Friday, January 02, 2015

What is Time?

What actually is time? There are many theories about time. The basic thing about it is the observation from old about the cycle of sunrise and sunset. The cycle is also observed about the season and the stars. They call this observation ‘time’.

Without any equipment, early man roughly divide time into day, night, month, year, seasons etc. As it goes along, there is a need to subdivide to smaller sections called “hour”. Man start to use various method of defining the sections. In the advent of science, clock was invented to provide a easy and portable way of telling time.

It is then men began to wonder about ‘time’ itself. Since everything on earth is measured by length, breath, and height (3 dimension), they began to assume ‘time’ as the fourth dimension and called the four collectively as ‘space-time’.

In my earlier blog I talked about time travel. I did not discuss in length about ‘time’ itself. Here, I will try to explore the concept of time a bit further. Space-time concept has been deep rooted in man’s mind. However, can ‘time’ be really a dimension itself?

A dimension is something that can be measured. Therefore, time dimension should also be measured. However, the method of measuring ‘time’ is simply not real in relation with the other 3 dimensions. You can measure time from the moment you start to the moment you stop. You just can’t measure time from now into the past. Neither can you measure time from now to the future.  The past no longer exist. The future simply hasn’t exist yet. What you have is just ‘now’.

Time travel advocates will say that time dimension exist in multiple instances of ‘now’. The conservation of mass law is broken if this happens. Multiple instances of ‘now’ means the whole ‘now’ instance is replicated into infinity. That is equivalent of creating the whole universe countless times. If matter can be duplicated against the conservation of matter law, the science world would be in chaos.

Time, therefore, is the transition of instances. Matters change its form as it goes along. There will be only one instance of the matter. What we see is the progress of the change (or no change)  and the progress is called ‘time’. What we measured is actually clock cycle of the machine we created and not time itself. There is no 4th dimension. Space-time is simply imagination and not science.

Einstein said, ‘Time has no independent existence apart from the order of events by which we measure it,’ I fully agree.

Einstein later also say  “Speed of time change depending on the speed of the object, and its position in the gravitational field. As speed increases, time is shortened and compressed, and it slows down.”

I don’t quite agree. He is talking about relativity in this case. It does not have any relationship to the fact that time goes on regardless of whether we are moving or not. Since time is not a physical quantity that can be measured, the term “speed” has no meaning except in relative measurement with a clock which should be independent of the movement. If you let the movement interfere with the clock functionality then obviously time changes for you but not for the universe around you. That’s why the clock does not determine ‘time’. ‘Time’ exists before the clock is invented.

I saw an article about NASA use gyroscope in space to measure space-time deviation.  They did measured some deviations. The question is what are they measuring. Pointing to a distance star that was billion light years away and assume that is a constant? 

According to "Einstein's theory of general relativity predicts that every object bends light rays through its gravity. This is called gravitational lensing. For our Sun this effect is very weak, but it has been measured. For more massive and distant objects in the Universe much stronger lensing has been seen." What was measured was the light of the stars that reaches earth. So this is one deviation that may cause it.

Gyroscope did point to a consistent point. However, that is only if you rotates it in its place. What if you move the whole gyroscope? Does it points to the same point or does it point to a point that deviates the same distance as it moves?

We all knows that satellites orbits around earth. Earth orbits around the Sun. The sun orbits around the galaxy. The galaxy may also orbits around the universe. Similarly, the star will do exactly the same as earth but at a different orbit. So when you say the gyroscope points to a star. All the deviations will add to the measurement as they don't orbit in perfect circles. It also does not means that they will orbit exactly on the same axis. If it does then you would not observe galaxies merging together.

We were told that the big bang started from one point and is still expanding today. Earth and the distant star are not moving in the same direction (at least it is not known whether they happened to travel in the same direction). This also adds to the deviation.

The measurement period is only 1.5 years. It is not enough to conclusively says that the parameter shifts are constant. 

With all these variables, if you say there is no deviation then it is utterly rubbish. So, does the measurement measure the actual space-time deviation? I am really doubtful.

Thursday, January 01, 2015

Time travel the non-scientific explanation (aka common sense)

People are always intrigued by the idea of time travel. Is it even remotely possible? The following is an effort to try to see the possibility of it in a lay man's way.

First the 'time' element must be explored. What actually is 'time'? Early humans observed the rising and setting of the sun. They also observed the seasonal cycle. Therefore they call the cycle concept 'time'. Time is therefore a concept not a physical property.

As technology improves, people want to have a more precise definition of 'time' cycle. The therefore invented the thing called clock. Clock is supposed to be a machine that measures 'time'. It does resembles the cycle that man observes earlier. But does that actually make 'time' a physical property? It does represents a instrument to define cycles of its motion from the moment it starts to the moment it reaches back to the same position. We probably can call it a cycle of motion. But that does not equates to the 'dimension' (length, breath, and height) that we can measure physically. Generally, time is referred to as the fourth dimension. It is at best man's effort to quantify a measurement of a concept. There are a lot of theories about the space-time (4 dimensions).

With the clock, they invented another concept called 'speed'. The definition of 'speed' is distance divided by time. Its the beginning of mixing physical property with a concept. Obviously people will not regard 'time' as a concept now as they can now 'measure' it. Lets just leave the argument alone as it is not the topic of discussion. 

With the avent of 'speed', peoole start to measure all kind of things. The speed of light is thus derived. The next thing come into mind is that if one could travel faster than the speed of light, one could end up in the future . Thus the concept of time travel comes into being. The next obvious question is whether we could go back in time.

Going back in time already happening right now. The sunlight we see now is actually 8 minutes and 20 sec ago when it happened. We can actually see cosmic activities that happened billion years ago. The real question is going back to our own past. Now if we travel away from the place where we started at 300000 KM per sec (speed of light). We can only see the moment when we started (assuming the speed is 300000 KM in one sec). To see the moment before that, we have to travel much faster than that. At twice the speed of light we barely see the moment one second before hand.

Hold on. Now that we are 0.6 million KM away. How big is the picture that we can see? If you use a standard 50 mm camera (see the image the same size as real one) to take a picture of the starting position, you can practically see nothing. We actually need a huge telescope to see the starting point. How big is the telescope? I let you do the calculation yourself. Did I mention that it takes a few seconds to focus properly?

On the other hand, since the light has not reach us from the cosmic event, we are actually in their 'future' right? So if we travel fast enough towards it, can we reach it at the state in the past? It is equivalent to say that if you fires a gun at me but then I travel fast enough I can reach you before you do it. That is a interesting question. Can you reach a physical event before it happens? Common sense will tell you that it is not possible. No matter how fast we travel, we take time to do it. By the time we reach the object, the event is already gone. Seeing an event is not equal to be in the same physical event. That's why I say 'time' is a concept.

Let us now focus on the idea of travelling forward to the future. Well, before the light start to move, it does not exist. Just like before you switch on the light, you see no light. It is as simple as that. So, even when we tried to travel faster than speed, it still does not exist. 

Obviously some one will argue that what we are seeing now is actually in the past. It will remain an unknown at best.

We see in motion pictures that people travel to the past/future and interacts with the events in the past. Well, that remains only in fiction stories. Remember my very first message that 'time' is a concept? It is not real and cannot coexist with the present.

My concept of time is therefore 'a measure of event that occurred by comparing it with a device that has a constant cycle". It is not a physical property. We use time to predict what is the physical condition after a certain cycle that occurred. Like for example, I travel at 15 KPH for one hour. I can predict where am I after the cycle is completed. 

Time travel is therefore purely imagination. It should remain a flawed science fiction.