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BB: Chicken or egg redux

John Healy

We’re all familiar with the saying, “which came first, the chicken or the egg?” So, I have a similar problem with modern cosmology: which came first, fields or particles? After the Big Bang …

Well, the answer is sort of neither. There was a long evolutionary path from earlier organisms to creatures that laid eggs (like dinosaurs) and then to birds like the chicken.

In physics, once the first generation of particles appeared — electrons and quarks, for example — there must have been a field (or fields). In the Standard model of particles physics, the Higgs boson and Higgs field predate even those — so that the electron is imparted with mass (at between 10^−12 second and 10^−6 second after the Big Bang [1]).

From a practical standpoint, our visible universe always has had fields and particles. “Empty space” is not empty. That’s why I have trouble visualizing even the interaction of an electron and proton in a hydrogen atom. Charged particles have fields; fields interact with particles, as well as generate particles. Recursive interaction. Non-linear relations. Follow the math. In practice, descriptive models make adequate approximations.

All of which gets us back to energy, entropy (arrow of time), and chronology of the universe.

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[1] Note that current processors in personal computers operate at gigahertz frequencies — a clock rate in the 10^9 range. So, regarding cosmic evolution, we talking about events occurring in far less time than even one clock cycle of your PC’s microprocessor chip!

One thought on “BB: Chicken or egg redux”

  1. In this YouTube video of David Tong’s lecture “Quantum Fields: The Real Building Blocks of the Universe” 1 published on Feb 15, 2017, in The Royal Institution’s channel, he notes:

    So when the universe was very, very young, soon after the Big Bang, there were no particles, but there were quantum fields, because the quantum fields were everywhere. And there were these quantum vacuum fluctuations. And what happened was the universe expanded very, very quickly, and it caught these quantum fluctuations in the act. So the quantum fluctuations were stretched across the entire sky, where they became frozen. And it’s these vacuum fluctuations here which are the ripples that you see in the fireball [map of cosmic microwave background radiation].

    But it leaves lots of questions. The most important one is, which field are we seeing here? Which field is this that’s imprinted on the background radiation? And the answer is we don’t know. The only one of the standard model fields it has a hope of being is the Higgs. But most of us think it’s not the Higgs, but probably something new. But what we’d like to do moving forward into the future is get a much better picture of this fireball, in particular get the polarisation of the light. And by getting a picture of this, we can understand much better the properties of this field that was fluctuating in the early universe.

    [1] According to our best theories of physics, the fundamental building blocks of matter are not particles, but continuous fluid-like substances known as ‘quantum fields’. David Tong explains what we know about these fields, and how they fit into our understanding of the Universe. Tong is a professor of theoretical physics at Cambridge University, specialising in quantum field theory.

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