Time Travelling

[sinister42]

Here's a real problem with time travel. Unless your time machine can also calculate the orbit of the earth and its position in space at a given point in time, you're going to pop out of your time machine into the hard vacuum of space - cause the Earth moves, you know.

Also, you can't kill Hitler, because you didn't.

 

[BAYLOR]

I can just imagine finding myself in the court of King Henry the 8th. I think

Here's a real problem with time travel. Unless your time machine can also calculate the orbit of the earth and its position in space at a given point in time, you're going to pop out of your time machine into the hard vacuum of space - cause the Earth moves, you know.

Also, you can't kill Hitler, because you didn't.

You can do away with Hitler, what would likely happen is you would create an alternate timeline.

 

[Dennis E. Taylor]

Here's a real problem with time travel. Unless your time machine can also calculate the orbit of the earth and its position in space at a given point in time, you're going to pop out of your time machine into the hard vacuum of space - cause the Earth moves, you know.

Naw, it's not a problem. Observe! (waves hand)
Appearing in deep space has a couple of problems. First, it assumes an absolute reference frame, which Einstein assures us doesn't exist. Second, moving from deep in Earth's gravity well to deep space would required the same amount of energy as launching from the Earth to deep space. So it ain't gonna happen.

Instead, in the absence of an absolute frame, time travel occurs within the local frame, which is defined by constant gravitational potential. In other words, the Earth drags local time along with it, so you'll always end up on Earth. Also, angular momentum figures into it, so you'll also always end up on the same *part* of Earth.

(stops waving hand)

This example of handwavium brought to you by that Martian guy who wants to disintegrate things.

 

[Charles Parkes]

Here's a real problem with time travel. Unless your time machine can also calculate the orbit of the earth and its position in space at a given point in time, you're going to pop out of your time machine into the hard vacuum of space - cause the Earth moves, you know.

Also, you can't kill Hitler, because you didn't.

Ouch. You're really messing with my sequel storyboarding. Firstly - in fantasy, when you time-travel you don't pop out a million miles out in space where the world will be or had been because . . . magic.

Secondly, I'm pretty sure Quentin Tarantino already did go back in time and kill Hitler : ) so I think you must be some kind of time relic from the pre-inglorious basterds time-stream. You should be disappearing right about. . . . [pop]

[ - The whole WW2 historical fiction genre disappears, leaving men of my father's generation with nothing to do, and nothing to imagine that they'd would have been good at - had they been born into a different era whereupon they'd naturally been made an allied field marshal]

 

[Dennis E. Taylor]

[ - The whole WW2 historical fiction genre disappears, leaving men of my father's generation with nothing to do, and nothing to imagine that they'd would have been good at - had they been born into a different era whereupon they'd naturally been made an allied field marshal]

... in a fit of boredom, they form their own political party, which, strangely, uses the swastika as a symbol. They take over Canada, Mexico, and begin spreading across Central and South America, while eyeing Europe. Churchill makes a speech...

 

[BAYLOR]

Ouch. You're really messing with my sequel storyboarding. Firstly - in fantasy, when you time-travel you don't pop out a million miles out in space where the world will be or had been because . . . magic.

Secondly, I'm pretty sure Quentin Tarantino already did go back in time and kill Hitler : ) so I think you must be some kind of time relic from the pre-inglorious basterds time-stream. You should be disappearing right about. . . . [pop]

[ - The whole WW2 historical fiction genre disappears, leaving men of my father's generation with nothing to do, and nothing to imagine that they'd would have been good at - had they been born into a different era whereupon they'd naturally been made an allied field marshal]

In L Sprague de Camp novel Lest Darkness Falls . The main character Martin Padway a 20th century man is whisked back to 6th century Rome via a lighting bolt.

 

[sinister42]

Naw, it's not a problem. Observe! (waves hand)
Appearing in deep space has a couple of problems. First, it assumes an absolute reference frame, which Einstein assures us doesn't exist. Second, moving from deep in Earth's gravity well to deep space would required the same amount of energy as launching from the Earth to deep space. So it ain't gonna happen.

Instead, in the absence of an absolute frame, time travel occurs within the local frame, which is defined by constant gravitational potential. In other words, the Earth drags local time along with it, so you'll always end up on Earth. Also, angular momentum figures into it, so you'll also always end up on the same *part* of Earth.

(stops waving hand)

This example of handwavium brought to you by that Martian guy who wants to disintegrate things.

Keanu Reeves saying "Whoa."

 

[Vladd67]

Here's a real problem with time travel. Unless your time machine can also calculate the orbit of the earth and its position in space at a given point in time, you're going to pop out of your time machine into the hard vacuum of space - cause the Earth moves, you know.

Also, you can't kill Hitler, because you didn't.

Reminds me of this
Strontium Dog - Wikipedia, the free encyclopedia

Like all Search/Destroy agents, Alpha is armed with highly advanced technology including a variable-cartridge blaster, electrified brass knuckles, a short-range teleporter, a "time drogue" that can briefly "rewind" the last few minutes of time, and "time bombs" which can transport somebody minutes or hours forwards or backwards in time (by which time the planet has moved along in its orbit, so that the victim reappears in empty space).

 

[Kieran Song]

I can't live without my phone lol. I guess that'd completely compromise me.

 

[Dave]

I can't live without my phone lol. I guess that'd completely compromise me.

We discussed smartphones earlier in this thread - obviously, you'd have no cell reception, GPS or internet to connect to - but as a calculator, stopwatch, clock, calendar, notebook and camera it would still be a fantastic tool. Games and songs could still be played. It should be possible to easily create some kind of battery to charge it as the materials and knowledge required are fairly low tech. I see all time travelling wizards consulting on their smart phones behind their curtains.

I do have a problem with the trope in time travel stories of putting an advertisement in the newspaper to send a message to the future to retrieve the time traveller. This might work for a Newspaper like The Times of London (which has a great age and also copies have been kept and conserved.) It would not work for most Newspapers that lasted a few years or were very local. In recent years newspaper circulations have all but died. While many are available now digitally archived, a much larger number are not. Also, putting a advertisement in The Times would be incredibly expensive, and alert all of the bad guys you were hiding from. Additionally, I have searched the online digital Times archive and cannot find any messages for time travellers to be brought back home.

 

[Lew Rockwell Fan]

Additionally, I have searched the online digital Times archive and cannot find any messages for time travellers to be brought back home.

That's because I used code.

 

[galanx]

Here's a real problem with time travel. Unless your time machine can also calculate the orbit of the earth and its position in space at a given point in time, you're going to pop out of your time machine into the hard vacuum of space - cause the Earth moves, you know.
.

Gregory Benford dealt with that in "Timescape"

 

[Vertigo]

I don't see the big deal about charging any electronic devices you might take. There are plenty of very good solar chargers around now...

 

[sinister42]

Another theory of time travel I've been thinking about: What if you just travel through time - i.e. you rewind your own life, and when you arrive 10 years ago, you're just...you 10 years ago? Are you "you 10 years ago" with today's memories and experiences, or do you rewind those as well and just end up reliving the last 10 years exactly as they were? If you change something, is there still a paradox?

 

[Dave]

Kurt Vonnegut in TimeQuake has exactly that; people reliving 10 years again. They can't change anything though, it happens just as before. So, they go into a kind of automatic pilot mode. This is a disaster when the 10 years is up and they have to begin to make choices again. Aircraft fall out of the sky because they no longer fly by themselves, cars crash because they no longer drive themselves.