As I was reading The Elegant Universe, and two other of Brian Greene's amazing books, I always seemed to come across the same problem when reading about the speed of light and why we can never surpass it.

Every object has a certain speed that is distributed throughout space and time. That speed is about 186,000 miles/second, or c, the speed of light. So when an object is stationary, it is going at speed c through time; whatever it's velocity is through space is subtracted from it's speed through time. So if Usain Bolt were to run 100,000 miles/second through space (which we all know he can), then he would only be going 86,000 miles/second through space, much slower than normal.

Buuuuuut....

How can I go 186,000 miles/second through time when miles is a measure of space. How would I travel 100 miles through time if that is a distance through space??? It just doesn't make sense!

Do I have any awesomely nerdy internet buddies out there who can provide an answer?

Light isn't Usain Bolt though. The light reflecting of objects is travelling at the speed of light, the object isn't.

I am really confused by your question. x(

It's based on proportions. You aren't going a distance through time. You're going through less time, as a percentage derived from the ratio of your speed to the speed of light. http://en.wikipedia.org/wiki/Time_dilation#Overview_of_formulae.

For example, if you were traveling at the speed of light, from your perspective you would reach your destination instantaneously, no matter how far away it is. That's because the equation has reached the point where you're dividing by zero. Time is zero. It doesn't exist for you. It's not that you're traveling any faster or slower in it. It's gone. This wouldn't happen if it was just a linear equation, like adding or subtracting whole seconds (or, um, miles).

I think I understood what you're asking.

It's worth remembering that spatial velocity is (at least partially) a measurement of difference. That is, you calculate the speed of one object relative to another. A car that says it is traveling 60 mph is tracking its speed relative to the ground, it doesn't care about the speed of Earth's rotation or orbit, for example.

Velocity can be an objective, absolute value. But in that context I believe the issues you're confused about don't really pertain - at least not if I understand you correctly.

I like how you use Usain Bolt, whose last name also happens to be a reference to his lightning speed.

Miles per second is a measurement of space. And time.

You're confused. Space and Time are one thing. Speed is a unit of measurement that covers distance travelled over a period of time. Without this distinction, ANY form of movement cannot be defined.

Imagine a photo of a horse running. That's what it's like to measure a unit of distance is without a unit of time. No movement occurs. No movement can occur. By adding in the period of time (almost always forward) into the photo, we get a video, the horse runs off the edge of what was captured by the camera, or the camera attempts to follow the horse, with the background changing behind it.

What I want to know is how time has any relevance when discussing fractions of a second after the big bang, when time is affected by gravity and what not.

A second after the big bang could be 2 seconds or a googolplex years.

Time is affected by both gravity and speed. Generally speaking, for a value of gravity, you are treated as going at a similar velocity. Furthermore, it's likely that explanations as to what occurs during the Big Bang is a "what if?" scenario. The scenario being, "What if I observed the big bang happen from outside of it and measured the events that happen inside it?"

Um, what? That doesn't make sense. Light isn't insant. So how would you appear somewhere instantaneously on your perspective? It takes light 8 minutes to get from the sun to the earth. That's light, traveling at the speed..of light..and it takes 8 minutes. That's not insant.

Ahh, now we get into the heart of it.

For all observers, light must ALWAYS be observed as travelling 186,000 Miles per second. No matter how fast you yourself travel, it must always appear to travel that fast for you. As a result, the faster you travel, the faster through time you move. Now, i know what you're about to say. "But no matter how fast I travel, it's going to be travelling at 186,000 miles per second, right?" WRONG! If you travel at 86,000 miles per second, light normally would appear to travel at 100,000 miles per second from your perspective. But the universe will not allow you to view it going so slow. So, instead, time slows down for you so you observe light as travelling at 186,000 miles per second.

Here's a famous example, known as the Twin Paradox.

Suppose of a set of twins, one becomes an astronot and volunteers to be the first human explorer of Alpha Centurai. So, he gets into a rocket that travels at, say, 80% of the speed of light. The trip (to and back) would take about 10 years. The twin on earth would have aged 10 years. Yet imagine his surprize to find his twin having aged only 6 years!

This time dilation has been experimentally confirmed. Any atomic clocks in orbit need to be recalibrated upon returing to earth, and our GPS sattleites need to constantly run through an equation to make sure they're accurate, because they move faster than anyone on the ground.

From outside of it? You mean from Earth in this solar system apart from the big bang? But even then a second here isn't the same thing as a second near the sun or a second near the black hole in the center of the milky way.

I just watched a documentery on this.It said,not me,that you can never achieve the speed of light because as you approach it..it corrects itself.There for you could go 99.9% the speed of light of but never attain it.The show also went on to explain why time travel into the future was possible but into the past was impossible.Future time travel was not instantaneous.There was alot of stuff in it about how time is different in space and how it slows near heavier bodies,like planets or even the pyramids.

Basically it gave H.G. Wells a huge middle finger.

So theoritcally you could go 10 or 20 or 1000 years into the future but you would still age and its all dependent on how fast you could go.