speed of light to change as the universe expands, the electric permitivity and magnetic permeability of space would have to change (c is directly realted to those constants). Someone has mentioned that in a different thread of similar subject, and it’s especially relevant here. If we could find evidence that the E0 and u0 have changed, then it would mean c has changed also.
The speed of light in a medium is given by 1 / SQRT (E * U) with E being the electric permittivity and U being the magnetic permeability. Hence E and U are both proportional to the inverse of c. A change in one would have to be neutered by an equal but opposite change in the other to keep c constant.
A lot of research has been done on this, and there are definitely suggestions that this may be the case. I can’t say to what extent these suggestions have been accepted by the physics community. The following was copied from setterfield.org/theorymods.html and gives a brief account of the state of affairs.
It is generally accepted that the fabric of space was stretched out in response to processes operating at the inception of the cosmos. It is proposed that this stretching invested the fabric of space with an energy that eventually manifests as the zero-point energy, which is an intrinsic property of the vacuum. Evidence is deduced that the zero-point energy is increasing with time. The reason for the progressive change in the strength of the zero-point energy (ZPE) may be traced to the behaviour of the vacuum at the Planck length level. A smooth increase in the ZPE induces a smooth decline in the speed of light, c, and the rate of ticking of atomic clocks, while simultaneously smooth changes in the values of some atomic constants also occur. Evidence in the scientific literature indicates that the ZPE sustains atomic structures universally. Therefore it is proposed that, as more energy became progressively available to them from the vacuum, atomic particle and orbit energies underwent a series of discrete isotropic increases or quantum jumps when the ZPE increased to a quantum threshold. Within the quantum interval, energy was conserved in all atomic processes, as atoms could not access fractions of a full quantum of energy from the ZPE. Thus, with increasing time, atoms emitted light that shifted in jumps towards the blue end of the spectrum. With increasing astronomical distance (looking back in time), theory indicates that the resulting redshift should increase in jumps of 2.671 km/s, in accord with Tifft’s statistically treated observations that yield a quantisation of 2.669 km/s.
This is very intriguing, but like I said, I don’t know how generally accepted these notions are.