What time is it REALLY?

Everyone knows there's no such thing as a "true" time. We agree that it's a certain time where we live, and that the hour part changes by one as we move around the earth, 24 times by the time we get back to where we started. If we didn't make this adjustment, 12:00pm would occur at the same point in time everywhere in the world but it would fall on a different point in the day/night cycle. Not much use since people wake up and go to bed based more on the rise and fall of the sun than some arbitrary number. As it is, dawn doesn't take place at the same time everywhere anyway, because it changes as you move north/south. And it changes (in a smaller way) as you move east/west within a given time zone. Nothing in space or time (above the Planck length and time, of course - see quantum theory) is discrete, it's a smooth continuum all over the surface of this sphere and all over the universe.

What many people don't seem to understand is that it's this way with our position in space, too. We're not in some particular, objective location in the universe. If you imagine the universe as a three dimensional volume of space, then we'd have to be located somewhere within that space, and that would fix us with a specific location. But general relativity insists we are not at any specific location, that we can only meaningfully talk about our location relative to other objects and not in any sort of universal way. The reason that this is so is that the universe has no edges - no boundaries. That's not to say it's necessarily infinite. If this is hard to grasp, think of it like this: A sheet of paper is finite (has a surface areas less than infinity) and bounded (an ant can fall off the edges). A globe is finite (has a surface area that is less than infinity) and UNbounded (and ant can walk around on it all day and not fall off). If you proceed in a straight line in any direction on a sphere, you end up back where you started. This may be how the universe works as well, though you have to imagine that rather than a two-dimensional surface wrapping around and connecting to itself in three dimensions (the globe), space is a three dimensional volume that wraps around and connects to itself in a fourth dimension.

Of course, nothing's been proven yet. It's difficult to see how it even could be proven, but people called topologists have some pretty clever ideas they're going to try as telescopic and computational power increase. Nevertheless, whether the universe is finite or infinite in volume, it almost certainly is unbounded. What is "the universe," after all? Everything, right? Well if you had a boundary somewhere, you could ask what lay beyond that boundary, and even if the answer was "a void," that void should still be considered part of "everything." So almost by definition the universe has to be unbounded. The only remaining question is whether you'd go forever in the same direction or you'd eventually return to earth.

This unbounded condition means that we have no fixed location in space, because there is no "frame" against which to measure it. All absolute measurements require a frame of reference, some fixed outside coordinate system. The earth has logitude and latitude. But the universe contains everything, and therefore there is nothing outside the system to define where the edges are or where to start counting. So wondering where we are in the universe is pointless. We're not at the center, or near one edge, or anything else, because there IS no center, there ARE no edges.

This has some pretty interesting consequences. For example, most people think of the Big Bang as an actual explosion, something that happened at a certain point in space and at a certain point in time. But the truth is that space and time themselves were created in the Big Bang. There was no pre-existing volume for it to occur in; it occured everywhere and created the space that now exists. And, although this is much more speculative, there probably was no such thing as "a time before the Big Bang" either. If time was created when space was, then there never was a "before." There wasn't an infinitely long empty epoch prior to Creation anymore than there was an infinite empty volume of space for Creation to occur in.

The shape of the universe also makes for fun thinking. If light itself it curved by the geometry of space (and it is), then a phenomenon called "gravitational lensing" takes place. That is, if large objects distort space around them (the reason why the planets orbit the sun) then light traveling through such an area is also bent accordingly. So the stars we see in the distance may not in reality be in the exact direction we see them in. Heavy objects between them and us may deflect their light so we see them in a slightly different place. Not only may that star you're wishing on not be there anymore (it could have exploded 1,000 years ago but you're still seeing light that left it 2,000 years ago), but it may have never been THERE at all, it might have been an inch to the right, maybe even part of a double star system with an apparently unconnected companion. Not very likely, but possible.

The stranger part comes when we think that the entire volume of space might be curved in on itself. Then the entire universe acts as a gravitational lens and light, like our intrepid astronaut, can travel around in "circles" and end up where it started. If you could see far enough (a function of time and light-gathering capacity) you could see the Earth from the opposite side! You couldn't actually see the back of your head, because since light travels at a finite speed, you'd see the light that left that side of the Earth millions or billions of years ago. The exact number of years depends on the size of the universe. If it were 5 million light-years wide, you could observe the Earth as it was 5 million years ago, when hominids still looked much like other apes. 500 million light-years wide, and you could watch the first land animals crawl out of the sea. 4,550 million light-years wide, and you could watch the formation of the Earth itself. For a variety of reasons (one being that telescopes actually have looked "back" that far) it seems our universe, if it is finite in volume, must be at least 14 billion light-years in diameter. It could be much, much larger though, or it could indeed be infinite. Will we ever find out? It's possible, but I wouldn't hold your breath.