speed of light

if something could move at the speed of light would it turn in to light?

could it be that it is moving at such speed which is the only criteria for being light?

There is no condition that something must be visible light in order to travel at the speed of light, it need only have zero rest mass. All electromagnetic radiation travels at the speed of light in a vacuum , and neutrinos travel at almost the speed of light

I aint no physicist, but I do like to think of all things being states of energy, but of note that they are not isolated - rather being built on and within relationships with other energy.

So I like to think a photon (light) carries an electromagnetic interaction, and be made of bosons, which might give it mass through its capacity to interact with its environment, but not classify it as matter (fermions). These all just being names for states of energy in motion... the question then being about understanding the nature of this motion before getting too lost in the math of the labels used to describe the math!?

So I'd say no, but that it might very well go from matter to something fundamental and then the next easiest stable state for all that 'stuff which is no longer stuff' (might as well call it the Force LOL) could be light.... so it might appear that taking it to the speed of light would turn it to light yes, but no because it had actually ceased being stuff before becoming light. There you go, two answers for one question... it does my head in a bit, I think I need to go lay down on a planck now

OB1Shinobi wrote: if something could move at the speed of light would it turn in to light?

You mean something other than light? No, it wouldn't. Nor would it travel at that speed in the first place.

could it be that it is moving at such speed which is the only criteria for being light?

No.

What fascinates me about this sometimes is that the electromagnetic force will expand with light speed just as light particles will move with it, too, but at the same time, gravity will also expand with light speed yet mass cannot ever move with it... Perhaps an indicator that there is indeed only one phenomenon at the root of it all and that what we identified are but special cases of it.

Oh, and also

Adder wrote: ... understanding the nature of this motion before getting too lost in the math...

The math is the nature of those motions. Understanding them is understanding the math. Or, to be more specific, our brains didn't exactly evolve to the end of diving into the complexities of the workings of the universe. So we are, strictly speaking, stuck with the math, because this is the language that happens to be best at describing what we observe. We, in other words, have no means of understanding those things without the math. For our purposes, while the labels are necessary to draw the bridge out of the chalk board and into realiy, still, the nature of those things is indeed mathematical.

Fenton wrote: There is no condition that something must be visible light in order to travel at the speed of light, it need only have zero rest mass. All electromagnetic radiation travels at the speed of light in a vacuum , and neutrinos travel at almost the speed of light

I thought photons had an admittedly very tiny, but still very existent mass.

Whilst we're on the topic of the speed of light though does anyone know why it's not infinitely fast? I ask this because supposedly no time passes when moving at the speed of light so why does it not travel everywhere instantly?

Frost wrote: I thought photons had an admittedly very tiny, but still very existent mass.

Photons are thought of having relativistic mass proportional to their momentum, but the important distinction is that the rest mass is zero. As a photon can never be at rest, it may seem to be arbitrary, but it is an important distinction to make nonetheless.

To your other point: the speed of light in a vacuum is a universal constant. To ask why light speed must be what it is, is like asking why gravity is an attractive force. There may be an answer, or there may not, but I haven't heard of any definite answers yet, and we may never be advanced enough to comprehend the answer should it exist.

Matter has mass when at rest but also relativistic mass which is one of the reasons it cannot be accelerated to light speed.

As for the actual value of the speed of light, that is a matter of definition. If we take arbitrary units and measure both time and distance light travels, regardless of where we take the measurement or how fast our instruments move, the ratio of that distance over that time remains the same: A constant. Since all ratios are real numbers, it can therefore not be infinite. Besides, infinite velocity implies the presence in all places at any given time, which is not true of anything traveling with light speed.

We came to use feet and meters because those units are convenient to us, so we tried to see the value of that constant and found it. Of course, the foot and the meter were previously defined in ways that would be changing on a number of environmental factors, so for convenience's sake we can now use light speed to define them. Normally you would hear that light travels with 299792458 m/s, which makes you wonder how accurate that number is. Well, it is, as it were, perfectly accurate, not because we measured it to be, but because we defined the meter like this. 1m is the distance that light travels in a vacuum over the duration of 1/299792458 seconds, with the second being a multiple of another natural constant.

Frost wrote: Whilst we're on the topic of the speed of light though does anyone know why it's not infinitely fast? I ask this because supposedly no time passes when moving at the speed of light so why does it not travel everywhere instantly?

In Einstein's general relativity e=mc^2 (energy=mass x the speed of light x the speed of light).

If the speed of light was infinite then the energy in anything with mass (even a neutrino) would also be infinite (actually a larger infinity than the infinite speed of light). This would be obviously problematic as if everything had infinite energy, it would also have infinite mass.

The reality is that the speed of light is fine tuned along with many other (so-called) constants to allow protons, electrons and neutrons to form chemical elements and life. In universes with life as we know it - the speed of light is naturally constrained to within a couple of percent of what we measure it as today. If it were different - there literally wouldn't be anything or anyone to measure it.

Within the confines of this theory you are absolutely right when you say the photons arrive instantly - but that is only from their frame of reference. At the speed of light time stops flowing in that frame of reference. However, we as observers of light, not travelling at the speed of light, exist in a different frame of reference and measure them travelling at approx 300,000 km/s.

If c was infinite, no equation involving it would be well-defined. That doesn't mean mass would be infinite, but that the proportionality of mass and energy would not be identifiable. Reference frame dependant energy types lika pretty much all pre-relativistic stuff like mechanics, electricity, thermodynamics, all would have a concept of energy that would be very much quantifiable irrespective of the value of the speed of light.

The speed of light is also not finely tuned for the possibility of the elements we know nor life as we know it. Natural constants are not arbitrary and mutually independant and assuming that universes with different values to those constants are possible, there could be any number of them with vastly different values but with forms of energy nothing unlike the ones we are familiar with and therefore life just as we know it from ours and that is leaving out all the other types of life we probably haven't even dreamt of yet. Interestingly, things like population dynamics and the resulting evolution would be exactly the same no matter what the universal constants would be in the particular instance.

most of this i admit is over my head - i can understand it eventually but it takes a few go arounds so forgive me if i ask the same question again after its been answered

i just want to understand

anyway, speed is relative i understand that, and there is no speed without externality eg something outside of the moving object by which to measure speed

ive read that it is impossible for mass to move at the speed of light - which i can understand as being a rule but i dont understand what MAKES IT a rule

and so i was wondering if, since the rules all change as it
were after a certain speed,
is it theoretically possible that mass actully decreases at a certain speed?
or another way of asking is it theoretically possible that the process of achieving light speed actually transforms mass into light?

The laws of nature aren't so much given laws by which nature obides as they are our descriptions of what we observe in nature. In this sense, we don't know what makes anything a rule, but based on what we see we propose patterns and then test the predictions our patterns make to see if they are applicable to reality and to what extent.

Now classical speed, or Galilean velocity if you will is indeed relative. It is an approximation of the motions at speeds far below the speed of light. As things move faster, i.e. closer to the speed of light however we find that those models are too simplistic and increasingly fail to describe and predict observations. In the early twentieth century this was mostly theoretical and was hard to observe so it followed from other laws that were in turn easily observable. Now, with particle accelerators, we can actually induce high velocities and observe the resulting behaviour of mass. Now since I didn't thoroughly cover relativity myself, I shan't start with those and then deduce relativistic equations from them.

Now there is the so-called energy-momentum relation, an equation that relates any object's rest mass m₀, momentum p and total energy E:



where c is the speed of light.

Since the rest mass of a light quantum (and I mean any electromagnetic quantum, of course) is zero, you can see that the energy of a photon reduces to E=pc and since a massive object at rest has zero momentum (because in that case p=m₀v where v is the object's velocity), its energy at rest reduces to E=m₀c².
Now, we can trivially expand the latter equation by v/v=1 resulting in


and with mv=p


Now we solve for pc and feed that into our initial equation to get



Solving for E² we get


As you can see, as v approaches c, the denominator approaches zero and therefore the total energy E of that object approaches infinity. In other words, the faster you go, the more energy it takes to accelerate any further.

As for the change of mass, we come for the momentum p, twisting the variables we have so far around a bit, to

And since p=Mv where M is the total mass of the object, this reduces to

As you can see, the total mass of an object not only doesn't decrease with increasing velocity, but indeed, the opposite is the case: As a massive body accelerates approaching light speed, it actually quite rapidly gains mass, which explains why it gets increasingly impossible to accelerate it further the faster it already moves.

I would like to stress that I am very much a layman at this point. While the conclusions, as far as I know, are correct, I presume that my ways of getting to them that I presented here may be severely flawed in several places. Bearing that in mind I hope it was still marginally helpful.

no matter what you got my brain buzzing so yes it was helpful certainly

i wonder if traveling backwards in time would cause mass to transform into light

if mass gains mass as it picks up speed the only thing i can think of as the opposite of speed is reverse time

i may not be much of a scientist but im a pretty good story teller lol

it bothers me that speed of light is not possible

what if i build a machine which turns a cylinder to produce energy

the cylinder is originally turned through nomal magnet power but its got electro magnets attached also

the produced energy is stored into a capaciter or a battery
or something - every time a certain amount of energy is stored; let.me call it just call it 10

whenever 10 is stored 1 gets fed back into the spin of the cylinder by being directed to the electro magnets

the idea being that the more power used to turn the cylinder the faster it goes - every time it reaches the next 10 it puts another 1 back into the system making the cylinder spin just a little faster

unless it explodes its an infinitie progression - doesnt it HAVE to reach the speed of light eventually?

Study!! This 9 videos are great to see the relation between time & space. I am still studying.
KSP Special Relativity ( 1 of 9 ) Introduction : http://youtu.be/KKAwpEetJ-Q

A little song that I like (interlude)
Shall we gather at the river? : http://youtu.be/Qca8B5NbX5Y

Others video on relativity
Albert Einstein's Theory of Relativity : http://youtu.be/ev9zrt__lec

Relativity and Time Dilation : http://youtu.be/aZrjMmMBa_8

Don't contest the light....
Simple Relativity - Understanding Einstein's Spec… : http://youtu.be/TgH9KXEQ0YU

OB1Shinobi wrote: i wonder if traveling backwards in time would cause mass to transform into light

Positrons are sometimes thought of as electrons traveling back through time. They still have mass and are still not quite the same as a light particle... Then again, with only one direction of time available to our observation as of now, it is difficult to say. I wouldn't know why mass moving back in time should suddenly lose its mass. In fact, if its energy stay constant, then that'd mean it would have to gain momentum and why that would happen is also currently beyond me. In any case, numerous reactions, most prominently nuclear fusion and fission, operate on the equivalence of mass and energy. When you burn a piece of paper and you conserve the smoke and the ash, the total mass of the system will in fact decrease and the light and heat the flames emitted amount to just that difference.

if mass gains mass as it picks up speed the only thing i can think of as the opposite of speed is reverse time

Speed is defined as the euclidian norm of velocity. Let x and y be arbitrary linear independant directions, forming a two-dimensional vector space. Let t be time, vector v be velocity and v be speed.

Now, even with t being negative, indicating 'reverse time', if you will, since it is in every instance being raised to the second power, the entire expression can never be negative. Speed is always either zero or positive.

what if i build a machine which turns a cylinder to produce energy

You would win more than just the Nobel Prize. Before you get too hopeful though, bear in mind that such a device would violate the first law of thermodynamics and patent offices grew so tired of people trying that many have special policies on machines with that ambition.

the cylinder is originally turned through nomal magnet power but its got electro magnets attached also

It could be originally set in motion by a user or by a convenient assymmetrical configuration of electromagnets. You are describing an electromotor right now.

the produced energy is stored into a capaciter or a battery or something

every time a certain amount of energy is stored; let.me call it just call it 10

whenever 10 is stored 1 gets fed back into the spin of the cylinder by being directed to the electro magnets

So you are saying that for every one unit of energy it gets it puts out ten? Essentially what you are describing is an electric generator, which is a reverse electric motor, if you will, but this one not only doesn't lose any energy to friction, it somehow produces energy out of thin air. Where do the additional nine units come from?

the idea being that the more power used to turn the cylinder the faster it goes - every time it reaches the next 10 it puts another 1 back into the system making the cylinder spin just a little faster

unless it explodes its an infinitie progression - doesnt it HAVE to reach the speed of light eventually?

Unless your machine is made out of light rather than matter, it will have a rest mass. If it has a size, that mass will also not be located on the rotation axis but actually somewhere where it will experience motion. And as by the formula above, so long as the rest mass is not zero, with increasing speed, total mass will, again, increase ad infinitum. So even if we had a motor that we would feed more and more energy into the device, as long as we only have finite energy at our disposal, no part of it will get to light speed, eventhough we can get very close indeed. If we did have a self-sustaining device that could actually conjure up energy out of nowhere, until it reached light speed, literally infinite time would have to pass, because in a finite time only a finite amount of energy would be generated. The only way to get massive objects to light speed is to conjure up infinite energy in an instant.

i think what im describing is technically a magnetic dynamo

yes it could initially be set in motion by a light touch
actually even that wouldnt ve necessary i think

generally speaking its my thought that the basic dynamo concept could be applied to every hinge and sliding surface in a home which would mean that every time someone opened their refrigerator or cupboard or any door in the house they would generate a small charge of elecetricity which would be stored in a central battery or whatever the appropriate storage device may be

the dynamo was an elaboration on this concept so that the energy didnt have to be produced manually

if a dynamo is light enough at its fulcrum (ive found that others have thought of this part - there are magnetic fan blade dynamos on youtube) to be rotated by the influence of the normal magnets

but it also has electric magnets ready to add to the amount of magnetic pressure applied to the rotation of the cylinder or the fan blades (which was how i originally thought of it too) the the first thing the dynamo does is to create energy

this energy is stored until it reaches 10 points

the 11th point of energy is applied to the electric magnets

this cycle is repeated

also the 1-10 ratio is completely arbitrary

its probably not the most apporopriate ratio for either energy production for a home or for reaching light speed -though i guess im letting go of that ambition for the time. the point was free clean energy and this device would do that if my assumption about our technological ability to store measure and reapply electric energy and my understanding of electric magnets are both accurate

I am sure is possible to make free energy. Now they are working on nanotube of carbon. Thats really more advanced for the english im mastering but perhaps you are going to understand something.

Self Org. Systhems Vector Equilibrium Flower Of… : http://youtu.be/9n-vb71VZzk

Free Energy and the Equilibrium Constant : http://youtu.be/F1k8TJsVg_g

Einstein on faster-than-light speeds? : http://youtu.be/l9aLyfFnfOU

And nano carbon? It's military sciences. They are not giving the tech even if we need it to make plasma lightsaber... We are going need to do it with telekinesis.
There are some stone that have rubidium. Thats substance in gaz are the one who make the light with mass. Right now they are using this Tech for make quantum computer. A rubidium onze cost much more than gold.

When you ride your bicycle and switch on the dynamo on the go, you will immediately notice how it is slightly harder to push the pedals. When you open the fridge, the energy you put into the door moves the door. If you want to harvest that motion, you mount a spring on the door that will move some sort of harvesting device like a generator. You will be storing some energy, but you will also spend more on opening the door because now it is retained by an additional spring. That energy in turn will come from your body's metabolism, i.e. respiration, water consumption and food processing. Ultimately all we have is the materials Earth provides and radiation from the sun. An ideal closed system would retain all of its energy in a form that is still useful to keep the system going. The second law of thermodynamics disposes of that possibility. If in addition to keeping all the energy one wants to actually produce any, I'm afraid physical reality has an impressive track record of disappointing them.

The sun is the most free energy source at our disposal. To harvest it either directly or through biomatter is as close as we can get to free energy. And plenty at that, if we go as far as building a dyson sphere around it, but there will not come a machine that conjures up energy out of nothing unless it runs on magic. That's not a matter of technology either. That's just the universe we have to deal with for it is the one we've been dealt.

If something travelled at the speed of light, would it stop being a physical object if it became light? or would it simply travel so fast that it passes through some kind of barrier, abit like a sonic boom when the sound barrier is broken.

i shouldn't have peeked into this thread....all those formulas....triggering my college algebra ptsd..... :sick:

https://www.youtube.com/watch?v=ev9zrt__lec


this video proves that im on to SOMETHING - not that im right per se but that i am generally interpreting the relationship between light and time in a functional way

im going to spend a good bit of time on these and other related videos

this is an awesome thread
thanks to everybody
keep it coming!