In the beginning ...

[Sean]

lol - I'll expect to see you on the cover of New Scientist soon...

[@meric@nwom@n]

I expect to see his face on a box of Coco puffs.

[loCAtek]

A angry, albino, ermine selling cereal; are you serious?

[loCAtek]

If the limits have nothing to do with us, then how can we comprehend them?

Are you being serious? You think that the Universe must be understandable by us? Really?

Not at all, by that I didn't imply that we had to be able to understand it. In a way, I think we're agreeing but coming at this from different perspectives.

As for the wiki, no Strawmen please. I am nowhere near clever enough to have my own theory. I merely state what has happened or refer to the theories of others.

Granted, I just didn't know exactly who's theory it was. I've heard it before; I don't think the author of the webpage you linked to originally postulated it.

but that's conjecture and not observation; and not travel through time to the past or to the future of the individual

No, not conjecture - it has been observed!

I agree it is for particles and not people - if you look back over my posts you will see I have never said people have moved through time (at anything other than the standard 1 hour per hour).

Well, I thought you were discussing possible time travel for people all along?

That's time relativity, not time travel.

You haven't grasped this. If I travel 10 years into the future in a space ship and it takes me an hour, then I have travelled into the future. I start off in 2011. I end up in 2021. I stay the same age. How is this not time travel?

Like I said, I've heard and read of this before, it's a common reoccurring theme in SF: the life of the returning starfarer and how does he/she deals with space-culture-shock.
However, I have found the correct term and it is Time dilation


I just don't agree with saying that's a form of time travel. It's a form of space travel that experiences time dilation.

[loCAtek]

I have read the original novella 'Ender's Game' when it appeared in IASFM -Issac Asimov's Science Fiction Magazine.

Speaking of good SF, in that mag that you might like, Stoat. This was first published in pulb in 2007 (I have most copies of that magazine since 1977 ) It's a vision of the future with all your favorite pastimes: teleportation, telepathy and dimensional travel.

Enjoy!

The Great Awakening, by Rudy Rucker

[Andrew D]

Again, the mere knowledge did not cause it to happen.

Fine. Let's assume that to be true.

What does it have to do with the issue at hand?

Absolutely nothing.

How does it affect the implacable logic demonstrating the impossibility of the coexistence of free will with an omniscient, omnipotent God who created everything?

In no way whatsoever.

[thestoat]

Well, I thought you were discussing possible time travel for people all along?

Well yes, ultimately if we can't use the time travel then it is academic (though maybe we could send information to the future and back: easier than sending a person - and that way we may be able to talk to people from the future).

Ultimately it boils down to the fact that I believe time travel for people is possible. I assume, from the posts, you don't. But it is a bit like a god really - we can't prove one way or another

I just don't agree with saying that's a form of time travel. It's a form of space travel that experiences time dilation

Ok, that is interesting. Can you tell me the difference? In this (albeit hypothetical) scenario, it takes me, say, 10 minutes to travel 24 hours. How is this not time travel?

[Andrew D]

Exactly. If I get on a ship tomorrow, I come back in a week, and lo! it is 2367 AD, then I have moved 356 years into the future. Of course, it is still true that from my perspective, I have been gone only a week, but so what? My wife is centuries dead. All of my friends and loved ones are long dead, as are their children and their children's children and their children's children's children ....

And that is one thing that does not change by virtue of relativistic mathematics: From my perspective, as the person gone for a week, they are dead; and from the perspective of someone who has heard (and probably entertained doubts about it) that someone took off on a crazy time-travel adventure centuries ago, they are just as dead.

How does calling it "time dilation" instead of "time travel" make even the slightest difference?

[Rick]

Actually the point is moot.

You will be just as dead.

Unless you travel at the speed in which your mass doesn't kill you 1st.

The faster one travels the greater their mass.

Restated, mass increases with speed...

[Crackpot]

for those interested

Newcombs Paradox
Divine foreknowledge and Newcomb's Paradox

[Rick]

Mine is shorter...

[loCAtek]

I'm home now. I was also going to add that you could achieve this same effect by: Cryogenic Status AKA Corpicles. In other words: freezing living beings and re-animating them later. (another Science Fiction, but not applicable technology) Would halting one's life's functions and starting them again later be considered 'Time Travel'?

No: the time stream was uninterrupted, and flowed naturally; only some were more affected than others due to environmental conditions.

Time Travel is defying time's effects entirely and 'jumping' to periods without having to follow the time stream at all.



Which as stated, is unprecedented. Humanity has discovered how to take advantage of natural laws, but has never succeeded in breaking them

[thestoat]

Which as stated, is unprecedented

... and agreed upon. Nobody has mentioned cryogenically freezing you and then waking you up later.

You said "I just don't agree with saying that's a form of time travel. It's a form of space travel that experiences time dilation". I am wondering what, to you, is the difference? Nothing to do with cryogenics (your assertion of which I agree with).

Actually the point is moot.

You will be just as dead.

Unless you travel at the speed in which your mass doesn't kill you 1st.

The faster one travels the greater their mass.

Restated, mass increases with speed...

You are quite correct, Keld, that the theories state that mass increases with speed and become infinite at the speed of light. But this is just a philosophical discussion. Maybe there are ways round the mass thing that we just don't know about ...

[loCAtek]

Which as stated, is unprecedented

... and agreed upon. Nobody has mentioned cryogenically freezing you and then waking you up later.

You said "I just don't agree with saying that's a form of time travel. It's a form of space travel that experiences time dilation". I am wondering what, to you, is the difference?

The intent. Traveling at, or greater, than the speed of light has always been the objective of Space Travel, since interstellar distances can't be crossed in known conventional methods. In all the research done on FTL, time dilation was a yet another unfortunate consequence ...that could kill you. In reality, the effects of FTL would not be survivable to the human body, which is why only energies like light can achieve it. Your body wouldn't live to see your Grandchildren, should it make it back to Earth in the future in one recognizable piece.

What most SF authors do is cheat on this point. They say their ships achieve 'Warp Drive' or pass through 'Gates' which use wormholes or shortcuts in spacetime, to bypass the FTL problem altogether.

Again, I believe Time Travel is attempting to Dimension Travel. Humans can move along on a X, Y, or Z axis in space, because we're three(3) dimensional. The fourth dimension 'time' keeps us fixed temporally, and moving along those 3D points sequentially. To travel in time, would be the ability to disengage the fourth dimension, in order to change our point in space instantaneously, without sequences.

We didn't disengage gravity to fly. You can't disengage time, even at FTL speeds, it's just dilated.

I've argued (politely, I hope) before, that it would take all the power in the universe to bust into or out of another dimension. Traveling through time would expend and possibly extinguish our entire universe...


...and for what, winning lotto numbers?

[Andrew D]

Travel into the future of the kind which no less a scientist than Stephen Hawking contends is possible does not involve faster-than-light (FTL) travel. (And what it means to say that "only energies like light can achieve" FTL speeds is mysterious: How can light travel faster than light?)

Travel into the future involves traveling very fast, but not at any FTL speed: Traveling at one-tenth the speed of light would produce a large time-travel effect.

[loCAtek]

Faster-than-light (also superluminal or FTL) communications and travel refer to the propagation of information or matter faster than the speed of light. Under the special theory of relativity, a slower-than-light particle with nonzero rest mass needs infinite energy to accelerate to the speed of light, although special relativity does not forbid the existence of particles that travel faster than light at all times (see tachyons).

Wikipedia




Produce a large time-travel effect ...you could survive? but would achieve true time/dimensional travel?

[Andrew D]

Surviving travel at one-tenth of light speed presents technological difficulties which I am in no position to address. I can only observe that technological advances have a long history of overcoming obstacles that seemed insurmountable. Okay, so we didn't "disengage" gravity in order to fly. But we found a way to overcome the obstacles which gravity presented, and we ended up flying. Flying at one-tenth the speed of light presents obstacles, but I do not see the existence of obstacles as meaning that they cannot be overcome.

What I do not understand is the distinction you are apparently positing between "a large time-travel effect" and "true time/dimensional travel". If I place myself in the future by engineering a large time-travel effect, how is that not "true" time travel?

In other words, I do not see why time travel, in order to be "true" time travel, requires our being able "to change our point in space instantaneously, without sequences." That may be one (hypothetical) version of time travel, but why must it be the only one?

[Andrew D]

With respect to whether knowledge is causal:

I am not contending that God's knowledge of the occurrence of things causes the occurrence of those things. Whether it does or not is not part of the logic which forces the conclusion that God's omnipotence and human free will cannot coexist.

What that logic says is that if God is omniscient, then it necessarily follows, without regard to any causal relationship, that human free will is impossible. God's omniscience does not necessarily cause the impossibility of human free will; the (asserted) fact of God's omniscience is logically irreconcilable with the (claimed) existence of human free will.

An analogy in the context of ordinary human knowledge: If I walk outside, and the sky is dark except for starlight, then it follows that the part of the planet on which I am standing is facing away from the sun. The darkness and the starlight are not causing that part of the planet to face away from the sun. But it necessarily follows from the darkness and the starlight that that part of the planet is not facing the sun: Without regard to any causal relationship, the proposition that there are darkness and starlight is logically irreconcilable with the proposition that that part of the planet is facing toward the sun. Therefore, either there are not darkness and starlight or that part of the planet is not facing toward the sun.

But substitute God for me, and the first option no longer exists. If God knows that the sky is dark except for starlight, then there is no possibility that there are not darkness and starlight. So the conclusion necessarily becomes: Therefore, either there are not darkness and starlight or that part of the planet is not facing toward the sun.

That is the syllogistic proposition asserted (and proved) by the logic at issue -- not that God's omniscience prevents human free will from existing, but that God's omniscience and human free will are logically irreconcilable propositions: Without regard to any causal relationship, the proposition that God is omniscient is logically irreconcilable with the proposition that human free will exists; therefore, either God is not omniscient or human free will does not exist.

[Rick]

The rub in regards to starlight and darkness is only applicable on the side of the Earth (if that is the planet of reference) facing the sun. Pictures from outside the Earth's atmosphere clearly show darkness and starlight.

BTW the Sun is a star.

Knowledge is knowledge prescient or not.

Then your statement in logic is flawed as it deals with one small portion of knowledge (which is applicable to only one party).

If one restates it as knowledge (it is only prescient to us).

"Knowledge precludes free will" and the statement falls apart...

[loCAtek]

What I do not understand is the distinction you are apparently positing between "a large time-travel effect" and "true time/dimensional travel". If I place myself in the future by engineering a large time-travel effect, how is that not "true" time travel?

As stoat put it, we are all traveling through time; it is our very nature as material beings to 'flow' with time. The only way we stop moving through time is if we die.
As I understand it; someone going through time dilation isn't aware of it, per se. They feel as if their rate of travel is constant.

In another perspective, some have speculated that trees experience the passage of time in a similar way. They grow, mature and die at a much slower rate than other lifeforms do; living extended lives. If we could slow ourselves to match their rate of existence, just to observe it perhaps; then when we came out of it- again we'd be in the future. A tree's time is dilated, compared to ours.

Are trees time traveling?

As gravity is felt differently through the universe: whether you feel it underwater; while on land; while being forcefully propelled, or on a larger planetary body. The law of gravity hasn't changed, we are still 'traveling through gravity'; just our perspective has changed due to the environmental conditions.

In other words, I do not see why time travel, in order to be "true" time travel, requires our being able "to change our point in space instantaneously, without sequences." That may be one (hypothetical) version of time travel, but why must it be the only one?

That's just my opinion of it right now, based on the parameters available at this time. I don't recall saying it must be the only one; and I accept stoat's offer to agree to disagree. I'm not trying to 'win' an argument, just expressing my thoughts in the debate.

Another version of time says that 'the gods' are in control of it. Interestingly, the earliest recorded human account of time dilation was during a divine encounter in Hindu legend:

From the Mahabharata(Indian History of the World), 700s BCE to 300s CE;

Kakudmi, the King of Kusasthali's daughter Revati was so beautiful and so accomplished that when she reached a marriageable age, Kakudmi, thinking no one upon earth was worthy of her, went to the Creator himself, Lord Brahma, to seek his advice about a suitable husband for his daughter.

When they arrived, Brahma was listening to a musical performance by the Gandharvas, so they waited patiently until the performance was finished. Then, Kakudmi bowed humbly, made his request and presented his shortlist of candidates. Brahma laughed loudly, and explained that time runs differently on different planes of existence, and that during the short time they had waited in Brahma-loka to see him, 27 catur-yugas (a cycle of four yugas, totalling 108 yugas, or Ages of Man) had passed on earth (see time dilation theory). Brahma said to Kakudmi, "O King, all those whom you may have decided within the core of your heart to accept as your son-in-law have died in the course of time. Twenty-seven catur-yugas have already passed. Those upon whom you may have already decided are now gone, and so are their sons, grandsons and other descendants. You cannot even hear about their names.[2] You must therefore bestow this virgin gem (i.e. Revati) upon some other husband, for you are now alone, and your friends, your ministers, servants, wives, kinsmen, armies, and treasures, have long since been swept away by the hand of time."[3]

Wikipedia