axj
The Living Force
While this is probably not the most pressing issue, I have been wondering how time travelers avoid paradoxes from happening.
Or in a broader context, when something in the past is changed, does that mean the time traveler automatically switches to a different 'timeline' (if there is such a thing) or is there only one 'timeline'?
There has been some time travel research on the molecular level recently:
http://www.sott.net/article/280827-Molecular-time-travel-experiments-show-evolution-depends-on-non-adaptive-chance-mutations
So it seems that among physicists it is already widely accepted that time travel is possible through "closed timelike curves". They think that paradoxes can be avoided on the quantum level because of the "fuzziness" and "uncertainty" on that level:
So I'm wondering if this "uncertainty" (having several unmanifested probabilities) is how paradoxes are avoided on the larger non-quantum level as well - when a person travels through time, for example. Logically, it should not be possible since on the non-quantum level things are already "certain" and one particular probability is manifested.
Or in a broader context, when something in the past is changed, does that mean the time traveler automatically switches to a different 'timeline' (if there is such a thing) or is there only one 'timeline'?
There has been some time travel research on the molecular level recently:
http://www.sott.net/article/280827-Molecular-time-travel-experiments-show-evolution-depends-on-non-adaptive-chance-mutations
In the study, the researchers simulated the behaviour of a single photon that travels through a wormhole and interacts with its older self. This is known as a closed timelike curve - a closed path in space-time that returns to the same starting point in space but at an earlier time. Their study is published in Nature Communications.
In the first case, photon one "travels trough a wormhole into the past, then interacts with its older version,” Ringbauer explained. And in the second case, photon two travels through normal space-time, but interacts with another photon that is trapped inside a closed timelike curve forever.
_http://sciencealert.com.au/news/20142306-25717-2.html
So it seems that among physicists it is already widely accepted that time travel is possible through "closed timelike curves". They think that paradoxes can be avoided on the quantum level because of the "fuzziness" and "uncertainty" on that level:
According to Einstein’s theory, it could be possible to travel back in time by following a closed timelike curve. However physicists and philosophers have struggled with this theory given the paradoxes such as the grandparents paradox, where a time traveller could prevent their grandparents from meeting, thus preventing the time traveller’s birth in the first place.
But in 1991 it was suggested that time travel in the quantum world would avoid these kinds of paradoxes because the properties of quantum particles are “fuzzy” and “uncertain” - and this is the one of the first times anyone has simulated the behaviour of such a scenario.
So I'm wondering if this "uncertainty" (having several unmanifested probabilities) is how paradoxes are avoided on the larger non-quantum level as well - when a person travels through time, for example. Logically, it should not be possible since on the non-quantum level things are already "certain" and one particular probability is manifested.