# The universe's speed limit: there isn't one, it's all perspective



## qubit (Oct 9, 2011)

Here's a very interesting article on the speed limit of the universe being the speed of light - or not. Apparently, it's all to do with time dilation as you approach that magic speed not breaking basic cause and effect (time travel into the past). So, from the point of view of the hypothetical space traveller in his high tech starship, you can keep putting your foot down on that gas pedal and get to any point in the universe as fast as you like, literally cross it in a couple of minutes! The graph below illustrates this nicely:









> The recent news of neutrinos moving faster than light might have got everyone thinking about warp drive and all that, but really there is no need to imagine something that can move faster than 300,000 kilometres a second. Indeed, the whole idea is illogical.
> 
> Light speed, or 300,000 kilometres a second, might seem like a speed limit, but this is just an example of 3 + 1 thinking – where we still haven’t got our heads around the concept of four dimensional space-time and hence we think in terms of space having three dimensions and think of time as something different.
> 
> ...



Universe Today


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## techtard (Oct 9, 2011)

mind=blown


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## qubit (Oct 9, 2011)

Yes, it certainly is mind blowing. I always did wonder why there had to be a universal speed limit.

So, if this article is correct, there isn't a limit, it's just time dilation becoming extreme. How this makes a light signal go at a particular speed from our viewpoint is still not clear to me though, if light really travels instantaneously.


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## techtard (Oct 9, 2011)

For all we know, we might be in a pocket of time/space where our observed physical laws are an abberation and not the norm.

The more we learn, the more we realize we don't really know.

As a fan of science and sci-fi, this is pretty awesome though. Been a while since I've actually sat down and thought about anything of this magnitude.

It will make some epic thinking over Canadian turkey day.


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## Jegergrim (Oct 9, 2011)

So that puts a new perspective to "lightyears" ?


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## FordGT90Concept (Oct 9, 2011)

I still think mass has to do with maximum velocity (same goes for large objects).  Neutrinos are a whole lot less massive than photons, hence, the ability to move faster.


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## qubit (Oct 9, 2011)

FordGT90Concept said:


> I still think mass has to do with maximum velocity (same goes for large objects).  Neutrinos are a whole lot less massive than photons, hence, the ability to move faster.



Light actually has no mass, so you can't get less, unless it's somehow negative!


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## Jegergrim (Oct 9, 2011)

Everything with a wavelength has a mass, hence photons has mass (at least in quantum mehanics)


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## qubit (Oct 9, 2011)

Jegergrim said:


> Everything with a wavelength has a mass, hence photons has mass



No it doesn't, but it does have momentum. See this link from Illinoise University:

http://van.physics.illinois.edu/qa/listing.php?id=14123


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## FordGT90Concept (Oct 9, 2011)

Just because it can't be measured with modern instrumentation doesn't mean it isn't there.  It is near impossible to isolate a single photon and even harder to keep it on a scale.


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## Jegergrim (Oct 9, 2011)

qubit said:


> No it doesn't, but it does have momentum. See this link from Illinoise University:
> 
> http://van.physics.illinois.edu/qa/listing.php?id=14123



Been a while since I've had physics, years even, but I do recall where we had quantum mehanics lessons, and that certain formulas showed light has a mass, but it's gravitational field doesn't affect anything, also everything with a mass has a wavelength and vice versa, light has a wavelength thus has a mass, I donot quite recall the formula, but it's quite known. I hope I don't have a fractured memory


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## qubit (Oct 9, 2011)

FordGT90Concept said:


> Just because it can't be measured with modern instrumentation doesn't mean it isn't there.  It is near impossible to isolate a single photon and even harder to keep it on a scale.





Jegergrim said:


> Been a while since I've had physics, years even, but I do recall where we had quantum mehanics lessons, and that certain formulas showed light has a mass, but it's gravitational field doesn't affect anything, also everything with a mass has a wavelength and vice versa, light has a wavelength thus has a mass, I donot quite recall the formula, but it's quite known. I hope I don't have a fractured memory



Ok guys, I'll accept both your answers. I'm hardly an expert on this subject and was just going by the statement that light doesn't have mass that I read in many physics articles. Perhaps in some weird sense it has, in the quantum world nothing is as it seems - and don't I know it!


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## bucketface (Oct 9, 2011)

so they are saying that time just slows down the closer to the speed of light matter moves.... while that could be possible, how about they try to find soma actual examples of this hypothetical occurence happenening in the natural world or at least attempt to create one. is it really so hard to concieve that time is constant never changing, never faster nor slower. why can matter not exceed the speed of light just because we have never observed it before, recently. I'm still going with, if you have enough time and energy you can go faster than the speed of light, it just takes alot of both.

in a somewhat related topic. does anyone know the exact reason as to why heat slows electron transfer and why they paradoxicaly require abolute zero temps (0k requires no energy) to let them achieve speed parity with light?

edit*


Jegergrim said:


> Been a while since I've had physics, years even, but I do recall where we had quantum mehanics lessons, and that certain formulas showed light has a mass, but it's gravitational field doesn't affect anything, also everything with a mass has a wavelength and vice versa, light has a wavelength thus has a mass, I donot quite recall the formula, but it's quite known. I hope I don't have a fractured memory



from what i remember energy is supposed to be massless.


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## qubit (Oct 9, 2011)

bucketface said:


> so they are saying that time just slows down the closer to the speed of light matter moves.... while that could be possible, how about they try to find soma actual examples of this hypothetical occurence happenening in the natural world or at least attempt to create one. is it really so hard to concieve that time is constant never changing, never faster nor slower. why can matter not exceed the speed of light just because we have never observed it before, recently. I'm still going with, if you have enough time and energy you can go faster than the speed of light, it just takes alot of both.



You really need to read up on a layman's explanation for general relativity. Here's one from Wikipedia.

Scientists have proved experimentally that speed and gravity both affect time. Heck, every GPS satellite and receiver has a compensation factor calculated into it to adjust for this!

Just google on this subject and you'll find a ton of answers on why time isn't fixed and unchanging and one can't go faster than light in the traditional sense, not this article in my OP of course. Note that one doesn't actually break the speed of light even there from the point of view of the static observer.


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## slyfox2151 (Oct 9, 2011)

bucketface said:


> so they are saying that time just slows down the closer to the speed of light matter moves.... while that could be possible, how about they try to find soma actual examples of this hypothetical occurence happenening in the natural world or at least attempt to create one. is it really so hard to concieve that time is constant never changing, never faster nor slower. why can matter not exceed the speed of light just because we have never observed it before, recently. I'm still going with, if you have enough time and energy you can go faster than the speed of light, it just takes alot of both.



there already is evidence.... get on a plane somewhere and time moves slower ( only very slightly however... something in the order of nano seconds i think... is pico....)


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## Jegergrim (Oct 9, 2011)

Well theoretically, anything with a great mass will slow down time relatively, e.g. a huge pyramid (but we are talking about fractions of a sec) Stephen Hawkings made a documentary about this very easy to comprehend from his explanation.

As Qubit mentioned earlier, theres mathematical calculations in Satelites to account for the very tiny fraction of a second extra added to time inside the precise timers in satelites, if unaccounted for, GPS would stray off for 6 miles each day.


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## qubit (Oct 9, 2011)

Jegergrim said:


> Well theoretically, anything with a great mass will slow down time relatively, e.g. a huge pyramid (but we are talking about fractions of a sec) Stephen Hawkings made a documentary about this very easy to comprehend from his explanation.
> 
> As Qubit mentioned earlier, theres mathematical calculations in Satelites to account for the very tiny fraction of a second extra added to time inside the precise timers in satelites, if unaccounted for, GPS would stray off for 6 miles each day.



Yes, absolutely. In fact, I read in New Scientist recently that such super accurate atomic clocks have been built, that they can measure the difference in time's speed due to gravity with two clocks in the lab, where one is a mere metre or so higher than the other! So yes, your feet really do age at a different rate than your head. The difference is tiny, that's all.


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## bucketface (Oct 9, 2011)

qubit said:


> You really need to read up on a layman's explanation for general relativity. Here's one from Wikipedia.
> 
> Scientists have proved experimentally that speed and gravity both affect time. Heck, every GPS satellite and receiver has a compensation factor calculated into it to adjust for this!
> 
> Just google on this subject and you'll find a ton of answers on why time isn't fixed and unchanging and one can't go faster than light in the traditional sense, not this article in my OP of course. Note that one doesn't actually break the speed of light even there from the point of view of the static observer.





slyfox2151 said:


> there already is evidence.... get on a plane somewhere and time moves slower ( only very slightly however... something in the order of nano seconds i think... is pico....)



my understanding was that reduced temps resuted in faster electron transfer in the digital clocks, hence the tiny time difference. i studied electrincs and these were used as examples when it was being explained that electron transfer achieves light speed at absolute zero. i was assuming that whoever did those experiments had un/intentinally forgotten to factor that in. 
i guess i'll have to do some reading though.

if somehow gravity is affecting time... well my mind is blown because i just don't see how an energy field emmited by matter is interacting with time.


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## qubit (Oct 9, 2011)

bucketface said:


> my understanding was that reduced temps resuted in faster electron transfer in the digital clocks, hence the tiny time difference. i studied electrincs and these were used as examples when it was being explained that electron transfer achieves light speed at absolute zero. i was assuming that whoever did those experiments had un/intentinally forgotten to factor that in.
> i guess i'll have to do some reading though.
> 
> if somehow gravity is affecting time... well my mind is blown because i just don't see how an energy field emmited by matter is interacting with time.



Oh, you're right about temperature affecting the speed of the clocks. You know how it is, the minute one gets into any kind of accurate measurements, a zillion factors and then some have to be taken into account, lol.

Gravity is not an energy field. It's the curvature of spacetime, which is completely different. Have a read of that Wikipedia article (at least the initial parts) to have an idea of what we're referring to.


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## Inceptor (Oct 9, 2011)

Time dilation is old old news...*Special Relativity*.
As much as I sort of like Universe Today, that guy is a bit simple minded.


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## Drone (Oct 9, 2011)

Good God all this FTL buzz is getting really old.


Expansion of the universe is faster than light 
http://scienceline.org/2007/07/ask-romero-speedoflight/

Tachyons are faster than light
http://en.wikipedia.org/wiki/Tachyon

Spooky action is faster than light
http://www.telegraph.co.uk/science/...n-acts-at-10000-times-the-speed-of-light.html

Even gravitation is faster than light
http://metaresearch.org/cosmology/speed_of_gravity.asp




> Although faster-than-light force propagation speeds do violate Einstein special relativity (SR), *they are in accord with Lorentzian relativity, which has never been experimentally distinguished from SR—at least, not in favor of SR*.


 I think enough said.

http://en.wikipedia.org/wiki/Faster-than-light



> Faster-than-light communications and travel refer to the propagation of information or matter faster than the speed of light. Under the special theory of relativity, a particle (that has rest mass) with subluminal velocity needs infinite energy to accelerate to the speed of light, *although special relativity does not forbid the existence of particles that travel faster than light at all times* (tachyons).






Jegergrim said:


> Everything with a wavelength has a mass, hence photons has mass (at least in quantum mehanics)



And what in the universe doesn't have a wavelength anyway? Even *absolute vacuum* has fluctuations.


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## qubit (Oct 9, 2011)

Drone said:


> Good God all this FTL buzz is getting really old.



Rubbish man, I can type a post on this very forum faster than light. Muhahahahaha!!! 

Nice find.


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