Physics Archives

December 14, 2021December 14, 2021 by Andy Tomaswick

Gravitational Waves Could Explain why There’s More Matter Than Antimatter in the Universe

One of the questions underpinning both philosophy and science is “why are we here”? Ask an astrophysicist, and they might answer with an imbalance between matter and antimatter at the beginning of the universe. While that is a (relatively) simple explanation, it then begs the question – why was there an imbalance in the first place? Scientists have been seeking ways to test various theories regarding that imbalance but have come up empty-handed so far. Now, a team of theoretical physicists think they might have found a way to test some of those theories using gravitational waves.

September 29, 2021September 29, 2021 by Evan Gough

Even the Quiet Supermassive Black Holes are Blasting out Neutrinos and Gamma Rays

Is there anywhere in the Universe where we can escape from radiation? Certainly not here on Earth. And not in space itself, which is filled with diffuse radiation in the form of gamma rays and neutrinos. Scientists have struggled to explain where all those gamma rays and neutrinos come from. A trio of researchers is proposing a source for all that radiation in a new paper: resting black holes.

August 14, 2021August 14, 2021 by Brian Koberlein

Matter From Light. Physicists Create Matter and Antimatter by Colliding Just Photons.

An artistic view of light becoming matter. Credit: Gerd Altmann, via Pixabay

In 1905 Albert Einstein wrote four groundbreaking papers on quantum theory and relativity. It became known as Einstein’s annus mirabilis or wonderous year. One was on brownian motion, one earned him the Nobel prize in 1921, and one outlined the foundations of special relativity. But it’s Einstein’s last 1905 paper that is the most unexpected.

July 15, 2021July 13, 2021 by Paul M. Sutter

Don’t Be Surprised if EmDrive Experiments Never Work

Artist's concept of an interstellar craft. Credit and Copyright: Mark Rademaker

Every few years the “EmDrive”, a proposed method of generating rocket thrust without any exhaust, hits the news. Each time, everyone asks: could this be it? Could this be the technological leap to revolutionize spaceflight?

Don’t hold your breath.

June 10, 2021June 10, 2021 by Matt Williams

Sending a Spacecraft to Another Star Will Require a Million Lasers Working Together

An artist's illustration of a light-sail powered by a radio beam (red) generated on the surface of a planet. The leakage from such beams as they sweep across the sky would appear as Fast Radio Bursts (FRBs), similar to the new population of sources that was discovered recently at cosmological distances. Credit: M. Weiss/CfA

In 2016, Russian-American billionaire Yuri Milner founded Breakthrough Initiatives, a non-profit organization dedicated to investigating some of the most enduring mysteries of the Universe. Chief among their scientific efforts is Breakthrough Starshot, a proof-of-concept prototype that combines a lightsail, a nanocraft, and directed energy (aka. laser) propulsion to create a spacecraft capable of reaching the nearest star (Alpha Centauri) in our lifetimes.

Naturally, this presents all sorts of technical and engineering challenges, not the least of which is the amount of power needed to accelerate the spacecraft to relativistic speeds (a fraction of the speed of light). Luckily, scientists from the Australian National University (ANU) recently came up with a design for a directed-energy array made up of millions of individual lasers positioned across the Earth’s surface.

April 18, 2021April 18, 2021 by Matt Williams

Fermilab’s Muon g-2 Experiment Finally Gives Particle Physicists a Hint of What Lies Beyond the Standard Model

The Muon g-2 experiment at the Fermi National Accelerator Laboratory (Fermilab). Credit: Reidar Hahn/Fermilab

Since the long-awaited detection of the Higgs Boson in 2012, particle physicists have been probing deeper into the subatomic realm in the hope of investigating beyond the Standard Model of Particle Physics. In so doing, they hope to confirm the existence of previously unknown particles and the existence of exotic physics, as well as learning more about how the Universe began.

At the Fermi National Accelerator Laboratory (aka. Fermilab), researchers have been conducting the Muon g-2 experiment, which recently announced the results of their first run. Thanks to the unprecedented precision of their instruments, the Fermilab team found that muons in their experiment did not behave in a way that is consistent with the Standard Model, resolving a discrepancy that has existed for decades.

March 19, 2021March 19, 2021 by Brian Koberlein

There Could be Magnetic Monopoles Trapped in the Earth's Magnetosphere

A visualization of Earth's magnetosphere. Credit: NASA's Scientific Visualization Studio

Electricity and magnetism have a lot in common. They are connected by the unified theory of electromagnetism, and are in many ways two sides of the same coin. Both can exert forces on charges and magnetic fields. A changing electric field creates a magnetic field and vice versa. Elementary particles can possess electric and magnetic properties. But there is one fundamental difference.

March 15, 2021March 15, 2021 by Brian Koberlein

Wormholes Could Allow Travel Across the Universe, as Long as Your Spacecraft is Microscopic

Artist rendering of a wormhole connecting two galaxies. Credit: Davide and Paolo Salucci

In my last post, I talked about the idea of warp drive and whether it might one day be possible. Today I’ll talk about another faster-than-light trick: wormholes.

March 12, 2021March 12, 2021 by Brian Koberlein

Alcubierre Gives us an Update on his Ideas About Warp Drives

The Enterprise using warp drive, as seen in Star Trek Beyond. Credit: Paramount Pictures

If you want a galaxy-spanning science fiction epic, you’re going to need faster than light travel. The alternative is taking decades or centuries to reach an alien star system, which isn’t nearly as much fun. So, you start with some wild scientific idea, add a bit of technobabble, and poof! Quam Celerrime ad Astra. Everything from wormholes to hyperspace has been used in sci-fi, but perhaps the best known FTL trope is warp drive.

February 19, 2021February 19, 2021 by Brian Koberlein

A new Approach Could Tease out the Connection Between Gravity and Quantum Mechanics

In physics, there are two main ways to model the universe. The first is the classical way. Classical models such as Newton’s laws of motion and Einstein’s theory of relativity assume that the properties of an object such as its position and motion are absolute. There are practical limits to how accurately we can measure an object’s path through space and time, but that’s on us. Nature knows their motion with infinite precision. Quantum models such as atomic physics assume that objects are governed by interactions. These interactions are probabilistic and indefinite. Even if we constrain an interaction to limited outcomes, we can never know the motion of an object with infinite precision, because nature doesn’t allow it.