Time travel

Baron von Richthofen (Vaclav) · #1 23-10-2009, 05:21 PM

Who is interested in time travel, if you are have a look at this
http://www.brianbosak.com/

Nesti (Mark) · #2 23-10-2009, 05:43 PM

Don't mean to be a wet blanket. I don’t believe in time travel, it doesn’t lend itself toward supporting a stable reality. Also, time travel would necessitate the abolition of freedom of choice, since time travel would require a purely deterministic universe. That’s why there’s an arrow of time, freedoms must be accounted for.

In my opinion, there is only one type of temporal travel for us, time dilation…I don’t support teleportation either…it’s all hype.

Cheers
Mark

Bobbyoutback · #3 24-10-2009, 10:02 PM

Iv'e had an interest in this subject for a long time , some great minds have said it's not impossible !

From memory the main difficulty regarding paradoxes is going back , I do remember a convincing argument about not being able to go further in the past then when the time machine was built .

Love to jump into tomorrow for obvious reasons

Esseth (Alan) · #4 24-10-2009, 10:28 PM

From what I understand, while it doesn’t break any of the laws of physics it bends them quite a bit and would require a huge leap forward in our understanding of the universe.

Basicly when we are sending space crafts to other systems and have things like effective anti-matter engines and have worked out the kinks in fussion power... then we might make some break throughs.

"About not being able to go further in the past then when the time machine was built" yeah I’ve heard that as well. however there are several different theories on the matter...read all about them in Physics of the Impossible.

wavelandscott (Scott) · #5 25-10-2009, 06:00 AM

While I don't know all of the details, my Wife's Uncle who is a retired professor has a patent that supposedly makes time travel at least theoretically possible (as he self describes it).

The method is described but to my knowledge has not been built...

His Father (my Wife's Grandfather) was a patent attorney and as a "retirement" project completed the project.

James F. Woodward
Departments of History and Physics
California State University Fullerton

Theoretical consequences of the gravitational origin of inertial reaction forces, that is, Mach's principle, are explored. It is argued that Mach's principle leads to the conclusion that time, as we normally treat it in our common experience and physical theory, is not a part of fundamental reality; the past and future have a real, objective existence, as is already suggested by both special and general relativity theory. A laboratory scale experiment whereby Mach's principle, and thus radical timeless ness, can be established is mentioned.

I don't claim to understand it but it makes interesting cocktail conversation...

avandonk · #6 25-10-2009, 06:55 AM

If time travel was at all possible we would be inundated with tourists from the future.

Even if you could hypothetically 'travel' in time the spatial navigation would be a bit of a problem. Even if you maintained your initial inertial frame of reference.

Where exactly was the Earth ten years ago say or even ten seconds? What is your reference frame for spatial position?

The equator moves at about 1600 km/hour due to the Earths rotation. 0.5 km/sec
The Earth goes around the Sun. 30 km/sec
The Sun orbits the Galactic centre. 250 km/sec
Our galaxy is moving relative to other nearby galaxies. 300 km/sec
Our local group of galaxies are moving relative to others. ?>300 km/sec

And so on.....

Actually we are all time travelers as we are moving into the future at 1 sec/sec.

Bert

Omaroo (Chris Malikoff) · #7 25-10-2009, 07:55 AM

Quote:

Originally Posted by avandonk

If time travel was at all possible we would be inundated with tourists from the future.

You'd think!

... unless they were cloaked...

Quote:

Originally Posted by avandonk

The equator moves at about 1600 km/hour due to the Earths rotation. 0.5 km/sec
The Earth goes around the Sun. 30 km/sec
The Sun orbits the Galactic centre. 250 km/sec
Our galaxy is moving relative to other nearby galaxies. 300 km/sec
Our local group of galaxies are moving relative to others. ?>300 km/sec

I wonder what our actual linear velocity is on any chosen vector? I'd be some "carrier" landing to get back to, spinning like we do as a planet within a spinning solar system within a spinning galaxy within......

Rod66 (Rod) · #8 25-10-2009, 11:01 AM

Its simple. Whenever a time traveller passes through to our time , they create a new existence hence our future is not necessarily his future anymore. Of course getting back to his own future is problematic and some sort of dimensional marker may need to be created. This also avoids the grandfather paradox, he can kill as many of his ancestors as he likes, he won't disappear.

But it does make you wonder where are all these guys from the future???

Rod

Astro78 · #9 25-10-2009, 12:23 PM

So we're all but certain the earth is effecting space time. hmm

We've got lasers to bend around matter now, thanks Havard Uni.

No laws of physics prevent time travel whatsoever, hmm.

hmm hmm and hmmm

shane.mcneil · #10 25-10-2009, 01:10 PM

I am in no way qualified to comment on this but personally I think that time travel is unlikely, and if it is possible, one would not be able to change past or future events. I've often wondered though if an extra dimensional life form would be able to see all of our time stretched out before them? Just as a 3D being would see a dimension that a 2D being couldn't.

Having said all that, I have read that these experiments might imply some passing of information back through time on the quantum level.

Here and here.

Robh (Rob) · #11 25-10-2009, 03:00 PM

What is time? It is just the perception of one event followed by another; the ticking of numbers on a clock.
When an event has occurred here on Earth, an infinite number of events have simultaneously occurred throughout the Universe.
One cannot wind back this series of events. In fact, time itself is not absolute and its measure changes in varying gravitational fields.
To be able to recreate a whole Universe at a perceived point in time gone past is in the realms of pure fiction.
To be able to create a future Universe, which is a projection of every indeterminate event today, is even greater fantasy.

Regards, Rob.

renormalised (Carl) · #12 25-10-2009, 05:29 PM

Yeah, but what if we perceive as being "reality" is nothing more than an illusion. Let's say that time doesn't really exist, but is a consequence of the way our consciousness interacts with this existence at a quantum level.

sjastro · #13 25-10-2009, 06:40 PM

Just to add to the general confusion, in particle physics time has a very definable characteristic.

In particle decay involving the weak force, time reversal is required for the process to proceed.

Steven

Nesti (Mark) · #14 25-10-2009, 07:26 PM

Quote:

Originally Posted by sjastro

Just to add to the general confusion, in particle physics time has a very definable characteristic.

In particle decay involving the weak force, time reversal is required for the process to proceed.

Steven

Doesn't the pion decay occur instantaneously. In that the tunneling of the alpha particle, from within the strong force's expressed radius to outside the strong force's expressed radius, takes no time at all...the alpha particle then decays within the radius of its wavelength, radiating out as the weak force (radiation)?

Cheers
Mark

Baron von Richthofen (Vaclav) · #15 25-10-2009, 07:38 PM

I suffer from precognition under certain conditions which I try to avoid like the plague and which has been witnessed by reputable people like police and teachers
I say suffer because I found that you can not change the event, the best you can do is postpone it for a few minutes, I don't want to know the future if I cant do anything about it.

FredSnerd (Claude) · #16 25-10-2009, 08:04 PM

Quote:

Originally Posted by Nesti

Doesn't the pion decay occur instantaneously. In that the tunneling of the alpha particle, from within the strong force's expressed radius to outside the strong force's expressed radius, takes no time at all...the alpha particle then decays within the radius of its wavelength, radiating out as the weak force (radiation)?

Cheers
Mark

Thats what I was just about to say.

Nesti (Mark) · #17 25-10-2009, 08:07 PM

Quote:

Originally Posted by fredsnerd

thats what i was just about to say.

snap!!!

FredSnerd (Claude) · #18 25-10-2009, 08:17 PM

When I was a kid I'd think people who'd say stuff like anything is possible were just talking bunkum. But now as we're only just beginning to discover just how complex and vast the universe is I dont know that you can rule anything out, including time travel. We just simply dont know enough at this stage.

sjastro · #19 25-10-2009, 08:48 PM

Quote:

Originally Posted by Nesti

Doesn't the pion decay occur instantaneously. In that the tunneling of the alpha particle, from within the strong force's expressed radius to outside the strong force's expressed radius, takes no time at all...the alpha particle then decays within the radius of its wavelength, radiating out as the weak force (radiation)?

Cheers
Mark

Decay of the alpha particle does not involve the weak force hence time reversal doesn't occur. Beta decay does.

In particle physics, particle interactions occur if symmetry is invariant before and after the interaction.
Experimentally it has been found that parity (P) and charge conjugation symmetries (C) are not conserved in beta decay. Neither are the 2 symmetries together (CP). By introducing a time symmetry T, the combined symmetry CPT is invariant and the interaction proceeds.

A more technical description of this can be found at:

http://en.wikipedia.org/wiki/CPT_symmetry

Regards

Steven

xelasnave · #20 25-10-2009, 10:21 PM

I think folk can get carried away with hopes and dreams ..they hope time travel is a fact and so they lean that way....

Where do we get such notions I wonder...

and why ..as some scientific "news flashes" say.."black holes may hold the key to time travell"... what a long bow to draw when black holes still remain a matter we know very little about..and yet many read such "head lines" and away they go... I think many get their science from Hollywood when it comes to black holes.

Some folk seem to think if you can go faster than light that means you can beat time... why would this be so in any reality??? even if light travelled "instant" I can not see why or how such will have any effect upon time...and I do suspect the physics can lead us to find a mathmatical extrapolation to believe in such an idea but I feel such extrapolations lead us away from any reasonable reality.

Nature says time is merely a limit on "speed" at which a series of happening can occur and in this that suggests strongly it is a one way street.

alex