Time Traveler: Challenge Question (June 2013)

If only Anonymous Poster #1 would fall for that....

He did. He came back here brain dead.

As far as you know, it hasn't been discovered yet. Here are a couple examples to ponder: The earth was found not flat due to discovery; The earth was found not to be the center of planets due to discovery.

Heat Death. He went to Milliways, the Restaurant at the End of the Universe, but arrived late.

Entropy wins again.

He had reservations, but went anyway.

You are referring to an entropy catastrophe. If this is true, since S= H/T, then when the system is adiabatic, for S to decrease, T must increase. The occupant is pyrolyzed. During the return trip S increases, T must decrease. The occupant is frozen solid (dead either way), but why not dead for the scientist as well as the husband?

The husband set the return time asymmetrically from the destination time (distance). Assuming there is a heat transfer and storage device onboard (big assumption), he runs out of heat by traveling just a bit too far forward in time, and runs out of heat to exchange to keep the temperature constant while entropy increases. He freezes solid.

Yes, I think you are correct. it is the delta of the return time.

Yes, there are so many endless possibilities that are not pinned down with this challenge as to render it nearly impossible to "solve".

However, if the challenge is written with foresight and skill, such unknowns, possibilities, and improbabilities may be nothing more than a diversion.

Assuming that is the case, then is there something with the clues that could be immutable enough as to derive an answer? Remember, one trip into the past was successful

That was my approach, although I kind of did it tung-in-cheek, but if you went far enough into the future to a point where entropy is at its maximum, then all things would also be at absolute zero; no light, no energy, maximum disorder.

The other possibility suggested by another poster was that his time-space coordinates landed him into the vacuum of space.

Or, maybe this is just an extension of the riddle of how do you put a time traveler in a refrigerator? The obvious answer is you must first take the giraffe out. :)

Interesting point. I wonder, if you 'dialed it in' to go forward or back exactly one year, how many inches (or more distance) you would be away from your origin.

Inches won't be a very convenient unit to measure the distance away from your origin in a year.

The Milky Way is thought to be traveling through space at around 300 km/s.

There are several rules to time travel:

1. The device must stay in the same position relative to the center of the Earth or it would be space/time travel and one would not be able to return home.

2. The traveller must not be able to interact with the environment in which it arrives or he might kill his own grandfather before he had a chance of procreating, thus eliminating his father, himself and his children, born or unborn.

3. Travel to the future is not possible be cause it doesn't exist yet. If travel into the future were to take place, the future would be fixed and free will and all probabilities would be frozen.

I conclude that it was very cold before he started and that he went back a short time, set a short delay and return, and committed suicide. The alternative is that he delivered heat to a previous environment and changed it with all the consequences of breaking the laws of energy conservation.

Rule # 1 actually has a fault. The Earth rotates. So, the inertial reference point must reconcile that.

Rule # 2 may not be the only way it could work. Any change to the past timeline would potentially cause a paradox, but it may also be possible that a new timeline unfolds from that instant that our time traveler materializes. The original timeline remains intact and you also have a somewhat parallel time line based on whatever altered events have taken place. However, you need to be careful when you use the word timeline as that is only a perception and not necessarily a given reality.

Rule # 3 appears to be false. I provided a proof for this in an earlier post about time being an illusion. If you can follow my post you will see that past, present, and future all exist together simultaneously. It appears that consciousness acts like a projector, projecting each frame of a film in a preset order.

When the film or DVD is delivered to your house, all frames equally exist on the film or disk simultaneously. The projector or DVD player methodically presents each frame in succession to form a meaningful story.

The only question I can't answer is if free will is an illusion and only one possible future exists or if all possibilities exist (much like a probability wave for an electron). There are many, many good scholarly arguments both ways on this one.

The time machine was built in an old factory unit. To ensure that no timelines were altered, the scientist had gone back to the time the factory was empty, before she rented it. Her husband went back only three weeks earlier - and arrived inside Ben & Jerries warehouse coldstore. At least he died happy!

The Short answer:

The Scientist travels in one year increments. Where-as, The Husband goes to a time where there is lots of Space, and isn't inside or near the Earth.

The Long answer:

The scientist correctly goes back in time in exactly one year increments. The husband does not, thus going to a time where he is actually in space since the Earth moves, and matter can not occupy the same space as other matter, such as the Earth. So he didn't go to a time where the existence of Earth would interfere. In other words into a near-by mountain. The time machine returns to a time, near enough to it's origin time so that it's location in space has not changed relative to Earth.

That looks like the answer that they are looking for, but it assumes that the sun is stationary. Talking about being in the same place in the future is meaningless if all linear motion is relative and there is no absolute frame of reference.

Bingo. There are no privileged reference points in space-time.

So are you saying that a time machine was build already but nobody can prove it because nobody resolved the issue with the referenve points?

Just to let you know, I have such a machine and my husband just turn out cold . . .

If you go in that direction, you run into difficulty:

A point on the equator revolves at about 0.46 kilometers/second around the Earth's axis.

Earth is moving at about 30kps around the Sun.

The Sun is moving at about 200kps around the Milky Way.

The Earth actually travels a spiral around the curved path of the Sun.

The Milky Way is travelling with its companions in the local group of galaxies towards an attractor.

The Earth never returns to the same spot, and that is without considering that the Solar system is above the galactic plane and rising although the rate of climb is diminishing.

I agree, this is all true. The time machine would have to be capable of travel measured in the micro or milliseconds. Given that is a new technology, I'm guessing would need a clock similar to that used in computers running MHz or GHz. If it was that accurate it could come back within mm or Cm's of the place it 'left' from.

Clever. GA.

But there is the pre-programmed return after a few hours except the dude came back in minutes. That must be significant. The UK is five hours ahead of the East coast of the USA, I wonder if you can work that in.

The number of minutes or hours that pass in the past does not mean that more or less time must pass in the present. There is no requirement stating that the two times must be linked.

That is, if you go back to a point in the past, spend one hour, then return. Must you return to the point one hour after you left?

THis is like the difference in time between the twin paradox, which is also a time machine that only goes forward into the future. There is ship time and Earth time and they obviously do not agree.

"The number of minutes or hours that pass in the past does not mean that more or less time must pass in the present. There is no requirement stating that the two times must be linked."

The OP made a great point of the difference in duration; why if not to imply that they were away for different times. I think it is a necessary boundary for a solution.

You may be right.

"The time machine disappears and reappears a few minutes later (programmed to return automatically after a few hours)."

However, the way it is written, the machine returns after a few hours of ship time, not the passage of departure local time. I don't know what the significance of "a few minutes later..." means to this puzzle, but there is a disparity of time between ship time and time passage at the point of departure.

You would think, if it is a time machine it can return to whatever time-space coordinates it is programmed to.

Simple:

She knew that he will travel to see another girl he loved a lot too. Her husband programmed the machine to go to that time she put a poison, but she repented, now she revenges. (sorry for the bad english).

Interesting. Schrodinger's cat all over again.

The wife traveled as a spectator to not upset the time line. She was gone for 2 hours. The husband sets his destination time a few minutes earlier to warn himself against marriage. By contacting himself, he upsets the time lime. In the alternate time line, the husband dies.The time machine returned as programmed. It's cold because the time travel occurred during winter.

As doorman pointed out. A lot depends on the interpretation of that penultimate sentence.

It is very cold...

By "It": do they mean the time machine, or, the weather "now".

Assuming it's the time machine, and, knowing what the weather is like in some parts of the world: it could be as simple as going back to the middle of winter instead of the summer.

Aw, stop being so "grown-up".

How's this?

There's a learning opportunity here. Don't follow the KrisDel™ time machine design drawings to the letter; there might be something wrong with them....

Isn't mass in that whole theory of relativity thingy? You'd have to assume the woman scientist was smaller than her husband (it is a safe statistical leap). If the machine energy input was not adjusted to compensate for additional mass, the only readily convertible energy mass, heat, would be all sucked out. Surprised the machine even made it back...

Any chance the time machine manual was written in chinglish? S.M.

...or the PLC program, even?

Using what we are given (and not speculating out & beyond that). If the scientist set the destination time I believe she also set the return time, not waiting for the default return time. So I believe this has something to do with the fact that the husband changed the destination time but not changing the return time?

Did the time machine try but fail to return the husband (causing death) at the same time as it was returning the scientist/wife ? This has something to do with the auto return time. Did it reset after failing and then return him only a few minutes after he left if he left 2 hours after she returned? So what state of existence was he in in the two hours in between the time he had not left but had also not returned yet? Did he exist twice or not at all. Where was he - dead! Cold? ??

Ok, I officially confused myself here and now I see I cannot arrive at a plausible answer! Drat! Time is a strange enigma.

Entropy shmentropy, there is a clear case of an impossible (by the physical laws) let alone illegal transfer of energy from one time to another, which violated the conservation of energy laws at both ends. It was taken from the now universe and released into the then universe.

Perish the thought! he might have witnessed the Big Bang!!.

I don't think it is possible to witness the Big Bang. Rather one would have to be a participant of the Big Bang.

You mean we've stumbled on the cause of it??

Could be a Nobel Prize with your name on it. :)

The time of destination is changed - during this time the Earth has moved position (the Earth moves at 465m/s). The temperature of space in the vicinity of Earth is 123 degree C but in shadow it is -233C - as the machine is cold I can only assume the machine materialised in the moon's shadow or that it was orientated so that the base faced the sun and cast a shadow. The vacuum of space would of course kill the husband regardless.

Regards

Brady

the time machine is battery driven - what else?

the battery is empty and how he can return now?

He went back in time farther than his wife. Hence, his return time caused him to age past his normal life span. Consequently, he was dead and cold.

OK further to my post #29. And trying to take the simplest possible interpretation of the elements of the question.

It is now the middle of winter, but, the time machine is in a nice warm building, which, needless to say did not exist in the past. The scientist knew that she had to program a destination time n and a half years in the past to avoid freezing to death. The husband however just programmed a destination time of m years in the past, with the unfortunate consequences described.

The It in "It is very cold" can now refer to: the weather outside, or, the time machine after the trip.

where is my rubber?

(no, i'm not an archaeologist)

wouldn't you try too?

Not without my towel.

I think that was the fatal error.

The 'few minutes' is the time it takes to move one way in time hence this is the destination time - He went to the future to see if his wife would outlive him but unfortunately not and he has just died and in the morgue. It was programmed to automatically go back to the current time, whence he would still be alive but no happier in the knowledge she will outlive him.

His wife programmed the Time Machine to "Take Her Husband Out" if he set the destination, to a time when he was still dating his Hotty Hot Ex-Girlfriend. If he got caught, she knew her Lawyer Husband would play the "But honey, we weren't 'Officially Married' back then" card. Dirty Dog got caught!

The husband had paid to be cryogenically preserved, and then realised both that it wouldn't work and that his life had become miserable anyway. So he went and collected the body from a sufficient way in the future, went to a new time until shortly after the expected death of his wife, got out of the time machine, and let the cryogenically cooled body come back to greet her.

I'm probably wrong, but - assuming a time machine (not time-and-space):
The husband readjusting the time coordinates could be a red herring so far as mis-location is concerned, because the (later) start location is different - and thus (if no spatial change is allowed) just as certain to miss the earth.
If the wife is tio land safely on Earth, her task too is improbable: the tolerances are critical - even if she can find a time when a viable location is in the same place relative to universal average coordinates (currently unknown) and going at the same velocity as her original.
Then you need to arrive somewhere with air unless the machine is sealed; in which case you would materialise with your body filled with additional air corresponding to the normal atmosphere. Bends at minimum - possibly explosion...

He programms it so far in the future that the sun has fizzled out and the earth is dead. He doesn`t survive but the time machine takes his remains back to when he came from.

The problem is that he returned a few minutes later. He sould have returned at the exact same time. For those few minutes he was neither here nor there, schrodinger's cat. When he returned, the box was opened.

so many non scientific engineering answers...

the fourth derivative circuits of electricity...

with right and left hand rule magnetic tachyon fields??

without appropriate shielding...time travel may cause nervous system disorders??

Well, this is a little late but I thought I might try to add on top of the (good) comments my own modifications for fun....

A scientist builds a time machine and successfully travels to the past and returns. Her husband later gets into the time machine and changes the destination time. The time machine disappears and reappears a few minutes later (programmed to return automatically after a few hours). It is very cold and the husband is dead. Why?

And the answer is:

Unfortunately, the husband didn't know that his wife would first identify a most likely safe time and place to land prior to embarking on her journey. As a result, this hapless time traveler lost his life as will be explained later.

Because she was cognizant of potential sensitivities arising and dependent on initial conditions (Butterfly Effect), the wife took great pains to avoid changing events on Earth. Upon successive mappings of stellar objects large and small, the wife of this dead husband had identified with greater confidence her next step.

Such time travel experimentation decisions included confirming placement of reconnaissance micro-satellites in congruence with theories of safe time travel. Additionally, her success came not only from her own thinking but in collaboration with fellow associates of diverse backgrounds and capabilities.

Subsequently, this humble choice of alliance included bringing into the fold a sous chef and fellow dishwasher from a local eatery with no educational background in science or engineering. Such a decision to include someone who is neither a young fresh mind or well seasoned academic didn't seem wise.

However, this recently widowed time traveler liked to sit in the back dining area adjacent to the employee break area and would hear debates from time to time on topics such as why a recently launched space telescope failed.

This restaurant duo had belatedly proved their mettle by arguing the importance of masking or compensating for thermodynamic effects more precisely as one goes further back in time to ensure consistency of enthalpy of the present.

With further experimentation, short hops in time proved to be mostly negligible with changes in events but in the case of the dead hubby was a different matter. The unfortunate time traveler managed to transport slightly outside earth's orbit.

The time machine had redundant safety measures such as predictive modeling of the location of earth at different periods in time, removal/time transport equivalent thermal mass to the future, and placement away from civilization.

However, the husband traveled to a time prior to when a combination of large and small comets hit earth between his fateful time jump and her successful transport. These unforeseen events had changed the shape, spin, mass and orbit in ever so subtle ways over that time period. As a result, the calculations were off.

An additional result of the tragic journey, was a meteorite colliding with his environmental controls just as he was materializing in that period which led to the depletion of his oxygen before he could react (no surveillance satellites available to ensure safe arrival).

Although the motor control and other essential circuits had heaters to maintain operation of their components, the rest of the ship froze due to residing on the night side of the earth within 1 hour of arrival.

Upon returning from orbit, some vacuum of space was included within his trip home (due to the void created by the damaged environmental components) which resulted in a pressure drop within the hangar and remaining humid air interacting with the cold ship led to a rapid cool down within the enclosed space.

But the story is not over, the collision from the projectile with the ship along some slight shading of some nearby meteorites had created a subtle yet significant alteration of these tiny heavenly objects to collide with other objects they would have entirely missed altogether. This chain of events resulted in a comet large enough to cause significant damage to earth's population to now be on a collision course with our home planet within 30 days.

Given that the wife survived, the machine must have been built to swap the cargo with coincident material at the target destination. If the husband landed in empty space, there must have been one hell of a bang when he left.

The husband obviously neglected to consult CR4 for the wealth knowledge to be garnered to ensure a successful venture into time travel.

Only one question remains - should he have posted in General, Instrumentation, New Technologies & Research, Software & Programming, or Transportation?

Excellent question. Now, which section should we start that debate?

We are starting to sound like the crew of the B Arc.