Wormholes and time travel

[j d worthington]

I'm afraid I'd go even further; I think, from my understanding of the actual theory surrounding the concept, based on genuine astrophysics as well as as particle physics, etc., the energy required, were such a thing possible, would quite literally be more than our sun would produce in its entire lifetime, and that for only a very modest trip of a few moments. As reality, unless we invent an entirely new physics from the ground up (not piddling changes such as Einstein or Planck have introduced -- and they are piddling, compared to what I'm talking about), it simply is not realistically possible.

As speculation for fiction, however, I'm all for it (I love time travel stories, and I love paradoxes, as long as they're intelligently done). However, a flagrant violation of physics as we understand it tends to leech life out of most stories, and should be avoided if at all possible. Otherwise one ends up with a simple wish-fulfillment fantasy, not a mature piece of fiction that stands up under rereading, or any serious thought.

 

[Specfiction]

I agree. I was trying to be optimistic about the reality of the venture.

 

[steve12553]

One thing to consider. Within the span of our recorded history, most people believed the Sun circled the Earth. Our concept of the Sciences have changed by leaps and bounds since then. I am willing to grant our ability to misunderstand the universe to that degree and through changes in view and discoveries of better measuring equipment, that some day we may have such a different view of things as to make the concept of time travel possible. Other eras of humankind presumed they had a pretty good grasp on the universe. As I grow older and continue to learn, what I learn is how much I have left to learn. I suspect humanity as a whole should at least try to look at things the same way. I don't think we've reached "godhood" just yet.

 

[Briareus Delta]

Quantum Physics Rule 1 (or could be Rule 363 for all I know about the subject) - Anything is possible

 

[Specfiction]

One thing to consider. Within the span of our recorded history, most people believed the Sun circled the Earth.

At this time, science, as we know it, did not exist. Belief is not science. Science requires proof and critical peer review, and reproducibility. That's why it took so long just to get to this very modest state of development.

Quantum Physics Rule 1 (or could be Rule 363 for all I know about the subject) - Anything is possible…

According to QM there are a set of conservation laws that dictate what is possible. For example, processes that don't conserve energy and momentum are NOT possible. There are many other conservation laws as well as causality, which is respected by QM. Time Travel, on a macroscopic scale, violates causality.

The correct statement is: "Any state that does not violate physical laws is possible."

 

[SteveR]

Cool thread.

For me it's actually a non-argument. Time is....well exactly, what is it? It's a mental perception of something that does not actually exist. So if it does not exist, how can you travel through/in it?

I find it interesting that humans have a need the concept of time. Things are. We are. There is no past, no present just now. At the risk of sounding like I'm quoting from Babylon 5, the moments are all that we have.

Just like numbers - concepts our brains have developed to help us to 'understand'. But they are not real, just like time isn't real.

Ok, said my piece.

Oh, and nobody is alllowed to ask "But, what is real anyway?"

Steve

 

[Kbanfield]

Hey...here are my 2 cents...

Though we understand time as a mental perception does not mean we cannot travel through it. I think we have a long way to go to really developing an understanding of how time actually works which I think should leave the possibility of time travel still on the table.

We can reach a better understanding through our desire to do something. I was watchin this preview of a new movie called The Fountain and it was essentially about a guy going through time to find a cure to save his lady...I think its stuff like this that will push us to come up with the necessary methods to time travel.

What do u think?

The funny thing is...in 100 years...someone will travel back to read this conversation...

 

[j d worthington]

It's an interesting concept, yes; and as I said, I very much enjoy time travel stories. But the problem here is that, as opposed to the differences in viewpoint referred to earlier, when science as such was extremely primitive and understanding of the laws of nature was not only sparse but uncoordinated and often impossible to test, time travel completely violates several aspects of physics that, by all evidence, are constants; they are the very basis of how the universe works. So while I won't completely rule out the possibility of an entirely new science -- and, as I said before, this means an entirely new science, with everything we've learned so far scrapped and starting from zero -- the probability is indeed nil; and that is what science is: probabilities based on empirical, testable evidence. True, in order to be science it must be "falsifiable"; but there is absolutely no evidence indicating that such a thing as time travel is possible under any circumstances, while there is an abundance that it would, in fact, violate the conservation aspects of physics. It amounts to getting something from nothing... it can't be done. (And, lest someone bring up the Big Bang: no. That was not something from nothing. The original matter/energy of the Big Bang always was; it had no beginning, and it has no ending, it simply will be dispersed so widely that it will no longer be available for work, but will be a low-level radiant "heat" permeating the universe ... unless one accepts the "big crunch" as well -- mildly tenable, perhaps, but becoming less so with each new finding we make.)

 

[SteveR]

Kbanfield, well I would argue human perception of time is actually what we call memory and imagination. And for sure memory and imagination do exist explainable by science in terms of biology,brain activity, neurons and all that.

But again memories and imagination are not real things in that you could potentially touch them - but I accept this argument then heads for the how many dimensions are there really (perceptions once again) and if there are more then we can only see in our perceived dimensions anyway.

With regard to whether "Time" is a useful concept to advance knowledge then I think I would have to agree and say yes. It's a theory, and like all theory's they are a step (one way ot the other) to the truth, the reality. The motivation to develop our understanding is as you say very focused on our human values - long may it continue.

The funny thing is...in 100 years...someone will travel back to read this conversation...

I hope so, so if anybody is reading this in the year 2106 or later then please post the truth and put us all out of our misery!

Steve

 

[SteveR]

Hi J.D.

I hear what you saying about the laws of physics. I would argue however that the fact that 'time travel' can't be explained by physics is not the reason that it is not possible. As my argument goes I would say that physics simply describes what is real and not what is imaginary.

Hope that doesn't sound too pedantic!

Steve

 

[Specfiction]

I think there are some misunderstandings here.

1)Time, at least in at some level, is well understood in physics, especially thermodynamics and statistical mechanics.

2)Causality is NOT a physical conservation law like energy and momentum. It is put into all physical theory "by hand," because (like an axiom) it "seems" right to us. However, CPT “is” a conservation law (Charge Conjugation Parity, Parity, Time).

3)On the quantum level, time reversal is Ok! In fact, quantum states "require" that you have negative time or energy states for a complete description of a state.

4)There are some very hard to understand time/space reasons for believing that time travel "could" be possible given “extensions” of our current physics. These include models of accelerating frames in Minkowski space--this is very "speculative" and should be taken with a grain of salt.

The bottom line: the chances that macroscopic time travel is possible is almost zero--but not quite zero. That's why guys like Penrose, Hawking, Thorn, Gödel (maybe Vissor) and others keep coming back to it. It is a fascinating piece of fringe physics that cannot be totally discounted.

 

[Dave]

Okay if we have the technology to build time machines maybe we would also have the technology to build invisability cloaks

The US Army already has prototype invisability cloaks. There was an article in National Geographic magazine two years ago. Given a long enough timeframe who knows what can be invented.

When I said I didn't think we could have backwards time travel, as I said then that I was making a logical, philosophical argument against it. From a purely practical point of view, I'm sure science could find a way given enough time.

There is, however, a huge difference between making an atomic particle get younger, and a complete man. The same thing applies to matter transportation. There is also the problem of the energy that may be involved, already mentioned here.

I do love time travel stories though, especially the inconsistencies and paradoxes, so even if it is never possible, I will still want it to be.

 

[j d worthington]

I do love time travel stories though, especially the inconsistencies and paradoxes, so even if it is never possible, I will still want it to be.

Agreed.

 

[steve12553]

As an engineer deal with control system technology, I have many occasions to measure quantities and variables. As things get more accurate we use more significant digits. We measure more closely. But you know what? We never measure anything exactly. Everything in the world is rounded and less than perfectly accurate. Nothing is exact. Nothing will ever be exact. We will always get better and we will always come up with new and better ways until such time as somebody does something really stupid and nukes us back to the Stone Age. In the mean time, we probably will discover new laws, or new takes on existing laws, or new corollaries of existing laws of Science. It may take a thousand years. We might get a thousand years. We might travel in time. Only time will tell.*




*I couldn't help it.

 

[j d worthington]

Only time will tell.*




*I couldn't help it.

No, you could ... you just chose not to.

 

[Harpo]

"Time-travel will never be invented because we can't see any time-travellers" goes the argument against.

But what if, instead of a time-machine being a machine which travels through time, it is a machine in which people can travel through time (within the operational lifespan of the machine).

This way, time-travellers will be able to travel into the past as far back as the day the first working time machine gets switched on.

Suppose that day is December 21st 2012 - when the Mayan Calendar says our concept of time will change.

I'm looking forward to it.

Is it too late for me to patent the idea?
Time Travel Machine Outlined - Yahoo! News

"Ori emphasized one significant limitation of this time machine—"it can't be used to travel to a time before the time machine was constructed." "

Does my post from last september count as copyright for the idea?

 

[Interference]

Does my post from last september count as copyright for the idea?

Sadly, and I weep for you, but no, unless you've invented a time machine and can go back even further in time to be the first one to think of the idea.

I'm afraid your idea has been pre-dated and was the basis for the fictional fundament of Quantum Leap - it wasn't the basis for QL, just for its underlying limitation theme.

I think you'll find a semi-whimsical reference to the limitation of time travel to the life-span of the time machine in A Brief History.... and if I had a more encyclopaedic memory I'd tell you where else I've read the proposition, I'm sure I've read or read about or seen on telly the same or a similar notion. It's certainly one I've been aware of for a number of years as I have tried to circumvent it in notes I made in 1995/6, and I know I didn't come up with it myself.

Of course, fiction-wise, it's an annoyingly limiting concept. If you've read any Jenny Randles, you might come round to the idea that time travel isn't such a big deal, anyway, and with the right conditions, anyone might do it. Now, that's an idea I'd love to find out was real.

 

[Urien]

You need to end this conversation now. In three days it leads to a schism in the etheric consciousness of the disaggregated and naive human sub-culture. Two days after that demented warpuls breach the D wall and infect all six toed people, violence ensues.

Only by hopping in my time kettle and steaming back to today can I save you all.

 

[Interference]

Have you done it yet?

Have you done it yet?

Have you done it yet?

Have you done it yet?

Have you done it yet?

 

[ghost8772]

ok, on the original idea of time trasvel, possible or not. and all that jazz. there are too many possible things that have been shown could happen. one COULD make changes, butterfly effect stuff, that alters the future from that point, creating what could only be called an alternate timeline from where the traveller started. another view is that history is set, and that any changes that were made in the past HAD to be made, and if they weren't then the fabric of the universe would self-destruct, fire, brimstone, and all sorts of bad things would be incurred at that point. another possibility would be that the person travelling back in time could not interact with the past, but would be only an observer, with nobody being able to perceive his/her existence at that time..... hmmmm... maybe the reason for ghosts?