Nobody knows. We model them as wave-like perturbations of the appropriate zero-point field for the characteristics we are interested in. But a zero-point field is just a label to hang the basic mathematics on, we have no idea whether that makes any ontological sense either. And as I have been discovering on the Physics SE, there are many fundamental questions for which this quantum field theory (QFT) has no direct model and just fudges its way past.

The standard approach is to simply ignore the ontological issues and just use the math, fudges and all, to predict experimental results.

Any attempt at a real physical concept is known as an interpretation of the theory. Provided the interpretation is logically consistent with the maths, it cannot be falsified. There are a great many such interpretations, as I am sure you have discovered. The Copenhagen interpretation states that there is no such underlying reality of relevance to scientific enquiry, and because all those attempts cannot be falsified they are of interest only to metaphysicians.

Actually, it's worse than that. Historically, the ontological reality of the things which appear in the equations (such as the quantum fields), temporal causality, and the exclusion of faster-than-light or nonlocal influences, have all been taken for granted. However we have discovered through the famous entanglement phenomenon that these three - causality, localism and realism - cannot all be true. Physicists are left scratching their heads over which one or more of them is false and what they might want to test for in the lab. Since this has philosophical implications at least as profound as its scientific ones, Einstein's observation that scientists make bad philosophers is rather coming home to roost at the moment.

Again, part of that problem is that the quantum field equations are set on the pre-existing stage of Einstein's spacetime. Some physicists suggest that actually, space and/or time may be emergent properties of dynamic quantum systems. In such case, the quantum equations must be recast accordingly, but we have no idea what to aim for. So we don't even know what playing field we are on, never mind what game is being played on it. Despite this, the rulebook that we have compiled for the game is probably humankind's greatest intellectual achievement to date.

Hope this helps (ahem!).

Nobody knows. We model them as wave-like perturbations of the appropriate zero-point field for the characteristics we are interested in. But a zero-point field is just a label to hang the basic mathematics on, we have no idea whether that makes any ontological sense either. And as I have been discovering on the Physics SE, there are many fundamental questions for which this quantum field theory (QFT) has no direct model and just fudges its way past.

The standard approach is to simply ignore the ontological issues and just use the math, fudges and all, to predict experimental results.

Any attempt at a real physical concept is known as an interpretation of the theory. Provided the interpretation is logically consistent with the maths, it cannot be falsified. There are a great many such interpretations, as I am sure you have discovered. The Copenhagen interpretation states that there is no such underlying reality of relevance to scientific enquiry, and because all those attempts cannot be falsified they are of interest only to metaphysicians.

Actually, it's worse than that. Historically, the ontological reality of the things which appear in the equations (such as the quantum fields), temporal causality, and the exclusion of faster-than-light or nonlocal influences, have all been taken for granted. However we have discovered through the famous entanglement phenomenon that these three - causality, localism and realism - cannot all be true. Physicists are left scratching their heads over which one or more of them is false and what they might want to test for in the lab. Since this has philosophical implications at least as profound as its scientific ones, Einstein's observation that scientists make bad philosophers is rather coming home to roost at the moment.

Again, part of that problem is that the quantum field equations are set on the pre-existing stage of Einstein's spacetime. Some physicists suggest that actually, space and/or time may be emergent properties of dynamic quantum systems. In such case, the quantum equations must be recast accordingly, but we have no idea what to aim for. So we don't even know what playing field we are on, never mind what game is being played on it. Despite this, the rulebook that we have compiled for the game is probably humankind's greatest intellectual achievement to date.

Nobody knows. We model them as wave-like perturbations of the appropriate zero-point field for the characteristics we are interested in. But a zero-point field is just a label to hang the basic mathematics on, we have no idea whether that makes any ontological sense either. And as I have been discovering on the Physics SE, there are many fundamental questions for which this quantum field theory (QFT) has no direct model and just fudges its way past.

The standard approach is to simply ignore the ontological issues and just use the math, fudges and all, to predict experimental results.

Any attempt at a real physical concept is known as an interpretation of the theory. Provided the interpretation is logically consistent with the maths, it cannot be falsified. There are a great many such interpretations, as I am sure you have discovered. The Copenhagen interpretation states that there is no such underlying reality of relevance to scientific enquiry, and because all those attempts cannot be falsified they are of interest only to metaphysicians.

Actually, it's worse than that. Historically, the ontological reality of the things which appear in the equations (such as the quantum fields), temporal causality, and the exclusion of faster-than-light or nonlocal influences, have all been taken for granted. However we have discovered through the famous entanglement phenomenon that these three - causality, localism and realism - cannot all be true. Physicists are left scratching their heads over which one or more of them is false and what they might want to test for in the lab. Since this has philosophical implications at least as profound as its scientific ones, Einstein's observation that scientists make bad philosophers is rather coming home to roost at the moment.

Again, part of that problem is that the quantum field equations are set on the pre-existing stage of Einstein's spacetime. Some physicists suggest that actually, space and/or time may be emergent properties of dynamic quantum systems. In such case, the quantum equations must be recast accordingly, but we have no idea what to aim for. So we don't even know what playing field we are on, never mind what game is played on it.

Hope this helps (ahem!).

Nobody knows. We model them as wave-like perturbations of the appropriate zero-point field for the characteristics we are interested in. But a zero-point field is just a label to hang the basic mathematics on, we have no idea whether that makes any ontological sense either. And as I have been discovering on the Physics SE, there are many fundamental questions for which this quantum field theory (QFT) has no direct model and just fudges its way past.

The standard approach is to simply ignore the ontological issues and just use the math, fudges and all, to predict experimental results.

Any attempt at a real physical concept is known as an interpretation of the theory. Provided the interpretation is logically consistent with the maths, it cannot be falsified. There are a great many such interpretations, as I am sure you have discovered. The Copenhagen interpretation states that there is no such underlying reality of relevance to scientific enquiry, and because all those attempts cannot be falsified they are of interest only to metaphysicians.

Actually, it's worse than that. Historically, the ontological reality of the things which appear in the equations (such as the quantum fields), temporal causality, and the exclusion of faster-than-light or nonlocal influences, have all been taken for granted. However we have discovered through the famous entanglement phenomenon that these three - causality, localism and realism - cannot all be true. Physicists are left scratching their heads over which one or more of them is false and what they might want to test for in the lab. Since this has philosophical implications at least as profound as its scientific ones, Einstein's observation that scientists make bad philosophers is rather coming home to roost at the moment.

Again, part of that problem is that the quantum field equations are set on the pre-existing stage of Einstein's spacetime. Some physicists suggest that actually, space and/or time may be emergent properties of dynamic quantum systems. In such case, the quantum equations must be recast accordingly, but we have no idea what to aim for. So we don't even know what playing field we are on, never mind what game is being played on it. Despite this, the rulebook that we have compiled for the game is probably humankind's greatest intellectual achievement to date.

Hope this helps (ahem!).