Forgive is this subject has already been brought up. I could find no thread that pertained to my question. I was wondering if anyone could help to explain, what is time. I am not talking about the man made time, A way to know when it is lunch time or how to determine velocities. I am wondering about time in terms of physics. Like does time have to "exist"? Is there any other way to get the leading theorys for explaining the universe to work without using a time component? Also, if for some reason time does have to "exist", Wouldn't there need to be some sort of quantum unit to transmit is "force" to other particles? I have very little background in physics, but this is a question that has bugged me for a while. I appreciate any insights anyone can give me.