The question of whether it is possible to send information back through time using quantum entanglement is a topic of scientific speculation and ongoing debate. However, according to our current understanding of physics, it is generally believed that quantum entanglement does not allow for the transmission of information faster than the speed of light or enable time travel.
Quantum entanglement is a phenomenon where two or more particles become correlated in such a way that the state of one particle is dependent on the state of the other, regardless of the distance between them. However, entanglement alone does not provide a means to transmit information instantaneously or violate the principles of causality.
When measurements are made on entangled particles, the outcomes of those measurements can appear to be correlated, even when the particles are separated by large distances. However, these correlations cannot be used to transmit information faster than the speed of light. The measurements on one entangled particle cannot be used to communicate information to the other particle instantaneously because the specific measurement outcomes are not predetermined and cannot be controlled.
The no-communication theorem, derived from principles of quantum mechanics, establishes that it is not possible to use entanglement to send messages faster than the speed of light or violate causality. This theorem ensures that the principles of special relativity, which prohibit information from being transmitted faster than the speed of light, are not violated by quantum entanglement.
It's important to note that the possibility of time travel or faster-than-light communication remains a topic of scientific investigation, and our understanding may evolve as new discoveries and theories emerge. However, based on our current knowledge, it is widely accepted that quantum entanglement does not provide a mechanism for sending information back through time.