Far out cosmology:survival with balance with the Higgs field (Introduction)

by David Turell , Thursday, November 21, 2024, 21:01 (5 hours, 25 minutes ago) @ David Turell

Advanced quantum fields theory:

https://www.newscientist.com/article/mg26435180-800-the-universe-could-vanish-at-any-mo...

"...there is a more immediate cataclysm that may already be barrelling towards us at the speed of light: they call it the big slurp.

"The slurp in question starts with a quantum fluctuation that sets a bubble rolling across the universe like a cosmic tidal wave, obliterating everything in its path. We should take this possibility seriously, says John Ellis at King’s College London. In fact, it is less a matter of if this apocalypse will play out, but when. “It could happen while we’re talking,” he says.

"Theorists like Ellis are actually surprised that such a catastrophe hasn’t already occurred in the observable universe. But rather than taking our precarious existence for granted, they are using the plain fact we are still here as a tool. The thinking is that there could be some exotic physics preserving us.

***

"The Higgs had been hypothesised for decades, but we were in for a surprise when the particle was finally measured at CERN’s Large Hadron Collider (LHC) near Geneva in 2012. The result suggested that the Higgs field isn’t stable because it isn’t in its lowest possible energy state. We know that objects like atoms or particles tend to want to minimise their energy, so in theory the Higgs could suddenly drop to its lowest possible state in a process known as a phase transition.

***

"As a bubble formed, the quantum fields inside would suddenly shift, effectively rewriting the laws of physics and creating chaos. Terrifyingly, the bubbles would expand at light speed, swallowing everything around them.

"The appearance of this apocalyptic bubble comes down to chance. As an analogy, imagine the Higgs field is a ball at the top of a hill that has several valleys of differing heights beneath it. The ball could roll down into one of the higher valleys and stay there happily, while still not being at the lowest possible point. This is the situation the Higgs field is in now, which we call a “metastable state”. A ball in such a valley can’t roll out of it without a kick. But because this field conforms to the rules of the quantum world, it can mysteriously “tunnel” to a lower valley, or energy state. This is a quantum process akin to a ghost walking through a wall. We can make estimates for how likely the Higgs field is to do this in a given time period, but we can’t predict exactly when it will occur.

***

"Recent measurements of these particles at the LHC aren’t comforting. Aside from the Higgs itself, the heaviest known fundamental particle, called the top quark, has the greatest influence on the stability of the Higgs field. The heavier it is, the less stable the field is. In recent years, as measurements of the top quark mass have become more precise, it has become clearer that the Higgs is – according to the standard model – metastable. “The measurements are now so good that we pretty much know that we are in that metastable range,” says Rajantie.

"Assuming there’s no mistake, the universe is doomed – we just don’t know when the big slurp will happen. Based on the shape of these valleys, it is likely to be in billions of years. But it could be tomorrow.

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"There is, however, an alternative explanation for why the Higgs field hasn’t transitioned. Despite the precise measurements of the top quark and the Higgs boson, we can’t be certain that the Higgs is in a precarious metastable state after all. It might be that there are unknown particles and forces stabilising the Higgs field in a way that protects us from the big slurp. “If there’s some other particle that comes into play at some higher energy, then that will change the story again – we just don’t know yet,” says Katy Clough at Queen Mary University of London.

***

"The alternative, he says, is to resort to “special pleading” arguments, whereby most of the cosmos already flopped into its lowest-energy state, but a few regions, such as ours, were left in a metastable state on the brink of collapse. In this view, a metastable state is necessary for life, so we must find ourselves living in one of these precarious patches. (my bold)

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"But for all that the end of the universe depends on the whims of the Higgs, we may well owe our existence to it in the first place. Last year, Clough and her colleagues published research suggesting that quantum tunnelling effects could prevent a contracting universe from collapsing in a big crunch. In their model, this contraction squeezes a Higgs-like field in such a way that its lowest-energy state becomes negative. This would cause a collapsing universe to bounce outwards, creating a new, expanding universe perhaps not unlike our own."

comment: We have been here 13.78 billion years. That is stability despite all the smoke and mirrors in current far out cosmology. My thought is not to worry, but this is a theoretical area that is fun to learn about.