this was bring up because this is another example of particle is generated. Photon is released in the name of energy , but photon is more than just energy , it is a particle while is moving at speed of light, the space along its pass will experience a alternating electro/ magnetic field. two...
here we have another problem , an electron transition to a lower energy level, will release energy and the energy is in the form a photon. usually here not to talking about in this process, the photon has spin equal to 1, and the electron has to flip its spin after the transition to full fill...
The predicting power is photon able sacrify its own and make a pair of electrons ,while an electron can not just lost its kinetic energy to make extra pair of position and electron because one electron does nor contain more spinning charge.
A photon with enough energy can create a pair of electron and positron and we call it pair production. And a position and electron meet can create a photon , we call it annihilation of electron and positron. And we know a photon has a spin of 1, when pair production happen , require positron and...
two particle are entangle or not was decided at the moment when it was created. Such as an electron downward transition twice can create two photon with spin opposite entanglement.
If an electron at a higher energy level, it downward transition twice and emit one photon at each downward transition, the two photons created this way entangled each other , their spins always opposite.