Hello Everyone,

First of all, happy new year to all. New guy here with some typical newbie questions that defy all logic and common sense... shouldn't be a big shocker there, huh?

I was reading a thread several pages back where somebody asked about a car's headlights shining if the vehicle was traveling at the speed of light, and some of the responses got me thinking. As I understand it, some basic principles of Einstein's special relativity theory include that no known physical object can exceed the speed of light, which is a constant, or "c" in the equation. Another is that if a hypothetical object was to attempt to break light speed, it would have to gain infinite mass and also obtain production of massive propulsion energy. (Please stop at any time and berate my ignorance if I have got the theory wrong)

Now, here is my first question... Can somebody please explain why an object's mass increases as it approaches light speed? Is this due to some sort of stretching of space-time?

Second question (goes along with the first)... assuming Einstein is right, and anything traveling at light speed has infinite mass, then why isn't a normal beam of light so massive that it essentially collapses in on itself because of it's own super gravity?

Lastly, I understand the reasoning that time slows down when approaching light speed. If this is true, then is it reasonable to assume that light beams from distant stars actually took less time to reach Earth than previously thought?

Whew, ok. I think steam is coming out of my ears now. Can anybody help out, or am I just being ridiculous?
Thanks

I was part of that thread and I learned a lot, I think anyways heh.

This is all according to current mainstream theories and is subject to change at any time

Firstly, nothing can go past the speed of light..period.
Secondly, nothing with mass can reach the speed of light.

To answer your first question, it is my understanding that objects do not gain actual mass (As in matter) as they approach c, they merely gain kinetic energy which translates into mass, since energy = mass*the speed of like squared...i.e. E=Mc^2 and mass= energy.

Your second question is easier....light can travel the speed of light because light has no mass, it is a wave. While it is said light is a particle and a wave, it still has no mass.

Your third question is tricky because if you were riding on that beam of light time would slow down to nothing. However, since you are an outside observer the speed of light seems to travel at 300,000 km/sec. And it is always predictable at that speed. It does not speed up or slow down.

The first rule you seem to have missed is that light is not a form of matter as we know it. The particle or wave ( yes, both. ) have no rest mass. That is to say light only exists at C. If you stop it its gone. 0. The photon is a sub atomic particle which behaves as a wave under test conditions...
Light beams from distant stars are not that...beams. The pupil of your eye or the reflective optics of your telescopes mirror can and do receive the light photons that have traveled to you. By staking images or using massive exposure times a great deal more of that image can be made available to us. Time does not slow down... your perception of it can be distorted.
Why does the mass increase as you near light speed. You can not. Nothing with mass can achieve light speed because there is not sufficient energy in the whole universe to drive you at that rate. sorry.

Ok, thanks to both of you. I think I understand the first part. By approaching or matching the speed of light, you would in effect gain infinite energy, since mass = energy. Although this would not be possible, because nothing with mass can be propelled at that velocity.

Now I have another question though... if a beam of light has no mass, then how is able to be pulled into a black hole?

Back to the third question again and your answers... I think I understand what you are saying. By being either an outside observer or riding the light beam, it all boils down to relative perception. However, wouldn't this suggest that time is a constant, and cannot vary at all? I thought that most theories suggest that space-time can bend and change in certain areas of the universe.

On the other hand, if you somehow could be riding the light beam and time "stopped", then in theory couldn't you exist in several places at once?

Yikes, I think I just fried my brain.

How very clever, I wish I had asked that, lol.

../taps foot impatiently waiting for answer.

Arcane,

Well, I know very little about black hole theory, but as I understand it they do emit radioactive particles back into space. I don't see how the radioactive particles can escape the massive gravitational pull but light still gets sucked in.

Yes, in fact I had a theory going at one point that if you were a beam of light you were like God because you could live for infinity and you could be all places at once, aka omnipresent and eternal. Then of course there is the whole thing about God is the Light and Light is good and darkness is evil etc...which kind of got me really riled up lol. Sounds a bit crazy I know.

But then I came to my senses when someone pointed out that if you were traveling the speed of light you could not do anything. You couldn’t control your ship or see anything and eternity would go by and you wouldn't know it. The reason is, on your ship time has stopped. All of your clocks do not move. Time does not pass. You cannot control your ship because according to you, you have not left yet, that kind of thing.

So you either wander through space for infinity, which would seem like 0 seconds, or you would hit the gas and then go splat on some asteroid and be dead.

You are right, it is known as Hawking radiation. I can't explain that either. But from what I know it is 2 particles that are connected, one is sucked into the black hole and one is pushed away. Positive negitive kinda thing.

I may be wrong on that though...heh.

It could be argued that light itself is not pulled into the black hole...but the space its transversing is. The same can be said of time...
Time is not flexible. It rushes forward as always. If you could use so much force as to distort the very fabric of the universe then time could be seen to stop from your point of view. Relativity applies to both.
Your last comment regarding the leakage of energy from a black hole is 'Hawking radiation.' I have read of it but do not know or understand this subject. Who does..?

Not really. I think about the same stuff... I've got a simple theory of my own going about the general nature of things. I've been thinking about how everything is a reflection of it's smallest part.

I was researching the atom, and how electrons orbit around the nucleus. Then tie that into how our planets in our solar system orbit the sun, spinning all the while much like the electrons. Then, think about how the galaxies also spin and expand. In my mind, is it so hard to imagine that maybe the known universe perhaps does have an "end", and perhaps even revolves in orbit around an object or force so powerful and massive that it has numerous "universes" in orbit around it?

Hey, maybe it sounds crazy but who knows.

Oops...It looks like Arcane does...

Re Hawking radiation...

Hawking Radiation as in a Stephen Hawking theory? I will have to go look that up.

If these radioactive particles can indeed escape the event horizon of a black hole, does that mean that the laws of physics don't apply to them in their state of existence perhaps?

Are you serious? What would you base that argument on? "Space" from my gathering means emptiness. In other words, the lack of anything. How can nothing pull light in? And you are also assuming the particles around light would have the gravitational force to pull the light in with it...How could that be since light has no mass? Or are you saying the light is stuck in the space like a fly in jelly?

Makes no sense.

As astromark said, we don't really think of the light as being "pulled in", for just the reason you cite. Yet the light goes into the black hole, so why? The standard explanation is that light tracks what are known as "geodesics", which are the equivalents of "straight lines" when there is gravity. In other words, gravity is not a force, it is a change in the meaning of what "straight" is, and the light just goes straight. What's tricky is that the meaning of straightness here involves both space and time, not just space alone. But you can picture it like astromark said-- you may imagine the space itself is sucked in, while the light goes straight-- in that space. So light has no forces on it, and anything that has no forces on it goes "straight"-- but gravity does not count as a force, so even objects in free fall are going "straight".

Gravity isn't a force? That is a new one on me. i thought Gravity was one of the 4 forces of the universe?

What you said makes sense kinda Ken. I see how it could be maneuvered into the black hole, but why can it never get back out.

And why does everyone say that gravity is a force that light cannot escape, when it is nothing more than a dent in space that light falls into?

I mean you are saying that gravity is not a force at all and mass plays no real role as far as attracting object like a magnet would, but mass only puts a dent in space that things fall towards.

Interesting.

Gravity is a force, but we are not counting gravity as a force on light, since light has no mass.
ETA: re-reading Ken G's post about is Gravity a force- it's wording like "Cold does not exist. It is only the absence of heat" maybe cutting in here. IN GR and SR gravity is considered to be an observed effect of the warping of space more than an actual force.
In Quantum Physics it is considered a force, and there are those who theorized about Graviton particles interacting.
Light itself is not pulled into a Black Hole. As Ken G put it, Light always travels in a straight line.
Think of a curve that is banked. Ever watch NASCAR? The track is high up with a slope on the outside of the curves and low down on the inside curve. If you are driving in a straight line on a flat road and then the road curves the the left, but the road remains flat, you will need to turn the wheel to the left in order to make the turn.
However, if the road is banked properly, you could make the turn without ever touching the wheel, because with the proper banking, you would still be moving in a 'straight line'. If you are going fast, you need a higher bank. Slow, you need only a little bank.

The intense gravity around a black hole has banked the space around it to such a high degree, that light traveling outward in a straight line is still curved back around into the black hole again.

So Space isn't sucked bak inside. Neither is the light. Space is so warped that the curvature is great enough to redirect the light back inward.

Sadly, yes it does. Everyone seems to get caught by this one at some point in their lives, self included- so you are not alone

The problem is that it's comparing apples to oranges.
Celestial mechanics and planetary orbits are nothing like atomic orbits.

It is not the same principle that is scaled up or scaled down.

Similar thinking is wondering if the bacteria build cities on your skin and think of us as a planet.
Studying a wee bit of biology will quickly shatter this notion however

Space warpage and relativistic distortion can muddle our perceptions
However, the effects still interact physically. The warping of space around a black hole doesn't allow light out. Even though light has no mass and always travvels in a straight line, the black hole was able to 'cheat' and grab it by making the road so heavily banked that it curved right back inside again.
So an effect can be more than a perception.

However, if you were 'riding' the wave and time..."stopped" you would not be in several places at the same time. You would be wherever your matter is, even if to an outside observer you appeared to be in several places at once.


Why do I get the feeling you are thinking of an electron cloud now?

Yes that is what we are telling you... The words we all use are a little different the fact driving this question are the same. A black hole is a Object of such mass that total collapse of atomic structure has taken place. The gravity force so strong that light or any thing else can not escape. As for understanding the Hawking radiation... I can only sagest a read of his book to help you through that. Good reading..

Hawking radiation is a bit trickier.

In This Theory, given a substantial amount of time (In many cases maybe longer than the universe exists) a black hole can 'evaporate' due to the interaction of anti-matter and matter being pulled into the black hole.

Perhaps a couple of analogies can help clear things up. First, gravity is often called a "force" for reasons of convenience, but it really is not a force of "attraction." Gravity is the effect that mass has on spacetime - the "fabric" of space and time. (note that space is not really a "nothing" and it, according to current theory, is never really empty as in zero, zilch, nada, etc.)

Visualize a cannon ball resting on a trampoline. The cannon ball "warps" the fabric of the trampoline like a massive body (like our sun, or a black hole) warps the fabric of spacetime (warping both space and time). Now flick a marble across the trampoline at an angle towards the cannon ball. The marble follows a "straight" line across the surface of the trampoline. Now that straight line isn't really straight according to our point of view in 3D space but it's as straight as it can be to the marble on its 2D trampoline surface. Think about what you get when you draw a "straight" line on a sphere. In any case, the marble ultimately gets captured by the warp in the trampoline that the massive cannon ball makes. The marble may spiral in towards the cannonball and circle it for some time before it ultimately plunges in to meet the cannonball. Now, you should be able to see that there is no force of attraction between the marble and the cannonball, and only a warping of the spacetime paths around the cannonball are affecting the path of the marble. This is essentially how the Earth revolves about the Sun - our sun warps space time.

When light falls into a black hole, it is because the path of the light brought it to the event horizon wherein spacetime is so highly warped that there literally are no paths back out of the black hole.

At least this is how I understand it. Hope it helps.

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Oh, by the way, current theory has it that our universe is expanding because space itself is being stretched/expanded not because things are moving "through " space away from each other. It's like taping pennies on the surface of a balloon. As the balloon expands, the fabric of it is stretched and the pennies will all get further and further away from each other, not because the pennies are moving across the surface/fabric of the balloon, but because the stretching fabric of the balloon is carrying the pennies away from each other. But note that this applies to the largest of scales as in between galaxies. At smaller scales, like with our solar system, the local gravity of our star and planets overcomes and trumps any possible stretching/expanding of space locally.

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Have you ever been just about to grasp the truth when somebody else suddenly yanked it out of your reach?
Eclectic Universe website and Eclectic Universe Forum
Eclectic's Blog and Thinking With Reason

This analogy holds true only dependent on location.
I tried using this to demonstrate the effect and ended up trying to catch the balloon and removing a lot of pennies from the mouths of toddlers.

Its interesting to see so many saying the same thing...great.
The Hawking radiation explanation is the best I have yet seen, thanks for helping me understand that.
Neverfly; Do not play with money and children. These two objects are not compatible. Like anti mater and positive mater...

This is true. Children annihilate money. Put money with children and POOF! money's gone (as well as perhaps a few grams of the childs weight.)

Thanks for all the good stuff, folks. I've got some more info to look up now.

Blue Fire, you raised anything interesting question from me. I like that cannon ball and the marble analogy. Easy to understand and visualize... now I'm going to apply that theory to light getting caught in the "curvature" of the black hole. As the marble winds it's way down to the cannon ball, it will also speed up. Now I'm sure you see where I'm going with this....

Can light, like the marble, speed up as it gets closer and closer to the center of the black hole? Because it has no mass, will it remain at constant speed "c"?

You are thinking of the acceleration of gravity. This is due to mass, which light does not have.

Light is curved back into the black hole by the warping of space, not by gravity pulling on it.
C remains constant.

Also, the visual aid of the marble and ball on a rubber sheet is just that- a visual AID... Nothing more.

Try to visualize the gravatic warpage around a black hole that is so severe that light gets re-directed right back inside, from any direction and you may strain your pineal gland.

The visual representation will only help you conceptualize it for a better understanding. But that visual representation is no more substantial than ether- it doesn't exist. The actual space warp would "look" differently. Our 3D accustomed brains may or may not be able to visualize it.

Like a gravity well. I don't like that visual representation because it implies that a planet is at the bottom of a well. A larger planet should have a deeper well. Well looking at the plane of the ecliptic, we see that the planets are not sunken into wells. It is just a representation to help you understand, but you cannot use it as a fact upon which to build new theories.

That truly is hard to visualize, hehe. Don't want to strain that! Normally I think of a curvature like that in respect to a gravity "well" like you mentioned, meaning it curves in a downward manner. It's hard to visualize a space time curvature that's literally in every direction, because then I start thinking of a sphere.

I think what is screwing me up with this discussion about light is the fact that it is not considered matter, at least not in the traditional sense. The loose definition of matter is anything that takes up space and has mass, yet light has no mass, so how can it take up space, blah blah blah.

That's when my head wants to explode. Ever see that movie Scanners?

Actually... no Though I have heard about it as lot I never actually have seen it.

Have you seen any work by M.C. Escher?

Or even a Klein bottle. HenrickOlsen's avater shows one.

But you're closer to the mark when you say sphere. The problem with the gravity well is that it is almost 2 dimensional. Like the flat rubber sheet- one plane.

But the actual gravity well isn't like a plane. It surrounds the entire oblate spheroid of the celestial body.

Also, why are you thinking that light 'takes up space?'

Light cannot be pulled into a black hole.
It must be aimed at the event horizon to go in.
If light "misses" the event horizon, its path will be bent by the gravity well.
If the near miss is deep within the gravity well the transit time will be slowed down by time dilation (for the outside observer).
A great deal of electromagnetic radiation is produced, and subsequently escapes, from just above the event horizon.


Neverfly: go rent it! Michael Ironside is one of the all time great villains.

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