Time and Travel and Time Travel

Over the week­end I had a con­ver­sa­tion with B rd over at edlun­dart about time and since then I’ve coin­ci­den­tal­ly read sev­er­al short sto­ries deal­ing with time trav­el by Michael Swan­wick.

So, of course, I’ve been think­ing about time rather hap­haz­ard­ly. B rd told me a sto­ry about a sculp­ture pro­fes­sor whom he talked to about time. The exam­ple used was a trip from Bal­ti­more to NYC which takes about 4 hours. Yet, if you are lis­ten­ing to some good music and hav­ing a blast, it might only seem like it took 2 hours. The ques­tion was basi­cal­ly, why is objec­tive time con­sid­ered more impor­tant than sub­jec­tive time? Plen­ty of sci­ence fic­tion deals with this prob­lem in terms of tem­po­ral rel­a­tiv­i­ty. Light­speed or faster than light­speed trav­el caus­es this to kick in. A month can pass sub­jec­tive­ly for a per­son trav­el­ing at light speed, but objec­tive time back on earth, hun­dreds of years will have done the same. This is still slight­ly dif­fer­ent because sub­jec­tive time is real­ly just a mea­sure of objec­tive time while trav­el­ing at light speed. To the per­son trav­el­ing, the trip could seem years long if they are incred­i­bly bored. Objec­tive time gets more val­ue I think because it isn’t vari­able from per­son to per­son and can be used as a form of com­mu­ni­ca­tion.

Now, Swan­wick has sev­er­al short sto­ries deal­ing with time trav­el. One in par­tic­u­lar wres­tles with thoughts on whether time is deter­min­is­tic and fat­ed or mal­leable and uncer­tain. Oth­ers deal with the pos­si­bil­i­ties of para­dox. I think that time is deter­min­is­tic, sort of like a syringe. The present is where the plunger ends, the past is the amount of flu­id that has been drawn in and the future is the vac­u­umed space behind the plunger. This is my deter­min­is­tic mod­el because we know by the gra­da­tions that there will be a point where 15ccs become 20ccs and so on. I sup­pose the future in this sense is mere­ly an extrap­o­la­tion of mea­sure­ments from the past.

As for para­dox, I think this has two pos­si­bil­i­ties. One which Swan­wick address­es, is explained bet­ter by his exam­ple. If you mur­der the infant Charle­magne with a machine gun, a month lat­er it will be said he was stabbed to death, and hun­dreds of years after that peo­ple will have the his­to­ry that we now know. So, time fix­es itself. This, too is depen­dent on the past, on his­to­ry, on recount­ing what was once to be.

So from all this I have gath­ered that talk­ing about the future, or time trav­el, always ends up being about the past.

Anoth­er pos­si­bil­i­ty is that para­dox can­not hap­pen. By that I mean, a hereto­fore unknown law will pre­vent its occurence. Per­haps this will only kick in in large case sce­nar­ios like mur­der­ing your own grand­fa­ther and small­er things like [to use anoth­er Swan­wick exam­ple] send­ing your­self stock options so you become rich will fiz­zle on its own.

There is also a the­o­ry that I read about years ago that posits that each instant of time is its own uni­verse and con­tin­ues to exist inde­pen­dent of all oth­er instants some­where in mul­ti­di­men­sion­al space. We per­ceive time as a mea­sure­ment only because these instants blur togeth­er like the frames of a film strip.

I won­der if time is an illu­sion alto­geth­er. Per­haps only this instant exists, mem­o­ries and hopes are mere­ly flour­ish­es added as dec­o­ra­tion to this instant of exis­tence. If this is true, every­thing seems much small­er to me. I also have some dif­fi­cul­ty equat­ing time and space as things that are near to each oth­er. Per­haps I am being pur­pose­ful­ly dense, but time strikes me as noth­ing more than a mea­sure­ment. We speak­ing of count­ing time, but time can­not be spo­ken of with­out some sort of mea­sure­ment. Space is vis­i­ble on the oth­er hand. I sup­pose it is sort of like explain­ing three dimen­sions to a draw­ing on a piece of paper. Or, [and I’ll stop here] maybe that is wrong because Time and Space are both per­cep­tu­al and maybe even three-dimen­sion­al Space only appears to exist because it func­tions sim­i­lar­ly to film­strip time.