Theory Challenging Einstein's View On Speed of Light Could Soon Be Tested (theguardian.com)

mspohr writes: The Guardian has a news article about a recently published journal entry proposing a way to test the theory that the speed of light was infinite at the birth of the universe: "The newborn universe may have glowed with light beams moving much faster than they do today, according to a theory that overturns Einstein's century-old claim that the speed of light is a constant. Joao Magueijo, of Imperial College London, and Niayesh Afshordi, of the University of Waterloo in Canada, propose that light tore along at infinite speed at the birth of the universe when the temperature of the cosmos was a staggering ten thousand trillion trillion celsius. Magueijo and Afshordi came up with their theory to explain why the cosmos looks much the same over vast distances. To be so uniform, light rays must have reached every corner of the cosmos, otherwise some regions would be cooler and more dense than others. But even moving at 1bn km/h, light was not traveling fast enough to spread so far and even out the universe's temperature differences." Cosmologists including Stephen Hawking have proposed a theory called inflation to overcome this conundrum. Inflation theorizes that the temperature of the cosmos evened out before it exploded to an enormous size. The report adds: "Magueijo and Afshordi's theory does away with inflation and replaces it with a variable speed of light. According to their calculations, the heat of universe in its first moments was so intense that light and other particles moved at infinite speed. Under these conditions, light reached the most distant pockets of the universe and made it look as uniform as we see it today. Scientists could soon find out whether light really did outpace gravity in the early universe. The theory predicts a clear pattern in the density variations of the early universe, a feature measured by what is called the 'spectral index.' Writing in the journal Physical Review, the scientists predict a very precise spectral index of 0.96478, which is close to the latest, though somewhat rough, measurement of 0.968."

Comments

If it works

[calexontheroad66]

Then build a beam that warms a local space line to a ridiculous big temperature and then... try to get stuff faster than light in a vacuum. Photons or vapors...

Re:If it works

[saloomy]

This was my thought... a photon is a particle, that travels in a wave. It has some pressure when it shines on an object (see light sails, NASA). If light were to travel at an infinite speed, anything it encounters would be given an infinite amount of energy in the form of momentum. We can then deduce that this was not the case, since most of the sky is black and not full of stars (see Olbers' Paradox). An infinitely fast beam of light would have come into contact with "stuff", and given off an infinite amount of mass/energy (matter), and generated an infinitely dense universe with an infinite amount of energy.

E=MC^2 is dead. Long live E=MC^2!

Re:If it works

[silentcoder]

Temperature is a measure of the vibration rate of particles - it's not found in vacuums. I suspect the article/summary is oversimplifying or just using temperature as a convenient layman's analogue for heat (unless it refers to the vibration rates of particles in the early universe).

EIther way - do you have any idea how much energy it would take to build a beam that could heat anything up that much ? The amount of energy needed to heat something up depends on the specific heat of the substance, the amount you are heating up and the starting temperature. The last one doesn't much matter considering how huge the heat-up here is - it will be immeasurably small a factor. If we use water then 1g takes 1 calorie to heat up by 1 celcius. A calorie is 4.2 joules of energy.
So you would need 42 thousand trillion trillion joules of energy to raise just one gram of water that high. Just about any other substance - the number goes up.

As of 2012 Humanity produced 155105 TW/H of energy. That is just over 5 .5 trillion joules.

No problem, we just need to multiply the total energy production on earth by about ten thousand trillion times and we can do the experiment you're proposing.

But as the summary explains - we don't need to. The theory makes predictions about the universe which will be true if it holds, and false if inflation is correct - all we need to do is develop sufficiently good measurement technology to see if the prediction is true or not - which we should have fairly soon, and the fact that we are close to being able to do sufficiently accurate measurements to test it is literally the story you are commenting on.

Re:If it works

[Anonymous Coward]

2! = 2x1 = 2

Re:If it works

[calexontheroad66]

Yep, but you forgot about energy density, make the beam very compact.
How about pouring it into a plank length beam?
And that would be your carrier wave to pump other photons.

Re:If it works

[Anonymous Coward]

This was my thought... a photon is a particle, that travels in a wave. It has some pressure when it shines on an object (see light sails, NASA). If light were to travel at an infinite speed, anything it encounters would be given an infinite amount of energy in the form of momentum. We can then deduce that this was not the case, since most of the sky is black and not full of stars (see Olbers' Paradox). An infinitely fast beam of light would have come into contact with "stuff", and given off an infinite amount of mass/energy (matter), and generated an infinitely dense universe with an infinite amount of energy.

E=MC^2 is dead. Long live E=MC^2!

No. A photon is a quantized amount of energy which can exhibit particle like and wave like properties under different observations. It is not "a particle" that travels "in a wave"

Re:If it works

[PolygamousRanchKid]

So you would need 42 thousand trillion trillion joules of energy to raise just one gram of water that high.

I knew there was something special about that number being the answer . . .

Next you will tell me that the energy can be generated by a guitar amplifier that goes up to 11 . . .

Re:If it works

[silentcoder]

I just mulitplied the 4.2 joules by the 10 starting number in the target temperature - which was simpler than writing
4.2 * 10 thousand trillion trillion.

Re:If it works

[calexontheroad66]

Him?
What part of photons or vapors didn't you understand?
Glasses you need, hummm...
Or Troll you are...

Re:If it works

[PvtVoid]

Temperature is a measure of the vibration rate of particles - it's not found in vacuums.

The early universe was not a vacuum. It was an extremely dense, high-temperature plasma.

In any case, vacuum can in fact have a temperature, due to virtual particle production.

Re:If it works

[serviscope_minor]

Troll he most certainly is. Look at his posting history: it's filled with random nastiness.

Re:If it works

[silentcoder]

>The early universe was not a vacuum. It was an extremely dense, high-temperature plasma.
Agreed, but I was referring to the GP's suggestion to heat up a beam and send photons through a vaccuum.
I can see how my post could be ambiguous though.

>In any case, vacuum can in fact have a temperature, due to virtual particle production.
True again, but not really relevant to the point I was making. I am NOT going to try and calculate the energy required to heat up a vaccuum's virtual particles to the temperature of the big bang...

Re:If it works

[serviscope_minor]

It's interesting how you can invent complete lies about someone and they get modded up.

But go on, I'll bite. Provide a link to back up your accusation of space nuttery. 50 bucks says you can't.

Re:If it works

[Maury Markowitz]

> a photon is a particle, that travels in a wave

No. This is just wrong. Completely. You need to make your brain unlearn this.

Here is a toy model you can use on your journey... Think of the photon as a cheshire cat. You cannot see the cat, if you try to perceive it completely, it will vanish. You can, however, ask it questions. If you ask it "what is your gizifa", it will say "10". Or in this case, you can ask "what is your momentum", and it might say "5".

Asking certain questions will upset the cat and cause it to change all the other values just to piss you off. So if you ask it what its momentum is, the answer you *might* have got for its gizifa will now change. These values also change on their own over time. So even if you know that its location is 2,7 now, when you ask it again later you will get a different answer. No, this is not *because you asked* (another common misconception), this is inherent to the way the cat works. Some of these values are conserved (like electric charge), others are not (like location) and others are linked together (like momentum and location).

Photons are not particles. There are no particles. "Particles" is the term we use when we refer to these things when you keep asking them what their location is. If you do that, they will give you nice answers like 2,7 and then 3,7 and then 4.7, and you'll go "oh, this thing is travelling along positive X, and it's a point, so it must be a particle!". But the problem is that if you ask it different questions, like its position and the location, then any semblance of particle-like behaviour will vanish. You were fooling yourself, ITS NOT A PARTICLE. Neither is an electron or a proton, or anything else. They're just quanta. It's all quanta.

> It has some pressure when it shines on an object

This is also incorrect.

Newton thought momentum had something to do with mass because he only had large objects to work with. Shotputs have a lot of momentum, and so do planets. But in the "real world" of quantum, momentum is just a number. It's a number like any other, like energy. It's not related to mass. You ask a quanta a question and it will give you an answer. If you ask a photon its mass it will say zero. And if you ask it its momentum it will say 5. These questions are orthogonal, they don't have anything to do with each other.

So why does it LOOK like momentum has something to do with mass? Because the momentum of any one quanta is tiny, so in order to be measurable at macro scales, you need a WHOLE LOT OF QUANTA. It's very easy to make a ball of protons and electrons, because they attract each other. So you put a bunch together and call it a shotput and notice that it has a lot of momentum. But the fact that it has a lot of momentum isn't because it has a lot of mass - it has a lot of mass AND momentum because it *has a lot of quanta*.

It is much harder to make a big ball of photons, they don't attract each other. If you did such a thing, you'd find it had just as much momentum as a ball of matter, but still has no mass.

> and given off an infinite amount of mass/energy

No. Energy is also a measurement of the same sort, it's just a number you can ask for. It has nothing to do with "speed". Some of these values you ask for are more interesting than others because they are concerned, but that's not due to quanta, that's due to the shape of the universe.

Re:If it works

[Gr8Apes]

Besides the fact that your understanding of currently stated physics is sadly off the mark, as others noted before me with more than adequate detail. The other aspect you completely miss is that the physics of the early universe as described in TFS followed different laws than the current laws we have, which means all assumptions you make using currently understood physics based relationships are most likely invalid.

Re:If it works

[suutar]

totally wishing I had a mod point now. Thanks!

Re: If it works

[MightyMartian]

Absolutely correct. At its core, this crackpot theory doesn't even seem to understand what the Big Bang was. The whole point of Big Bang cosmology is that everything was, at the initial moment of the Big Bang at the same point. As to differences in CMBR temperature, those, along with the large scale structure of the observable universe are explained by quantum fluctuations in the early universe.

What this "theory" purports to explain has in fact been explained for decades. There are lots of mysteries in cosmology, but the general homogeneity with some temperature structural variation isn't among those mysteries.

Re:If it works

[amicusNYCL]

I totally agree. Modern physics luminaries like yourself and I understand that nothing that we know ever changes, that chemical propellant is the pinnacle of universal space flight technology, that Newton had everything correct, and since Newton had everything correct then Einstein was wrong in the first place and therefore this story about his so-called "theory" being challenged is fundamentally flawed. Einstein was a space nutter and should have stuck to the stupid patent office. I don't know who this Stephen Hawkins fellow is but he sounds like a real idiot.

Re:If it works

[ShanghaiBill]

What he is proposing it to use it to send a spacecraft to a distant star so he and his buddies won't have to live life here on Earth with the rest of the common folk.

Also, we want to have sex with green Orion slave girls. We aren't having much luck with Earth girls.

Re:If it works

[Anonymous Coward]

The thing your post misses is, why is a quanta not a particle? You say that repeatedly and effectively, but you don't say why.

This is a profound question. The concept of Planck quanta is common. Yet it's perfectly valid to conceptualize quanta as fundamental particles. Simply calling these objects "quanta" does not resolve the issue of what it is that they are.

The standard answer is "they are waves". Yet this too is a limited answer. Multiple lines of evidence suggest that fundamental entities are both particles and waves. They switch identities based upon what you measure (unless they simply have both identities simultaneously, and by asking the question, i.e. measuring with a biased outcome preference, you self-select). This is how we arrive at the particle/wave duality.

Re:If it works

[Fragnet]

I just want to confuse the issue. The photon travels at the speed of light. From the photon's point of view it "arrives" as soon as it departed due to time dilation. In order to travel an infinite distance in zero time, the distance travelled must be zero too (Lorentz Contraction). So from our point of view the photon has taken 14.7 billion ly to travel from the edge of the observable universe to our telescope. From its point of view it's travelled nowhere in zero time.

Please correct me if I'm wrong. I'm not a physicist. I read about this and thought it completely ridiculous...

Re:If it works

[jeff4747]

The thing your post misses is, why is a quanta not a particle? You say that repeatedly and effectively, but you don't say why.

Because it doesn't behave like a particle.

Using the previous poster's question analogy, you ask a quanta particle-based questions, and you get answers that look like a particle. And those answers make it impossible for that quanta to be a wave.

But if you ask that same quanta wave-based questions, you get answers that look like a wave. And those answers make it impossible for that quanta to be a particle. (For example, the classic double-slit experiment.)

Re:If it works

[silentcoder]

>Next you will tell me that the energy can be generated by a guitar amplifier that goes up to 11 . . .
Just don't play it at 85 miles an hour or you will create a paradox by travelling back in time.

Re:If it works

[silentcoder]

I actually used Google to that calculation - even if you're right and Google was wrong (or I made a typo) - that's only two orders of magnitude, we need a whole lot more... more orders of magnitude.

Re:If it works

[silentcoder]

Not quite. But not for the reason you think. At that early point in the universe - time did not exist. Since speed is a factor of time. Speed therefore did not exist. Saying infinite speed is no different from saying velocity of zero - because neither concept actually existed yet. The universe had to reach at least the point where time existed (which happened as it begun to expand - so is not true at the 'singularity' level) before velocity could exist.

Re: If it works

[kyjellyfish]

Maury, I want to thank you for making quantum theory more accessible and a bit more palatable. Well done!!ðYOEYðYOEYðYOEYðYOEYðYOEY

Re:If it works

[RockDoctor]

The paper is at http://journals.aps.org.secure...

I suspect the article/summary is oversimplifying

You're probably right - it's a safe bet.

Temperature is a measure of the vibration rate of particles - it's not found in vacuums.

I'm not sure that works, r is relevant. There is no such thing as a vacuum - you can remove every particle and all photons from a volume of space ... and as you're doing it the space will remain populated with virtual particles springing out from the void in accord with Heisenberg's Uncertainty Principle. Those particles will have a spectrum of velocities and therefore a temperature in the sense you're denying the existence of.

So you would need 42 thousand trillion trillion joules of energy to raise just one gram of water that high. Just about any other substance - the number goes up.

Water has an unusually high specific heat capacity. In the units you use, yes, it's 4.2 ; for most materials it's 1.0 or lower. Not that that changes your point by much.

Re:If it works

[lucien86]

The whole problem with the theory is that E = mc^2 doesn't fail. If C is infinite then a single photon has infinite energy. I have worked on FTL theories for years and one old idea is that the universe began as a single photon with an enormous energy, this decayed to produce the big bang and also created the absolute frame that forms the FTL universe. The phase space of the absolute frame is completely empty because its infinity becomes impossible to reach for anything with less energy than that initial photon. The photons described could still exist but by the definition of the absolute frame their energy and speed would be finite.

Infinity is one of the hardest parts of the FTL region of physics because its maths is alien to the maths used in theories like general relativity. The basic solution is to give all infinites an arbitrary finite value. The special case of n/0 is treated as an imaginary infinite, and it has the base of net 0. Photons have a net zero mass made of positive and negative fractions - ie have imaginary mass. The definition also means that from the context of the STL space photons have an infinite energy and speed, which appears as the familiar 'finite' speed of light 2.99E8 m/s. By all this logic even that first photon ultimately has a finite mass - at least to whatever is outside the universe.

Most of this FTL physics stuff is always ultimately unprovable anyway. That's a big part of why most physicists hate it so much.. :)

Nature varies

[MrKaos]

Why would anything in the universe be constant? Maybe the variability is beyond our ability to observe.

Re:Nature varies

[abies]

Anti-arbitrage rule. E = mc^2. If c varies, then you could find a moment where converting energy to matter and later matter to energy would produce surplus energy, allowing you to perform arbitrage against laws of thermodynamic, producing perpetual motion/free energy.

Re:Nature varies

[fph il quozientatore]

This is a circular argument. To quote GP, why would energy be constant? Maybe the variability is beyond our ability to observe. Maybe thermodynamics is wrong, and free energy can be produced but only in very small quantities.

Re:Nature varies

[geekmux]

...Maybe the variability is beyond our ability to observe.

Uh yeah. This.

Even with all of our technological advances we can observe what, a sliver of a fraction of our galaxy? That's like predicting the temperature across the entire history of Jupiter's existence based off a single weather report from central Kansas last Tuesday.

Oh, and one more thing. Since we has defined the 'spectral index' down to the numerical gnats ass here presumably for accuracy, exactly how fast is "infinite" again?

Re:Nature varies

[locofungus]

If there's no mass then E=cp (from E^2 = c^2 p^2 + m_0^2 c^4)

So you've still got a problem with infinities

You've asserted that Energy is still conserved so E=hf should still hold (for a photon). Assuming Planck's constant doesn't change then \lambda must become infinite if c becomes infinite which, in turn implies that the universe must be infinitely large.

The problem with all these hairbrained schemes is that people throw them around without working through all the consequences and explaining exactly how they are all dealt with.

When that is done it's almost always the case that there's something apparent that we already know to be false.

(I'll leave it as an exercise to see what happens if Planck's constant also changes :-) I don't recall if it was Fantastic Voyage or Asimov's sequel but I vaguely remember that the basic theory was that they wanted to reduce h but it turned out that this actually increased c at the same time - so the idea isn't new, it's already been played with by SF authors. What would turn this from SF to science is working through all the implications instead of just handwaving them away)

Re:Nature varies

[ledow]

Pi is constant.

Zero is constant.

Both appear in the natural world an awful lot.

Re:Nature varies

[limaxray]

You miss understand what E=mc^2 means - it has nothing to do with converting mass to energy or energy to mass. It is stating the fact that energy has mass, and that the majority of the mass of an atom comes from incredible amounts of potential energy in the nucleus (and thus nuclear energy). If c varies it would just mean the mass of a given amount of energy would vary with it, assuming E=mc^2 holds true.

Re:Nature varies

[Scarred Intellect]

... E = mc^2. If c varies...

Slashdot's quote on the bottom of the page: "In any formula, constants (especially those obtained from handbooks) are to be treated as variables."

Re:Nature varies

[Anonymous Coward]

To the extent that they relate to the physical world, they are not constant. The ratio of the circumference of a rotating disk to it diameter is less pi, and it is also altered by gravitational fields. Zero is not necessarily zero as far as many quantities are concerned (zero-point fluctuations).

Re:Nature varies

[Buchenskjoll]

exactly how fast is "infinite" again?

It's considerably faster than half infinite.

Re:Nature varies

[Rockoon]

Perhaps the exponent of 2.0 is just an approximation .. an average

And it seems to me that if space isnt perfectly flat (and we know it isnt) then assuming "2" could be wrong.

Re:Nature varies

[JoeMerchant]

The varying of c could change the energy content of matter in the affected space, preventing the creation of "Free Energy" - or, there may be layers of the Universe of which we are not fully aware, and when the first successful perpetual motion machine is demonstrated, its "apparent free energy" may be being drawn from there.

Without Einstein's theories, a nuclear explosion certainly would look like the magical creation of large quantities of free energy.

Re:Nature varies

[PvtVoid]

The problem with all these hairbrained schemes is that people throw them around without working through all the consequences and explaining exactly how they are all dealt with.

When that is done it's almost always the case that there's something apparent that we already know to be false.

I'm sure this never occurred to the authors of the work, given that they are actual theoretical physicists and all. (Theories with varying speeds of light, which are entirely consistent with relativity, have been around for many decades. )

Re:Nature varies

[DerekLyons]

Even with all of our technological advances we can observe what, a sliver of a fraction of our galaxy?

Um, no. Much larger than that - more like a considerable way back to the Big Bang.

Re:Nature varies

[shess]

Anti-arbitrage rule. E = mc^2. If c varies, then you could find a moment where converting energy to matter and later matter to energy would produce surplus energy, allowing you to perform arbitrage against laws of thermodynamic, producing perpetual motion/free energy.

Doesn't sound like the Big Bang at all!

Re:Nature varies

[Anonymous Coward]

You _almost_ have it right; thanks.
I'm sure that you have some concept of the value of "c", in Meters per second. But "E" and "M" have values as well, I'll leave a few spaces for you to figure them out or look them up before cheating:

"E" was specifically chosen, and only through convention is it associated with Energy. "E" stands for an old non-SI unit of measurement for Energy called an "Erg", and "M" stands for a unit of Mass called a "Gram". Einstein wasn't just playing with abstract Algebra on a chalkboard; it's actually pretty basic Arithmetic. Oh, Algebra does make it easier to derive a whole lot of Relativity out it, based on only one Constant: The Speed Of Light, which was already well known before Einstein got to it. I'll paste the Arithmetic below:
Energy in Ergs = 1 Gram x ( 30,000,000,000.0 cM/sec) x (30,000,000,000.0 cM/sec).

That is in essence the Mass Energy Equivalence in Units that we can play with. "Ergs" are uncomfortable to use these days; some of us prefer "Watts". Well, one Watt per second is equal to 10 Million Ergs. As an exercise for Students; derive the Equation above in Watts per second instead of Ergs, or Horsepower or BTU, and for Mass, use the Roman "Libra".
The formula "E=M(C^2)" does get a bit messy then, so if asked to calculate how fast a Proton needs to be accelerated to, to double its Relative Mass, a very practical and routine derivation, start with the basic equation, and for Mass, convert Grams into Electron Volts, which by the way, due to Mass Energy Equivalence, is a perfectly cromulent unit of Mass. Start with One Proton equals 938.28MeV or 1.6726(10^(-24)) Grams.
https://einstein.stanford.edu/content/relativity/q388.html
https://en.wikipedia.org/wiki/Erg

captcha: relegate

Re:Nature varies

[geekmux]

Even with all of our technological advances we can observe what, a sliver of a fraction of our galaxy?

Um, no. Much larger than that - more like a considerable way back to the Big Bang.

Mapping our historical universe is a bit different than defining our observable universe.

We're still doing a lot of this work in the dark, both figuratively and literally.

Re:Nature varies

[geekmux]

exactly how fast is "infinite" again?

It's considerably faster than half infinite.

So, I would assume somewhere between Ludicrous and Plaid, then?

Sorry to be such a bother, just trying to figure out if I need to change the combination on my luggage.

Re:Nature varies

[pD-brane]

I can recommend the amusing and educational SF book Mr. Tompkins in Paperback by George Gamow, where the main character experiences the effects of a reduced speed of light and an increased Planck's constant.

Re:Nature varies

[lgw]

Not, that's just unit conversion stuff. Anyhow, real physics is done in units where c=1, so the exponent doesn't matter (as you'd expect, if it's just about the unit of measure).

Re:Nature varies

[lgw]

Much of the observable universe is the historical universe. "Long ago" and "far away" are two ways of saying the same thing. We can directly observe the universe at different stages of history back to about 300k years old (everything before that, including everything inflation-related, is indirect guesswork).

Re:Nature varies

[geekmux]

Much of the observable universe is the historical universe. "Long ago" and "far away" are two ways of saying the same thing. We can directly observe the universe at different stages of history back to about 300k years old (everything before that, including everything inflation-related, is indirect guesswork).

This is true, but since 300K years is essentially a sliver of a fraction of the age of the universe, I think we've both observed how much of this is in fact guesswork.

Re:Nature varies

[lgw]

"Pi" in Nature occurs very rarely, so rarely that I'm having difficulty thinking of just one instance.

Pi is everywhere. Circles are how pi is introduced to children. Pi is everywhere waves are, and since everything is a wave, well, it comes up a lot. Of course, the pi is often hidden in the definition of units, since it gets old writing 2pi all over the place (h-bar, the Coulomb constant, etc).

Even "Zero" is a convention,

No, not really. Math isn't about counting or computation, you know. And any sort of abstract algebra needs its 0 (and its 1, if you want a field).

Re:Nature varies

[buchner.johannes]

We have some observational constraints on the speed of light.
11 billion years ago (when the universe was 2 billion years old), the speed of light was about the same as it is now. https://arxiv.org/abs/1609.087...
Otherwise, the light crossing certain objects would be different. This result is essentially independent of cosmology.

I guess that the cosmic microwave background also places limits. If the speed of light had been infinite at that time, I suspect the last scattering would be affected. This is ~300.000 years after the big bang.

But at the time of inflation ... sure, could be infinite, I guess.

Re:Nature varies

[lgw]

You possibly misunderstand (or I misunderstand your post). We can directly observe the universe at times between now (universe 13.8 billion years old) and when the CMBR was emitted (universe 300k years old).

It's only the very early stuff that's indirect, and even then the properties of the universe at 300k years old tell us some very interesting things about earlier times - thus all the inflation theories.

Re:Nature varies

[DerekLyons]

Mapping our historical universe is a bit different than defining our observable universe.

Not at all - because they are one and the same. Even looking as close as the Moon, the finite speed of light means we're seeing the past. Looking out to (say) the Andromeda galaxy, it's both observable and millennia in the past. (And M31 is far from the furthest object we can see in distance or in time. We can see much more than "a tiny sliver of our own galaxy".)
 

We're still doing a lot of this work in the dark, both figuratively and literally.

No, not at all. "This work" is either being done by direct observation, or extrapolated from direct observation. (Which extrapolation is then proved or disproved by further comparison to direct observation.) It's not guesswork.

Re:Nature varies

[geekmux]

You possibly misunderstand (or I misunderstand your post). We can directly observe the universe at times between now (universe 13.8 billion years old) and when the CMBR was emitted (universe 300k years old).

It's only the very early stuff that's indirect, and even then the properties of the universe at 300k years old tell us some very interesting things about earlier times - thus all the inflation theories.

Fair points, and very true. Thanks for the clarity.

Re:Nature varies

[painandgreed]

This is a circular argument. To quote GP, why would energy be constant? Maybe the variability is beyond our ability to observe. Maybe thermodynamics is wrong, and free energy can be produced but only in very small quantities.

To an extent, it is circular argument as science does have some basic assumptions. One being that the laws of physics work everywhere and another being that they do not change, thus experiments are repeatable in any location. These are like the axioms of mathematics. They have served us well and have held up when we make predictions using them. It could be that they might not be quite true. In that case, it's not like everything we've known will cease to work, we'll just have to redefine some things. An example of this would be the theory of relativity and its effects on our knowledge of Newtonian physics. Why should some things be constant throughout the universe, because we have defined them a such. One example being the speed of light in a vacuum. If we do find that the speed of light is conditional, then that will require a reworking of physics to some extent. Still, when dealing with the big bang and the time we are speaking about, such bizarreness might not be all that foundation shattering as the expansion of space is a pretty weird phenomenon itself driven means we probably aren't sure about. Add in suspicion that the universe could have been at a false vacuum at some point, and if it was, the universal constants would have been different as would have been the laws of physics.

Re:Nature varies

[clovis]

Why would anything in the universe be constant? Maybe the variability is beyond our ability to observe.

Anyone who has studied the time cube already knows this.

Re:Nature varies

[TechnoJoe]

Not if c only varies by time. If c is constant throughout all points in space and varies only by time, then you wouldn't have any of those problems.

Re:Nature varies

[TechnoJoe]

I'll leave it as an exercise to see what happens if Planck's constant also changes

Mod parent up. And I mean to Stephen Hawking levels. He seems to be the only person (at least on slashdot) who picked up the implications for Planck's constant. Planck's constant has to change inversely proportional to the speed of light.

Hear are some things going on that scientists don't like to talk about.

The speed of light is decreasing over time. Over the past 400 years, there have been about 30 different methods for measuring the speed of light, and all of them produce lower results than historical results, even when performed by the same people using the same equipment.

Planck's constant is increasing, proportional to changes in the speed of light. Probably related.

The red shift is quantized. If red shift were really due to velocity, it would be smooth and continuous, like notes from a trombone. It's not. It's quantized, like keys on a piano. If you believe that's due to velocity, then you have to believe that the universe expands, suddenly stops, and then expands some more.

Atomic time is slowing. At least compared to mechanical clocks. But it's not just that the clocks are off. They are consistently off by larger and larger amounts, which indicates a drift.

I believe all of these can be explained by changes to the Zero-point energy. Before you label me as nutty, please research these things for yourself. If I'm really wrong, it should be easy enough to prove.

Kudos to locofungus for being on the ball!

Re:Nature varies

[Anonymous Coward]

I'd love to see some links to back up these assertions

He's been banging this drum a long time

[Maritz]

I read his book back in the 90s when I was in school. Was an interesting enough idea, but going up against Einstein and Inflation at the same time - it's a looooong shot.

The summary crediting Hawking for inflation is a complete joke. Goes to show if you get a bit of fame in a field you get credited with everything.

Re:He's been banging this drum a long time

[ilguido]

Well, it says "cosmologists including Stephen Hawking", so this time the summary is not that wrong.

Re:He's been banging this drum a long time

[Anonymous Coward]

It's 2016, not reading the summary is the new 'not reading the article'.

Don't forget all the options

[TheDarkMaster]

Is interesting to remember that may be possible that there has not even been a big bang to start (and therefore the answer may be that the universe has always been more or less uniform).

Re:Don't forget all the options

[BlueStrat]

Is interesting to remember that may be possible that there has not even been a big bang to start (and therefore the answer may be that the universe has always been more or less uniform).

To quote 'Forrest Gump'; "Maybe...maybe it's a little bit of both?...both happening at the same time?"

Maybe there was a 'Big Bang' but what actually happened was that it exploded into tiny bits of space-time+matter+energy which, being essentially pieces of space-time, had no limits regarding 'velocity', and then some time later coalesced into a single fabric forming our universe. In fact, it may still be coalescing and is responsible for what we interpret as 'expansion'.

Strat

Re:Don't forget all the options

[wonkey_monkey]

Is interesting to remember that may be possible that there has not even been a big bang to start

Only in the same sense that it's possible dinosaurs never really existed and all the bones were put there by God.

Re:Don't forget all the options

[TheDarkMaster]

It's also possible, true

Re:Don't forget all the options

[BlueStrat]

Maybe there was a 'Big Bang' but what actually happened was that it exploded into tiny bits of space-time+matter+energy which, being essentially pieces of space-time, had no limits regarding 'velocity', and then some time later coalesced into a single fabric forming our universe. In fact, it may still be coalescing and is responsible for what we interpret as 'expansion'.

Apologies, don't normally respond to my own posts, but it also occurred to me that these pieces of space-time that have not yet joined may be where scientists find that 'missing mass'/'dark matter'. It's out there, it just hasn't joined the rest of us yet in this meta-bubble of space-time. There are likely other cosmological/astrophysical/physics phenomena, observations, and properties of the universe this might explain as well.

Strat

Re:Don't forget all the options

[serviscope_minor]

Am I "fighting" you?

Very well, I shall insult you again. Your mother was a hamster and your father smelled of elderberries.

Curious how did you respond in minutes to a comment that was not addressed to you :shrug:

Or, you know, I happened to be reading the thread at that time, as you can tell by my other comment with an earlier timestamp. Though honestly given your delusions about physics, I am not surprised you have paranoid delusions about me too.

I said before go bother someone else.

Why should I? It turns out that my mere existence is enough to bother you into replying to random ACs. To be honest I find that pretty funny, so I don't really see why I should stop :)

Re: Don't forget all the options

[TheDarkMaster]

All this time to be able to think a excuse? As i said before kiddo, go bother someone else.

Re: Don't forget all the options

[serviscope_minor]

All this time to be able to think a excuse?

oookaaay. You're as delusional about me as you are about physics. Tell you what when the EM drive works and we have free energy forever, I'll start stalking you as an AC. Deal?

go bother someone else.

Nope!

Re:Don't forget all the options

[wonkey_monkey]

Yikes, settle down. Just trying to give a simple analogy for how strong the evidence is for the Big Bang.

What I am saying is that we should not disregard other possibilities such as the universe simply be far, far, far bigger than we can see.

We already know it is. But we're also pretty damn sure it puffed itself up about 13.8 billion years ago.

Re:Don't forget all the options

[wonkey_monkey]

ah, the /. friendly discussions! * I'm a different AC, not the GP

Too right. As if I'd be caught dead starting a sentence with a lower-case letter or forgetting a closing full stop, the very idea...

Re:Don't forget all the options

[TheDarkMaster]

Something I do not like in purely written communication, the other side have no way of knowing if you are offended or if you are just wanting to make your point very clear. It is necessary because my experience shows that most people are unable to interpret the most basic texts and they then resort to forcing what they read in some version that fits into their simple-minded way of seeing the world (black/white, yes/no, friend/foe).

This said, I assure you that I know perfectly well the big bang theory and I agree that it makes sense... I just think it important to always remember that theories are not Laws and that we may be wrong about everything we know so far (scary, but not impossible), so therefore is healthy to always think about we might be missing out something important. Otherwise we'll end up looking religious fanatics with inverted polarity like this kiddo who's been bothering me.

Re:Don't forget all the options

[TheDarkMaster]

The AC you mentioned does not seems able to understand the simplest idea expressed in a sentence (in this case my signature) and relate it correctly to what was said in the comment. What else I could think of him?

Re:Don't forget all the options

[lgw]

Ah, found the on-topic thread.

Look, we know from direct observation that the universe was much smaller and hotter when it was 300K years old. You might argue "we don't know that there was a singularity", and that's a strong argument. You might argue "we don't know the universe keeps getting smaller or hotter the farther back you go", but that's not a scientific argument unless you have an alternative that explains all the same stuff (as Penrose has with his cyclic cosmology). But to claim everything might be steady state is just nonsense.

theories are not Laws

A law is just a terse theory. It's not a better kind of theory or anything.

healthy to always think about we might be missing out something important

Sure, but "missing something important" is very different from "all our observations might be wrong". The latter is shunned even by philosophers as pointless to consider, as it leads nowhere.

old news

[Anonymous Coward]

Mainstream media reported this a week ago. I wondered back then why Slashdot was reporting Trump related articles instead of this.

Re:old news

[PPH]

Information (light) travels more slowly around dense objects.

Infinite speed?

[TanjaTheMoogle]

I'm no physics professional, but I read up on it here and there. I could be wrong, but I seem to recall that arriving at infinities in physics meant that something was wrong. I definitely recall that being said in my college-level physics courses. There's also the Ultraviolet Catastrophe that immediately comes to mind. https://en.wikipedia.org/wiki/...

Re:Infinite speed?

[ledow]

This kind of physics is not physics, It's maths.

Maths has no problem with infinities. Hell, we classify different types of infinities and apple actions to them in different ways. An infinity doesn't scare a mathematician.

The problem is then applying that to a real-world interpretation as "infinite" anything - space, time, energy, matter - is hard to conceive and generally impossible. However, infinities themselves can cancel out, present only in impossible situations anyway, and so on. Same with quantum physics - the maths tells you WHAT happens, and we've confirmed the maths by multiple observations of exactly all the weird things the maths predicts, but we're still not entirely sure we're describing EVERYTHING as there are a few oddballs.

Infinities don't mean something's inherently wrong. And infinities come up in Maths all the time, from basic arithmetic onwards.

The problem is not that there's an infinity. It's having an infinity as the answer without a real-world analogue to that mathematical answer.

Re:Infinite speed?

[CrimsonAvenger]

Hell, we classify different types of infinities and apple actions to them

Just curious, do we ever pear actions to them? Or even apricot actions to them?

Re:Infinite speed?

[ledow]

It's related to pi.

Re:Infinite speed?

[Binestar]

Just curious, do we ever pear actions to them? Or even apricot actions to them?

No. Pears and apricots aren't suitable for actions against infinities due to the extra cost associated with shipping them.

Re:Infinite speed?

[lgw]

Just curious, do we ever pear actions to them?

Quantum entanglement is all about particle pears!

Re:Infinite speed?

[TanjaTheMoogle]

This kind of physics is not physics, It's maths.

I would argue that this isn't about purely mathematical entities. They are talking about photons (a thing in physics; strictly speaking, "photon" has no mathematical meaning). These photons are traveling at a certain speed (m/s, km/h, cm/day....), which is also a physical quantity. I think it's safe to say that they are talking physics, not pure mathematics.

sounds totally backwards

[dltaylor]

If the speed of light is dependent on the strength of the gravity field, as we seem to measure today, then the early universe, with all of the matter/energy (yes. that is redundant) should have had such a deep gravity well that the speed of light should have been about 0 for the first few milliseconds of the universe' existence, if not longer.

Re:sounds totally backwards

[NatasRevol]

And one reason why it was so hot - no radiation of heat until the energy overcame the massive gravity well.

Re:sounds totally backwards

[Mes]

As I understand it, there is no gravity in the early universe. For there to be gravity, you need a direction. If all the universe is uniform, every point pulls equally on every other point, so there is no direction to go and you would feel no gravity.

That Einstein's name? Albert Einstein

[wonkey_monkey]

according to a theory that overturns Einstein's century-old claim that the speed of light is a constant

Did Einstein ever make any claims about the speed of light being constant over time, or has a journalist just assumed he must have in order to shoe-horn his name in?

Re:That Einstein's name? Albert Einstein

[Anonymous Coward]

It's not really the speed of light, but a universal speed limit for everything.
While mass are our breaks, so anything without mass (light) will constantly travel at this limit.
Light just happen to be massless, thus will travel at this limit.

Here's someone explaining it better:
https://www.youtube.com/watch?v=msVuCEs8Ydo

Re:That Einstein's name? Albert Einstein

[NatasRevol]

While that line is taught in intro quantum mechanics, it was presented before we knew that light changed speed going through a gravity well.

Re:That Einstein's name? Albert Einstein

[bfpierce]

No, because relativity is more about the measurement of the speed of light being constant between observers in different places/states regardless of how fast/what direction you're moving relative to each other. I don't recall ever reading about an observer in the future and the past being a consideration, but I've been out of the loop for a while.

So unless this article is claiming that two observers in the initial universe would measure two different speeds of light I don't see this overturning 'Einsteins View' of the speed of light.

Re:That Einstein's name? Albert Einstein

[Comrade Ogilvy]

Exactly. Einstein was simply saying that observations were always consistent for any one observer in very certain ways (and not necessarily consistent in other ways we might naively expect). Many of his thought experiments used two observers, in order to elucidate the consistencies and apparent inconsistencies. But the underlying physics is about what is true about any one observer.

There is actually nothing in physics that says so-called physical constants were always the same over time. In fact, there have been ambiguous observations about very distant galaxies twenty five years ago, that have had proposed explanations built around the idea that the speed of light was very very slightly different 6 billion years ago. I do not think that topic has been put to rest because I ran into a blurb about similar work ten years ago. Obviously if there is a measurable tiny change in the speed of light "merely" 6 billion years ago, that is highly suggestive that there could have been a huge difference in the speed of light in the very early universe.

Re:That Einstein's name? Albert Einstein

[lgw]

Did Einstein ever make any claims about the speed of light being constant over time, or has a journalist just assumed he must have in order to shoe-horn his name in?

There's simply no difference between saying the speed of light changes over time, and saying the universe expands or contracts, except to make the math harder.

It much like how the "tired light" idea turns out to be mathematically equivalent to existing physics, just expressed in a way that makes the math harder.

Re:That Einstein's name? Albert Einstein

[TWX]

Actually by definition light travels at the speed of light. What's being argued is that the speed of light itself may not be as constant as we understand it to be right now.

Re:That Einstein's name? Albert Einstein

[painandgreed]

according to a theory that overturns Einstein's century-old claim that the speed of light is a constant

Did Einstein ever make any claims about the speed of light being constant over time, or has a journalist just assumed he must have in order to shoe-horn his name in?

I believe what he claimed is that the speed of light is the same to all observers. From there you are dealing with frames of reference whose times are related by some transform and possibly what we would call different. Thus if two observers measure the speed of light as the same and are at different times, then the speed of light would be constant over time. That being said, I doubt if he really intended to handle all corner cases such as the time when the entire universe was a singularity or when other laws of physics break down. If the speed of light was different than what we see now, then old light from that time should have certain peculiarities to it. I believe those peculiarities are what they are proposing to look for in the article.

Re:That Einstein's name? Albert Einstein

[Trogre]

Yes, and we can change the speed of light ourselves by changing the medium through which it passes. We can even observe particles travelling faster than light within a medium. See Cherenkov radiation for an example of this.

Of course, that has nothing to do with c, which is defined as the speed of light in a vacuum, but interesting nonetheless.

Re:You know what this means?

[geekmux]

Faster than light travel is possible! We will be visiting far flung star systems soon. All you need to do is recreate the Big Bang in a local region of space then travel through it. This is the logical conclusion. Signed, Mr. Space Nutter

Nah, what fun is a Big Bang when you can create a black hole instead? Sure, everyone will say your party sucked but still...

uhm

[m76]

Is this the young earth creationist wet dream, that would make it possible for the earth to be 5000 years old?

Re:uhm

[Anonymous Curmudgeon]

Is this the young earth creationist wet dream, that would make it possible for the earth to be 5000 years old?

Definitely not new. I remember reading an article back in the late '80s that followed that line of thinking: that C is constant now, but was faster when first measured, allowing a magical curve that placed earth's age between 5,700 and 10,000 years old.

Theory or hypothesis?

[Roodvlees]

Christians often get criticized for saying evolution is only a theory.
When a theory is really very well supported by evidence, as evolution is.
But can we really complain when something like this, which is clearly an hypothesis, is called a theory.
"String theory" seems the biggest offender to me.
No wonder people tend to describe any idea they have as a theory.

Re:Theory or hypothesis?

[Joce640k]

Christians often get criticized for saying evolution is only a theory.
When a theory is really very well supported by evidence, as evolution is.
But can we really complain when something like this, which is clearly an hypothesis, is called a theory.
"String theory" seems the biggest offender to me.
No wonder people tend to describe any idea they have as a theory.

Huh?

"Theory" is simply the name given to the second step of the Scientific Method. That's it.

Christians are criticized because they don't understand that the method doesn't stop there, that there's still a couple of steps to go ("prediction" and "experiment"). It's these other two steps that make the difference between proper science and woo-woo.

Re:Theory or hypothesis?

[Anonymous Coward]

Christians often get criticized for saying evolution is only a theory.

I want to point out that it is a sub-set of Christians that are getting hung-up over this issue. It is most certainly not a majority view among Christians. It is unfortunate they also seem to be the most vocal Christian group, because the rest of us feel like we're getting tarred with the same brush. It's also giving a lot of non-Christian folk a very bad image of Christianity.

To be clear: Creationism vs Evolution is a non-issue to most Christians.

To the rest of us, the whole thing with Creationism is actually starting to feel like almost cult-like. I'd compare it with those guys who preach that you should handle poisonous snakes or the nutters who persecuted Galileo. They're taking a specific piece from in the Bible, twisting it out of context and turning it a major pillar of faith.

Christianity isn't supposed to work that way. There is only one pillar of faith, and that's a belief in Jesus. As for the rest: sure, it's there and open for debate; you might even have some valid points, but don't get dogmatic about it.

Re:Theory or hypothesis?

[Comrade Ogilvy]

I partially agree, but the underlying issue is that many words have multiple definitions and which meaning should be clear from context. Scientists cannot police every journalist's and every layman's language, or they will get dinged for being even more highfallutin' than they already are. In this case, the meaning is adequately clear, even if the language is imperfect.

In this context, String Theory and Fast Light Theory are understood as speculative theories, that are more developed than simply a hypothesis but much less so than a well tested theory like Evolution. At least their status is well understood by practicing scientists.

To be more explicit, String Theory and Fast Light Theory are complex and carefully developed speculative ideas that (hopefully) generate testable hypotheses. That is why they do not quite fit into the word "hypothesis". If not "hypothesis", what word we we choose? Is there a word for something in between "hypothesis" and "theory"? Neither choice is 100% correct here.

I would further note that practicing physicists sometimes say out loud that String Theory is not (yet) quite real science due to a lack of testable hypotheses.

For your other point, a certain small subset of Christians like to play word games, by purposefully misunderstanding the meaning of words as easily properly interpreted in context, as a tactic to avoid discussing the meat of the issues.

Re:Theory or hypothesis?

[Joce640k]

I would like to expand on your point; it's not wrong, it's as Science Wonks like to say, incomplete:

""Theory" is simply the name given to the second step of the Scientific Method. That's it."

So: Theory, Hypothesis, Research, Experiment, Conclusion

Not to nitpick, but ... "Theory" is the second step. The first step is "Observation".

Also, what happened to "Prediction"? A theory is worthless unless it makes predictions about the outcomes of future experiments.

Re:Theory or hypothesis?

[Roodvlees]

Thanks, I like your definition of these words, makes sense. Maybe I should take things more lightly, it's better if words never provide authority.
The problem of people respecting authority too much is separate and worth fighting anyway.

1bn km/h

[Overzeetop]

Of course, because when I think of physics and the speed of light km/h is the unit I work with the most. And yet we wonder where Brexit and Donald Trump came from.

Re:1bn km/h

[NatasRevol]

Depends on what continent you're on.

https://en.wikipedia.org/wiki/...

        Trillion (short scale) (1,000,000,000,000; one million million; 1012; SI prefix: tera-), the current meaning in both American and British English
        Trillion (long scale) (1,000,000,000,000,000,000; one million million million; 1018; SI prefix: exa-), the former meaning in British English and current usage in some non-English-speaking countries

Re:1bn km/h

[jgullstr]

And yet we wonder where Brexit and Donald Trump came from.

From the two most prominent countries still using mph?

So there's something faster than plaid?

[Anonymous Coward]

Wow. Learn something new every day!

Sheldrake's idea - proposed years ago

[Anonymous Coward]

Rupert Sheldrake is an incredibly insightful and intelligent man who figured this out by comparing historical measurements of the speed of light and noticed very small variation. Of course, as he was not part of the scientific "elite", such groundbreaking, status-quo-destroying discoveries were not allowed for him, so he was quickly and effectively humiliated and declared persona non grata, basically ruining his further career. Now some bottom feeder dug up Sheldrake's research and is trying to steal his achievements for himself. He will probably succeed, just like Einstein did with De Pretto's research. Only frauds are allowed to succeed.

Alternate theory

[Anonymous Coward]

God placed lamps everywhere in the universe so he could see as he was building it.

Well..

[uohcicds]

It always struck me (even as an undergrad 25 years ago when we were talking about SR and GR) that this could be the case - that c could be "instanteously" or "episodically" constant, but need not have been the same value for ever. It's not unreasonable to suppose that the value of c could look like a decay curve, or some function whose value tends to the limit we are now seeing over time from some earlier maximum. I just never got around to asking anyone why not at the time - pity. I suppsoe it goes back to a calculus way fo thinking for me - at any instant in some changing system, even things which are changing may appear from within that system to have fixed, immutable values, even if that's not what they truly are.

Creation proven?

[freak0fnature]

If light and other particles could travel and infinite speeds during the creation of the universe....wouldn't that throw off all methods of dating the universe? In fact, wouldn't that make Biblical creation very plausible?

Re:Creation proven?

[MrLogic17]

My first thought was that yes, it would throw off pining down a date for the Big Bang.

As for Biblical creation, do keep in mind that the story starts with "the face of God moving over the deep". The earth, formless and void though it be, existed before day 1. The universe was created, and was in place for an undetermined period of time before the 7 days of creation.

If you consider the frame of reference, the surface of the earth, the 7 days of creation play out logically. You can't see the sun or moon until the atmosphere is cleaned up and put to into a usable-for-life state, for example.

$0.02. Opinions on the topic are many and varied.

Re:Creation proven?

[110010001000]

Creationist nutter detected. No, it wouldn't throw off anything. They are saying that the speed of light was temporarily infinite for a VERY SMALL FRACTION of a second. Just f*ck off.

Re:Creation proven?

[Jogar the Barbarian]

Just f*ck off.

Wow. Your powers of rhetoric are stunning. I had better believe everything you say if I know what's good for me.

Re:Creation proven?

[david_thornley]

If the speed of light is infinite, how would you measure time? Pretty much everything above the level of quantum mechanics is run by electromagnetic forces, which would propagate infinitely fast, so what sort of clock could you have?

Not plausible

[sjbe]

In fact, wouldn't that make Biblical creation very plausible?

No. There is nothing that would make creation as "described" in the bible plausible. The bible is a man made fable with no evidential support whatsoever made in a time when man lacked the technological capacity to make necessary observations. The bible makes no testable predictions nor does it describe any observed events. Any similarity to actual observations and scientific theories is purely coincidental.

Particle wave duality

[sjbe]

This was my thought... a photon is a particle, that travels in a wave.

Stop right there. Your understanding of particle wave duality is incomplete. Go back and study before you continue. MinutePhysics has some excellent videos on the topic.

Re:You know what this means?

[110010001000]

Bullshit. The EmDrive nutters just haven't woken up yet.

Does this account for dark energy?

[Dan East]

I'm trying to understand how this affects the redshifting of extremely distant objects.

Pretty much any distant stars / galaxies we look at from earth are redshifted, which indicates they are moving away from us. However we know we aren't the center of the universe (where the big bang happened), but that any observer at any other point would see the same affect we see - everything far away is redshifted. This is why we think the universe is expanding - because everything distant is redshifted. Further, the expansion of the universe seems to be increasing, which has resulted in the theory of dark energy to explain why the universe is expanding faster and faster.

However, if the speed of light is slowing, wouldn't it result in the opposite affect (blueshifting)? Photons en route to us from other distant objects (and thus that have been travelling for a very long period of time) are now moving slower than they were at first, according to the theory of this article. If the speed of light is slowing, then that would decrease the wavelength / increase the frequency, which would blueshift, right? Further, the universe isn't just expanding at a static rate, but the expansion is accelerating, hence the theory of dark energy. According to this theory is that explained by the fact that c is still decreasing? If c is decreasing does that mean that the rate of time is also decreasing? Or must that not be the case or otherwise the speed of light would not seem to be changing?

Re:Does this account for dark energy?

[110010001000]

Assuming you are serious: only Creationist nutters believe that the speed of light is slowing down. The theory here is that the speed of light was infinite at the start of the Big Bang, not that it is slowing down. The speed of light is not slowing down, and this has already been proven.

Re:Does this account for dark energy?

[Dan East]

The theory here is that the speed of light was infinite at the start of the Big Bang, not that it is slowing down. The speed of light is not slowing down, and this has already been proven.

So the speed of light was infinite, but now it is not. That is the very definition of "slowing down" is it not? At which point did it slow down I suppose is my question. If this theory can replace the concept of expansion, then it also must explain the acceleration of the expansion, which is what dark energy is theorized to do. So this theory must somehow take into account dark energy as well, which infers that the speed of light must still be changing since expansion is still accelerating.

Another part of this theory doesn't make sense. If the speed of something is infinite, then the size of the universe must also be infinite to accommodate it, otherwise it would "bunch up" as it hits whatever the "every corner of the cosmos" means (which implies there is a finite size to the universe).

However if you spread a finite amount of energy / matter over an infinite distance, the density would approach zero, thus we would not even perceive that it exists. So I guess this theory assumes there is a finite size to the universe that is independent of the amount of distance or expansion that could happen at the speed of light.

Re:Does this account for dark energy?

[PvtVoid]

However we know we aren't the center of the universe (where the big bang happened)

In the Big Bang picture, the universe has no center, and the Big Bang did not happen in it. The Big Bang happened everywhere in space at once.

Re:Does this account for dark energy?

[Comrade Ogilvy]

The big differences in the speed of light presumably occurred in the first picoseconds of the universe, long before there was anything like a galaxy (or even a stable atom). Very likely, almost all the slowing down of the speed of light occurred within seconds of the beginning of the universe. But the redshift numbers we seen from the most distant galaxies galaxies record events from a several billion year old galaxy.

BTW, there has been some ambiguous data about very distant galaxies that could be interpreted as a tiny, tiny change in the speed of light. The proposed changes in the speed of light are far too small to have the kind of effect you are suggesting.

Re:Does this account for dark energy?

[Quince alPillan]

However if you spread a finite amount of energy / matter over an infinite distance, the density would approach zero, thus we would not even perceive that it exists.

This assumes an even distribution of mass / matter / energy. If the distribution weren't even (because another unstable force, like gravity, caused it to collect together) you would see vast swaths of "empty" space and clumps of matter / energy as it collected together.

Also consider that "speed" is a function of distance over time and "time" is actually space/time and altered by gravity. It could very well be that the qualities of time did not exist as it does today, making the speed of light infinite.

Re:Speed of light is zero point?

[110010001000]

I have a hard time believing you were an average student.

Black holes in early universe?

[sjbe]

So a black hole forms when matter is condensed into a sufficiently small space so that even light cannot escape because gravity bends spacetime so much that there is no path to get outside the event horizon. Assuming the big bang theory is plausible, early in the universe the universe would (presumably) be incredibly dense with matter for some period of time. So how is it that having all that matter so close together didn't results in nothing but a bunch of black holes? How does the big bang theory get around much/all of the matter in the universe collapsing into a black hole in the early universe? What was different about spacetime to allow this to happen?

Re:Black holes in early universe?

[painandgreed]

So a black hole forms when matter is condensed into a sufficiently small space so that even light cannot escape because gravity bends spacetime so much that there is no path to get outside the event horizon. Assuming the big bang theory is plausible, early in the universe the universe would (presumably) be incredibly dense with matter for some period of time. So how is it that having all that matter so close together didn't results in nothing but a bunch of black holes? How does the big bang theory get around much/all of the matter in the universe collapsing into a black hole in the early universe? What was different about spacetime to allow this to happen?

Space was expanding. There is plenty of evidence from different directions to indicate that this is what happened. It was expanding fast enough to over come the effects of gravity. It's still expanding and that's how we get red shifting today. Why did this happen? Well, that's because *cough* *cough* *mumble into a corner*. My guess at a simple answer that can be written down in a post in a place like /. is that it came from other dimensions. Just like they say that before the big bang, there was no time or space, there possibly was something, just not the something we know. These are the other dimensions that string theorists talk about and the current idea is that they are getting smaller to make our space get bigger, like that experiment with two unequally sized balloons and the smaller one continues to shrink and force it's air into the larger one (because of differences of surface pressures of the two balloons).

Re Inflation

[NEDHead]

Always safe to credit Hawking for cosmological theory, but a gratuitous mention might have better used Alan Guth

Relativity deniers!!!!

[0xdeaddead]

Science is about consensus, not challenging dogma?

Re:Relativity deniers!!!!

[PvtVoid]

Science is about consensus, not challenging dogma?

If you look at Maguejo's theory, you will find that it is consistent with everything we knew before about relativity. It is not: "ZOMG! Einstein was WRONG!", rather "We noticed it is possible to extend relativity theory in a way which accommodates a variable speed of light, yet reproduces other known physics perfectly." Look up dilaton theories, for example.

Re:You know what this means?

[serviscope_minor]

Bullshit. The EmDrive nutters just haven't woken up yet.

'fraid they have. One particularly delusional one is busy arguing with an AC he's convinced is me. Hi TheDarkMaster if you're reading.

Re:You know what this means?

[garyoa1]

Yabutt that still doezn't explain Penny.
Just sayin...

The Matthew Effect

[FranklinWebber]

Crediting Hawking for inflation is yet another example of the Matthew Effect.

More specific credit could have gone to Guth, Linde, and Starobinsky who won the Kavli Prize for "pioneering the theory of cosmic inflation" but who's heard of them?

Re:The Matthew Effect

[Actually, I do RTFA]

Crediting Hawking for inflation is yet another example of the Matthew Effect.

So is crediting Einstein for the idea that light, in a vacuum, moves at a constant speed. In fact, that was the assumption he used, which then caused him to invent special relativity and general relativity to explain away paradoxes that arose from reconciling that rule with, you know, non-quantum physics.

Overturned? More like explaining an edge case.

[bfpierce]

c as a constant is derived from Maxwell's equations, held as invariant in a vacuum.

If that were true everywhere we wouldn't be looking at trying to find a GUT.

Would not in the least surprise me that relativity doesn't hold at the beginning of the Universe, considering I can't imagine Maxwell's equations used in that derivation being true there either.

But didn't Einstein say light speed varies sorta?

[EricTDuckman1414]

But didn't Einstein say light speed varies in his paper "On the Influence of Gravitation on the Propagation of Light "?

From the proposition which has just been proved, that the velocity of light in the gravitational field is a function of the location, we may easily infer, by means of Huygens's principle, that light-rays propagated across a gravitational field undergo deflection.

? Is this like Snell's law of refraction, but with the refraction causing variation in the speed of light caused by a gravitational field instead of a change in the density of the media that the light wave is passing through? Could this mean that gravity is caused by a change in the density of space around a massive object, rather than its "warping" of space? Is it possible that the only actual physical substance in the universe is the media we know as space, with both energy and mass existing as transverse and longitudinal waves in that media?

What if the speed of light ...

[PortHaven]

What if the speed of light is related to the size of the universe? However perception and size is also related.

So the universe is expanding. What affect does that have on perceived speeds?

What if the speed of light is relational to size of the universe? Would it cover more distance in a smaller universe? If so, does that mean C was faster? This is where the normal brain starts to spin wheels a bit.

But it's a lot of fun. And I'll be highly amused if their experiment bears support for their theory. As I first heard this theory decades ago.

I always expected this

[s122604]

How else could the universe be more than 6000 light years across when it was all created 6000 years ago by YHWH

Re:I always expected this

[vandamme]

"For a thousand years in your sight are like a day..." Ps. 90:4

OK, a little off, that's only 2.19 billion years. Somebody moved a decimal point.

Speed of light is not affected by gravity

[sjbe]

If the speed of light is dependent on the strength of the gravity field

It's not. Speed of light is a constant. Gravity affects its trajectory but not its speed.

should have had such a deep gravity well that the speed of light should have been about 0 for the first few milliseconds of the universe' existence

All that matter would affect its path but (so far) there is no evidence that gravity affects the speed of light at all or that it ever did. The reason light cannot escape a black hole isn't that gravity is pulling on the photon so hard but rather because gravity warps spacetime so much that there is literally no path for light to take which can get beyond the event horizon. It's kind of like being in a maze with no exit.

Re:You know what this means?

[lgw]

Have you accepted Jesus Christ into your life as your personal savior?

You're about as fun to be around as the guys who turn every conversation into pushing their religion on you. Really, just stop.

Universal constants

[sjbe]

Why would anything in the universe be constant?

Why wouldn't something be constant? Equally valid question. So far we have observed some things that seem to remain constant. Why that is the case is a separate and interesting question. We also have models based on those constants that fit really, really well with our observations.

Maybe the variability is beyond our ability to observe.

Perhaps but it's kind of hard to make rational scientific models and predictions about something that cannot be even theoretically observed. You're getting outside of science at that point.