The annual Breakthrough Prize, the world's largest science prize, has announced the winners of the 2021 Breakthrough Prizes in Fundamental Physics, Life Sciences, and Mathematics, as well as several prizes for early-career researchers. The prizes, now in their eighth year, will see the laureates taking home $3 million for their contribution to scientific advances.

One prize in Mathematics, four in Life Sciences, and one Physics prize were awarded this year. Like last year, the board has also awarded one Special Prize in Fundamental Physics. Nine early-career physicists and three early-career mathematicians have been recognized by the New Horizons Prizes.

This year sees the first three laureates of the $50,000 Maryam Mirzakhani New Frontiers Prize awarded to outstanding early-career women in mathematics, named after the late great mathematician, the first woman to win the Fields Medal in mathematics.

The winner of the Breakthrough Prize in Mathematics prize is Martin Hairer, whose work to find sense in random (or stochastic) processes established regularity structures that can be used to model physical systems. “Math is truth. Once you discover something in math, it applies to all eternity," Hairer, who works at Imperial College London, said in an emailed statement.

The four Life Sciences prizes were given to several individuals working in different fields. David Baker from the University of Washington won the prize for developing technology that allowed the design of proteins that do not naturally occur in the world. Dennis Lo of The Chinese University of Hong Kong discovered that fetal DNA is present in maternal blood and could be used in prenatal screening instead of the riskier amniocentesis. Richard J. Youle from the National Institute of Neurological Disorders and Stroke won for his work on understanding how cells die and in particular the way this contributes to Parkinson's disease and other neurodegenerative diseases.

The final Life Sciences winner is Catherine Dulac, who deconstructed instinctive parental behavior in mice all the way down to neurons and how they are connected. “When the members of the committee told me [I won this award], I was stunned, like my brain didn’t make the connection; it was all fuzzy,” she laughed when we asked her about the prize.

In her research, Dulac found that parenting behaviors are hardwired in the brain but they are not binary. Maternal and paternal behaviors are present in both males and female mice and they are impacted by environmental and other factors.

“The simple assumption that males behave like males and females behave like females seemed to be wrong,” Professor Dulac told IFLScience. “It turns out that when we look for neurons that control parental behavior, these neurons exist both in the brain of males and females. And when we look at neurons that control infanticide behavior, they also exist both in the brain of males and females. We cannot really simplistically think about male behavior and female behavior.”

The Fundamental Physics prize went to Eric Adelberger, Jens Gundlach, and Blayne Heckel from the University of Washington – for producing incredible measurements that test our understanding of gravity. Starting in 1986, as new ideas about gravity were proposed they decided to put them to the test. In particular, they looked at possible violations of the strong equivalence principle that states that the gravitational motion of a small body doesn’t depend on its constitution. The group has performed the most accurate tests over short distances of the strong equivalence principle.

“The Equivalence Principle is deeply rooted in physics. That’s really what drives me to look for [these possible violations]” Professor Gundlach told IFLScience. But it's not just the equivalence principle. Another important aspect of our formulation of gravity is the inverse-square law; force is inversely proportional to distance, or being twice as far from an object means that its gravity is four times weaker. The inverse-square law could be used to test a very intriguing theory to explain why gravity is so weak compared to the other forces of the universe. One idea suggests that more than our 3+1 dimensions exist but these extra are curled up so tightly that we can’t see them.

“We are confined very tightly to the ordinary 3+1 dimensional world, but gravity knows about these extra dimensions and because it can spread out in the extra dimensions, it gets much weaker. There's no non-gravitational experiment you could ever do to see these extra dimensions even if they were there,” Professor Adelberger explained. “And that was a very exciting idea that by testing the inverse square law, you could have a sort of a bomb-proof test for this idea.”

With their experiments, they were able to put the most stringent limit yet on the size of these dimensions: They must have a radius smaller than one-third of the average human hair.

The special prize for Fundamental Physics went to theoretician and Nobel Laureate Steven Weinberg “for continuous leadership in fundamental physics.”

The three 2021 New Horizons Prize in Mathematics were won by Bhargav Bhatt from the University of Michigan, Alexander Logunov from Princeton University, and Song Sun from the University of California, Berkeley. Each of these early-career mathematicians takes home $100,000.

The winners for the 2021 Maryam Mirzakhani New Frontiers Prize are Nina Holden from ETH Zurich, Urmila Mahadev from the California Institute of Technology, and Lisa M. Piccirillo, from the Massachusetts Institute of Technology. Each received $50,000.

Tracy Slatyer from the Massachusetts Institute of Technology won one of the three $50,000 New Horizons in Physics prizes for her work focusing on dark matter models producing critical contributions to astrophysics.

“One of the things I find pretty amazing about dark matter is just that there's such an enormous range of possibilities for what it could be like that. While we only have limited information on [the true nature of dark matter], that doesn't mean that it's hard to come up with possible ideas,” Dr Slayter told IFLScience. “I feel extremely fortunate to get to spend most of my time just thinking about what dark matter could be and how we might go after it.”

Her incredible work in understanding dark matter has led to an important but unrelated discovery. Back in 2010, she and her team announced the discovery of the Fermi Bubbles, two large structures extending for 25,000 light-years above and below the plane of the Milky Way. Slatyer was investigating potential signals related to dark matter when they discovered these structures.

“I see it as sort of a demonstration that if you develop techniques and you have datasets that are capable of seeing the very faint signals that we would expect from dark matter, and even if you don't find dark matter, you may find lots of other really interesting things,” Slatyer said.

The second New Horizons in Physics recipients include four physicists working on the dark matter experiment SENSEI, Rouven Essig, Javier Tiffenberg, Tomer Volansky, and Tien-Tien Yu, and the final is shared among Ahmed Almheiri, Netta Engelhardt, Henry Maxfield, and Geoff Penington for their work on calculating the information content of a black hole. This is a thorny and complex problem first highlighted by Stephen Hawking and Jacob Bekenstein in the 1970s and tackling it continues today.

Black holes have a feature called the event horizon from which nothing can escape since the escape velocity beyond that point exceeds the speed of light. According to the theory of general relativity, once something crosses the event horizon it's lost forever, including all information. However, this is not allowed by the other pillar of modern physics.  

“Quantum mechanics doesn't like that. Quantum Mechanics says: ‘No! Information that you throw in has to come out at some point’. And so there seems to be this conflict between what we like to call the causal structure of space-time due to this event horizon,” Dr Almheiri, from the Institute for Advanced Study, told IFLScience.

“The word causal comes from the fact that things inside can't have any cause or effect on things outside and this conflicts with expectations from quantum mechanics. And so what I've been thinking about for the longest time, since my Ph.D. almost 12 years ago, is about trying to understand the physics of how to mesh these two things together.”

Almheiri and his colleagues are trying to comprehend the theory that underpins these extreme objects and their discoveries might open a window to a completely new understanding of physics.