April 10, 2016

"The most convincing argument against time travel is the remarkable scarcity of time travellers."

"However unpleasant our age may appear to the future, surely one would expect scholars and students to visit us, if such a thing were possible at all. Though they might try to disguise themselves, accidents would be bound to happen — just as they would if we went back to Imperial Rome with cameras and tape-recorders concealed under our nylon togas. Time travelling could never be kept secret very long."

Wrote Arthur C. Clarke in 1985.

I encountered that today... doing a NYT acrostic from November 2012. The most interesting clue was: "Bill Clinton, for Nixon, or George W. Bush, for Reagan."

Eulogist.

39 comments:

jr565 said...

Time travel can't happen because there is no such thing as time which progresses. We can count minutes and think that it has progressed, its just a measurement we have assigned to it

tim maguire said...

Pace r565's comment, I find it helpful to focus on the present--which has no beginning or end, encompasses no passage of time, but instead is the moment that the future becomes the past. It, itself, is not a segment of time and it's where we spend all our lives.

Sal said...

All of the time travelers went into the future. We haven't met them yet.

Robert Cook said...

Also, assuming the impossible--that time travel were possible--who says the time travelers would be in corporeal form in the past or future era they visit? Perhaps time travel would be a form of traveling in a different dimension, such that one time period and another, rather than being separated by linear past and future sequencing, were side by side--e.g., ancient rome sitting aside 2016--each in its own dimension. The time travelers would be more akin to observers, not actually physically present in the alternative time period, but watching it, invisible and incorporeal to those being visited/observed.

Ken Mitchell said...

Time travel is a logical impossibility. If time travel is possible, then EITHER:

1. You can go back in time, but you cannot CHANGE anything, because it already happened; the past and the future are fixed, like medieval "predestination". Free will is an illusion.

OR

2. You can go back in time and change things. But changing the past eliminates that future, so the "new" future progresses differently. But if time travel is possible, then some other time traveler will go back and change THAT timeline. Since we remember the past, then we exist in the timeline in which time travel was never invented.

In Larry Niven's story "All the Myriad Ways", and in James P. Hogan's "Thrice Upon a Time", the authors explore some of the possible complications of time travel. The bottom line is: You'll never have a time machine.

Ken Mitchell said...

Sal said... "All of the time travelers went into the future. We haven't met them yet."

We are ALL time travelers, moving into the future at a rate of one second per second.

RNB said...

Desmond Wurtzel wrote a hilarious short called 'Wikihistory.' It consists of chat on the International Ass'n. of Time Travellers' message board. First thing new members invariably do is to journey back in time and kill Hitler.

khematite said...

And then there was (will be?) John Titor.

https://en.wikipedia.org/wiki/John_Titor

dustbunny said...

Thoughtful comments folks! I've never thought too much about time travel but there is an interesting tv show called 11-22-63 I've just started watching about a man who travels back to stop the assimilation of JFK.

n.n said...

Space. Time may be a virtual dimension that measures motion. In this case, for time travel to be possible, it would be necessary to exert a causative force capable of arranging every aspect of space within an independent or isolated frame.

southcentralpa said...

By far, the most convincing argument against the existence of time travel is that George Lucas was not killed right after the release of "Return of the Jedi" by an oddly-dressed fellow of a decidedly geekish nature who immediately vanished afterwards.

(apologies to whoever first put that in print, but I've certainly thought it for a long time)

The Godfather said...

Time travel makes for good stories. That's all that matters. It doesn't have to be true. If being true were important, it would mean the end of politicians and pornography.

William said...

Wouldn't it be a pitch if someone invents time travel, goes to the past, kills Hitler, and thereby enables the Nazis under the prudent direction of Albert Speer to win WWII........There are parallel universes. A person who ruptures the space time continuum engenders a whole new alternate universe whose history proceeds from that point with time travel as an accepted part of life. It would be even cooler to find a way to jump between the different universes. I've got a sneaking suspicion that this isn't the best of all possible worlds.

Cath said...

What is the answer to the presidential acrostic clue?

Bill Peschel said...

Cath: Check the end of the post. It's in bold letters.

MayBee said...

I don't get what the first part of the post has to do with the acrostic.


Too much of a puzzle for me.

tom swift said...

Science fiction (great stuff though it is), and related speculation, rarely considers economics. Even if technically possible in some form or sense, time travel may just be horribly expensive.

Consider as illustration a simpler case, space travel (which as we can all agree is indeed physically possible). A vehicle about the weight of a compact car (that is, not much, as machines go) traveling between stars at a mere quarter of the speed of light (slow by SF standards, and in real life nowhere near fast enough for interesting special-relativity effects to become significant) would have a kinetic energy about forty times the annual energy production of the entire United States. So, even if we had the technical wherewithal to efficiently accelerate a small ship to that speed, not even the government could afford to do it.

bagoh20 said...

"I've just started watching about a man who travels back to stop the assimilation of JFK."

Eventually adultery became much more mainstream while Catholics still struggle to assimilate.

Gahrie said...

The answer is simple...we are living on one of the central timelines in the timestream. As time travel is developed and used, those timelines branch off. When time travelers go to the past, they create a new timeline that branches off from their original timeline.

Time travel to the future is probably impossible, because there is no where to go yet.

Ken Mitchell said...

RNB said..."Desmond Wurtzel wrote a hilarious short called 'Wikihistory.' It consists of chat on the International Ass'n. of Time Travellers' message board. First thing new members invariably do is to journey back in time and kill Hitler."


https://xkcd.com/1063/

fivewheels said...

Didn't we just have a debate cycle in which Republicans were forced to opine on whether they would kill baby Hitler?

I liked Artie Lange's response to that: "Hitler's kind of a no-brainer, isn't it? The real question is farther down the line ... I think I'd kill baby A-Rod."

Unknown said...

Perhaps--and this has been discussed in scientific literature attempting to look at this seriously--you can only travel back in time to the point the time machine was created. None have been created yet.

Terry said...

Why would anyone think that there are things called the future and the past to travel to and from?

David said...

Who says they are not here?

What do you suppose Althouse and this mysterious Meade guy are doing? Aliens and time travelers always adopt non threatening identities. A Law Professor and a self taught horticulturalist-philosopher? Give me a break.

David said...

The astronomers will tell you they they spend much of their lives traveling back in time. Just a generation or two ago, who would have thought we could watch events that took place billions of years ago.

Rob McLean said...

a man who travels back to stop the assimilation of JFK.

You mean the Borg got Kennedy? I knew it!

rhhardin said...

Godel found exact closed time curves in the Einstein field equations, astounding Einstein among others.

Left Bank of the Charles said...

If there were a time travel accident, perhaps someone else is sent back I time to prevent it.

JAORE said...

I just exited my time machine after my trip to the past. I'll know I was successful if Germany lost WWII and Tuesday comes before Wednesday.

[Stolen, and paraphrased, no doubt. I can not recall the source. Lost in the sands of time, perhaps.]

mishu said...

This is the biggest obstacle to going back in time.

https://xkcd.com/1203/

sykes.1 said...

Time travel would violate Special Relativity, and is, therefore, impossible. Go over to Lubos Motl's blog and what him eviscerate time travel promoters.

tim in vermont said...

Einstein showed you can travel forward in time if you go fast enough. A photon never experiences time. You just can't get back.

Darrell said...

I went back in time and killed Gustav Kimler. When I came back, I saw that some guy named Adolph Hitler came to power instead.

Peter said...

If time travel forks the time stream and thereby creates parallel universes then how would those living in a newly created alternate universe know of the time travel, or of the travelers?

After the world changed, it's not as if you'd remember ever having lived in a world in which the archduke's driver didn't take that fateful wrong turn in Sarajevo in June, 1914.

Darrell said...

The TV show based on Stephen King's 11.22.63 just ended. SPOILERS. He saves Kennedy and returns to the present and the US is a post-apocalyptic hell hole. He gets the story from a guy that is dull-witted, but Kennedy serves two term. George Wallace is next. The US is bombed. Ex-President Kennedy is put in charge of creating camps for displaced Americans, which turn into hell holes because of insufficient guards--scum turn them into rape camps, steal the food, etc. He goes back through the worm hole and resets time by doing so. He resumes his teaching job in present-day Maine.

Static Ping said...

Science fiction writers have a field day with time travel. There are so many, many different ways of handling it to make interesting stories. Star Trek was rather notorious in playing up any and all of them interchangeably. Somehow, in the Star Trek universe the fact that different time travel incidents seemingly contradicted each other as to physics and things like causality were regularly confused all made logical sense in universe. At least once during the show one of the characters complained how much he hated time travel mechanics as they seemed to make no sense.

It seems that the popular theory now is alternate universes. Gone back into the past and made a change? The universe you came from has not changed at all, but your actions split off a new universe starting at your change point. Sometimes time travel is impossible; you are simply hopping from one universe to an alternate one that happens to be at the time in the "past" that you are interested in.

Personally, I tend to go with the theory - not sure who came up with it - that a universe with a time machine is also a universe which never had a time machine, or at least it will eventually depending on how you define "eventually" in a time-flexible environment.

Darrell, I know there is at least one piece of media that goes with your theory of Hitler killing. The time police in the setting need to ensure the timeline, warts and all, and every time someone goes back and kills Hitler they need to reverse it. The twist is the original leader of Nazi Germany was not Hitler. After the original guy was killed, they propped up another person to take his place, and WWII and all that messiness continued as before. Then someone went back and killed that guy, they replaced him with someone else, and so forth and so on. When they got to Hitler, they eventually got the bright idea to clone him.

tim in vermont said...

That's why Lubos would have a hard time writing Sci fi. First you have to assume your readers are nincompoops. Which logical contradictions do you ignore?

Darrell said...

This recent notion that time is sapient and would self-correct is stupid. And it comes from atheists--the mother of all ironies. And yet, this is considered to be the "scientific" take. Where is the database of the trillions of things that happen worldwide each second that you would need to compare to detect changes? What non-God "intelligence" exists to spot the change and make the correction?

tim in vermont said...

Atheism is hard for us, given our evolution.