Physics Archives

September 17, 2019September 17, 2019 by Evan Gough

Physicists Don’t Know the Mass of a Neutrino, But Now They Know it’s No Larger Than 1 Electron Volt

The NUmI (Neutrinos from the Main Injector) horn at Fermilab, which fires protons that degrade into neutrinos. (Image: Caltech)

The Standard Model of Particle Physics is one of science’s most impressive feats. It’s a rigorous, precise effort to understand and describe three of the four fundamental forces of the Universe: the electromagnetic force, the strong nuclear force, and the weak nuclear force. Gravity is absent because so far, fitting it into the Standard Model has been extremely challenging.

But there are some holes in the Standard Model, and one of them involves the mass of the neutrino.

June 27, 2019June 28, 2019 by Matt Williams

French Scientists Claim to Have Created Metallic Hydrogen

Using two diamonds, scientists squeezed hydrogen to pressures above those in Earth's core. Credit: Sang-Heon Shim, Arizona State University

Scientists have long speculated that at the heart of a gas giant, the laws of material physics undergo some radical changes. In these kinds of extreme pressure environments, hydrogen gas is compressed to the point that it actually becomes a metal. For years, scientists have been looking for a way to create metallic hydrogen synthetically because of the endless applications it would offer.

At present, the only known way to do this is to compress hydrogen atoms using a diamond anvil until they change their state. And after decades of attempts (and 80 years since it was first theorized), a team of French scientists may have finally created metallic hydrogen in a laboratory setting. While there is plenty of skepticism, there are many in scientific community who believe this latest claim could be true.

June 8, 2019January 26, 2021 by Matt Williams

Black Hole Simulation Solves a Mystery About Their Accretion Disks

Credit: ESA/Hubble, ESO, M. Kornmesser — Researchers at WSU have created a fluid with a negative effective mass for the first time, which could open the door to studying the deeper mysteries of the Universe. Credit: ESA/Hubble, ESO, M. Kornmesse

Black holes are one of the most awesome and mysterious forces in the Universe. Originally predicted by Einstein’s Theory of General Relativity, these points in spacetime are formed when massive stars undergo gravitational collapse at the end of their lives. Despite decades of study and observation, there is still much we don’t know about this phenomenon.

For example, scientists are still largely in the dark about how the matter that falls into orbit around a black hole and is gradually fed onto it (accretion disks) behave. Thanks to a recent study, where an international team of researchers conducted the most detailed simulations of a black hole to date, a number of theoretical predictions regarding accretion disks have finally been validated.

May 14, 2019May 14, 2019 by Matt Williams

Antimatter Behaves Exactly the Same as Regular Matter in Double Slit Experiments

In 1924, French physicist Louis de Broglie proposed that photons – the subatomic particle that constitutes light – behave as both a particle and a wave. Known as “particle-wave duality”, this property has been tested and shown to apply with other subatomic particles (electrons and neutrons) as well as larger, more complex molecules.

Recently, an experiment conducted by researchers with the QUantum Interferometry and Gravitation with Positrons and LAsers (QUPLAS) collaboration demonstrated that this same property applies to antimatter. This was done using the same kind of interference test (aka. double-slit experiment) that helped scientists to propose particle-wave duality in the first place.

April 24, 2019April 24, 2019 by Paul M. Sutter

Barfing Neutron Stars Reveal Their Inner Guts

Artist's illustration of two merging neutron stars. The narrow beams represent the gamma-ray burst while the rippling spacetime grid indicates the isotropic gravitational waves that characterize the merger. Swirling clouds of material ejected from the merging stars are a possible source of the light that was seen at lower energies. Credit: National Science Foundation/LIGO/Sonoma State University/A. Simonnet

We don’t really understand neutron stars. Oh, we know that they are – they’re the leftover remnants of some of the most massive stars in the universe – but revealing their inner workings is a little bit tricky, because the physics keeping them alive is only poorly understood.

But every once in a while two neutron stars smash together, and when they do they tend to blow up, spewing their quantum guts all over space. Depending on the internal structure and composition of the neutron stars, the “ejecta” (the polite scientific term for astronomical projectile vomit) will look different to us Earth-bound observers, giving us a gross but potentially powerful way to understand these exotic creatures.

March 13, 2019March 13, 2019 by Matt Williams

Using Black Holes to Conquer Space: The Halo Drive!

Close-up of star near a supermassive black hole (artist’s impression). Credit: ESA/Hubble, ESO, M. Kornmesser

The idea of one day traveling to another star system and seeing what is there has been the fevered dream of people long before the first rockets and astronauts were sent to space. But despite all the progress we have made since the beginning of the Space Age, interstellar travel remains just that – a fevered dream. While theoretical concepts have been proposed, the issues of cost, travel time and fuel remain highly problematic.

A lot of hopes currently hinge on the use of directed energy and lightsails to push tiny spacecrafts to relativistic speeds. But what if there was a way to make larger spacecraft fast enough to conduct interstellar voyages? According to Prof. David Kipping – the leader of Columbia University’s Cool Worlds lab – future spacecraft could rely on a Halo Drive, which uses the gravitational force of a black hole to reach incredible speeds.

March 11, 2019March 11, 2019 by Paul M. Sutter

Massive Photons Could Explain Dark Matter, But Don’t

A computer simulation of the distribution of matter in the universe. Orange regions host galaxies; blue structures are gas and dark matter. Credit: TNG Collaboration

I’ll be the first to admit that we don’t understand dark matter. We do know for sure that something funny is going on at large scales in the universe (“large” here meaning at least as big as galaxies). In short, the numbers just aren’t adding up. For example, when we look at a galaxy and count up all the hot glowing bits like stars and gas and dust, we get a certain mass. When we use any other technique at all to measure the mass, we get a much higher number. So the natural conclusion is that not all the matter in the universe is all hot and glowy. Maybe some if it is, you know, dark.

But hold on. First we should check our math. Are we sure we’re not just getting some physics wrong?

March 4, 2019March 4, 2019 by Paul M. Sutter

Astronomers are Using NASA’s Deep Space Network to Hunt for Magnetars

An artist's impression of a magnetar, a highly magnetic, slowly rotating neutron star. Credit: ESO/L. Calçada

Right, magnetars. Perhaps one of the most ferocious beasts to inhabit the cosmos. Loud, unruly, and temperamental, they blast their host galaxies with wave after wave of electromagnetic radiation, running the gamut from soft radio waves to hard X-rays. They are rare and poorly understood.

Some of these magnetars spit out a lot of radio waves, and frequently. The perfect way to observe them would be to have a network of high-quality radio dishes across the world, all continuously observing to capture every bleep and bloop. Some sort of network of deep-space dishes.

Like NASA’s Deep Space Network.

February 5, 2019February 5, 2019 by Paul M. Sutter

How The Sun’s Scorching Corona Stays So Hot

We’ve got a mystery on our hands. The surface of the sun has a temperature of about 6,000 Kelvin – hot enough to make it glow bright, hot white. But the surface of the sun is not its last later, just like the surface of the Earth is not its outermost layer. The sun has a thin but extended atmosphere called the corona. And that corona has a temperature of a few million Kelvin.

How does the corona have such a higher temperature than the surface?

Like I said, a mystery.

January 17, 2019January 17, 2019 by Evan Gough

CERN is Planning to Build a Much Larger Particle Collider. Much, Much, Larger.

CERN's Future Circular Collider. Image Credit: CERN

CERN, the European Organization for Nuclear Research, wants to build a particle collider that will dwarf the Large Hadron Collider (LHC). The LHC has made important discoveries, and planned upgrades to its power ensures it will keep working on physics problems into the future. But eventually, it won’t be enough to unlock the secrets of physics. Eventually, we’ll need something larger and more powerful.

Enter the Future Circular Collider (FCC.) The FCC will exceed the LHC in power by an order of magnitude. On January 15th, the FCC collaboration released its Conceptual Design Report (CDR) that lays out the options for CERN’s Future Circular Collider.