Why do particle physicists like spending time in fields?

When we were first preparing to launch my column for New scientistmy editor asked me what I would like to call it. “Field notes from space-time,” I said. This title has a double meaning that may not be obvious, but was fun for me as a physicist. This is a reference to the scientific idea of ​​taking field notes – a sort of laboratory notebook. At the same time, it alludes to a specific concept that is very important in particle physics: the field itself.

You might think of a field as a large open space found on a farm, but in physics it’s more abstract. Essentially, a field is a mathematical relationship that assigns a number to every point in space and time. The intention is to characterize a physical phenomenon at this location. For example, when you feel the pull of a refrigerator magnet near a refrigerator door, there is a magnetic force between the two. This force has a magnetic field value at each location in space that becomes stronger as the distance between the magnet and the refrigerator decreases.

In fact, the first time a physicist used the word “field” in this way was when 19^thThe 19th century scientist Michael Faraday was studying the magnetism of the element bismuth. While I was working on my new book, I read his journal entries and saw for the first time that he had invoked the idea of ​​the field, but I wondered how Faraday arrived at this language. I’m not sure, but my own theory is that it has to do with the fact that Faraday was unusual for his time. Unlike other physicists of his time, he came from a working-class family. His parents were born and raised in a village and came from an agricultural background. In other words, they were people who lived in close relationship with the land. In my mind, I imagine Faraday pondering the invisible properties of the great outdoors operated by families like his.

The idea of ​​the field did not remain in the world of magnetism. One of the most phenomenal innovations of the 20^th The century was the intersection of fields with the transformative theories of quantum physics, which had already challenged scientists to understand that particles and waves had a dual relationship. In other words, particles like electrons are also waves and waves like the electromagnetic field are also particles (which we call photons). Soon after the community became familiar with the idea of ​​wave-particle duality, it became clear that there must be a deeper relationship between the quantum and the field.

In the process of developing a complete quantum image of the photon, fields became necessary again. But this time it was about quantum fields. Just as the magnetic field quantifies the magnetic force existing at each point in space, a quantum field determines how many particles can be created or destroyed at each point in space. Consequently, all electrons are said to emerge from a quantum electronic field, and so on for the other particles. We also suspect that dark matter, which appears invisible but otherwise behaves as if it were made of particles, has a similar field that we have not yet discovered. The universe is full of particles emerging from the void, thanks to quantum fields. In this sense, whenever I write about anything in this column, I am writing literal field notes, from space-time.

What are you reading?

I’m completely obsessed with Herman Melville’s Manifesto by Barry Sanders.

What are you looking at?

I love the last season of Tips.

What are you working on?

Having finished throwing At the edge of space-time In the US, I’m now focusing on the UK release!