Time

The definition of time has puzzled and perplexed many great minds, and no single, uniform definition exists, making the concept of time a great source of debate.

Isaac Newton defined time as a container, and along with space, all events occurred within that container. His beliefs were based around the concept of absolute time and space, meaning that time is moving at the same rate for everything in the universe, or can be scaled for everything in the universe.

Albert Einstein revised the theory of absolute time, and proposed the theory of special relativity, and then later revised this theory to form The General theory of Relativity. [Wikipedia article] In simple terms, this theory states that time is measured by motion. It states that time can be effected by things such as gravity, and the motion of objects. It also states that time is a fourth dimension, meaning that in our three dimensional world we cannot "see" time. The best way to visualize the concept of another dimension is to think about an apple sitting in a bowl. If someone asked you where it was, you could say how far forward the apple was, or how far to the left, but you could only describe where the apple is now, not where it will be tomorrow or the next day, because those measurements exist in a different dimension. This also implies that the past, present and future exist equally within that dimension.

This theory is the most widely accepted, and most new theories or ideas about time are based upon this theory.

Beginning of time
Time, according to the big bang theory, began 15(some sources say 10) billion years ago. Time began with the formation of the universe. This is explained by the fact that, before the big bang, all of the matter in what would be the universe was compressed into one unit (technical term: a singularity). For the sake of understanding this concept, you can think of it as a small box. (understand that it has no volume or any real measurements). This box has an infinite density. this means that all of the laws of physics cannot apply to this pre-universe box. Because scientific laws don't apply to this pre-universe box, anything that happened to this pre-universe box isn't measurable by the standards that apply to our universe. Therefore, it cannot be on the same time frame as our universe, because the laws of our universe do not apply to the pre-universe box. Time had to begin with the big bang.

Note- That was only a visualization to understand the concept. The matter of the universe was not literally compressed into anything remotely similar to a box.

There are other theories and ideas about the beginning of time (or the lack of a beginning), however I just explained the most common theory. Some theories deny that a singularity ever existed; thus making time infinite.

End of Time
Time as we know it can only exist within the confines of our universe, according to the big bang theory, which is why time began with the big bang. This would also imply that time could end with the end of the universe. One such explanation for this is known as the theory of Heat Death. This theory states that it's possible for the universe to reach a frozen state, in which energy is non existent to sustain motion or life. Because time is measured by motion (General Theory of Relativity) and motion could not exist, time would have ended. This theory can only hold true, however, if the universe could reach a state of maximal entropy. Most scientists do not believe this will happen, and that the universe will expand indefinitely.

Good Resources
http://www.thekeyboard.org.uk/What%20is%20Time.htm
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970613d.html
http://en.wikipedia.org/wiki/End_of_Time
http://www.hawking.org.uk/lectures/bot.html
http://www.guardian.co.uk/science/2008/apr/26/starsgalaxiesandplanets.universe3
http://en.wikipedia.org/wiki/Time (the sites used as sources are often more helpful than the actual article)

Potential Discussion Questions
1- What is time?
2- Does time have a beginning/end?
3- Does time exist in it's own dimension?
4- How does this relate to time travel possibilities, or impossibilities?
5- Should our ideas on time's existence be based around the big bang theory?
6- Is time relative, absolute or universal? (or a combination of the three)

:shifty Alrighty then, discuss!

Why are there only 12 hours around a clock?

Well, I think I understand 'the beginning of time'. So time can only be applied to what we define as 'the universe'? Because before the big bang, all universal matter was concentrated, and the universe as we know it now didn't exist. It was a pre-universal ball of matter.

Although it could be argued that it depends on your definition of the universe. Linguistically, the universe is an all-encompassing term; as my Physics teacher used to say, "the universe is not just everything, but it is also everywhere". So did the universe exist before the Big Bang, and therefore before the beginning of time? If the universe truly is everything, and everywhere, then it would be logical to say yes.

The way I understand time, is that it is a human value which we place on the universe so to understand it better. We derive time from the universe, the length of one earth rotation defines the length of our day. The fact that time exists, and that the passing of time ages us along with the rest of the universe, allows humanity to place itself in context with the universe, and so is vital.

Ultimately, though, what is time?
The answer, I think, is that time is an abstract noun. (:

My brilliant self:

Therefore, it cannot be on the same time frame as our universe, because the laws of our universe do not apply to the pre-universe box. Time had to begin with the big bang.

The big bang theory and general relativity are brilliant, unil they combine and produce this. Matter existed before the big bang, just not under the same laws, but we still consider it matter. Therefore, if we say that matter existed before the big bang in a singularity obeying different laws, how is it logical to say that time didn't exist because it didn't obey the laws we have now?

Stephen Hawking:

Since events before the Big Bang have no observational consequences, one may as well cut them out of the theory, and say that time began at the Big Bang.

I disagree with that, and I don't think the words "may as well" have any place in a legitimate scientific theory. Time before the big bang is hard to explain, but thats a silly reason to assume it didn't exist. We just don't know yet, we "may as well" just be honest about that.

And of course, someone is going to throw out the Second law of thermodynamics (says that disorder will always increase with time). to disprove the universe existing infinitely. But you cannot apply the laws of our universe now to what it was before the big bang, they (supporters) even have to use that logic to validate their theory that time had a beginning, so it's totally irrational to then use a universal law to prove their theory.

Kurtni Von Teese:

Therefore, if we say that matter existed before the big bang in a singularity obeying different laws, how is it logical to say that time didn't exist because it didn't obey the laws we have now?

No, I meant to say that it would be logical to say that time did still exist, because the universe still existed. Just under a different state.

Bloodraine:

Kurtni Von Teese:

Therefore, if we say that matter existed before the big bang in a singularity obeying different laws, how is it logical to say that time didn't exist because it didn't obey the laws we have now?

No, I meant to say that it would be logical to say that time did still exist, because the universe still existed. Just under a different state.

My reply wasn't aimed at you. :shifty I'm arguing with myself.

Oh right. Do carry on then (y)

Kurtni Von Teese:

Therefore, if we say that matter existed before the big bang in a singularity obeying different laws, how is it logical to say that time didn't exist because it didn't obey the laws we have now?

Bloodraine:

No, I meant to say that it would be logical to say that time did still exist, because the universe still existed. Just under a different state.

There is no "before the Big Bang". Spacetime was created with the Big Bang so saying "before the Big Bang" doesn't make sense.

1- What is time?
It is a measurement of phenonema that occurs invented by humans in order to not get confused.

2- Does time have a beginning/end?
Yes. Time is not infinite.

3- Does time exist in it's own dimension?
Time is a dimension, beyond ours, and we pretend to know somewhat of what it is.

4- Should our ideas on time's existence be based around the big bang theory?
No. The Big Bang did not occur.

5- Is time relative, absolute or universal? (or a combination of the three)
Relative.

I could be wrong and probably am but this is what I believe...and my people.

Dujo:

Spacetime was created with the Big Bang so saying "before the Big Bang" doesn't make sense.

The National Science Foundation disagrees with you. :file: Spacetime in the sense that we know it was created with the big bang, but that isn't to say what exists now was all that ever existed.

The Doctor.:

1- What is time?
It is a measurement of phenonema that occurs invented by humans in order to not get confused.

2- Does time have a beginning/end?
Yes. Time is not infinite.

3- Does time exist in it's own dimension?
Time is a dimension, beyond ours, and we pretend to know somewhat of what it is.

4- Should our ideas on time's existence be based around the big bang theory?
No. The Big Bang did not occur.

5- Is time relative, absolute or universal? (or a combination of the three)
Relative.

I could be wrong and probably am but this is what I believe...and my people.

That's what daddy taught me :shifty

I also visualise time as a circle, not a line like most people do.

Peter Petrelli.:

That's what daddy taught me :shifty

I also visualise time as a circle, not a line like most people do.

Time is...a circle. That makes sense. Thats why there's twelve hours in a clock. And that's why history repeats.

I read this book, Timekeeper by Jeannette Winterson. Amazing piece of work. She wrote it around the theory that there are 24 centuries in time and at the end of the 24th century, time will stop, the world as we know it will be gone and a new God will be born. And Maria Prophetessa, that sly old bitch, takes advantage of it.

Peter Petrelli.:

That's what daddy taught me :shifty

I also visualise time as a circle, not a line like most people do.

More wibbly-wobbly, timey-wimey...stuff.

Peter Petrelli.:

I also visualise time as a circle, not a line like most people do.

Time is not a circle. A circle is a two dimensional shape, and time doesn't exist in that dimension.

lyrical_mess:

Time is...a circle. That makes sense. Thats why there's twelve hours in a clock. And that's why history repeats.

An hour is not a literal element of time. It's an interval that we, humans, created. There are 12 hours on a clock because we chose to have a clock with 12 hours, that isn't explained by what time is or it's properties.

Can time exist without intervals? Because then, it would just be...eternity?

lyrical_mess:

Can time exist without intervals?

Of course. Intervals are our way of measuring time. Even if we couldn't measure it, it would still exist. If you weren't able to weigh an object, would the mass still exist? Of course. Would the mass be infinite? No, we just wouldn't know what it is. Without intervals, time would exist in the exact same way it does now. Intervals like hours or minutes are irrelevant to what time actually is because we created them. We decided that we'll call X amount of time an hour, and X amount of time a minute, that isn't determined by any phsyical properties of time.

The Doctor.:

Peter Petrelli.:

That's what daddy taught me :shifty

I also visualise time as a circle, not a line like most people do.

More wibbly-wobbly, timey-wimey...stuff.

yeah.

Not one of those time linessome people i've spoken to think it is.

Kurtni Von Teese:

lyrical_mess:

Can time exist without intervals?

Of course. Intervals are our way of measuring time. Even if we couldn't measure it, it would still exist. If you weren't able to weigh an object, would the mass still exist? Of course. Would the mass be infinite? No, we just wouldn't know what it is. Without intervals, time would exist in the exact same way it does now. Intervals like hours or minutes are irrelevant to what time actually is because we created them. We decided that we'll call X amount of time an hour, and X amount of time a minute, that isn't determined by any phsyical properties of time.

Time doesn't have any physical properties. It's an idea/concept/non-physical thingy.

lyrical_mess:

Time doesn't have any physical properties.

Yes it does. :shifty By physical, I mean pertaining to physics and time does have properties. Time is affected by motion and gravity, both properties discussed in the general theory of relativity. Time is not just an idea. You're looking at time from a philosophical point of view, this is about the scientific view of time which is totally different.

Kurtni Von Teese:

Spacetime in the sense that we know it was created with the big bang

How would you define "before" without time?