cosmology....?

Question

1. why is the speed limit of the universe EXACTLY the speed of light?

2. why cant we go faster than that?

3. Why does time slow down the faster you go?

4. Just in theory, if we could, what would it be like if we went faster than the speed of light?

Answer 1

1. Why is the speed limit of the universe EXACTLY the speed of light? Einstein postulated this limit 102 years ago in his first ("Special") Theory of Relativity. Eleven years later he elaborated in his second ("General") Theory. The theories have since been confirmed in such experiments as precise measurements of the orbit of Mercury, the first nuclear explosion at the Alamogordo Test Range on July 16, 1945 and eventually the measurement of minute time discrepancies between atomic clocks flying in supersonic airplanes and their stationary counterparts back on terra firma. So there's lots of evidence that Einstein was right, and that is why the speed limit of the universe is "c".

2. Why cant we go faster than that? Well, in theory we could, but we would have to leave the universe: Stephen Hawking and many others have said that we would be able to do this by crossing folds or warps in the spacetime fabric, if we could find or create them. The term "wormhole" has been coined for such a passage. Wormholes consist of a "throat" joining the fold in spacetime with a "mouth" at either end to enter or exit.

3. Why does time slow down the faster you go? Relativity predicted it and scientists observe it. In order for the speed of light to be absolute, EVERYTHING else, including Time and Space has to be relative. So things stretch and shrink and get heavier and lighter according to their relative velocities and accelerations. The famous equation E=mc² shows how mass and energy vary in proportion with c. Gravity is explained as a significant warping of the spacetime fabric around exceptionally large masses such as stars and black holes.

4. Just in theory, if we could, what would it be like if we went faster than the speed of light? Jodie Foster's character did this in the movie "Contact" by entering a wormhole in Japan and exiting several thousands of lights years away. Scientists show that we could actually go back and meet our grandparents when they were babies and create all manner of gruesome paradoxes that would make our own existence seem impossible... they conjecture that pastward time travel must take us through higher dimensions into OTHER universes where such events can happen.

It's complicated.

Answer 2

1. The speed limit of the universe is exactly the speed of light, because it is confirmed that nothing material can move faster.
2. We can but in no material state, only as radiation or energy.
3. Time slows down in regard of another observer who is fixed on Earth. It doesn´t get slow intrinsically
4. I don't really know.

Answer 3

1. why is the speed limit of the universe EXACTLY the speed of light?
Because the speed of all electromagnetic (EM) wave functions is determined by the magnetic and electrical properties of the universe. Put them together and they determine propogation speed of waves and the matching speed of all massless particles (you do recall that EM radiation can produce wave results and particle results, don't you.) All massless particles, if they move at all, instantly move at the speed of light in the local medium.

2. why cant we go faster than that?
We actually can't go that fast. The closer an object with mass gets to the speed of light, the greater its mass and the more energy it takes to accellerate it faster, the energy going into making it more massive. It would take all the energy in the universe to move what started as a gram (or an ounce) at rest.
The discovery of the effect is based on one of the most famous failed experiments in science, when Michelson and Morley tried to measure the effect of the earth moving in the "ether" on the speed of light and found no effect. Therefore, the speed of light is the same at all speeds, therefore length and time change with speed - the insight of Einstein

3. Why does time slow down the faster you go?
It actually slows as a consequence of the acceleration to get to the speed or to change direction. Orbiting atomic clocks are constantly accelerated sideways to stay in orbit and those in orbit keep time differently than those still on earth. Changes in dimensions keep the speed of light constant in the moving vehicle. Again, an insight of Einstein.

4. Just in theory, if we could, what would it be like if we went faster than the speed of light?
Well, in theory, what would it be like if your head were inside out - since your head is a sphere with a brain inside, what does inside-out mean? Science fiction writers have proposed what it would look like from an FTL (faster than light) ship - usually grey hard to look at void. Elizabeth Moon in "Once a Hero" has her heroine and a couple of other people crossing the outside of a very large repair ship when it goes into FTL and has some fun with weird behavior of the spot light beams from their helmets and light from an open bay looking like vapor (along with their not being able to judge their time or use radios - they touch helmets to talk), but she carefully avoids explaining the behavior in scientific terms and has her heroine refuse to talk about it with her guy because it was so weird.

Answer 4

One problem of going faster than the speed of light is that you start to loss the cause-and-consequence logic. Imagine you call your relative about your upcoming visit, but arrive before they get the message which travels at light speed. Slow down, man, or it would be very confusing.

Answer 5

1. The fundamental property of c is that it is invariant, i.e. that everyone agrees that bodies traveling at c travel at c relative to themselves, regardless of their own velocity. Anything massless travels at c because it is the fastest possible speed. It just so happens that we discovered c by studying the properties of light, and light was the first thing discovered that was massless and traveled at c.

2. Because you can never catch up to it. It is NOT about mass. The reason you cannot travel at c is geometric, NOT dynamic. Imagine running faster and faster to try to catch up with a light ray. Well, c is invariant. No matter how fast you run, you measure the light ray to travel 300,000 km/s faster than you are going. Since you can never catch up to that light ray, no one else can see you catching up to it, so no one ever observes you going faster than c.

3. It is NOT about accelerating to get to that speed, although acceleration changes the rates of clocks as well. A clock in motion runs slowly, regardless of how it came to be in motion. Since c is a fundamental constant, the most perfect clock imaginable is a pair of mirrors with a light flash bouncing up and down between them. Each time the light flash returns to the bottom mirror, the clock ticks. If you have two such identical clocks, one right next to you and one moving past you, the moving clock always runs slower than yours. This is because the light flash has farther to go when it bounces between the moving mirrors, since it's not just bouncing up and down but must also be moving horizontally with the clock. But both light flashes move at the same speed, c, so the moving clock takes longer to tick. Of course someone standing on the "moving" clock sees it tick normally, and observes the first clock in motion and running slow.

4. The Theory we are talking about is Relativity. Relativity states that you cannot go faster than light. So "Just in Theory," it is not possible to go faster than light.