Entanglement and communication speed

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SUMMARY

The discussion centers on the phenomenon of entangled photons and their instantaneous reactions over distances, specifically referencing a recent article about experiments conducted with photons 10 miles apart. It is established that while entangled particles exhibit instantaneous changes, this does not equate to faster-than-light (FTL) information transfer due to the necessity of a classical communication channel. The concept of "spooky action at a distance," famously questioned by Einstein, is highlighted, emphasizing that without access to both entangled particles, one cannot extract meaningful information. The conclusion is that entanglement does not allow for FTL communication.

PREREQUISITES
  • Understanding of quantum entanglement
  • Familiarity with classical communication channels
  • Knowledge of photon polarization
  • Basic principles of quantum mechanics
NEXT STEPS
  • Research "quantum entanglement experiments" for practical applications
  • Study "quantum communication protocols" to understand limitations
  • Explore "Einstein's spooky action at a distance" for historical context
  • Investigate "quantum teleportation" for advanced concepts in quantum mechanics
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Physicists, quantum mechanics enthusiasts, and anyone interested in the implications of quantum entanglement on communication and information transfer.

mcjosep
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I was just reading the new article that saying that people sent information through entangled photons, and that the photons were 10 miles apart. when entangled photons change they do so instantaneous of each other. so does this mean that even though they were ten miles apart they reacted to each other at the same time. how does this work, while still retaining that nothing can travel faster than the speed of light.
 
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There can be no information transfer without a classical channel to communicate with. Therefore, no FTL information transfer is possible even with entanglement. Yes, the entangled particles may react "instantaneously" to the other being observed, but someone with only 1 of the entangled particles will never be able to see more than just random bits from it. You need to have information on both the particles to verify that they were in fact anti-correlated.
 
The states change instantaneous. Even Einstein wondered about this instaneous change and he called it "spooky action at a distance".

But you can't use it to send information faster than the speed of light. That is because you cannot for example "force" the photon to have vertical polarization

More on "spooky action at a distance" can be found here:
1) http://whyfiles.org/shorties/133quantum_leap/
2) Wikipedia: Action at a distance
3) Spooky action and beyond: Interview with Anton Zeilinger
4) Spooky action at a distance? Blog post by Steve Luttrell
 

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