Time travel paradoxes

Chris [BEANS];22534615 said:
But that isn't time travel, that's time slowing relative to you, 'IF' you can travel fast enough.
Even if that could be considered time travel, we as humans can't travel anything like fast enough to do that to a significant degree.
Click to expand...

Yet - but it's proven to be a possibility.

With respect to the reference frame of the fast-moving object, compared to an external "more inert" reference frame... it is time travel.

It's certainly not of the scale that's usually referred to as time travel, though & theoretically can only operate in one direction.
 
crinkleshoes said:
One things that's been of great interest to me lately is for things along the lines of this.

I think our human experience/perception of time has a drastic effect on how we perceive time and subsequently how that effects our interpretation of physical principles.

Just because we perceive it in a certain way (ie, a relatively linear duration that can appear to be affected by external reference frames), doesn't mean that's how the main body of the universe "perceives" it.

Our brain interprets it almost like a computer in terms of frames per second... we see many snapshots per second as that's how our brain interprets and converts the information.

It's extremely hard to get out of this method of thinking, even Einstein struggled.


One other thing about how we interpret the universe that's wrong... "Solid" matter is actually more empty than populated, significantly - on similar scales to the solar system/galaxies... we can't see/interpret this as our brains have no need to interact with our surroundings at that level.





I wish more people could look past our very simple, infantile experience of the universe.
Click to expand...


Or we live in a Holographic Universe:eek::eek:

Have i gone mad saying that again.
 
Spook187 said:
Or we live in a Holographic Universe:eek::eek:

Have i gone mad saying that again.
Click to expand...

I believe that idea has only appeared because of humans' perception of the universe (as per my post).

We perceive it as if it were a hologram (sort of) thanks to the way our brains store information.

I strongly dislike the idea.
 
Kenai said:
That's like saying two cars approaching each other on a motorway doing 70mph are doing 140mph relative to each other and so then they must be doing 140mph each. That makes absolutely no sense, you can't just say 'speed relative to each other = absolute speed of each object' :p
Click to expand...

A few things to note:

1) I was saying that a particular argument was wrong. I was not making that argument.

2) I was not saying 'speed relative to each other = absolute speed of each object'. If you read my post, you won't find that anywhere in it. Your statement "so they must be doing 140mph each" does not follow from anything I wrote. I agree that it makes absolutely no sense. That's why I didn't write it or anything like it or anything that leads to it as a conclusion.

3) There is no such thing as absolute speed. Speed is a measurement of movement over time. Movement has to be relative to something else. SO speed has to be relative to something else.

So in your example, the speed of the two cars is:

70mph relative to the surface of the motorway.
140mph relative to each other.
~1000mph relative to the centre of the Earth.
~67000mph relative to the sun.

etc.
 
Athanor said:
You’ve got to be kidding me. I’ve been further even more decided to use even go need to do look more as anyone can. Can you really be far even as decided half as much to use go wish for that? My guess is that when one really been far even as decided once to use even go want, it is then that he has really been far even as decided to use even go want to do look more like. It’s just common sense.”
Click to expand...

:D:D:D:D:D:D That is the funniest thing i've ever read:D:D:D:D Brilliant.
 
crinkleshoes said:
One other thing about how we interpret the universe that's wrong... "Solid" matter is actually more empty than populated, significantly - on similar scales to the solar system/galaxies... we can't see/interpret this as our brains have no need to interact with our surroundings at that level.
Click to expand...

Absolutely, the vast majority of an atom is empty space.

But then let's look at something equally baffling. Let's imagine some empty space - i.e. a vacuum. Counterintuitively, within the vacuum there will be virtual particles popping in and out of existence over very short timescales (known as quantum vacuum fluctuations) so the concept of "empty space" is a lot more complex than at first one might think. Vacuum fluctuations mean that a vacuum has an underlying background energy, even though it is devoid of matter. :)
 
My take

If you travel back in time and kill your mother would not your mother then not give birth to you thus stopping you going back and changing something major? in other words you wouldnt be born to do the killing? If theres a loophole there please point it out.

Im assuming same universe etc
 
Morbius said:
Absolutely, the vast majority of an atom is empty space.

But then let's look at something equally baffling. Let's imagine some empty space - i.e. a vacuum. Counterintuitively, within the vacuum there will be virtual particles popping in and out of existence over very short timescales (known as quantum vacuum fluctuations) so the concept of "empty space" is a lot more complex than at first one might think. Vacuum fluctuations mean that a vacuum has an underlying background energy, even though it is devoid of matter. :)
Click to expand...

Yeah - we can only observe what we can see (or effects on what we can see)... it sounds incredibly obvious, but I don't think many people realise that there is a lot out there that we can't even imagine, let alone perceive. It's really as simple as we haven't evolved the need to perceive those things as we're just animals who only "need" to exist on this planet (as far as evolution is concerned).

What causes zero point energy of a vacuum could just be energy that exists in a different state or is part of a different dimension... string theory has tried, in part, to expand upon this... but unfortunately I think that's complete and utter clap trap too :(

I'm not keen on the big bang theory, either... lol

Alternately... a "true" vacuum on a large scale could simply be noticably more powerful than we realise. A few times I've speculated that the acceleration of the universe's expansion could simply be the "pull" on matter of a more powerful vacuum that resides outside the confines of the existing matter.

I'm no better... can't think of something that can explain things better... only try and de-bunk current theories :( Wish I was more creative... lol
 
al4x said:
My take

If you travel back in time and kill your mother would not your mother then not give birth to you thus stopping you going back and changing something major? in other words you wouldnt be born to do the killing? If theres a loophole there please point it out.

Im assuming same universe etc
Click to expand...

That would stop it from being a paradox. You've missed something there :p

Mother gives birth -> you live -> travel back in time to kill mother -> you never existed in the first place -> you never killed your own mother -> mother gives birth -> etc etc repeat over and over


I would explain it away with multiple timelines / parallel universes
 
Morbius said:
Why? It's backed up by lots of experimental evidence.
Click to expand...

Not really - our current understanding of physics can't find a start (granted, it gets to what we perceive as something like 10^-17 seconds after the event - which in our understanding is effectively zero).

It's the first few fractions of the first "second" I don't like... then how it was bodged with "inflation" to magically become much bigger. The only way I can explain that is by twisting or creating time in the process.

However, this could be skewed by our perception of time or the way time was potentially created from it.

Did dimensions even exist "before", or were they spurred by the creation? Was there even a before? Now I'm getting stuck in human perception of time...

Various documentaries try using a balloon as an example - that's not at all what the physics actually describe - just a visual representation most can understand.

I feel it's one of the things that's been skewed by our very limited experience/perception.

The whole current systems are too much of a stretch & it feels as if they've been "bodged" together... MADE to fit... to me, it feels like cutting the pieces of a jigsaw in to a new shape to try and make it look ok. The pieces might appear to fit together, but the overall picture is completely wrong.

That's the best way I can think to explain it... I can't think of much of a valid alternative... although to agree with inflation - I prefer the idea of it being more like a bubble, yet that doesn't explain other behaviours well enough :(

Another issue I have is with one of two things... either maths itself or the specific term infinity. With maths, you cannot have contradictory terms... infinity is just that. Infinity is used to express that there is no limit and yet it's also there to impose a limit (such as 1/inf = 0... which should actually be written 1/inf = e^-inf). Using it as a term breaks maths, yet technically it's supposed to be a term.

This term/limit/non-limit... is used in a lot of proofs - which makes me question them.

Hope that gives you a little insight in to my madness/musings :) I'm also not very good at communicating my ideas... so I'd make a terrible frikkin research scientist if I'd pursued that path... lol



Oh... and I'll happily be proved wrong / whatever... it's still interesting to think about :D
 
Last edited:
The whole thing fascinates me, need to read through the whole thread once I have space to think! I love the whole idea of time travel but also have read some of the theories too, I tend to read the New Scientist quite a lot and read up online as it's very interesting to me.
 
crinkleshoes said:
Not really - our current understanding of physics can't find a start (granted, it gets to what we perceive as something like 10^-17 seconds after the event - which in our understanding is effectively zero).
Click to expand...

That's because initially the universe was dense and hot. It was energetic enough to strip electrons from atoms and so the universe consisted of a plasma. Now, plasmas are electrically conductive and appear opaque to radiation. When the universe cooled sufficiently, atoms could regain their electrons and the universe was transparent to radiation for the first time. The last scattering surface is the set of points in the universe where photons emitted at this time would just be reaching us now. We can see no further back than the last scattering surface.

The spectrum of observable cosmic microwave background radiation fits the spectrum of an idealised black body almost perfectly. Then there's the observable expansion of space. Not only can we observe the expansion but recently it was determined that the expansion is actually accelerating with time.

I'm not a particle physicist so I don't understand how the extrapolation up to the Planck epoch works, but I tend to trust particle physics. From what physics I do know, the evidence is supportive of the big bang theory.

Finally, if you've got an hour to spare, here is a cracking lecture from Professor Lawrence Krauss called "A Universe From Nothing". He knows the physics much better than I do and it's a great insight into the world of big bang cosmology.

 
The notion of time travel is fascinating to me, but also confusing.

The only way I can logically think about it is as previously stated in this thread, which is a machine basically making a rift with a machine by which you can travel through, but only to when the rift was originally opened, a wormhole type thing in time.

But my logical thinking fails at some of this, If we had a time machine open right now which for arguments sake was opened in 2000, and someone stepped into it, firstly how would you dictate which direction you go? Would you go back to 2000, where the rift was originally opened? or would you go into the future where the rift is potentially opened in the future?

If you were able to go into the future, where would you be? There would never be any "Present" time inside the rift, as there's an infinite possibility of times. How would you ever exit, there would be no end to the rift if it stays open for an infinite amount of time, the only time it would ever close would be if power was cut to it, how would you ever be able to escape? I don't imagine it to be an instant "Walk into rift, and pop out the other side instantly", I imagine it to be a travel. Maybe that's just my way of thinking.
 
You must log in or register to reply here.
Back
Top Bottom