Well..Time Travel is a pretty hard concept to explain with it being hypothetical and all.But I will try my best and I will not add any physics to this ( 'cause I have absolutely no idea about physics of Time Travel whatsoever ).
First lets try to visualize the flow of time.Assume Time as an infinite misty ocean.The flow of time is like a long endless bridge that spans across this infinite misty ocean.On the bridge , people can only travel forward (duh!).
The destination is unknown and the immediate path in front of them is not visible (because its misty).Nice and easy isn't it?? and it describes the flow of time pretty accurately.
Lets see... Now there are two possible ways for the bridge (flow of time) to exist as i see it
1.Assume the whole bridge is already there and when u travel into the past or into the future u are just jumping from one point to another (on the bridge).
2.The bridge is made as u travel i.e. the length of the bridge is present time. The choices that u make decides the direction of the bridge. To make future time travel possible in this theory we need to supplement it with the multiverse theory. (If u didn't get anything above don't worry,will explain it in detail below).
Case 1:
In this case we assume that the whole bridge is already built i.e. the whole flow of time is decided.It can be easily seen that in this case whatever we do we cannot change the course of the future (i.e. our fate is sealed) .We can easily describe time travel as mere jumping from one point of the bridge to another. The implication of this is huge. Suppose a guy travels back into the past messes with stuff (u know the usual time traveling messing... revealing the future to a couple of dudes etc ) and comes back. He will see that everything remains the same as when he left. Because in this case whatever mess he caused will be the reason the world in his present exists as it is i.e. ' him travelling back into the past and messing with stuff ' was an inevitable event as the flow of time has to remain the same. The phrases ' everything happens for a reason ' , ' Man does not control his own fate ' etc applies perfectly with this universe (as in this case there will be only one universe. The parallel universe theory a.k.a multiverse theory is not applicable here).
Case 2:
Here we apply the multiverse theory.Let me first explain the multiverse theory. In layman's terms there is a very infinite number of universes, and everything that could possibly have happened in our past but didn't , has occurred in the past of some other universe or universes i.e suppose the guy here is an engineer in our present world.Multiverse theory states that there will be a world were the same guy is a doctor, a world were the same guy will architect etc. Hence by applying the rule on the millions of humans present on the world ( and maybe millions and millions of aliens present somewhere in our universe) we get an infinite number of universes as a combination of all the possible possibilities.
This can be expanded by adding a 4th dimension - Time. We can state that there are an infinite no of each of these infinite universes whose time-lines are slightly different than the other.(since infinity x infinity = infinity).We have an infinite number of universe with all possible combination of time-lines and possibilities.
Okay lets get back to our bridge approach. Lets apply the bridge concept on the multiverse theory. The big infinite ocean remains but now spacially there are infinite destinations and there are infinite bridges to 'each' these destinations.The length of these bridges vary i.e. the time-line varies.
Now traveling to either the past or the present would mean that jumping from one bridge to another one whose destinations are the same but time-lines are different.Lets now analyze time travel to past and future individually.
Time travel to the past: Suppose a guy jumps from his present bridge to a bridge with a slow time-line(slow in the sense it is 'past' with reference to the bridge). He messes stuff up i.e. tells people what's going to happen and comes back to exactly the same time he left.Now there will be no change in his present time-line as nothing actually happened.He never disappeared.But the time-line he visited , he gave people information on what the future is going to be.This will affect their decision making and hence that destination of the particular bridge changes.
Time travel to the future:A similar thing happens here.Suppose the same guy travels through the future
(the same way...u know..jumping across bridges of time.. :-P ).He learns stuff about the past and then comes back.Now his decision making is affected since he knows the future.Hence the destination of his bridge changes.
Phew.. that was a long and complicated post. I really hope u guys understood it and i really really hope u guys find some fault in my logic so that i can sit and break my head on it again ( :-P ).
P.S. : I left out case 3 where the multiverse exists and u can jump back in your own bridge (not front).Still pondering about its implications. Maybe the next post will be about it (:D).
Saturday, June 26, 2010
Wednesday, June 23, 2010
Global Warming!!!
Lets see...Most of you must be knowing why global warming is caused..but i will go on and give a gist of it...
Gases such as Carbon dioxide , Methane etc let short wavelength infrared radiation pass through the atmosphere ( heat from the sun ) but contain long wavelength infrared radiation ( radiation emitted by earth (or any object) after heating up) , basically it acts like glass lets heat in but doesn't let it out.Hence these gases are called Greenhouse gases since its behavior mimics a Greenhouse.
Now it can be understood that as the concentration of greenhouse gases in the atmosphere increases the temperature of earth increases. So bascially our major job is to decrease the concentration of greenhouse gases and the planet can be saved??? No, there are two more major factors which enchances the global warming effect , basically these are positive feedback loops i.e. the input is dependent on the output positively,the more the output implies more input which further implies even more output and so on.
Positive Feedback Loop 1:
Now the north pole and the south pole are the two places which receive continuous 24 hr sunlight during the summer and the winter respectively.Antartica is basically a big mass of ice and the arctic ocean is almost always covered by frozen sea ice. Now these ice act as mirrors and reflect 99% of incident radiation back to space , unlike water which absorbs most of the incident radiation.
Hypothetically if both the poles did not have ice , then the solar radiation (heat) would have been absorbed by the sea , its temperature would increase which would eventually increase the average temperature of earth. (since oceans cools the land , all the trade winds etc originate from the oceans).
Okay... now what is happening is that Greenhouse effect is increasing the average temperature of earth.This causes the ice in the polar caps to melt which in turn reduces sunlight reflected by ice and increases the sunlight absorbed by water.This in turn increases the temperature again.As u can see this is the positive feedback i was talking about. Ice melts->water absorbs sunlight->temp increases->ice melts.
Thankfully for the above positive feedback to become self sustaining there has to be an initial threshold.
The initial threshold maybe the average temperature or the amount of ice left on Antarctica.It could be anything and we have no way of finding out (scientists are running advanced weather models to find out the exact threshold and have been unsuccessful till now). Once this happens consider our planet's climate system would go out of control.(in BITS lingo GGWP).
Okay now on to the second feedback loop..
Positive Feedback Loop 2:
We all know that most of Greenland is covered with ice. But underneath that ice are massive reserves of Methane ( Natural Gas ). Now as the ice melts, methane leaks out into the atmosphere.As you know Methane is one of the major greenhouse gases.Again a positive feedback loop has uncovered itself.
Ice melts->methane leaks->green house effect..temp increases->ice melts->and so on
Hence Global warming is a result of Greenhouse effect and the two feedback loops mentioned above
Our present carbon emission rate + both the positive feedback loops.We are looking at an avg increase in 2 to 3 degree from a optimist's view and an increase of 6 degree's from a pessimist's view in the next 10-20 years.
So i suggest all of the readers to GO GREEN!!
Hope u guys understood my post.... anyway i was able to kill some time :P
P.S. About the methane leaking thing, there are several videos of it. Scientist's light the jet of methane leaking out of ice (:D).Looks really cool , check it out on youtube. :)
Gases such as Carbon dioxide , Methane etc let short wavelength infrared radiation pass through the atmosphere ( heat from the sun ) but contain long wavelength infrared radiation ( radiation emitted by earth (or any object) after heating up) , basically it acts like glass lets heat in but doesn't let it out.Hence these gases are called Greenhouse gases since its behavior mimics a Greenhouse.
Now it can be understood that as the concentration of greenhouse gases in the atmosphere increases the temperature of earth increases. So bascially our major job is to decrease the concentration of greenhouse gases and the planet can be saved??? No, there are two more major factors which enchances the global warming effect , basically these are positive feedback loops i.e. the input is dependent on the output positively,the more the output implies more input which further implies even more output and so on.
Positive Feedback Loop 1:
Now the north pole and the south pole are the two places which receive continuous 24 hr sunlight during the summer and the winter respectively.Antartica is basically a big mass of ice and the arctic ocean is almost always covered by frozen sea ice. Now these ice act as mirrors and reflect 99% of incident radiation back to space , unlike water which absorbs most of the incident radiation.
Hypothetically if both the poles did not have ice , then the solar radiation (heat) would have been absorbed by the sea , its temperature would increase which would eventually increase the average temperature of earth. (since oceans cools the land , all the trade winds etc originate from the oceans).
Okay... now what is happening is that Greenhouse effect is increasing the average temperature of earth.This causes the ice in the polar caps to melt which in turn reduces sunlight reflected by ice and increases the sunlight absorbed by water.This in turn increases the temperature again.As u can see this is the positive feedback i was talking about. Ice melts->water absorbs sunlight->temp increases->ice melts.
Thankfully for the above positive feedback to become self sustaining there has to be an initial threshold.
The initial threshold maybe the average temperature or the amount of ice left on Antarctica.It could be anything and we have no way of finding out (scientists are running advanced weather models to find out the exact threshold and have been unsuccessful till now). Once this happens consider our planet's climate system would go out of control.(in BITS lingo GGWP).
Okay now on to the second feedback loop..
Positive Feedback Loop 2:
We all know that most of Greenland is covered with ice. But underneath that ice are massive reserves of Methane ( Natural Gas ). Now as the ice melts, methane leaks out into the atmosphere.As you know Methane is one of the major greenhouse gases.Again a positive feedback loop has uncovered itself.
Ice melts->methane leaks->green house effect..temp increases->ice melts->and so on
Hence Global warming is a result of Greenhouse effect and the two feedback loops mentioned above
Our present carbon emission rate + both the positive feedback loops.We are looking at an avg increase in 2 to 3 degree from a optimist's view and an increase of 6 degree's from a pessimist's view in the next 10-20 years.
So i suggest all of the readers to GO GREEN!!
Hope u guys understood my post.... anyway i was able to kill some time :P
P.S. About the methane leaking thing, there are several videos of it. Scientist's light the jet of methane leaking out of ice (:D).Looks really cool , check it out on youtube. :)
Subscribe to:
Posts (Atom)