And here we go again, focusing on what is real and what not. I think I said several times that many of the constructions we use today are in fact only objects “of our mind” with no real presence in nature at all, other than the one needed for our brains to understand reality… One of these non-real objects are the quantum fields… Yes, there are no such things as quantum fields. Gauge theories say this pretty clearly and we know that from the old works of Batalin and Vilkovisky… What are out there are particles. There is no such thing as a “universal Higgs field”… there is however a Higgs boson which is a particle that interacts with other particles. Fields are things that tell us how particles move but they are not real. We can construct a theory that simply tells you that when there is an electric charge somewhere in space the electrically charged particles or the other particles sensible to e.m. interactions will move in some specific ways. You can simply write a theory that simply does not contain ANY fields at all but is perfectly correct from any mathematical or physical point of view. The same is true for all the other “fields”… Particles are physical objects. They are not “classical” particles and they obey a quantum statistics, that is clear… and sometimes the probabilities associated to them (like cross sections, decay rates, etc.) are accessible only through this or that field representation… but this is so because we are used to think in terms of fields… They are not “physical” in any sense… Nor is space-time “physical”… it is another way of thinking in situations when a metric is needed to make “life” easier for us to understand… However, one can describe all aspects of quantum mechanics without using a metric at all… it is indeed harder and less intuitive but definitely possible. If we have to think in terms of quantum gravity then it may be very likely that we have to give up the notions of space-time that are too closely related to ideas like metrics or distance… so, space-time is also “not real”… physicality is a very strong restriction…

# Are fields real?

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