June 07, 2004

Theory No. 1

I'm no scientist. I don't analyse data in a scientific way, or form a hypothesis based on facts. But I like to dabble with the abstract. I like to make up concepts sometimes that try to explain stuff, even when I know that this is pointless. A lot of things fascinate me, but nothing holds my attention for a long period of time. Only when you try to be pointless can you explain your point of view...

Lets talk about time travel, the famous Grandfather Paradox. You know, if someone creates a time machine to go back to the past, and kills their grandfather, or by some seemingly random action causes his parents to never meet and ultimately this leads to his never being born. How can he alter time if he never exists? This leads to a theory I have, where there can be no paradox.

As I see it, there are two possibilities. The Universe is pre-determined, everything occurs at it's time, the future is definite, we only don't know it yet. Or there are infinite parallel universes, every choice you make leads you to a new Universe. Now, if the Universe was predetermined, there can be no paradox. Even if you develop a time machine and go back to the past, you cannot change everything as you already have changed it before, if this makes any sense. So you cannot affect your past, because it has already been affected. So, there is no paradox. Or if there are multiple universes, which is simpler to imagine, then travelling through time leads you to a parallel Universe, and what you affect there does not change the future you.

I know it's a load of crap, but this is something to fill the long hours of insomnia...

BTW, Nandish should enjoy this post
Robert Heinlein in his classic short story "All You Zombies" wrote something that is even more mind-numbing than the Grandfather Paradox. Read about it here.


nandish said...

hey, this time travel thing is quite debatable. The two theories that ur talking about r d only ones proposed by any living person so far...There is nothing new to it.
The Oxford English Directionary defines time as "a limited stretch or space of continued existence, as the interval between two successive events".

We glance at our wristwatches and notice the second hand slowly counting the passing seconds. We are in our own time machines: Our hearts are pumping blood, we're breathing, we are existing through time (at least until our own personal time machines seriously malfunction).

What are the possibilities of moving through time at a rate different to one day per day? Common sense tells us that it's all nonsense - time travel is impossible. However, common sense is not always such a good guide. Some hundred years ago common sense said man could never fly, now we travel all over the world.

There are problems. The commonest are the so-called paradoxes. For example, if we could travel through time, imagine what would happen to a time traveller if he (or she) travelled back in time and killed his own grandmother at birth. In theory the time traveller will therefore never be born, so the journey could never have been made in the first place; but if the journey never occurred then the grandmother would be born which means the time traveller would have been born and could make the journey ... and so on and so on. This is a paradox.

There are two possibilities to resolve this paradox. The first is that the past is totally defined, i.e. everything that has happened or must happen, including the time traveler's attempt to kill his grandmother, cannot be altered and nothing will change the course of history. In other words, the time traveller will experience endless "mishaps" in trying to kill his grandmother and will never achieve the murder, thus keeping time (or at least events) intact.

The second possibility is more complex and involves the quantum rules which govern the subatomic level of the universe. Put simply, when the time traveller kills the grandmother he immediately creates a new quantum universe, in essence a parallel universe where the young grandmother never existed and where our time traveller is never born. The original universe still remains. Stephen hawking believes he can explain the origin of our universe in a variation of this parallel-worlds theme.

Having explained these paradoxes, how does one travel through time? The secret is to travel at speeds faster than the speed of light. The main text of the web site explains this in great detail. The obvious problem with traveling very near the speed of light is that as you approach C (the speed of light), time slows down until at C time stops. How can you go faster if time has stopped? The answer involves a complex process called quantum tunneling.
Once the velocity becomes greater than C time moves backwards. We have entered into the realms of negative time.

Ankit said...

Nice one, thanks. A quote from Douglas Adams comes to mind: "In the beginning, nothing existed, which was a paradox due to it's own existance, so it exploded"

nandish said...

Now back to the paradox of the Father killed by his son. In five dimensions we can finally lay to rest our paradox as follows. The man travels back in time. In doing so he enters a reverse time, mirror image, of our Universe. When he starts moving forwards in time again, the same direction as ourselves, he is in an alternative Universe. There he is at liberty to kill the man who would have fathered not him, but his alternative in that Universe. There is then no paradox: his father, unmurdered, inhabits an entirely different Universe, some distance in the fifth dimension from the one in which the murder is committed.