written about 3 or 4 weeks ago
Is it possible for you and me to travel backward … … … … ?
Shyam Dash : Can You Time Travel ?
Manmohan Dash: NO, but you can sit in your car and act. the reverse gear and go backwards … in space
SD: what is … The fourth dimension?
MD: time is called the 4th dimension because at very very high speed it is impossible to differentiate between space and time dimensions, if you do it in one frame in all other frames they will be mixed again, that is if you are sitting at home “what you call a distance will be partly a distance and partly a time delay for a person sitting in a car that is moving wrt you sitting at home”
MD: distance and time can only be separated in a frame in which these distances are not moving wrt each other, in all other frames of view they are mixed.
SD: we are only able to move forward in time … ..
MD: On an average, the average being taken at the smallest perceivable scale, we are drifting towards future. But in a virtual way we can say there is a little uncertainty that we did not move forward rather backwards, but a very very little, but in the end it does not matter because it takes us forward in time, on an average. That is why We age, that is why everything around us ages. We do not grow younger, never, nothing in universe is a reversible process ..
There are many arrows of time. eg if two places on earth are separated they have two different time arrows. Because we are advanced enough and can communicate back and forth we say we have the same time (synchronization). But we did not have this privilege in the past. Also think, if we are not communicating with certain portions of the universe where a different time scale and arrow may be working we better be out of communication as they will tell us about strange processes in nature. But in essence that is what has been happening when we discover newer processes. WE work them out with what we understand as natures laws but then there are discrepancies, eg we start with gravity and find that there is anti-gravity. But we haven’t soundly formulated all these into the laws as we understand them today … there is plenty of work that needs to be done.
Insight on 16-9-2014 from Manmohan Dash
3 years ago I had written a small article (in a discussion on face-book). One of the implications of that article is the following. (Article is linked)
In a small region, a very small region, processes drift along with a sense of time. An arrow of time ensues in the occurrence of phenomena. We say the tail of the arrow as past and the arrow tip is concurrent with future. Then the region swells. Lets say now we focus our spotlight on a large enough region. Lets say galaxies apart.
Its not necessary that in the grandest of scales in our Universe, the arrows of time will be uniform or isotropic or unidirectional.
In other words there will now be many different arrows developing across the Universe. If one arrow is fast and long another might be slower and short. In other words depending on where you are located in our universe, your sense of future and past are totally different. While one solar system might be experiencing one particular supernovae another might be moving away from this experience. Sense of future and past are no more scale invariant.
Also there is no guarantee that the laws of nature will be same everywhere in the universe, although thats what we tend to believe now, in the absence of contrary observations. What if G changes from regions to regions, with the arrows of time. Now G is taken to be an universal constant. What if there is a slight difference of G from Galaxy 1 to another galaxy, Galaxy 2, located far far away. The dwarfs on Galaxy 2 would be able to jump off into air miles higher while we are essentially stuck on our planet. Its for no other reason that we call ourselves “down to earth”. But they might be singing “up in the sky, up in the sky, in the dwarf nation, up in the sky **”.
The future and past might be accruing at very different rates, at very different directional priorities. Past and present would become very relative although in a grander way, so grand that its implications would baffle the local residents.
** Or even dwarf kids;
Up in the sky we go.
We are not bound.
To our own ground,
Up in the sky we go.