Lakshmi Chandrasekaran

Machine learning could help astronomers tighten constraints on the cosmological parameters that dictate the past, present, and future of the cosmos.
For almost as long as humans have existed, we have been trying to make sense of the cosmos. What started as philosophical musing has, following the advent of the telescope and the ability to look ever farther into space (and ever earlier in time), become a thriving field of research.
Today, scientists seek to understand the properties governing h...

If a ninespine stickleback fish could choose between a diet that was rich or poor in nutrients, what would it pick? A 2010 study found that these fish tend to copy each other when choosing a meal, opting for the feeder at which other fish have already foraged [3]. A 2018 mating experiment with fruit flies revealed similar social behavior [1]. The male flies were artificially colored pink or green, and a set of female flies watched other females choose their male partners; the females tended t...

Maybe you’ve heard of the TV show The Great British Bake Off. Its contestants take part in baking challenges in hopes of being named champion. But have you heard of The Big Internet Math-Off? At its end, one person is crowned the “world’s most interesting mathematician.” Meet Angela Tabiri: She became its 2024 champion.
To win, this celebrated mathematician from Ghana, Africa, had to find a way to make math fun for everyone. Sixteen mathematicians were challenged to present something cool abo...

Qubits are to quantum computers, just as transistors are to classical computers. However, unlike their classical cousins, qubits are fussier and more sensitive. Qubits are so fragile that any fluctuation to their environment—like an imperceptible change in temperature, magnetic fields, or even a stray cosmic ray—could disrupt the qubit from performing computations.
The delicate nature of qubits has spurred research into discovering special types of materials with quantum properties that can p...

Does math leave you anxious? Maybe you feel it’s unforgiving — that unless everything is perfectly right, it’s totally wrong. Perhaps it just doesn’t compute for you. It’s like looking at a foreign language — one in which you’re far from fluent.
If this is you, you’re not alone. “Math anxiety is a widespread, worldwide problem affecting all age groups,” a trio of researchers in Austria noted in a 2018 review on the subject. They cited work finding that more than nine in every 10 U.S. adults, ...

The original version of this story appeared in Quanta Magazine.

It’s not easy to study quantum systems—collections of particles that follow the counterintuitive rules of quantum mechanics. Heisenberg’s uncertainty principle, a cornerstone of quantum theory, says it’s impossible to simultaneously measure a particle’s exact position and its speed—pretty important information for understanding what’s going on. In order to study, say, a particu...

Simons Institute

In this episode of our Polylogues web series, Summer 2023 Science Communicator in Residence Lakshmi Chandrasekaran interviews former Simons Institute Scientific Advisory Board member and program organizer Irit Dinur. Their wide-ranging conversation touches on Irit’s career and research, the trajectory from basic science...more

Introduction

Theoretical computer scientists deal with complicated ideas. But whenever possible, they’d prefer to work with simpler ones. A 2009 tool known as the regularity lemma gives them a great way to do this. It effectively lets them break a given computational problem or function into simpler pieces.

For computational complexity theorists, who study the relative hardness of different problems, this ability to simplify has long helped them understand unwieldy mathematical functions. But...

Physicists have done a remarkable job explaining the chaos of the universe with well-behaved equations, but certain situations remain mysterious. Among these are collections of many tiny particles — they can be atoms, electrons, anything sufficiently small — that interact in surprising and complicated ways. These interactions gi...

Quantum computers are poised to become computational superpowers, but researchers have long sought a viable problem that confers a quantum advantage — something only a quantum computer can solve. Only then, they argue, will the technology finally be seen as essential.

Even after decades, they’re still looking. “Part of the reason it’s challenging is because classical computers are pretty good at a lot of the things they do,” said John Preskill, a theoretical physicist at the California Instit...

Have you noticed how oranges are stacked at the store? Grocers know that the most attractive and stable arrangement is a pyramid. Johannes Kepler suspected this pyramid-stacking was superior, way back in the 17th century. But the German scientist also noted that he couldn’t prove it. Sadly, like Kepler, many mathematicians may never live to see the confirmation of their discoveries. Or the full impact of their insights.
In Kepler’s case, it took nearly 400 years for mathematicians to confirm ...

Introduction

The traveling salesperson problem is one of the oldest known computational questions. It asks for the ideal route through a certain list of cities, minimizing mileage. Despite seeming simple, the problem is notoriously difficult. While you can use brute force to check all the possible routes until you find the shortest path, such a strategy becomes untenable after just a handful of cities. Instead, you can apply a rigorous mathematical model called linear programming, which rough...

Understanding the quantum universe is not an easy thing. Intuitive notions of space and time break down in the tiny realm of subatomic physics, allowing for behavior that seems, to our macro sensibilities, downright weird.

Quantum computers should allow us to harness this strangeness. Such machines could theoretically explore molecular interactions to create new drugs and materials. But perhaps most important, the world itself is built upon this quantum universe — if we want to understand how...

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As the world began to cautiously emerge from the ravages of COVID-19 in early 2022, a new global outbreak arose: monkeypox/mpox, a viral infectious zoonotic disease. According to the World Health Organization (WHO), the virus has spread to 110 countries thus far. WHO also reported that smallpox vaccines are roughly 85 percent effective in preventing mpox. Nevertheless, public health experts still debate a central question: Should public policy mandate vaccinations to prevent the spread ...

Imagine you’re a general in ancient times and you want to keep your troop counts secret from your enemies. But you also need to know this information yourself. So you turn to a math trick that allows you to achieve both aims.
In a morning drill you ask your soldiers to line up in rows of five. You note that you end up with three soldiers in the last row. Then you have them re-form in rows of eight, which leaves seven in the last row, and then rows of nine, which leaves two. At no point have y...