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The Science and Physics of Back To the Future
overthinkingit writes "A scientist has tried to apply serious math and physics, including the Law of Cosines, to analyze how the DeLorean in Back to the Future travels through both Time AND Space: 'in order to pull off the kind of time travel we see in the Back To The Future trilogy — the kind where the traveler is transposed in time, but remains stationary in the same relative position to where he/she left — the DeLorean would have to be an outstanding space ship, in addition to its already laudable work as a time-ship. According to Doc Brown's stopwatch, Einstein the dog travels precisely one minute into the future on this first jump, arriving, relative to their frame of reference, at the same location he left. But how far has this reference frame itself traveled during that one minute?'"
The universe really DOES revolve around the earth in the movie universe, so no special measures are necessary beyond "simply" moving in time.
First off, there are WAY too many pages to this article for me to read but it looks fun so maybe later.
But in regards to this, I would like a physicist to boil large problems down to "We can't do X because of the simple problem of Y." Example with Mr. Fusion: We can't do Mr. Fusion because the amount of energy that goes into creating the conditions for fusion outweigh the amount of energy produced. That's something measurable and approachable to me, a starting point.
If it comes down to the problem requiring a Free Lunch, I'd probably give up early--I'm not one to disobey the laws of thermodynamics.
In middle school I devoted large amounts of time and reams of paper to developing a formula f(n) to produce the nth prime number (at the time I was searching for O(1) oh how naive I was about mathematical induction!) and it was all because a teacher explained how powerful such a formula would be for encryption and many other things.
While I (obviously) never solved it, I sure the hell enjoyed the simplified form of a much more complex problem. And on top of that, it kind of set the tone for computer science in my life. Could hoverboards & time machines turn a movie goer into a physicist? Maybe not often but it happens.
My work here is dung.
anyone that has (in the past) managed to create a time travel device and has tried it, probably thought they made a disintegration machine, because anything they sent back or forward in time was never seen again. (or before, I suppose)
Because a second/minute/year/millenia ago that spot was occupied by empty space. The earth is moving very fast through space.
I've always used that reason to concede that even if we DO make time travel possible, it will be of little practical value.
Then there's the other snag of transposition... if you say, send yourself back in time, what happens to that volume of space where you arrive? Is it destroyed? And what fills in the void where you left? Or one more expected result is it's transposed with your time's space. Thus all time travel is time swapping, something goes forward and something goes back. Now lets say you do make a time travel machine, and test it without considering the earth-travels-through-space issue... that means whatever you send out, you get a big ball of vacuum back. If it's a very brief travel, you may get a chunk of earth, high pressure ocean, or more likely, high pressure magma. Ouch... hope you got insurance. That'll turn your lab into a disaster area real quick.
There are so man "problems" with time travel, that it really doesn't matter if its possible or not. It's not useful.
I work for the Department of Redundancy Department.
Reference frames don't travel with respect to themselves. By definition.
However, you could say that we're that much closer/farther from Vega, or in a different season in our Solar orbit, or in a different timezone, etc. Or the Earth's core has counterspun in relation to its own crust. Or tectonic shifts have occurred.
Just assume the car is locked onto a specific reference frame, such as a given latitude/longitude relative to the Earth's axis of rotation and the nearest large mass: the Earth's crust under the car. And pass the popcorn, it's a movie for chri'sakes.
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Coincidentally, the first draft for Back to the Future had a fridge for the time machine, but that was changed because the director thought it would end up with kids watching the film, playing around climbing into fridges, and getting trapped.
Bogtha Bogtha Bogtha
i know it was a joke, but i watched the special features on the DVD, and they said that they just thought that it'd be cool if it was hot when it left point A in time and was cold when it got to point B (they put liquid nitrogen in on scene)
Those of us who think they know everything annoy those of us who do.
That depends a bit on how you remove yourself from the flow of time. First, there's how you stay in one place, and that's only half the problem.
If you cause all atoms, down to the smallest level, within the envelope of your craft to be trapped in a void that stops experiencing the timestream and doesn't appear to the outside world, but the void itself is still acted upon by the forces of the outside world, then the void should remain in place until the occupants exit at the designated "arrival" time. The downside to this is that the void should be easily detectable, since you're not jumping through space, you're simply pausing your experience of existence until you want to be un-paused.
Or, as with the latter, the void can be locked to the reference point without actually being interacted with, this would have the same result without being detectable.
Then again, maybe the craft would be detectable, but only if you knew to look for it and happened to look in just the right spot while it was sitting there, just out of visible space, perhaps creating a gravity and energy signature as if it were dark matter.
The third method would be to calculate the exact position of the craft based on the earth moving through space at a perfectly predictable rate and somehow teleport (portal, wormhole, stargate, whatever) from your starting point and time to your end point and time. Obviously, if this were the method employed, interplanetary travel would instantly become trivial as a side effect of time travel. (Pern, anyone?)
I think the middle method is what's implied in the movies, but I'm not sure how you'd get the void to follow the reference frame without being detectable.
The second half is traveling backward through time as well as forward. With the third method, above, this is part of the same operation, the teleportation method's destination coordinates simply include a time component. (Ok, "simply" is a stretch, but...) For the first two methods, creating a forward moving void is, well, "relatively" trivial compared to causing the void to experience the timestream backwards, and still be locked in the backwards-moving reference.