According to the article general relativity allows time travel. But it doesn't says that time travel is ok with quantum dynamics.
I'm not a physicist, but I think time travel of things larger than a sub-atomic particle is not possible.
The laws of quantum mechanics provide information of the state that a system will have in the future given the state of the system in the present. But they also can be used to calculate the state of the system in the past. So, if I'm alive now, the laws of quantum mechanics say that my parents were alive when I was conceived. So the laws wouldn't permit that I traveled to the past and killed one of them.
In fact, they wouldn't permit that I change nothing of the past, because breathing there wold cause a perturbation that wouldn't be allowed by quantum mechanics.
What changes in ocean levels? Did this just happen yesterday or something?
The sea level has risen 15 to 20 cm in the last 100 years. And by the acceleration in the global warming I supouse it will start rising faster. If this continues there will be a lot of costal cities sunk under the sea by the end of this century.
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According to the article general relativity allows time travel. But it doesn't says that time travel is ok with quantum dynamics.
I'm not a physicist, but I think time travel of things larger than a sub-atomic particle is not possible.
The laws of quantum mechanics provide information of the state that a system will have in the future given the state of the system in the present. But they also can be used to calculate the state of the system in the past. So, if I'm alive now, the laws of quantum mechanics say that my parents were alive when I was conceived. So the laws wouldn't permit that I traveled to the past and killed one of them.
In fact, they wouldn't permit that I change nothing of the past, because breathing there wold cause a perturbation that wouldn't be allowed by quantum mechanics.
The sea level has risen 15 to 20 cm in the last 100 years. And by the acceleration in the global warming I supouse it will start rising faster. If this continues there will be a lot of costal cities sunk under the sea by the end of this century.