Annaka Harris writes: “I think the flow of time is not part of the fundamental structure of reality,” theoretical physicist Carlo Rovelli tells me. He is currently working on a theory of quantum gravity in which the variable of time plays no part. And throughout our conversation, I’m trying to get my mind around the idea that even though the universe is made up of “events,” as Carlo explains, a single interval between two events can have different values. There…
Nicholas Cannariato writes: The nature of time. Black holes. Ancient philosophers. The struggle for democracy. Climate change. Buddhist philosophy. In his new collection of essays and articles, Carlo Rovelli, one of the world’s most renowned physicists, broadens his writing to include questions of politics, justice and how we live now. “I look at myself as much more than a physicist,” he said in an interview at his home in London, Ontario, on a cold, calm day in February. The new…
Live Science reports: After nearly 13.8 billion years of nonstop expansion, the universe could soon grind to a standstill, then slowly start to contract, new research published in the journal Proceedings of the National Academy of Sciences suggests. In the new paper, three scientists attempt to model the nature of dark energy — a mysterious force that seems to be causing the universe to expand ever faster — based on past observations of cosmic expansion. In the team’s model, dark…
Nature reports: One of nuclear physicists’ top wishes is about to come true. After a decades-long wait, a US$942 million accelerator in Michigan is officially inaugurating on 2 May. Its experiments will chart unexplored regions of the landscape of exotic atomic nuclei and shed light on how stars and supernova explosions create most of the elements in the Universe. “This project has been the realization of a dream of the whole community in nuclear physics,” says Ani Aprahamian, an experimental…
Dr Katie Mack writes: “From a tropical rainforest to the edge of time itself, James Webb begins a voyage back to the birth of the Universe” – so went the launch narration when astronomy’s latest superpowered space explorer, the James Webb Space Telescope (JWST), lifted off from French Guiana on Christmas Day. Like most launch announcements, it employed a bit of poetic license to add to the drama. But now that JWST is settled into its orbit and sending back…
Mathematics is the language of the universe. (Shutterstock) By Peter Watson, Carleton University Almost 400 years ago, in The Assayer, Galileo wrote: “Philosophy is written in this grand book, the universe … [But the book] is written in the language of mathematics.” He was much more than an astronomer, and this can almost be thought of as the first writing on the scientific method. We do not know who first started applying mathematics to scientific study, but it is plausible…
Shutterstock By Sam Baron, Australian Catholic University Does time exist? The answer to this question may seem obvious: of course it does! Just look at a calendar or a clock. But developments in physics suggest the non-existence of time is an open possibility, and one that we should take seriously. How can that be, and what would it mean? It’ll take a little while to explain, but don’t worry: even if time doesn’t exist, our lives will go on as…
Nature reports: From its resting place outside Chicago, Illinois, a long-defunct experiment is threatening to throw the field of elementary particles off balance. Physicists have toiled for ten years to squeeze a crucial new measurement out of the experiment’s old data, and the results are now in. The team has found that the W boson — a fundamental particle that carries the weak nuclear force — is significantly heavier than theory predicts. Although the difference between the theoretical prediction and…
Charlie Wood writes: When two black holes collide, the titanic crash ripples out through the very fabric of the cosmos. Physicists have used Albert Einstein’s theory of gravity to predict the rough contours of these gravitational waves as they pass through Earth, and wave after wave has been confirmed by the LIGO and Virgo gravitational-wave detectors. But physicists are starting to flounder as they attempt to use Einstein’s thorny equations to extract ultra-precise shapes of all possible reverberations. These currently…
Ben Brubaker writes: Almost anytime physicists announce that they’ve discovered a new particle, whether it’s the Higgs boson or the recently bagged double-charm tetraquark, what they’ve actually spotted is a small bump rising from an otherwise smooth curve on a plot. Such a bump is the unmistakable signature of “resonance,” one of the most ubiquitous phenomena in nature. Resonance underlies aspects of the world as diverse as music, nuclear fusion in dying stars, and even the very existence of subatomic…
Charlie Wood writes: A group of scientists may have stumbled upon a radical new way to do cosmology. Cosmologists usually determine the composition of the universe by observing as much of it as possible. But these researchers have found that a machine learning algorithm can scrutinize a single simulated galaxy and predict the overall makeup of the digital universe in which it exists — a feat analogous to analyzing a random grain of sand under a microscope and working out…
Tom Siegfried writes: Scientists are like prospectors, excavating the natural world seeking gems of knowledge about physical reality. And in the century just past, scientists have dug deep enough to discover that reality’s foundations do not mirror the world of everyday appearances. At its roots, reality is described by the mysterious set of mathematical rules known as quantum mechanics. Conceived at the turn of the 20th century and then emerging in its full form in the mid-1920s, quantum mechanics is…
The evolution of the cosmos after the Big Bang. NASA By Alastair Wilson, University of Birmingham READER QUESTION: My understanding is that nothing comes from nothing. For something to exist, there must be material or a component available, and for them to be available, there must be something else available. Now my question: Where did the material come from that created the Big Bang, and what happened in the first instance to create that material? Peter, 80, Australia. “The last…
Discover reports: After decades of exploration in nature’s smallest domains, physicists have finally found evidence that anyons exist. First predicted by theorists in the early 1980s, these particle-like objects only arise in realms confined to two dimensions, and then only under certain circumstances — like at temperatures near absolute zero and in the presence of a strong magnetic field. Physicists are excited about anyons not only because their discovery confirms decades of theoretical work, but also for practical reasons. For…
Paul J. Steinhardt writes: Impossible! The word resonated throughout the large lecture hall. I had just finished describing a revolutionary concept for a new type of matter that my graduate student, Dov Levine, and I had invented. The Caltech lecture room was packed with scientists from every discipline across campus. The discussion had gone remarkably well. But just as the last of the crowd was filing out, there arose a familiar, booming voice and that word: “Impossible!” I could have…
Geralt / Pixabay By Sam Baron, Australian Catholic University Many people think that mathematics is a human invention. To this way of thinking, mathematics is like a language: it may describe real things in the world, but it doesn’t “exist” outside the minds of the people who use it. But the Pythagorean school of thought in ancient Greece held a different view. Its proponents believed reality is fundamentally mathematical. More than 2,000 years later, philosophers and physicists are starting to…