Thus, what should we do? Assume that a particle is endowed with prophecy about people's decision? Or, simply say that we don't yet understand properly how entanglements work, and as Danu formulated it better, to seek another explanation ? That, because superluminal signals that appear in one frame as sent from B to A, appear in another frame as sent from A to B.īut, no matter from whom to whom they are sent, the price to be paid if one accept this protocol is that at Alice's site and time-of-measurement, it's known which type of measurement Bob will choose, even before Bob will at all make a decision about which type of measurement to choose. But, at the same time it sends to B all the signals with which type of experiment is done on B, and with which result. Now, let's ask Charlie what he can say about the above protocol: Particle A indeed sends to particle B, all the signals with info about the type of measurement done and the result.
Superluminal game explanation trial#
Therefore, by Charlie's clock, Alice measures in each trial before Bob, while by Dan's clock, Bob measures in each trial before Alice. To an observer on Earth, their velocity is equal in absolute value. Charlie travels in a rocket in the direction of Alice, and Dan in a rocket in the direction of Bob. I'll focus on two travellers, Charlie and Dan. To provide the details, consider the following. The whole superluminal signalling program seems to be not enough to explain entanglement. By standard relativity arguments, if these events are spacelike separated different observers can disagree about which happened first, so there isn't a consistent story about which one happened first, and which sent information to the other. I will just say that on the Earth the two experimenters appear to be done, at each trial, simultaneously. I don't get into details of which emitter/receiver A and B possess, and how many bits it takes to describe a type of experiment. Particle B transmits to particle A, by superluminal signals, the following information: The experimenter Bob measures his particle, B. Particle A transmits to particle B, by superluminal signals, the following information: A flies to a lab where the experimenter Alice works, while B flies to the lab of experimenter Bob. In order to get the right results, it looks like the alleged faster than light protocol would go like: Some people propose (and I argue against) that particles can transmit their results Faster than Light (FTL) to the other particle. But if you need the results of the other lab to generate consistent results here, how can the data from about $Y$ and $b$ be available to Alice's Lab? Otherwise it is hard to agree with the correlations required. Similarly, if particle A were measured first, then the result $b = b(X, Y, a)$. You might postulate that if particle B were measured first, the result $a$ produced by particle A needs to be a function $a = a(X, Y, b)$, where $X$ is the type of measurement done on A, $Y$ the type done on B, and $b$ the result produced by B at the measurement $Y$. So let's consider the situation where there are two labs (Alice's Lab to measure particle A, Bob's lab to measure particle B), and they are selecting (potentially) different things to measure. In particular, some people try to be explicit about a signalling between particles, but that does not seem consistent with relativity.įor example, if you have two particles, entangled and spatially separated, then the results of experiments can be predicted easily by a local hidden variable theory if the experimenters are forced to pick known (and equal) choices about what to measure (out of complementary variables, such as the x component of spin and the y component of spin). Is this really a satisfactory explanation, or should be look for something better? Some physicists currently understand entanglement as transferring information instantaneously, yet not violating causality.