BLOG

Posted on 3 July 2021 by Benjamin Skuse

Hidden Physics Gems at #LINO70

F. Duncan M. Haldane, moderator Heiner Linke and J. Michael Kosterlitz

The 70th Lindau Nobel Laureate Meeting has been littered with talks from Laureates who have made key breakthroughs in a swathe of physics disciplines – from those who exposed fundamental building blocks of the universe to researchers who had a hand in some of the most important technologies we enjoy today (or will enjoy tomorrow).

With such a packed timetable, attendees could be forgiven for focusing on the hot topics and the subjects they are most familiar with. But sometimes, the more niche or out-of-the-ordinary talks can be the most illuminating and inspiring.

Time and Energy

Two Laureates whose talks certainly fell into the ‘out-of-the-ordinary’ category were Sir Anthony Leggett and Carlo Rubbia (Nobel Prize in Physics 2003, respectively 1984). Though the physics disciplines for which they were awarded their Nobel Prizes ­– superfluidity and particle physics – are deeply fascinating, both chose to talk about completely different topics.

Leggett’s lecture was a rumination on a question we all may have asked ourselves: why can’t time run backwards? “One of the most basic features of our everyday world is that we can remember the past and affect the future, but not vice versa – how nice it would be if I could go back to that party the other night and correct that awful social gaff that I made,” he joked. But this issue points to a serious problem in our understanding of the universe. The basic laws of physics (with one tiny exception) are “completely insensitive to the direction of time”.

Sir Anthony J. Leggett
Sir Anthony J. Leggett answered the question “Why can´t time run backwards?”

Leggett took audience members on a journey through the history and latest thoughts on why time’s arrow appears to always points forward. He described the various arrows of time derived from observations and laws in different areas of physics – such as the psychological, thermodynamic and cosmological arrows – and how making connections between them might provide clues to time’s forward-leaning tendency. And he suggested that perhaps we simply don’t understand the laws of physics and cosmology well enough right now. It could turn out that time’s forward direction is just a “trivial” consequence of better future models. “The really difficult questions in physics are the ones where you don’t know which questions you should be asking – and this is one of those,” he concluded.

Meanwhile, Rubbia completely changed the original focus of his talk from ‘Particles Generated on Earth and in the Cosmos’ to a subject that he has devoted his time to for the past 20 years: a sustainable energy supply for the future of humankind. Rubbia presented a wide range of ideas for clean energy, all centred on clean fossil fuels through the little-known process of methane decarburation.

According to Rubbia, methane decarburation of natural gas is a valid alternative to renewables, using current infrastructure and producing no negative environmental impacts. “Why should it not be widely used in the future?,” he challenged his audience.

Big Efforts in the World of the Small

Not all of the out-of-the-ordinary talks at #LINO70 went quite so off-piste. For example, 2020 Nobel Prize in Physics recipients Duncan Haldane and Michael Kosterlitz’s Agora Talk ‘The Topology of New Materials’ was very much within their purview.

What was most surprising and fascinating was hearing just how close scientists are to applying understanding of the topology of new materials in quantum computers. A topological quantum computer is theoretically just as powerful as a ‘regular’ quantum computer (which, again theoretically, can make certain calculations rapidly that would take a traditional supercomputer longer than the lifetime of the universe to solve). But crucially, a topological quantum computer is far more stable, offering topological protection against quantum information errors.

“On paper, this is actually a much better solution to the problem of protecting your information against local dirt and noise and destroying it,” said Haldane. “We don’t yet actually have a qubit, but this is something Microsoft has actually been working on – I believe it’s a realistic dream, but we’ll have to see.”

At the same time as Haldane and Kosterlitz were extolling the merits of topologically-protected quantum computing, an equally fascinating Agora Talk was being presented by Takaaki Kajita and Arthur McDonald. Sharing the 2015 Nobel Prize in Physics for proving neutrinos have mass, their presentations were always going to focus on these miniscule particles thought to play a key role in the evolution of the universe.

But for those unfamiliar with neutrino physics, including moderator Adam Smith, the sheer scale and technological ingenuity feeding into the experimental effort to characterise neutrinos was mind-boggling. Kajita and McDonald described literally dozens of current and future experiments, including, for example, the Deep Underground Neutrino Experiment (DUNE) in the US, a huge collaborative effort involving 1,300 researchers and consisting of two enormous underground neutrino detectors spaced 1,300 kilometres apart.

In explaining why these gargantuan underground facilities are being built or upgraded around the world, Kajita and McDonald managed to encapsulate what physics and science more generally is and means today: a global collaborative effort to understand the world we live in.

Benjamin Skuse

Benjamin Skuse is a professional freelance writer of all things science. In a previous life, he was an academic, earning a PhD in Applied Mathematics from the University of Edinburgh and MSc in Science Communication. Now based in the West Country, UK, he aims to craft understandable, absorbing and persuasive narratives for all audiences – no matter how complex the subject matter. His work has appeared in New Scientist, Sky & Telescope, BBC Sky at Night Magazine, Physics World and many more.