Could every electron and/or photon be quantum entangled by having a common origin in the Big Bang? How could we prove or disprove this?
Short answer: no. We can create entanglement in the lab between particles that have no common origin in a process called entanglement swapping, which is similar in principle to quantum teleportation.
Thanks..Good link too. But..even if not all entanglement entails common origin, might all common origin entail entanglement?
Please think about it. Entanglement no longer exists as soom as one particle interacts with some quantim entity. When you make measurements of one member of an entangled pair, you gain information about the other memeber of the pair. However, the two particles are no longer entangled.
To measure something you have to bounce a photon or an electron off it. This interferes with it, and as such destroys the entanglement. (if i'm not mistaken) In very basic terms.
No, not necessarily. Actually, the view among people who work with quantum mechanics is that measurement creates entanglement. The idea (the von Neumann measurement scheme) is that if you want to read the state of a particle, you arrange an apparatus in such a way that the particle's state becomes entangled with a "pointer" variable in the apparatus. For example, if you want to measure the spin of a spin-1/2 particle, sending it through a Stern-Gerlach magnet would cause its spin state to become entangled with its position. Then looking at whether the particle went up or down tells you its spin along the vertical axis. It's the quantum analogue of a bit. A classical bit is a variable that can take on one of two possible values. A qubit is a quantum state in a two-level quantum system, eg. a spin-1/2 state, a photon polarisation state, some superposition of two atomic states, etc. The major difference between a bit and a qubit is that, while a classical bit takes only one of two discrete values, a qubit can be any (complex) superposition of two base states. You can identify a bit with one of the values 0 and 1. With qubits there are many more possibilities, and one representation is to identify a qubit with a point on the sphere.
