Philosophy Now Forum

With time travel, you go back to kill your mother which prevents your birth so you can't go back to kill your mother in our universe, but in a multiverse with different laws (including different logic), you can do this (how? is another question).

I can't say whether a multiverse exists, but I can't deny it either. Nowadays the physics community seem more open-minded to a multiverse so if a multiverse does exist, how much more likely does a paradox exist?

PhilX

Time travel into the past would violate the laws of physics specifically the law of cause and effect. Only time travel into the
future is theoretically possible. But although entirely beyond your control you are actually travelling forward in time anyway

surreptitious57 wrote:Time travel into the past would violate the laws of physics specifically the law of cause and effect.

It is not entirely clear just what the law of cause and effect is. Quantum theory has already shown that some of our traditional ways of understanding causation are probably wrong.

The grandfather paradox is a concern, but if time travel involves universe jumping, then the paradox need not arise.

David Lewis, as I recall, contended that all the "paradox" shows is that no successful back in time traveler shoots her grandfather when in the past. (If, e.g. the shot hadn't missed, she would never have been born to have a chance to time travel.) The past of none of us contains any events inconsistent with our being here now -- whether or not there were time travelers in that past,

Philosophy Explorer wrote:With time travel, you go back to kill your mother which prevents your birth so you can't go back to kill your mother in our universe, but in a multiverse with different laws (including different logic), you can do this (how? is another question).

I can't say whether a multiverse exists, but I can't deny it either. Nowadays the physics community seem more open-minded to a multiverse so if a multiverse does exist, how much more likely does a paradox exist?

PhilX

If there is a separate universe, perhaps it is just moving 20 years behind ours. Then if we break through (somehow) we might conclude we are in the past. The illusion of time travel. Then if you come back, you won't be able to find any evidence that you changed anything. Your history back home remains just as it always was. I hate most time travel in films & TV. It always amounts to some sort of magic, wearing the clothes of science. "Looper" was the worst - my tattoos are changing, and as I watch them I am surprised. But wouldn't my whole history be changing at the same moment, so that everything that is changing on my skin is in accord with my expectations and memories? Then only the audience will be wowed - none of the characters.

Here's something else to think about. In a multiverse setting, there's theory about colliding universes. If so, what lies in between?

PhilX

Philosophy Explorer wrote:With time travel, you go back to kill your mother which prevents your birth so you can't go back to kill your mother in our universe, but in a multiverse with different laws (including different logic), you can do this (how? is another question).

I can't say whether a multiverse exists, but I can't deny it either. Nowadays the physics community seem more open-minded to a multiverse so if a multiverse does exist, how much more likely does a paradox exist?

PhilX

There is NO such thing as time travel to the past.
Time is simply the occurrence of events and man has made a pretty good attempt by observing events to sync a thing that we now call 'TIME'.

If there is not an electron spinning, a photon emitting, then where is time - there is NO time. Time IS the occurrence of an event.

By traveling close to the speed of light you could in essence travel to the future and remain at an age where all others have long since met their death thanks to the ageing process, simply because your local time was far slower than theirs on account of your movement near to the speed of light.

attofishpi wrote:

Philosophy Explorer wrote:With time travel, you go back to kill your mother which prevents your birth so you can't go back to kill your mother in our universe, but in a multiverse with different laws (including different logic), you can do this (how? is another question).

I can't say whether a multiverse exists, but I can't deny it either. Nowadays the physics community seem more open-minded to a multiverse so if a multiverse does exist, how much more likely does a paradox exist?

PhilX

There is NO such thing as time travel to the past.
Time is simply the occurrence of events and man has made a pretty good attempt by observing events to sync a thing that we now call 'TIME'.

If there is not an electron spinning, a photon emitting, then where is time - there is NO time. Time IS the occurrence of an event.

By traveling close to the speed of light you could in essence travel to the future and remain at an age where all others have long since met their death thanks to the ageing process, simply because your local time was far slower than theirs on account of your movement near to the speed of light.

In regards to your first paragraph, it's possible to have a different universe where time travel to the past can occur.
Can you prove that this universe can't exist?

To clarify your third paragraph, you actually mean the faster you travel, the further into the future you would go (alive).

PhilX

Time travel:
Stop thinking in reality based in bad films. Start thinking for yourself in what time is.
Or if you prefer this, sure, it is possible. You can "travel" in time, at the "velocity" of 1s/1s.

Multiverse:
Keep seeing rick and morty. Forget that thing about thinking yourself, I'm bored.
If you can travel between two Universes, there would be the same Universe. Multiverse is something people "think" to escape reality. You can try to imagine a Universe were 2+2=5. But, well, is there the sentence "mental fap" in English? If it doesn't exist, I make a Universe were it exist. That's a mental fap.

TSBU wrote:Time travel:
Stop thinking in reality based in bad films. Start thinking for yourself in what time is.
Or if you prefer this, sure, it is possible. You can "travel" in time, at the "velocity" of 1s/1s.

Multiverse:
Keep seeing rick and morty. Forget that thing about thinking yourself, I'm bored.
If you can travel between two Universes, there would be the same Universe. Multiverse is something people "think" to escape reality. You can try to imagine a Universe were 2+2=5. But, well, is there the sentence "mental fap" in English? If it doesn't exist, I make a Universe were it exist. That's a mental fap.

These days, "multiverse" is not always an escape - but head-scratching attempt to understand quantum randomness. 2+2=4 in all of those universes.

OuterLimits wrote:

TSBU wrote:Time travel:
Stop thinking in reality based in bad films. Start thinking for yourself in what time is.
Or if you prefer this, sure, it is possible. You can "travel" in time, at the "velocity" of 1s/1s.

Multiverse:
Keep seeing rick and morty. Forget that thing about thinking yourself, I'm bored.
If you can travel between two Universes, there would be the same Universe. Multiverse is something people "think" to escape reality. You can try to imagine a Universe were 2+2=5. But, well, is there the sentence "mental fap" in English? If it doesn't exist, I make a Universe were it exist. That's a mental fap.

These days, "multiverse" is not always an escape - but head-scratching attempt to understand quantum randomness. 2+2=4 in all of those universes.

quantum randomness is in my eyes an escape.
Add that to the list: time travel, multiverse and quantum randomness.

TSBU wrote: quantum randomness is in my eyes an escape.

Whatchoo smokin? Quantum randomness was a very unwelcome discovery of the early 20th century. Scientists would have gladly escaped into opium trances to get away from it.

OuterLimits wrote:

TSBU wrote: quantum randomness is in my eyes an escape.

Whatchoo smokin? Quantum randomness was a very unwelcome discovery of the early 20th century. Scientists would have gladly escaped into opium trances to get away from it.

"discovery". Like the earth, it was discovered and evident that it was not a "sphere", we would evidently fall.
Well, as a start, I don't know a lot about phisics. You don't know either, all we know is about a copuple of books and articles in internet. But I know a couple of things about logic... and you are using and falling in an authority argument, even if they are right.
Wait! me!, who do I think I am, what am I smoking to think that I can say that all that scientists are wrong!

I can be wrong. Or they. Or both. But we can't be right in both sides.

Well, sorry, yes we can (Obama sentence ), smoke quantum weed every day

TSBU wrote:

OuterLimits wrote:

TSBU wrote: quantum randomness is in my eyes an escape.

Whatchoo smokin? Quantum randomness was a very unwelcome discovery of the early 20th century. Scientists would have gladly escaped into opium trances to get away from it.

"discovery". Like the earth, it was discovered and evident that it was not a "sphere", we would evidently fall.
Well, as a start, I don't know a lot about phisics. You don't know either, all we know is about a copuple of books and articles in internet. But I know a couple of things about logic... and you are using and falling in an authority argument, even if they are right.
Wait! me!, who do I think I am, what am I smoking to think that I can say that all that scientists are wrong!

I can be wrong. Or they. Or both. But we can't be right in both sides.

Well, sorry, yes we can (Obama sentence ), smoke quantum weed every day

You are either harshing my buzz or freaking me out. Possibly a little bit of both .

Philosophy Explorer wrote:With time travel, you go back to kill your mother which prevents your birth so you can't go back to kill your mother in our universe, but in a multiverse with different laws (including different logic), you can do this (how? is another question).

I can't say whether a multiverse exists, but I can't deny it either. Nowadays the physics community seem more open-minded to a multiverse so if a multiverse does exist, how much more likely does a paradox exist?

PhilX

All evidence so far, both physical and mathematical, apparently points to the impossibility of time travel to the past, although some experiments suggest that there may be some retrocausality at subatomic scales. However, most dynamics vary at the quantum realm.

As for multiverses, maybe it's possible. I have wondered whether the universe as we understand it is just a supercluster of galactic superclusters, and just one of many. Each would be as relatively far away from each other as galaxies are from each other, much to far to ever hope to see, unless universes collide.

For the benefit of those who are unfamiliar with retrocausality, we have this Wikipedia article:

https://en.m.wikipedia.org/wiki/Retrocausality

PhilX