What is more fundamental, particles or fields? I keep reading what appears to be conflicting answers on this, but I am sure it is just a limitation of my understanding. I have heard some physicists say that everything is fields. That the particles are the excitation of these fields. The way to help you visualize this would be like a rope (the field) is moved up and down and the particle would be the wave in the rope. Ok. Then I read that, for example, the electromagnetic field is made up of photons. So does that mean the field is actually made of a huge number or photons making a field. Which is it? The field excited to make the photons or the huge number of photons making the field. It seems to make more sense that the field comes first but I don't know. Can someone clarify this?
Quantum field theory is the most powerful theory of reality we have at the moment. It states that the fundamental nature of reality are indeed fields. The photon is an excitation of the electromagnetic field. You might have seen written that an electromagnetic wave is "made up of photons". What this really means is that the energy of the wave is not continuous, but instead comes in packets of energy. This packets are photons, which are quantised excitations of the electromagnetic field.