A time crystal, in theory, isn’t a crystal in the conventional sense, where a lattice of particles interconnects in a repetitive pattern. Instead, the quantum state of the system returns to its original state a finite and predictable amount of time later, a phenomenon which can in theory be repeated indefinitely. (Credit: igorda888/pixabay, public domain)

Is it really an otherworldly revolution, leveraging quantum computing, that will change physics forever?

It’s tempting, whenever a new discovery comes along, to imagine a whole slew of revolutions that might soon ensue. After all, anytime you can suddenly do or accomplish any task that was previously impractical or even (thought to be) impossible, that’s one fewer obstacle standing in the way of even your loftiest, pie-in-the-sky dreams. However, no matter what discoveries ensue, the fundamental laws of physics that underlie reality must always be obeyed; you might be able to cajole nature into doing a lot of clever things, but you can’t very well break the rules that govern it. If you could…


Electrons exhibit wave properties as well as particle properties, and can be used to construct images or probe particle sizes just as well as light can. Here, you can see the results of an experiment where electrons are fired one-at-a-time through a double-slit. Once enough electrons are fired, the interference pattern can clearly be seen. (Credit: THIERRY DUGNOLLE / PUBLIC DOMAIN)

An exclusive interview with physicist Lee Smolin reveals how abandoning Einstein’s dream may have been a terrible mistake.

At a fundamental level, we often assume that there are two ways of describing nature that each work well in their own regime, but that don’t seem to play well together. On the one hand, we know that the matter and energy that makes up the Universe, from stars to atoms to neutrinos to photons, all require a quantum description in order to extract their properties and behavior. The Standard Model, the pinnacle of quantum physics, works perfectly well to describe every interaction we’ve ever measured in the Universe.

On the other hand, we also have General Relativity: our theory…


Countless scientific tests of Einstein’s general theory of relativity have been performed, subjecting the idea to some of the most stringent constraints ever obtained by humanity. Einstein’s first solution was for the weak-field limit around a single mass. (LIGO scientific collaboration / T. Pyle / Caltech / MIT)

Mathematically, it’s a monster, but we can understand it in plain English.

Although Einstein is a legendary figure in science for a large number of reasons — E = mc², the photoelectric effect, and the notion that the speed of light is a constant for everyone — his most enduring discovery is also the least understood: his theory of gravitation, General Relativity. Before Einstein, we thought of gravitation in Newtonian terms: that everything in the Universe that has a mass instantaneously attracts every other mass, dependent on the value of their masses, the gravitational constant, and the square of the distance between them. …


From distant sources of light, like galaxies and quasars, intervening gas clouds can be probed. Anything present, including molecules, atoms, or even ions, can be probed for absorption features. If the right combination of elements and their isotopes are present, a value for the fine-structure constant at that location can be extracted. (SPECTRUM: NASA/CXC/UNIV. OF CALIFORNIA IRVINE/T. FANG. ILLUSTRATION: CXC/M. WEISS)

Signals from across the Universe point towards a fascinating possibility.

Whenever we examine the Universe in a scientific manner, there are a few assumptions that we take for granted as we go about our investigations. We assume that the measurements that register on our devices correspond to physical properties of the system we’re observing. We assume that the fundamental properties, laws, and constants associated with the material Universe don’t spontaneously change from moment-to-moment. And we also assume, for many compelling reasons, that although the environment may vary from location-to-location, the rules that govern the Universe always remain the same.

But every assumption, no matter how well-grounded it may be or…


One peek into a small part of the sky, one giant leap back in time. This small patch of sky represents less than 1/100,000,000th of the volume of the Universe, but reveals nearly 1,000 galaxies that had never been seen before. This small fraction of the original Hubble Deep Field image is a huge part of how we learned what our Universe looks like. (R. WILLIAMS (STSCI), THE HUBBLE DEEP FIELD TEAM AND NASA/ESA)

But the upcoming James Webb Space Telescope compels us to add, “so far.”

Beginning with its 1990 launch, NASA’s Hubble Space Telescope revolutionized our conception of the Universe.


Image credit: NASA/JPL/Ted Stryk, of Europa with its uniquely curved stripes, for the Galileo mission.

How the search for alien life is taking place right here in our own Solar System.

If you want to understand the origin of life in the Universe, you have three basic ways to do it. One is to search for intelligent aliens directly: through a program such as SETI. Another is to search for life in Solar Systems beyond our own: looking for bio-signatures, or perhaps bio-hints, on extraterrestrial worlds many light-years away. But within our own Solar System, there are a plethora of worlds, including the ice-and-liquid-rich bodies we have, that are fascinating candidates for life of non-Earth origin.

There’s so much to explore and so many different aspects of what’s out there that…


A combination of X-ray, optical, and infrared data reveal the central pulsar at the core of the Crab Nebula, including the winds and outflows that the pulsars care in the surrounding matter. Pulsars are known emitters of cosmic rays, but there’s a reason we don’t situate these detectors primarily in space. (X-RAY: NASA/CXC/SAO; OPTICAL: NASA/STSCI; INFRARED: NASA-JPL-CALTECH)

The highest-energy particles of all come from space, not human-made colliders.

When it comes to the most energetic particle collisions of all, you might think that the Large Hadron Collider is the ultimate place to go. After all, that’s what it’s specifically designed to do: to accelerate particles, in a controlled fashion, to the highest energies and greatest speeds possible, and then to collide them with one another at specific “collision points,” where we’ve set up detectors to monitor the properties of everything that comes out.

With sufficiently sophisticated equipment — pixel detectors extremely close to the collision point, calorimeters to monitor the energy and momentum carried by the particles, magnetic…


A new conspiracy theory, promoted by Sen. Rand Paul, vilifies Dr. Fauci and attempts to tie him to the notion that the novel coronavirus SARS-CoV-2 was engineered in and leaked from the Wuhan Institute for Virology. The scientific evidence says otherwise on all counts. (SUSAN WALSH-POOL/GETTY IMAGES)

Without these two elements, we’re doomed to fail.

In this day and age, it’s virtually impossible to have sufficient expertise to figure out what the complete, comprehensive, scientifically validated truth surrounding any issue is. Unless you yourself have spent many years studying, researching, and actively participating in furthering the scientific endeavor in a particular field, you can be certain — with an incredibly high degree of confidence — that your non-expertise will fundamentally limit the depth and breadth of your understanding. …


The quarks, antiquarks, and gluons of the standard model have a color charge, in addition to all the other properties like mass and electric charge that other particles and antiparticles possess. All of these particles, to the best we can tell, are truly point-like, and come in three generations. At higher energies, it is possible that still additional types of particles will exist, but they go beyond the Standard Model’s description. (E. SIEGEL / BEYOND THE GALAXY)

Why are the rest masses of fundamental particles related like this?

When it comes to the nature of matter in the Universe, the Standard Model describes the known elementary particles perfectly well and without exception, at least so far. There are two classes of fundamental particles:

  • the fermions, which all possess non-zero rest masses, half-integer spins, and can be charged under the strong, electromagnetic, and weak interactions,
  • and the bosons, which can be massive or massless, possess integer spins, and mediate the strong, electromagnetic, and weak interactions.

The fermions come in three generations and are split between the six types of quarks and leptons, while among the bosons, there are no…


An aerial view of CERN, with the Large Hadron Collider’s circumference (27 kilometers in all) outlined. The same tunnel was used to house an electron-positron collider, LEP, previously. The particles at LEP went far faster than the particles at the LHC, but the LHC protons carry far more energy than the LEP electrons or positrons did. Strong tests of symmetries are performed at the LHC, but photon energies are well below what the Universe produces. (MAXIMILIEN BRICE (CERN))

More energy means more potential for discovery, but we’re topped out.

If your goal is to discover something completely novel, you have to look in a way that no one else has looked before. That could mean probing the Universe to greater precision, where every decimal point in your measurement counts. It could occur by gathering greater and greater numbers of statistics, so that extremely rare, improbable events are revealed. Or a new discovery could be awaiting us by pushing the frontiers of our capabilities to ever-increasing extremes: lower temperatures for cryogenic experiments, farther distances and fainter objects for astronomical studies, or to greater energies for high-energy physics experiments.

It’s by…

Ethan Siegel

The Universe is: Expanding, cooling, and dark. It starts with a bang! #Cosmology Science writer, astrophysicist, science communicator & NASA columnist.

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