Well, I don't know what you've read or heard but no one really knows nor understands what time is. And there is some problems here:
1.)There is no time without space. There is only spacetime (space and time together according to our current understandings). If you were about to fall in a black hole and let's suppose you won't die (chuck norris?) you could feel no change at all. But 1 second for you would be 900000 years (or so) for humans in Earth. This is kind of mysterious because it's kinda like travelling at the end of spacetime (but this is a bit weird).
2.)You can't measure time with time. Does it even make sense? I mean there is nothing you can compare time with.
3.)Spacetime is relevant to speed. Think for example that you are light. What do you see? You make no progress in time and space. You are instantly in everytime and everywhere. But let's use relativity here. You are light and you say (mark my words here it can become confusing) I AM NOT MOVING AT THE SPEED OF LIGHT,but EVERYTHING ELSE IS! This means everything else is light and light isn't light but something else(notice how you became light)!
4.) Time has a start. It was created exactly at the "time = 0" ? Go back and read 2.) when the big bang happened. I don't think "time before the start of time" thing makes any sense.
And it gets more complicated with more questions.What about other dimensions? What about time is an illusion. What shape is the universe? How was it born (Well Big Bang Theory)? Is time travel possible or is it prohibited by the laws of nature?What is light? Is there such thing as negative mass? And that's just a few of the questions.
About the chaos theory (butterfly effect), it's true. Future is unpredictable because it simply doesn't exist, it just WILL HAPPEN! The most simple system can have outcomes that are entirely unpredictable.
Well in fact I will stop here because I can even write a whole essay about this.
I have read one book recently and it's amazing it explains many about this topic.
Black Holes Wormholes And Time Machines by Jim Al Khalili.
Also a great documentary about the butterfly effect ( The Secret life Of Chaos BBC).
If you want to discuss more just reply. I just have too much to say (things I read from the book and general knowledge) and I don't know from where to start. I would be happy to (try) answer questions that you have. It is one of the most amazing subjects (I could say the most amazing subject) I know.
(I am not advertising any of the previous books/documentaries there is a ton of stuff to read and you can choose whatever you want).
For example other books that I have found (not read though but will do when i find time)
The Fabric of the Cosmos - B. Greene
The Tao of Physics - F. Capra
Mad About Modern Physics - F. Potter, C. Jargodzki
Perfect Symmetry - The Search for the Beginning of Time - H. Pagels
An Introduction To Black Holes Information And The String Theory - Susskind, Lindesay ( Requires great mathematical and physics knowledge)
Black Holes - Don Nardo
I recommend whoever created this thread (if he wants) to add in the first post all the questions we have so that we don't have to search the whole thread to see them. Thanks, at last someone came up with this awesome topic.
I agree that there is not such thing as "now". At least we can't live in "now because "now" is already in the past as I write this sentence. Think "now" to time as vertex to space. Vertex is a 0D version of space. Now is a 0D version of time.