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The Science and Physics of Back To the Future

ScuttleMonkey posted more than 5 years ago | from the how-many-giga-which? dept.

Sci-Fi 436

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?'"

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Black to the Future (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26519705)

Coon, coon, black baboon,
Brutal, worthless, thieving goon,
Often high, thrives in jail,
his welfare check is in the mail!
Some 40 offspring had been had,
Not one will ever call him dad!
And yet he hollers day and night:
"I blames de white man fo my plight!
It's him spreads trash all round my shack!
It's him what makes me smoke dis crack!
He push my kind to burn and loot,
And sends de po-lice dat we shoot!
But inch by inch we takin' hold,
Like when de white bread starts to mold,
We'll overrun yo homes and soon-
dey be only fit fo de blackassed coon!"

Re:Black to the Future (1, Funny)

Anonymous Coward | more than 5 years ago | (#26519843)

1.21 niggawatts? 1.21 niggawatts? Great Scott! The only power source capable of generating 1.21 niggawatts of theft/welfare is a nigger.

Re:Black to the Future (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26519883)

Happy Martin Luther King day, honkey.

I'll bet your just mad cuz I fucked your wife last night.

Happy Martin Lucifer Coon to you, too (-1, Troll)

Anonymous Coward | more than 5 years ago | (#26519947)

I wish I was a nigger, I could drive a Cadillac with class
My pocket stuffed with welfare checks, and I could sit on my big black ass
Now you take a nigger, he aint nobody's fool
He doesn't buy any gasoline, to drive his kids to school

Our government has gone crazy, I'd change things if I could
If I was only a nigger, I could afford to live in a white neighborhood
Oh the things that I could do, if I was black and Hell-bent
I could send my kids to college, and it wouldn't cost me one damn cent

The wife and I were down on our luck, we were really getting uptight
They said at the welfare office, "You aint black, you're white."
Oh how I've tried to get a job, a diploma I had with pride
The post office man laughed, and said "You're not dark enough to even qualify"

I took a civil service exam, and passed it without shame
A nigger took one next to me, he couldnt even write his own name
The nigger, he got the job, now he's government top brass
He couldn't qualify for a trash truck, while I'm out on the street on my ass

If I was a Jesse Jackson, I'd be nobody's slob
Wearing $500.00 dollar suits, that nigger hasn't even got a job
If I was Barack Obama, I could sit back and relax
And when sworn in as President, I could paint The White House black

Damn, I wish I was a nigger

If I was a jig-a-boo, I could find me my roots
With a afro big as a watermelon, and a pair of white disco boots
If I was only dark complected, I could stand tall in this life
I could live high off the hog, just me and my white wife

Things used to be segregated, but things are a little off-key
I've never seen a white man as head of the NAACP
It aint that I don't like a nigger, if I've rubbed you wrong by chance
Take a look at that mistletoe hanging on the seat of my pants

If I was a kinky top, I could be a Martin Luther King
I'd have me a vision on a mountain top, my song the whole world would sing
I could have me a peace march on the streets of Memphis, Tennessee
I could tear up the whole damn city, and the police wouldn't dare stop me

A lot of things in life I know, but one thing I cant figure
Why a nigger can call me a honkey and I cant call a nigger, a nigger
If I was a jungle bunny, I could ring a golden bell
I could be a Mohammed Ali, and be loved by Howard Cosell

Damn, I wish I was a nigger

If I was a golliwogg, 7 foot tall and lean,
I could be a famous player on the Washington basketball team
If I was only chocolate brown, I could have me some turnip greens
A possum fat and watermelon, chitlens and a pot of butter beans

Now when Martin Luther King was buried in Washington with class
They put him face down in his box, so the politicians could kiss his ass
I guess its just politics, but it sure gets my goat
Kiss assing with a nigger, just so you could get his vote

If i was only a burr-head, I'd live high on the hill
Selling cocaine and prostitutes, and popping all kinds of pills
Now take the NAACP, they can march and raise all kinds of hell
Let the KKK start to move, and they'll all wind up in jail

I dreamed my life was over, I heard Saint Peter say,
"Today we're taken only niggers, you've gotta go the other way"
Then I heard the Devil, he said "I heard what Peter had to say
But I'm sorry to tell you son, Today in Hell is Nigger Day."

Damn, don't you wish you were a nigger?

Does it explain (5, Funny)

oodaloop (1229816) | more than 5 years ago | (#26519729)

how it leaves tracks of fire on asphalt? Or in the air? Never quite understood that part. The rest of the movie, OTOH, makes perfect sense.

DeLorian problems (5, Funny)

EmbeddedJanitor (597831) | more than 5 years ago | (#26519835)

The fire was probably due to a well known fact that DeLorians leaked fuel and oil badly. That's why they quit making them.

Re:DeLorian problems (5, Funny)

Anonymous Coward | more than 5 years ago | (#26520081)

The fire was probably due to a well known fact that DeLorians leaked fuel and oil badly. That's why they quit making them.

Why don't the British make computers?

Because they haven't figured out how to make them leak oil yet.

I'm sure you'll get a set of complimentary tightening wrenches with them when they do though.

Re:DeLorian problems (4, Informative)

confused one (671304) | more than 5 years ago | (#26520243)

Actually, you can still buy them, new. DeLorian may have gone out of business but another guy bought all the parts and manufacturing equipment. He repairs existing ones and will build you a brand new one if you have enough money.

Re:DeLorian problems (1)

LatencyKills (1213908) | more than 5 years ago | (#26520257)

OK, smartypants, then why was the car covered in ice when it returned? Leaky A/C as well?

Re:Does it explain (3, Interesting)

overcaffein8d (1101951) | more than 5 years ago | (#26520213)

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)

It's really quite simple (5, Interesting)

Diss Champ (934796) | more than 5 years ago | (#26519731)

The universe really DOES revolve around the earth in the movie universe, so no special measures are necessary beyond "simply" moving in time.

Re:It's really quite simple (1)

Samschnooks (1415697) | more than 5 years ago | (#26519905)

Oh thank God!

You see, if I went back in time and my Mother was as hot as Lea Thompson, then, well, I'd have a "Time Enough For Love" (Robert A. Heinlein) moment - when Lazarus meets his Mother.

Re:It's really quite simple (4, Funny)

gmuslera (3436) | more than 5 years ago | (#26520107)

Beware... you could end in "All you zombies" version of RAHeinlein time travel, and you will enjoy twice meeting with your mother.

Re:It's really quite simple (1)

MobileTatsu-NJG (946591) | more than 5 years ago | (#26520333)

The universe really DOES revolve around the earth in the movie universe, so no special measures are necessary beyond "simply" moving in time.

How do we know that wasn't what the whole 'time circuits' thing was about? Doc Brown talked about witnessing Jesus' birth, notably without mentioning the small geographical problem they'd have with that.

Doesn't need to be a spaceship (5, Insightful)

Yvan256 (722131) | more than 5 years ago | (#26519735)

Since it was in space for 0.0000E+999 seconds, i.e. never.

It did travel in time and moved from one point to another in the universe (to stay in the same spot on earth) but it didn't "travel in space", hence no need to be a spaceship.

Re:Doesn't need to be a spaceship (1)

mog007 (677810) | more than 5 years ago | (#26519915)

The earth moves around the sun, which moves around the galactic center, which is moving away from all the other galaxies in the universe.

Re:Doesn't need to be a spaceship (2, Interesting)

Yvan256 (722131) | more than 5 years ago | (#26519957)

Read my post again.

Re:Doesn't need to be a spaceship (2)

Yvan256 (722131) | more than 5 years ago | (#26520207)

Sure, someone can't bother to actually READ what I wrote and suddenly I'm a troll.

What part of "It did travel in time and moved from one point to another in the universe (to stay in the same spot on earth)" don't you people understand?

Re:Doesn't need to be a spaceship (2, Interesting)

TheRealMindChild (743925) | more than 5 years ago | (#26519937)

But it HAS to travel in space. See, space and time are as intertwined a green and grass. Let's skip the over-the-top explanation and illustrate where this mistake is comprehensible. While, in your frame of reference, you are not moving, in the grand scheme of things you are. The earth is rotating and revolving around the sun. The solar system is likely gyrating around something else. This very galaxy is moving as a whole. So many movements going on that no one even thinks of.

So, think about it... if you moved through time, forward one minute, and somehow skipped any spatial movement, the earth is going to be AT LEAST 1000 miles away from the point, relative to JUST its movement around the sun. That says nothing about how our solar system is moving through the galaxy or the galaxy moving in the universe.

Re:Doesn't need to be a spaceship (1, Troll)

Yvan256 (722131) | more than 5 years ago | (#26519979)

Read my post again too.

Re:Doesn't need to be a spaceship (1, Flamebait)

Yvan256 (722131) | more than 5 years ago | (#26520225)

Sure, someone can't bother to actually READ what I wrote and suddenly I'm a troll.

What part of "It did travel in time and moved from one point to another in the universe (to stay in the same spot on earth)" don't you people understand?

Re:Doesn't need to be a spaceship (5, Insightful)

shaitand (626655) | more than 5 years ago | (#26520043)

'So, think about it... if you moved through time, forward one minute, and somehow skipped any spatial movement, the earth is going to be AT LEAST 1000 miles away from the point, relative to JUST its movement around the sun. That says nothing about how our solar system is moving through the galaxy or the galaxy moving in the universe.'

I think you misunderstood his point. Yes being at the same location on earth requires a spacial movement. But in back to the future that movement is instantaneous just as your movement through time is. You never actually occupy the space in between and are never in outer space. There is no reason the delorian must be pressurized or carry oxygen tanks, exercise equipment, etc like a 'space ship'.

Re:Doesn't need to be a spaceship (1)

Yvan256 (722131) | more than 5 years ago | (#26520237)

This is exactly what I meant, thank you.

Re:Doesn't need to be a spaceship (3, Insightful)

EllisDees (268037) | more than 5 years ago | (#26520095)

I think the problem is that there is no universal frame of reference that you are moving through. Sure, the Earth is spinning, the galaxy is rotating, etc. - but without some force acting on whatever is moving through time, it would follow the exact same trajectory as the surface of the planet.

Re:Doesn't need to be a spaceship (4, Insightful)

Cederic (9623) | more than 5 years ago | (#26520309)

So when travelling back in time, the car moves forward to where the Earth would be as far into the future as the car went in the past - while the earth in the past hasn't reached where it was in the present yet.

To go back in time inertia is insufficient.

Re:Doesn't need to be a spaceship (2, Interesting)

snowraver1 (1052510) | more than 5 years ago | (#26520105)

Let me take a shot Yvan. The car does travel trough space, but not through the void of space. The car departs from a mall parking lot, then arrives at the same mall parking lot one minute later. Sure, earth has moved 1000km or so in that time, but you are not thinking fouth dimentionally. The car (and the dog) never experianced that minute, so to the dog in the car, nothing abnormal would have appeared to happen. The car never "Travelled" through space. It was in one location and time, then another. There is no transition.

Re:Doesn't need to be a spaceship (1)

Bill, Shooter of Bul (629286) | more than 5 years ago | (#26520145)

You're assuming that the Delorian is moving through our 4 dimensional universe to get from point A to Point F. What if there was a worm hole/time tunnel/extra dimension that allowed you to go directly from point A to point F with out going through points B ->E? No need for space travel at fantastic speeds.

Re:Doesn't need to be a spaceship (1)

Yvan256 (722131) | more than 5 years ago | (#26520259)

Please don't add Star Trek DS9 or Stargate theories into the mix, some people already can't understand what I meant in my first post. ;)

Re:Doesn't need to be a spaceship (1, Funny)

Anonymous Coward | more than 5 years ago | (#26520375)

No need for space travel at fantastic speeds
only 88mph.

Re:Doesn't need to be a spaceship (2, Insightful)

Ephemeriis (315124) | more than 5 years ago | (#26520293)

Since it was in space for 0.0000E+999 seconds, i.e. never.

It did travel in time and moved from one point to another in the universe (to stay in the same spot on earth) but it didn't "travel in space", hence no need to be a spaceship.

Seems to me that you're misunderstanding the terminology.

Nobody is claiming that the DeLorean needs to be able to survive the vacuum of space. Nobody is claiming that it is capable of leaving the Earth's atmosphere.

The article is referring to the two seperate aspects of spacetime - space, and time. Space as in the distance between two locations. The inches between my keyboard and monitor...the feet between my desk and the door...the miles between my office and my house. That kind of space. Not the interstellar void.

The Earth is constantly spinning as well as orbiting the sun. The sun itself, as well as our entire galaxy, is moving. The only reason we don't notice all that is because we're stuck to the ground and moving along at the same speed as everything else.

If you were to simply remove yourself from the flow of time for a moment, the rest of the universe would keep chugging along. It would leave you behind. The Earth would spin away from you, as well as orbit away from you. When you re-entered the flow of time you'd be in a different place than where you started from.

Given the (literally) astronomical distance that everyone moves over the span of a few years... Any machine that was capable of traveling through time would also have to be able to travel great distances in space. Otherwise you wouldn't pop back in to the same geographic location you left from.

Granted, this is all fiction. There was no real DeLorean that traveled through time or space. It's all made up. But that's kind of the point of this article... To explore what it would actually take to accomplish that kind of feat, using real world mathematics. To illustrate just what a fantastic proposition it is.

Reference Frame (1)

njfuzzy (734116) | more than 5 years ago | (#26519743)

The obvious question is "relative to what"? Once you are moving in time, relativity is out the window. So, I assume, would be any frame of reference in XYZ space. Once you pull of magic in terms of the time position, magic in space positions seems easy. Maybe the whole trick is to change the reference frame, and time travel comes along with the teleportation for free.

Re:Reference Frame (1)

FredFredrickson (1177871) | more than 5 years ago | (#26519803)

Exactly. It's quite simple when you reference the original reference point is merely just another reference point in a sea of infinite reference points, which are rendered irrelevant when you remove the 4th dimensional constraint. When moving through time, the only frame of reference neccessary is a clock - which further supports my theory that flavor flav was a time traveler: (proof) [artofthesteal.com] .

stasis field food storage (4, Funny)

frovingslosh (582462) | more than 5 years ago | (#26519761)

This explains the problem that I have trying to use a stasis field in place of a refrigerator. Every time that I shut down the field the food comes flying out of it real fast! (but fresh)

Re:stasis field food storage (4, Interesting)

Bogtha (906264) | more than 5 years ago | (#26520089)

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.

Re:stasis field food storage (0)

Anonymous Coward | more than 5 years ago | (#26520329)

I call BS.

Re:stasis field food storage (4, Funny)

blueZ3 (744446) | more than 5 years ago | (#26520361)

Reminds me of my favorite children's book (that didn't make it): The Magical World Inside the Abandoned Refrigerator.

Of course I also liked:

Eggs, Toilet Paper, and Your School
Microwaves and Hamsters: An I Can Do It! Book
Daddy Drinks Because You Cry
Curious George and the Electric Fence

1.21 Jigawatts (0)

Anonymous Coward | more than 5 years ago | (#26519765)

1.21 Jigawatts. How many watts are in a lightning bolt anyway? And, for bonus points, if you had a Mr. Fusion, explain how it could generate 1.21 Jigawatts without burning out the wires in the car. (or are we talking 3 or 4 gauge cables now throughout?)

Re:1.21 Jigawatts (1)

argent (18001) | more than 5 years ago | (#26519875)

They use ducted plasma transmission, obviously, just like the Enterprise's replicators.

Re:1.21 Jigawatts (1)

snowraver1 (1052510) | more than 5 years ago | (#26519993)

Well, Mr Fusion was far from perfect. If you recall, they were unable to use it in BTTF3, and had to use the clock tower's lightnint. It is likely that the wiring was substandard and that the intense power melted the wires. You have to remember that the Flux Capaciter would help with voltage spikes, and it's what ultimately makes time travel possible.

Oh by the way, there are EXACTLY 1.21 jiggawatts of power in a lightning strike.

Re:1.21 Jigawatts (1, Informative)

Anonymous Coward | more than 5 years ago | (#26520137)

Sorry, but that was BTTF1, and there was no Mr. Fusion in BTTF1 until the last scene when Doc comes back from the Future. They had to use the lightning bolt from the tower because Mr. Fusion wasn't yet installed, and Marty had run out of Plutonium rods.

BTTF3 was the Wild West, and there were no issues with Mr. Fusion then--then it was a problem with no gasoline in existence, and their inability to travel to 88mph.

Re:1.21 Jigawatts (5, Funny)

Drakkenmensch (1255800) | more than 5 years ago | (#26520033)

1.21 Jigawatts: the energy output of a man dancing a 1.21 minute jig. So next time you jig, be very careful to dance either more or less than 1.21 minute, lest you suddenly go back in time to the 1950s where your dad is a spineless wimp.

Re:1.21 Jigawatts (2, Interesting)

Jerry Coffin (824726) | more than 5 years ago | (#26520037)

That one really does admit to a simple answer from real, current (pun intended) knowledge: you need larger wires to carry more current, but NOT to carry more voltage. If the 1.21 gigawatts is 1 amp at 1.21 gigavolts (for example) the wire wouldn't have any reason to be any larger than one carrying 1 amp at 110 volts, or 1 amp at 0.1 volts.

Of course, even though the wire itself can be the same size, it'll normally look a lot thicker, because 1.21 gigavolts requires pretty serious insulation.

Re:1.21 Jigawatts (1)

CnlPepper (140772) | more than 5 years ago | (#26520079)

It varies, depending on a variety of factors a lighting discharge on Earth has a peak power output between ~30-300TW.

Boiling It Down (3, Interesting)

eldavojohn (898314) | more than 5 years ago | (#26519773)

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 [wikipedia.org] .

Re:Boiling It Down (1)

Zironic (1112127) | more than 5 years ago | (#26520411)

When I last read up about fusion it the problem wasn't that it takes too much energy to start the reaction(it does take quite a lot and all current fusion reactors are energy negative and although they're currently building the first energy positive fusion reactor right now in France) but rather the problem is that if you try to make a reaction large enough to produce more energy then you put in it has a tendency to melt the container.

So basically it has become a material sciences problem where they have to figure out how to build a reactor that can withstand the enormous forces.

Re:Boiling It Down (4, Interesting)

thedonger (1317951) | more than 5 years ago | (#26520413)

I spent some time in high school looking for a common form of a 2-digit multiplication trick and wound up deriving the quadratic formula. No one was impressed. So much for public school...

But back on topic, I think Homer Simpson's time traveling toaster is accurate with regards to the time portion: anything you do while in the past creates an alternate time stream only into which you may move forward. The problem the Simpson's didn't deal with is that if you exist in that new future, you will be a duplicate if you are able to travel forward in time to when you are alive. But I don't think forward time travel is possible since there is not/will not be a future.

Physical position notwithstanding, BTTF - while fun to watch - can't happen. Once you move backward through time you are screwed.

Extra Dimensions (5, Funny)

awitod (453754) | more than 5 years ago | (#26519791)

What you fail to grasp is that the 7th dimension works like quantum sticky tape to hold you in place relative to the things around you as you travel through time. So, you don't really need a space ship because of the relativistic affects of the items around you relative to each other pulling you along. Plus there's the whole inertia thing which requires you to go 88 miles an hour exactly so you always wind up where you started whether you go forward or backward. Try it yourself by drawing two 8's. On is for space space and the other one is for time space.

Also, don't forget that the velocity has to be in miles per hour, because the metric system is gay.

DUH!

cosines (1)

weirdcrashingnoises (1151951) | more than 5 years ago | (#26519801)

they are serious.

Re:cosines (3, Funny)

Samschnooks (1415697) | more than 5 years ago | (#26519837)

Um, you really don't want to go off on a tangent because the mods will mark you off-topic. I can see the sines in your post of that happening.

Re:cosines (0)

Anonymous Coward | more than 5 years ago | (#26520067)

once again something that could've been brought to my attention YESTERDAY

Re:cosines (0)

Anonymous Coward | more than 5 years ago | (#26520307)

Yes, that is really serious math. If all you've done is grade 10 math.

Teleportation and aging issues. (0)

screenbert (253482) | more than 5 years ago | (#26519805)

Teleportation would be the next logical step to answer the moving through space issue.

However remember it involves more than moving through space. Things will last longer. According to Einstein's theory, say you were 15 years old when you left Earth in a spacecraft traveling at about 99.5% of the speed of light, and celebrated only five birthdays during your space voyage. When you get home at the age of 20, you would find that all your classmates were 65 years old, retired, and enjoying their grandchildren! Because time passed more slowly for you, you will have experienced only five years of life, while your classmates will have experienced a full 50 years.

If we get the teleportation thing down, I'll be able to add a lot more clips to my juggling video. :) http://www.youtube.com/watch?v=lvp8m8CqIDc [youtube.com]

And I always thought time-travel was throwing my alarm clock against the wall.

Re:Teleportation and aging issues. (1, Funny)

ForAllTheFish (1191163) | more than 5 years ago | (#26520057)

According to Einstein's theory, say you were 15 years old when you left Earth in a spacecraft traveling at about 99.5% of the speed of light, and celebrated only five birthdays during your space voyage. When you get home at the age of 20, you would find that all your classmates were 65 years old, retired, and enjoying their grandchildren! Because time passed more slowly for you, you will have experienced only five years of life, while your classmates will have experienced a full 50 years.

The only way the mismatched aging is possible is if you can travel in one direction in a straight line and get back to the same point you started at. Why? Say on your trip you travel away from your classmates in a straight line, so relative to your classmates you age 5 years and they age 50 years (45 more than you). Now, how are you going to get back? You travel back in the reverse direction, so you age 5 years and (relative to you) your classmates age -40 years. Everybody is 25.

Re:Teleportation and aging issues. (2, Informative)

EllisDees (268037) | more than 5 years ago | (#26520151)

Fail!

It isn't the trip that causes the slowed aging, it's the acceleration. When you get back, all your classmates are going to be dead, and you'll still be 25.

Re:Teleportation and aging issues. (1)

Locklin (1074657) | more than 5 years ago | (#26520153)

your classmates age -40 years. Everybody is 25.

Huh?

Re:Teleportation and aging issues. (1)

xZoomerZx (1089699) | more than 5 years ago | (#26520321)

Not if you travel in an arc to the position the earth will be in time/space in 40 years.

Re:Teleportation and aging issues. (1)

CannonballHead (842625) | more than 5 years ago | (#26520299)

Throwing an alarm clock against the wall would be more an example of time suddenly stopping and coming crashing down, wouldn't it? A very special and localized case of the end of time, so to speak.

serious math = law of cosines (0)

Anonymous Coward | more than 5 years ago | (#26519823)

don't you understand why computer scientists/engineers/it professionals are the butt of mathematician's jokes...

in b4 I/my friend studies algebraic geometry/topology.

My head.... (1)

starblazer (49187) | more than 5 years ago | (#26519839)

It's exploding at this conversation.

This typical american response brought to you by Time Warner.

Gee.. seems I need a ... (1)

3seas (184403) | more than 5 years ago | (#26519865)

browser that can handle the math...... seems he need to calculate in the slashdot effect...

Re:Gee.. seems I need a ... (3, Funny)

BobSixtyFour (967533) | more than 5 years ago | (#26520085)

Wrong, as you can CLEARLY see, his server doesn't have the 1.21 Jigawatts necessary to jump OVER the slashdot effect and into your browser.

wear your space suit (5, Interesting)

v1 (525388) | more than 5 years ago | (#26519873)

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.

Re:wear your space suit (1)

cowscows (103644) | more than 5 years ago | (#26520143)

Couldn't you minimize a lot of these problems by testing your device out in space? Find a location that's mostly empty, and that you would expect to be equally empty at your target time.

Of course, this assumes some decent space travel technology, but I'd hope by the time humanity has figured out time travel that they've also managed to make spaceflight reasonably accessible.

Re:wear your space suit (1)

StaticEngine (135635) | more than 5 years ago | (#26520265)

This leads to the series of time machines that provide their own frames of reference, where an object can only travel within the duration for which the machine is "turned on". See the movie "Primer" for an example.

Of course, this makes me wonder, if a person gets into such a machine at 2PM to travel back to 10AM, what would another person see inside if they entered at 1PM to leave at 11AM? Is the device empty? Do they meet the other traveler? What if the other traveler is themselves?

Re:wear your space suit (3, Insightful)

gardyloo (512791) | more than 5 years ago | (#26520339)

Because a second/minute/year/millenia ago that spot was occupied by empty space. The earth is moving very fast through space.

You're assuming some immutable aether to give an absolute reference. Why assume that the place the object might appear later in time is some position stationary with respect to Sol, but not to the galaxy? Or the parent supercluster? Or some other object? We've abolished the Machian idea of an absolute reference frame by now.

Re:wear your space suit (1)

osu-neko (2604) | more than 5 years ago | (#26520345)

Um, was there any objection raised above that has any impact at all on a spaceship?

Earth moved relative to me. Check. Does that all the time, not a problem.

What was at the arrival point gets sent back to the departure point. Right. I'll take the one a quadrillion chance that the point of empty space at the destination is significantly different than the point of empty space I'm jumping from.

What was the problem supposed to be?

"Law of Cosines" ... (5, Insightful)

Sebastopol (189276) | more than 5 years ago | (#26519887)

as serious math?

Did a communications major write this?

Re:"Law of Cosines" ... (0)

Anonymous Coward | more than 5 years ago | (#26520359)

Considering that the website is named "overthinking it" and "serious math" is the law of cosines you are more than likely correct.

erm, (4, Interesting)

Speare (84249) | more than 5 years ago | (#26519913)

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.

Re:erm, (1)

ShakaUVM (157947) | more than 5 years ago | (#26520323)

>>Reference frames don't travel with respect to themselves. By definition.

Right. I'm glad someone else noticed that.

Relativity tells us that there's no absolute velocity. So while we say that the Earth is traveling very fast through space, if we set, say, London as our reference frame, there's no motion at all.

Re:erm, (0)

Anonymous Coward | more than 5 years ago | (#26520397)

Reference frames don't travel with respect to themselves. By definition.

I guess part of the problem is that accelerating reference frames and rotating reference frames don't make sense for time travel, then neither does any reference frame in my opinion.

inertia (1)

gobbo (567674) | more than 5 years ago | (#26519927)

Time travel stories very very rarely accommodate the notion that an object made independent of the earth's-sol's-milkyway's current position in time/space might fail to match the movements (future or prior) of these systems, and not return to the same spot on earth, never mind even staying in the solar system.

That always bugs me. Isn't it an obvious problem? Wouldn't your 'magical' explanation of a 'magical' tech need some explanation of it?

Re:inertia (2, Insightful)

thedonger (1317951) | more than 5 years ago | (#26520209)

Distilling down time travel for the masses requires some dumbification of the minutia. Did you see "Primer"? Excellent, but required a flow chart. That's why the BTTF series was more popular.

no, not a problem (1)

BoxedFlame (231097) | more than 5 years ago | (#26520417)

Before we discovered Relativity it was a problem, but Einstein had made it abundantly clear that it is NOT a problem.

However, Einstein also showed that gravity is an accelerating reference frame, which might be a problem since then shit is actually moving.

Reference frames are relative (5, Insightful)

omnilynx (961400) | more than 5 years ago | (#26519959)

But how far has this reference frame itself traveled during that one minute?'

Relative to what? Relative to itself, it hasn't traveled at all. And since we don't know the mechanism for time travel, there's no reason to use any other reference frame. Really, until we understand how they are supposed to travel through time we can't discuss the interactions of reference frames across time skips.

Obvious fact (1)

SnarfQuest (469614) | more than 5 years ago | (#26519963)

Don't they realize that "it's fiction"?

They might as well play around with radioactive spiders. Whose turn is it to be bitten today?

Re:Obvious fact (1)

CannonballHead (842625) | more than 5 years ago | (#26520363)

Well, we CAN play around with radioactive spiders, that's not new.

Probably would lose more experimental subjects that way, though. I am guessing that the life expectancy of radioactive-spider-bite testers is fairly low. :)

Who says it has to move in space by itself? (1)

Zocalo (252965) | more than 5 years ago | (#26519969)

Maybe at the moment the DeLorean actually travels through time, it simply moves relative to whatever it's resting on, namely the Earth (or a patch of air) just like Wells' Time Machine is shown as doing in the 1960 film of the same name. Of course, you'd need a little extra handwavium to explain how it also temporarily becomes invisible to an external observer, something to do with causality perhaps...

Meh! Physicists! It *always* has to be ohhh sooo complex!

Curving Spacetime FTW (1)

ultraexactzz (546422) | more than 5 years ago | (#26519973)

It's simple - large masses such as the earth curve Spacetime. When the Delorean transits time, its path is bent by this natural curvature of spacetime. This serves to keep the time machine firmly rooted in position as related to that of the Earth, regardless of where (or when) it is at either the departure or destination times. This would also mean that time travel between points not on or in orbit around a large mass would be impossible. So that bootleg script for Back to the Future Part IV: The Search for More Money is right out.

Aether Drag (3, Funny)

argent (18001) | more than 5 years ago | (#26519977)

Since Professor Brown is obviously using Steampunk technology (look at the ending to the final BTTF), it seems clear to me that the solution to this problem is that the Time Machine is carried along in the Earth's "Aether Drag", the distorting effect that any large mass has on the Luminiferous Aether!

Try this one out (1)

SoundGuyNoise (864550) | more than 5 years ago | (#26519999)

Couldn't you just tie a tether to the DeLorean, anchor it to the ground, and then make the time jump?
You arrive at your temporal destination, and the tether would keep you bound to the Earth's surface. It would only have to be long enough for the 88mph ramp up speed.

However, this means 1 second time jump would result in being physically yanked several kilometers in a split second. Barring astronomical whiplash, this should keep you relatively stationary to the Earth.

Maybe Timecop did have the better time travel scenario. Launch from a bunker, and suddenly splash into the river.

The Velocity Parameters (1, Redundant)

Ralph Spoilsport (673134) | more than 5 years ago | (#26520019)

Just remember that you're standing on a planet that's evolving
And revolving at nine thousand miles an hour.
It's orbiting at nineteen miles a second, so it's reckoned,
The sun that is the source of all our power.
Now the sun, and you and me, and all the stars that we can see,
Are moving at a million miles a day,
In the outer spiral arm, at fourteen thousand miles an hour,
Of a galaxy we call the Milky Way.

Our galaxy itself contains a hundred million stars;
It's a hundred thousand light-years side to side;
It bulges in the middle sixteen thousand light-years thick,
But out by us it's just three thousand light-years wide.
We're thirty thousand light-years from Galactic Central Point,
We go 'round every two hundred million years;
And our galaxy itself is one of millions of billions
In this amazing and expanding universe.

Our universe itself keeps on expanding and expanding,
In all of the directions it can whiz;
As fast as it can go, that's the speed of light, you know,
Twelve million miles a minute and that's the fastest speed there is.
So remember, when you're feeling very small and insecure,
How amazingly unlikely is your birth;
And pray that there's intelligent life somewhere out in space,
'Cause there's bugger all down here on Earth!

RS

Made up physics is fun. (1)

Chris Burke (6130) | more than 5 years ago | (#26520023)

When the DeLorean becomes unstuck from time, it does not actually also become unstuck from space. Since it does not experience time, that means it can't interact with physical objects, but the interactions before and after must be consistent. For example if the DeLorean didn't "move" at all, so the earth moved away from it, that would mean a massive change in its potential energy without any change in time, which requires infinite energy. Thus the point in space where the DeLorean becomes unstuck serves as a reference point, and that reference point is dragged along with earth's gravity well, and the electrostatic fields that were holding the DeLorean up, etc. In a way it as though the Delorean is sitting there, motionless, the entire time but simply not visible, until it appears again and of course has the same amplitude of momentum that it had when it became unstuck (88 mph).

Obviously this works just the same if you're traveling forward or backward in time.

That's all ludicrous made-up BS, but so is the Flux Capacitor. I mean it doesn't make much sense to me to accept time travel just to poke holes at the "but you always end up in the same place" part. Since it's made up physics anyway, it can work however the author wants it to. This isn't the same as when you have say a super-hero with magical powers, but he behaves in a completely illogical way (like forgetting he has certain powers when it would short-circuit the plot). This is like accepting that the hero can fly, but rejecting the laser eye vision. That's just silly.

Meh, gravity wells (1)

holophrastic (221104) | more than 5 years ago | (#26520049)

We're talking about time travel, so we get to go a little nuts. Much like when landing in a valley, as long as you're close, you'll fall into it. Call it a funnel you like. So as long as you're generally close the Earth's gravity well will suck you into the same spot that you left -- relative to the gravity well. It's one of those pendulum and gyroscoping effects.

  - Q.E.D.

(In case it isn't obvious, I know nothing. But love the trilogy.)

Power requirements (0)

Anonymous Coward | more than 5 years ago | (#26520063)

I have an arsenal of a Chevy Malibu and a Nissan Versa, in my garage, at the ready to convert into time machines. Better yet, the breaker panel is just on the other side of the wall, so there's my power source.

My main breaker is 200 A, so at 240 VAC and 80% load, that's 38.4 kW. To get 1.21 GW at 240 VAC, I'd need a 6.3 MA main. Better call the city utility to upgrade me.

Alternately, Caterpillar has 5.2 MW gas turbines available for rental--I'd need to rent 233 of these to make 1.21 GW. If each one of these needs 600 square feet, that's a total of 139,800 square feet, or 3.2 acres. My house is only on one acre, so I'd need to build a parking deck that could accommodate 233 semi-trailers; probably 5-6 levels.

Law of Cosines? (0)

Anonymous Coward | more than 5 years ago | (#26520071)

Yes, I'm sure with some high school-level trigonometry we can figure out this trivial time-travel business.

No no no (1)

dvh.tosomja (1235032) | more than 5 years ago | (#26520097)

Who cares about the science, it's delorean!

Back to the Future Tech (1)

johnkzin (917611) | more than 5 years ago | (#26520109)

I care MUCH more about the other 2 technologies presented in BttF than time travel:

1) Mr. Fusion ... a device that will take a few liters organic waste and generate enough power to power your car like it was running on plutonium? heck yeah!

2) Anti-Gravity ... for cars, skate boards, etc.

Those two technologies are FAR more interesting, compelling, and desirable, IMO, than the time travel technology. And, in the current climate, the energy source is probably more compelling than the levitation device.

old-hat hard science fiction (2, Interesting)

retchdog (1319261) | more than 5 years ago | (#26520135)

These kinds of considerations aren't anything new, and injecting them into soft sci-fi like Back to the Future is a waste of time. BttF is enjoyable, though, and does make a great accidental (?) satire of the American dream and hubris. For science, read some Larry Niven or Stanislaw Lem instead.

For example, Vernor Vinge did something like this, involving teleportation. A teleporter could control both the outcome position and velocity, but velocity was "harder" and took effort proportional to the difference in velocity.

Therefore, long distance teleports were only feasible along a longitude, and to the opposite latitude, since you had to match momentum or die by either being crushed or flung off into space. The earth's spin matches at lat X long Y, and lat -X long Y, but nowhere else.

As a result, one of the world's superpowers controlled both semi-polar regions, alternating by season; while the other stuck to the equator.

Can't run into yourself?? (0)

Anonymous Coward | more than 5 years ago | (#26520185)

So Doc told Marty he couldn't run into himself or it'd screw up time and he'd cease to exist.....however Biff was able to go back in time and talk to himself w/o any problems.....what's the deal?!?!

A whole lot of variables have to be matched here (1)

barakn (641218) | more than 5 years ago | (#26520205)

Not just time and space, but you have to arrive with the right velocity, orientation, and spin. If you landed in the future in a DeLorean spinning at 380 rpm on its top and traveling at 483 mph with respect to the local terrain, you might not survive to make your next movie.

garbage in garbage out. (1)

plasmacutter (901737) | more than 5 years ago | (#26520223)

The science and physics of superman racing the flash.

"A scientist has tried to apply serious math and physics, including the Law of Cosines, to analyze who would win in a race between superman and the flash"

In other news, said scientists' funders have threatened to pull their grants citing too much idle time.

What a frickin genius (1)

dangitman (862676) | more than 5 years ago | (#26520229)

Now, if this scientist had simply realized that Back to the Future is a fictional movie, he could have saved a lot of time.

McFly (0)

Anonymous Coward | more than 5 years ago | (#26520249)

Hello McFly!!!

It should be obvious (1)

ab_iron (622116) | more than 5 years ago | (#26520263)

You need a Tardus for this kind of work.

Tom Wilson (Biff) explains it all here (0)

Anonymous Coward | more than 5 years ago | (#26520271)

http://www.youtube.com/watch?v=iwY5o2fsG7Y

too much time on their hands..... (1)

inerlogic (695302) | more than 5 years ago | (#26520347)

i haven't RTFA yet.... but this clown better not have been doing this on taxpayer dimes.....

Things that make you go 'hmmmm....' (1)

rickb928 (945187) | more than 5 years ago | (#26520415)

- Like the unfortunate Federation officers that get stuck in 'phase' after a transporter accident. And all they can successfully interact with is the deck. They go through ceilings, walls, equipment, even Mr. Spock, but not the deck. And of course, they are fortunate to still be able to breath the air, despite not being able to actually move any of it sufficiently to wave at fellow crewmembers and cause them wonderment at the drafts...

- Or the ghosts that also can walk about on Earth, but sadly cannot help falling through walls, etc. No, I would not walk through a wall for Demi Moore. well, maybe after she got her boobs for Stiptease. No, but for Jennifer Connelly I might, even though hers really are fake.

Yes, the complexities of time travel would, in a real world, include navigation to the point in relative space where you wanted to be at the desired time.

I guess that's why it's so damned hard in real life. That and getting a DeLorean that runs for more than a month straight.

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