Monday, April 02, 2007

Time Travel

Okay, this happens to me whenever I am reading about/working with non-causal systems. I start thinking a lot about time-travel. Wouldn't it be great if we could travel back in time and set right many of our wrongs? Or if we could travel to the future and see how our great-grand children would look? Practicalities aside, it is an amazing concept.

Time-travel has been a pet subject for sci-fi movie makers, for a long time, and it does not seem to get old at all! There used to be this series telecast on the Sci-fi channel. A man is tossed from one body to another body and another, all in different times, so that he can set right the wrongs done by other people, and finally return to his own body to the present. He has only one friend throughout this exercise - Al (I think), who appears to him as a hologram. It was an enjoyable series. Fi, yes, but Sci? I should think very little Science was involved :)

And there are those gadgets that have invited a lot of speculation but have always eluded serious research for practical reasons - the time machines. H.G. Well's book 'Time Machine' was even made into a movie starring Guy Pearce. I still have to read the book. A more famous movie and a personal favorite involving time machines, is the 'Back to the Future' trilogy. Who can not love the bungling 'Doc' and the spirited young Michael? And there is another good movie called 'Frequency', where a man communicates with his father from the past and saves his parents from fatal accidents. Even the famous 'Star Trek' has a few episodes on time travel. Coming to Indian cinema, we have 'Aditya 369' which is a pretty good movie too.

There is this theory about how time-machines may work. I had read it someplace, years ago. The events happening on the earth can be seen from the Sun eight minutes later, because the light from the earth takes eight minutes to reach the Sun. So, if you can travel faster than the speed of light (Ah, there is that limit again!), you can 'view' the events that happened eight minutes ago, first hand. There is no way of checking it because we still have not found a way to travel faster than light. And interfering with the past still cannot be explained.

Traveling to the future only gets trickier. There is absolutely no explanation that even remotely makes sense, of how one can travel into the future. Some argue that there are millions of futures etched out for you, and you just pick one each nanosecond of your life. Keep choosing futures one after another and - well, you can travel to the future! However, this argument is not even worth considering. There are just too many unknowns in the equation.

Theoretical physicist Kip Thorne suggests that wormholes, which are allowed by the laws of Theoretical Physics, can be used for traveling in time. Something that comes from an eminent physicist like him cannot be disregarded. But we have to continue being in the present, and see what direction research takes.

As far as I know, the concept of time-machines and time-travel is quite recent. I have not come across that in Indian or Western mythologies that I have read. From all practical observations, our conclusion is that Time flows only in one direction. That is what our ancients also seem to have thought.

That is the sensible thing to think, too. As a subhAShita goes -
गतशोकं न कुर्वीत भविष्यं नैव चिन्तयेत्
वर्तमानेषु कार्येषु प्रवर्तन्ति विचक्षणाः ।


mouna said...

it reminds me of one thing: in harry potter, hermione, uses a time turner to go back in time...

the same time turner helps them in the climax. yes this subject has witnessed a lot of speculation.... and it turns out to be interesting too..

ತಲೆಹರಟೆ said...

back to the future, aditya 369, star trek ಬಗ್ಗೆ ಓದಿದ ಮೇಲೆ ಹಳೆ ನೆನಪುಗಳೆಲ್ಲ ಮರುಕಳಿಸಿದವು.
ಆರ್ನೋಲ್ಡ್ ಶಿವಾಜಿನಗರ್ ಒಂದು ಫಿಲಂ ಯಾವ್ದೋ ಇದೆ... ಇದೇ ಟೈಂ ಕಾಂಸೆಪ್ಟ್ ಬಗ್ಗೆ.... ಈಗ್ ರಿಕಾಲ್ ಆಯ್ಥು...Total Recall.

"Time flows only in one direction."
I say: Time is only a perception. It doesn't really exist.


bellur said...

nice post.
shloka meaning haakidare olledu.

have been listening to sri ks narayanacharya's lecture on ramayana since this sunday. he was telling y'day that in vaikunta, there is no concept of time and space.
he just asked the audience to imagine about it.
beyond our ability, alwa!

parijata said...

mouna avare,
Thanks for visiting my blog. Yes, you have the time turner in Harry Potter too. It is my favorite in the Harry Potter series.

taleharaTe avare,
Thanks for the comment.
Total Recall ನೋಡಿದ ನೆನಪಿಲ್ಲ. ನನ್ನ ಸಿನಿಮಾ ಜ್ಞಾನ ಸ್ವಲ್ಪ limited :)
According to Einstein, time cannot exist independently - it can exist only in conjunction with space. You need something to be changing to be aware of time. So, if there is *absolutely* no change, we cannot percieve Time!

bellur avare,
Thank you.
ಶ್ಲೋಕದ ಅರ್ಥ ಹೀಗಿದೆ:
'ನಡೆದುಹೋದದ್ದಕ್ಕೆ ಶೋಕ ಪಡಬಾರದು, ಭವಿಷ್ಯವನ್ನು ಕುರಿತು ಚಿಂತಿಸಬಾರದು. ಬುದ್ಧಿವಂತರು ಈಗಿನ ಕಾರ್ಯಗಳಲ್ಲಿ ತೊಡಗಿಕೊಳ್ಳುತ್ತಾರೆ' ಎಂದು.

Einstein would certainly agree with Narayanacharya. True, it is beyond our ability to imagine timelessness, forget "spacelessness". It is really mind-boggling.

Bit Hawk said...

I know that time travel has got relatively high respect from the scientific communities. There are various explanations that are too complex for my little brain. As mentioned in your post, there is this theory of traveling faster than light, which is a very popular and easily understood by common men explanation. But, I think 'time' and 'light' are two different things. Sight is just one perception. If we travel faster than sound, does it mean we might hear something before the sound was generated? What about smell - does it depend on speed of the wind? Touch? Taste? Well, time travel does not talk about these things. To me, its just a fantasy to daydream about the regrets of the past and the uncertainties of the future!

parijata said...

Welcome to my blog.
I think that though time and light are two different things, they are highly interdependent. Time is experienced only when there is change. This change is mostly perceptible because of light. But as you said, sight is just one perception.

We are now able to travel faster than sound. And I think that if you fired a gun, heard the sound and moved quickly to another spot, you would hear the sound of the gunshot again. Of course, this is what I am expecting. I do not now if an experiment like that has been tried anywhere. A Google search did not yield anything :(

Bhel Puri & Seekh Kabab said...

Ok, pretty belated comment. Grab-bag of thoughts:

I think Einstein proved, pretty definitively, that the speed of light cannot be exceeded. That's a universal constant.

Re. Indian mythologies, time travel is a difficult concept to figure out, because of the very nature of mythology. For example in the Mahabharata, Arjuna stumbles (literally) across Hanuman. If you started calculating the amounts of times involved (the amount of years per yuga, years/Kanda between Threyta/Dwaapar etc.) we are probably talking thousands of years. So one could make a reasonable case for saying that Hanuman-ji went through a worm-hole, assuming he was following the laws of physics.

"Some argue that there are millions of futures etched out for you, and you just pick one each nanosecond of your life."
- have you read 'One' by Richard Bach ('Jon Seagull')? That book has the same premise.

My favorite movies on time travel: Terminator 2, Groundhog Day, Stargate, Black Knight

Btw, I did look up the definition of non-causal systems on Wiki, but am still not sure how that applies to a regular yob.


Subhashita Manjari said...

Some more subhashitas can be found at Subhashita Manjari

Srinivas Murthy said...

ಟೈಮ್ ಟ್ರಾವೆಲ್ ಎಂಬುದು ಭಾರತೀಯ ಚಿಂತನೆಗೆ ಹೊಸತೇನಲ್ಲ.
ಪುರಾಣ, ಭಾಗವತ, ಉಪನಿಷದ್ಗಳಲ್ಲಿ ಇದರ ಬಗ್ಗೆ ಸಾಕಷ್ಟು ಸನ್ನಿವೇಶಗಳಿವೆ.

ಉದಾಹರಣೆ: ಲೀಲಾ ಮತ್ತು ಸರಸ್ವತಿ ಸಂವಾದ, ಯೋಗ ವಶಿಷ್ಠ