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Archive for the ‘theoretical physics’ Category

Time: The Elusive Creature

As I walked through the park, late on New Year’s Eve, I passed a duck pond (unsurprisingly, given that the pond is always there). This time, when I passed the pond I noticed something strange. Something that was always there but had never dawned on me before:
The ducks quacked and swam and flew as if nothing had changed. The ducks did not perceive the passing of the old year into the new. Was it the case that ducks have so little in their lives to consider that they need measure no time other than the passing of the day?
I began to think; if humans had the same outlook on life and there was no necessity to measure time then where would we be now? Physics, economics, civilisation would cease to exist in the way we know them. If our lives contained the mundane nature of a duck’s, whereby we live each day as and when it comes then perhaps we would never have developed as a civilisation at all.
This odd series of thoughts led me to perhaps an even more interesting question though: If this thing we call time is so pinnacle to society then what exactly is time? It is a question that has plagued physicists in society for years, possibly decades and yet we still have no concrete answer. We safely conclude that it is not an entity – an object, if you please – as it is not physically attainable nor is it conceivable in any given state. As hard as any Bose-Einstein condensate is to conjure up for the mind’s eye, it is still possible. The conception of time as a viable state or sub-state however, is nonexistent. Our best approximation currently, of time as any presently available medium is that of a dimension. Time could be a dimension couldn’t it?
There are several arguments for time as a dimension. First of all, we do travel through “time” as we live our lives; one of the problems however, is that we appear to travel through time at a constant speed (for the pedantic few out there, I use speed rather than velocity as I am analysing only one dimension and I shall addresses directions as forwards and backwards). Ah, a physicist would say, but we can slow down the effective appearance of time, thus decreasing our speed through the dimension. As you take a clock, for example, further away from the Earth the hands will move more slowly than would an identical clock’s hands on Earth. This is because of gravity’s influence on time. That makes sense, you might say, just as a spacecraft closer to the Earth will have a greater gravitational force acting upon it and will thus travel faster than a spacecraft further away from the Earth (assuming that other cosmic bodies have no influence). Gravity can accelerate objects through time as well as space which would be expected of a dimension.

Those of you who are familiar with Einstein’s famous special theory of relativity will be aware of time dilation, starting at the approximate speed of 3 x 10^7 m/s. This basically states that the faster we go, the longer time will appear, until eventually (at the speed of light) time stops and we perceive nothing but the current time. So therefore, there is a way to stop in the dimension of time, just as we would be able to in any other dimension.

So, in conclusion, time could be another dimension. Possible even another dimension of space that we perceive differently from the others but for now we simply don’t know. Also, I’d like to give my thanks to the Ancient Greeks who essentially, were the first people recorded as measuring precise times.

There are just a few interesting facts and a few things to think about. We need to continue to question everything that surrounds us, even time, in the hope that some day we might finally understand the world around us. But for now, chin up and keep asking questions!

The Hidden Reality

Recently, I have been reading Brian Greene’s book, detailing many of the fascinating wonders of the cosmos. “The Hidden Reality” is a rather basic explanation of some rather major theories and breakthroughs made in the field of theoretical physics, as concerns the structure of universes.

I was most fascinated by his overview of the universes most probable start point, which appears to be the big bang. I have always been an advocate of the big bang and support it as the most credible theory at this point in time. He also confirmed my current belief that the universe is most probable not the first and will most probably not be the last in existence. Instead, scientists are viewing the universe as one of many, in an oscillating repetition of fiery creations and catastrophic ends. We now live in an age where the most probable creation theory is . . . there was never a beginning. And there most probably will never be an end.

This gives scope to a whole new view of time. Time as we know it has always had a start and an end. A simple race, for example, starts when we hear the starting gun and ends when the last person reaches the finish line. Work start, most generally, at nine o’clock and finishes at five o’clock. Everything we know has a start point and an end point on the axis of time. Now, however, time is more likely to be infinite: Stretching in either direction an undefinable and unmeasurable distance.

As for Brian Greene’s insights into string theory; who knows if these are right or wrong. String theory definitely provides us with answers to some of the most profound questions and a mathematical description of almost everything but it has not, most crucially, provided us any evidence. Yes, we can presume that there are tiny string that vibrate and create the illusion of particles but we could equally presume that something else, such as a tiny graviton-pixie creates such an illusion. Of course, this is a case of reductio ad absurdum but I feel that it displays the need for evidence of such a claim. I would say that string theory is highly merited and definitely shouldn’t be dismissed but it is most definitely the only considerable theory.

Higher dimensions, branes and universal flux have a long way to go before they are proven also. The thought of our universe having imperceivable and possible non-existent boundaries from within and yet a clearly visible and absolute boundary from out with the universe is almost unimaginable and yet, it is almost undeniably possible (from a theoretical stand-point, that is). The Hidden Reality pg 68-71. The idea of branes is most naturally thought of in a two-dimensional form as a fourth dimension for three-dimensional branes to exist in is practically inconceivable. However, a two-dimensional existence reveals the essence of branes clearly enough for understanding to grasp. All of these theories are, of course, possible and highly probable but science must be careful in its attempts to prove such theories.

Science must be careful that experimental results that support one theory may also support another and that we should never usher in one candidate without examining the others. We also must be careful that experimental results are not misconstrued and are examined very carefully, as with the controversy over neutrinos in CERN.

Physicists will never answer everything but they are coming very close to answering some things that could reshape our way of thinking. However long and twisted the path ahead of us becomes, physics will get there eventually.