A calculated reboot
Einstein’s field equations
What it means: The entire set of field equations for general relativity can be expressed in this compact form, with the left side describing the precise way in which space and time can be bent. The right side shows how matter moves under the influence of gravity. Together they show that gravity is the product of an interaction between matter and space, with space guiding the path that matter takes while matter creates gravitational pockets that anyone in a spacecraft would require energy to climb out of. The theory shows that light is affected by gravity in the same way and bends when it passes by a heavy mass. A black hole is what happens when matter creates a pocket with sides so steep not even light can escape it.
Noether’s fundamental identity
What it means: This expression lies at the heart of Noether’s first theorem. The left side is a group of mathematical entities that exhibit symmetry when their value goes to zero. When that’s the case it implies that a property of nature described on the right side of the equation is unchanging and must be a law of physics. For example, the existence of a mathematical symmetry related to rotation is directly linked to what is known as the conservation of angular momentum – the reason that spinning tops tend not to fall down. The same approach can be used to deduce more subtle laws about the behaviour of particles and forces.
By any measure 1915 was a grim year for humanity. A century ago this week, The Globe’s front pages were crammed with news from the battlefields of the First World War, the most mechanized and destructive conflict yet known.
Yet in the heart of wartime Germany, 1915 also saw two remarkable ideas glimmer to life that today rank among the most profound insights ever granted to mortal minds.
The first is general relativity, Albert Einstein’s radical rethinking of gravity that gave us warped space and black holes.
The second is Emmy Noether’s first theorem, a tour de force of abstract reasoning that demonstrates the relationship between forms of symmetry in mathematics and the physical laws that govern the way the universe operates.
Both ideas are being celebrated this week as part of a unique gathering organized by Canada’s Perimeter Institute for Theoretical Physics in Waterloo, Ont. – a haven for those who ponder the nature of things. But the point is not merely to recognize the achievements of a century ago. It’s to channel their daring originality to help spark a revolution.
“We want to reboot physics – globally,” says Neil Turok, Perimeter’s director and the driving force behind Convergence, a four-day physics summit that kicked off here on Sunday.
The meeting’s premise is that theoretical physics has worked itself into the tall weeds, getting more complex and less connected to experiment than it ought to be. To get back out, Dr. Turok says, the field needs ideas as rich and startling as those that came from Einstein, Noether and their peers.
He could well be proven wrong. Results from the newly upgraded Large Hadron Collider, the giant particle accelerator near Geneva, or observations of the deep cosmos, could soon show that physics has been on track all along. Dr. Turok is betting otherwise and there are more than beautiful ideas at stake.
While breakthroughs in fundamental physics often have little practical impact at the time they are made, they can spur extraordinary technical developments a few generations later. For example, the work of Einstein and Noether, revolutionary but without application in 1915, have already enabled the development of lasers and GPS navigation, two advances that would be hard for the modern world to do without.
It’s impossible to predict what spinoffs may come from the next big insight, Dr. Turok says, “But I believe we’re on the verge of similar revolutions and the people who are going to bring them about are probably going to be young people.”
They may also be outliers. Einstein and Noether stood apart from the mainstream Germanic culture of their day. Both were Jewish and Noether was a woman. It was their extraordinary brilliance won them access to the leading intellectual centre of their day.
Of the two, the 36-year-old Einstein was the more established in 1915, with a prestigious position at the University of Berlin. But he was still working with the ideas he’d had when he was labouring in obscurity as a patent clerk in Switzerland.
Emmy Noether, now counted among the great mathematicians of all time, was just 33 then and far less known. Initially prevented from earning a degree because of her sex, she was awarded a doctorate in 1907 – but without a professional pathway to apply it.
Noether was invited to the University of Göttingen in 1915 to work on mathematical questions related to relativity. It was then that she forged a sweeping connection between mathematical symmetry and the so-called conservation laws of physics (such as the rule that energy can’t be created or destroyed). Essentially, Noether handed physicists a tool for uncovering other rules that govern the fundamental particles of matter.
“It underlies our entire way of thinking,” says Dr. Ruth Gregory, a professor of physics at Britain’s Durham University, who came to Perimeter this week to speak about Noether’s enduring impact.
That way of thinking led physicists to postulate the existence of the Higgs boson in 1964. The particle’s discovery at the Large Hadron Collider made front-page news in 2012, but it has so far left theorists without any new clues that could take them further.
That’s why Dr. Turok wants the physicists to get more creative, with Perimeter leading the charge. Central to that effort is the need to identify and foster young people who are bright enough to understand where physics is at today but bold enough to turn it on its head.
Shaking up the status quo has been part of Perimeter’s DNA since the institute was founded fifteen years ago with a $100-million donation from former Blackberry CEO Mike Lazaridis (he has since donated another $70-million). In its pursuit of brilliant minds, Perimeter has continued to pursue both public and private dollars. This week, the institute announced it will receive over $4-million to support its efforts, including three new faculty chairs, underwritten by Gluskin Sheff, a Bay Street investment firm, oil and gas magnate Clayton Riddell and Alberta-based Cenovus Energy. Donations from the Godsoe Family Foundation and RBC will go toward student programs.
The programs are not an afterthought, but a key part of Perimeter’s strategy says Turok. The institute’s intensive 10-month master’s course has become a magnet for international students whose promise might otherwise have escaped attention. Among this year’s graduates is Vasudev Shyam, a 19-year-old who entered straight out of high school in India. He discovered Perimeter by watching lectures from the institute’s video archive.
“I watched these things and I eventually realized that this was probably a class that someone was sitting in,” he says. He is now staying on to do a PhD with a focus on shape dynamics, a different take on relativity partly developed at Perimeter.
The challenge in working with such individuals, says James Forrest, who runs the institute’s academic programs, is “how do you teach physics to the people who are already good at it?” It’s a dilemma universities seldom worry about – but for Perimeter, which aims to optimize the randomness of human brilliance, the question is crucial.
Another way in which the institute has tried to leverage the global talent pool is to bring in more female researchers. Women are conspicuously underrepresented in physics but through a funding stream called the Emmy Noether Circle the institute has significantly boosted its share of young women theorists.
“They’re highly sought after by many institutions,” said Patrice Merrin, a Toronto executive who helps oversee the effort. But at Perimeter, she says, “I think we have a demonstrated community that is intellectually welcoming.”
Yet while the brain power streaming into Perimeter and other institutions today is more diverse, better trained and selected from a vastly larger population than German-speaking Europe a century ago, physics has not been leaping forward in direct proportion.
Dr. Turok hopes this week’s meeting will help turn the corner, by refocusing the community and perhaps triggering the right individual in just the right way.
“In the end it comes down to a flash of inspiration,” he says. “That’s the nature of theoretical physics.”
Back to reality
The problem is not that the universe is a puzzle, it’s that the pieces – so far – don’t seem to fit together.
That’s the situation theoretical physicists find themselves in when they try to combine ideas such as Einstein’s general relativity with the Standard Model of particle physics. One handles gravity, one handles just about everything else – but mathematical problems arise whenever theorists try to frame one theory in the language of the other.
One approach, known as string theory, posits that particles are made of tiny, vibrating one-dimensional strings. It has played a prominent role in recent decades because it initially seemed to offer a way toward the ultimate “theory of everything.”
“Unfortunately we found out it was harder than that,” says Rob Myers, a string theorist and founding faculty member of the Perimeter Institute.
These days, string theory has been shown to describe many possible realities rather than one. It’s still not clear how its complex formulations relate to the world we know. Nevertheless, Dr. Myers says string theory has proved to be extremely revealing. Many theorists maintain it is telling us something crucial about the universe, including the possibility that space itself is not a fundamental part of reality but something that emerges from a deeper set of mathematical relationships.
But Perimeter director Neil Turok says string theory has also helped to foster a bandwagon effect that may have taken physics in the wrong direction – one that leads to the notion that our universe is just one of countless others and that the laws of physics are the product of random chance rather than something more fundamental.
Some theorists are enamoured of the idea – collectively known as the landscape, or the multiverse. Dr. Turok is among those who are not, in part because it makes all predictions possible.