Question

Alright, I've been reading a few books by Stephen Hawking, and I found out that I was right about light's speed being relative to the observer, i.e. light is always travelling 300,000 km per second faster than you at any given moment. Can anyone get Ferret to come out and talk to me without lambasting me with wrong information?

 

Short:
The speed of light in vacuum (simply "c") is the universe's speed of transfering electromagnetic waves. Nothing that has mass can ever move at a speed greater than or equal to c. Something with zero mass will always move at c (light will move slower than c when coursing through matter, but that's because of interaction with matter, and it will move again at c when it gets out of matter. Something can move in matter faster than light, but will give off radiation - it's a whole different matter). Tachions, particles which are thought to have negative mass, will never move at a speed less than or equal to c. Since c is the universal electromagnetic wave speed, you will always see the light move at c in vacuum, because that's what your senses can ever understand (or any matter can ever understand, as interactions between matters are always in the end based on electromagnetic interactions between particles). Instead, you will see other things move in time slower, look shorter etc. as the matter gets nearer to c.

I can give more detailed explanation if you want on each subject.

Note: Possible future physicist here.

 

That's what I was saying. As you move faster toward light, it will effectively slow down, but the change in velocity will be imperceptible to you as a passive observer, meaning it's always moving at 300,000 km per second relative to your particular speed. When red shift occurs, the photons reaching you aren't less, but their wavelengths are dilated, resulting in the red hue.

Preaching to the choir, no offense intended. I'm majoring in physics and minoring in computer programming.
Now, the funny thing about tachyons is that they work out well mathematically, but don't really have a purpose. As far as I can tell, watching a tachyon go backwards in time will look like watching one go into the future, so no information of the future will ever be gained.

The one thing I'm most interested in is Hawking radiation, mainly because it means that under certain conditions, matter is able to move faster than light over short distances.
What ticks me off about Ferret's rant is he spoke as though he believed in the universal ether, an antiquated idea of universal, constant time. Case in point:

Spoiler

Unfortunately, according to the theory of general relativity, no matter how fast you're moving, light will always appear to be going at the same speed. Even in a black hole.

Under that theory, it was thought that there would be delays in recieving light signals depending on your velocity toward or away from the light source. However, under examination, this hypothesis proved to be most incorrect. Now, I would rather speak to him privately;
There's no need to embarrass a person in public if all you want to do is teach them something.
On second thought, I might not talk to him. I reread his posts in the thread of concern, and it seems that all he was doing was arguing with me for the sake of arguing. I don't need to prove to him that I'm right. I do have to say, I don't like when people talk down to me, though...Hey, do you guys still want to talk about physics or are you bored with it?
I actually have a theory of black holes, but this may be common sense to you guys;
Light is effectively a two dimensional picture of three dimensional objects. However, due to the curvature of spacetime around massive objects, light will bend around itself infinitely in the event horizon of a black hole. The reason we can't see the black hole (aside from the gaping maw that is the event horizon) is because we can't see all three dimensions of any object at one time, so I'm thinking the only way to photograph a black hole would be to go at it from all directions. From that we could reconstruct a three dimensional model of the hole itself. Now, as far as image definition goes, we wouldn't really see a black anything, but we could definitely use the light distortion to extrapolate a proper computer simulation. If we could find a black hole and measure its mass, we'd be able to dind a safe orbital distance and leave a few satellites around the hole for approximately a year, taking images at different intervals. Travelling to the hole itself would be another matter, however.

 

I'm always up for a talk. I didn't know you were majoring in Physics, I quickly took a look at the first part and assumed it was some general question about physics. My bad.

I don't understand how Hawking Radiation may allow for matter to go faster than c though - I thought it had to do with matter/antimatter appearing in vacuum just out of the Black Hole's event horizon (or the limit where the particle would fall down), resulting in one particle going away from the Black Hole while the other falls into the Black Hole, making it lose mass. I'm not extremely knowledgable about it though.

P.S. What branch are you specializing in? Theorhetical physics, nuclear physics, etc.?

 

Theoretical physics. I want to know everything.
I even got to understand wormholes just a few days ago. It's one thing to know it's a bend in time and space, but it's another to understand it's a bend in time and space. The effect of a four dimensional object (wormhole) is that its surface is completely three dimensional, however the directions are inverted. It's left is on the right, it's bottom is on the top, etc. This is what allows the wormhole's potential as a travel medium;
It switches the location of three dimensional objects without actually moving them. Now, the problem would be stabilizing the wormhole. You could do it either electromagnetically, or you could try it the old-fashioned way (fill the wormhole with matter). If you don't do this, it's as if you're stepping into a perfect vacuum, and you expand into four dimensions. Not a fun way to die. Travelling through the surface of a wormhole would be easy, since it's got three dimensions. The wormholes in Stargate are actually a decent analogy, though it doesn't have to appear like water. You'd actually see your destination as though it was through a window, but it's a window out of nowhere.
Se if you can picture this;
There's a wormhole in front of you. A small one, you think, because the "window" you see is only two feet wide. Say the destination is six feet from the window. Staring through the wormhole, it's as though you've got a view six feet ahead of where you're standing, but only in a circular shape just in front of your face. All around you, save for the wormhole, the view is normal. The problem with travelling through wormholes is their length can't be determined, so filling one with matter to allow for safe travel might be pretty damn impossible. Well, even electromagnetically stabilizing it would be impossible, if it was somehow infinite in length.
Now, part of why I'm going into physics is because I love it, and the other part is that it's all easy to me. I run thought experiments in my head constantly, and end up figuring things out, like what I just said in my first paragraph.

 

Salt is salty.

 

Hmm wormholes. As I remember, there was once a hypothesis that wormholes could be used to time travel. I think someone later showed that the wormhole would become unstable and collapse the moment it tried to break causality (go faster than light and do things it shouldn't do), let alone allow for a window to a past time.

 

Actually, theoretical physics is interesting as a mind exercise, but I had problems getting too interested in it as it has little immediate practical application in the real world. Also, my strengths lie more in the biology/chemistry/biopharmaceutics area.

I was really tired last night, saw this thread, and decided my scientific contribution would be what I posted above.

 

Philes, a welcome contribution. But it asks the question, "Why is salt salty?"

 

...so, if Discworld exists in four dimensions by default, does this mean everything there is inverted directionally?

 

So that would mean every time I land the plane in the water I'm really landing it on the aircraft carrier.

 

Well they do end up falling back round on the Disc if they fall of the edge.

 

And they will hope that the Dungeon Dimensions does not break loose this time.

 

Unlike this heroic individual, you still just crash in the water.

 

The principle behind hawking radiation is that a black hole is capable of losing mass more quickly than it will gain it by normal means. This happens because when the virtual particle-antiparticle pairs appear outside of the black hole, they're boosted into reality and the negative particle is absorbed, causing the hole to lose effective mass. This is a quantum tunneling effect, by which vacuum energy generates the particle pairs, and the positive particle tunnels through the event horizon (making it appear that the particle actually came from the black hole). The problem with this radiation is that it gives absolutely no information about the black hole, unlike thermal radiation would from a star or other body.

 

So basically what you are all saying is we can't achieve warp 9 just yet?

 

You're a pharmacist, right? Or interning since I last recall?

I still have nightmares from my physics classes, so maybe someone can explain to me why So-and-so travels light years away and returns to Earth having only aged 2 years while everyone else on Earth has aged 20. I found that part interesting but just couldn't pick my brain up off the floor long enough to grasp the theory behind it.