But all the particles that exist, at the core of their nature, are just excited quantum fields themselves. That's the topic of this week's question, coming to us from Richard Hunt, who wants to know:I have a question about Quantum fields. The electromagnetic (QED) field and color-charge (QCD) field, among others, are also fundamental quantum fields. In other words, these are quantum fields not in their lowest-energy — or zero-point — state, but in some higher-energy state. Up until this point, we've been thinking of fields in terms of empty space: the quantum fields we're discussing exist everywhere.

Source: Forbes January 13, 2019 18:56 UTC