Category: SCIENCE

LHC scientists just showed that spooky quantum entanglement applies to the highest-energy, shortest-lived particles of all: top quarks.

Of all the spooky quantum phenomena in our Universe, perhaps the spookiest of them all remains quantum entanglement. The basic idea behind it is that particles don’t just exhibit this weird sort of indeterminism — where they propagate as waves, in indeterminate states, but interact like particles with definitive and measurable properties — but that the quantum state of even disconnected particles can be related to one another. When you measure the quantum state of one entangled particle, you instantly know something about the pair that it’s entangled with: not an exactly-determined state, but with sets of probable outcomes that are superior to mere random chance.

Quantum entanglement has been well explored for conventional particles such as photons, electrons, positrons, protons, neutrons, and other atomic nuclei. However, nearly all of these tests have occurred at relatively low (conventional) energies and for relatively stable (long-lived) particles. Does quantum entanglement work the same way at high energies, and/or for extremely unstable, short-lived particles?

It’s possible to remove all forms of matter, radiation, and curvature from space. When you do, dark energy still remains. Is this mandatory?

Here in our Universe, one of the few things we can be certain of is that every signal we’ve ever observed has originated within the fabric of spacetime itself. Galaxies, stars, planets, atoms, particles and antiparticles, photons, gravitational waves and more all exist within, and propagate through, the fabric of space, affecting everything they encounter. Although it’s difficult, it is possible to find regions of space that are exceedingly empty: with only the smallest traces of matter and radiation, found in the deepest voids in intergalactic space. However, even in those regions, space itself not only has no problem continuing to exist, but the fabric of spacetime itself continues to expand, just as it does throughout the rest of the Universe.

Is there something profound about this? Does it mean that space and the energy that cannot be extracted from it — also known as dark energy — depend on one another for their mutual existence? That’s the question of Allan Hall, who asks:

“If you could remove all baryonic and dark matter from space it seems to me that…

With the discovery of Porphyrion, we’ve now seen black hole jets spanning 24 million light-years: the scale of the cosmic web.

How much of an influence can one single object in the Universe have? Until recently, we didn’t think it was all that much. Sure, individual objects can emit lots of things: photons of all wavelengths, neutrinos and antineutrinos of enormous energies, gravitational waves, and jets of energetic particles that can extend for thousands, hundreds of thousands, or maybe even millions of light-years. Collapsing massive stars can make core-collapse supernovae; merging neutron stars can make kilonovae; supermassive black holes can feed and transform into active galactic nuclei or quasars. All of these objects can, under the right conditions, emit more energy than all the stars within their host galaxies combined.

However, it won’t last. Unlike the steadily shining stars within galaxies, these energetic objects are temporary and transient: shining brilliantly for a brief amount of time, and then fading away back to a quiescent state. They’re capable of not only creating energetic bursts of radiation, but of interacting with the matter that surrounds them:

• creating ionized regions of space,

Within our observable Universe, there’s only one Earth and one “you.” But in a vast multiverse, so much more becomes possible.

Here in our Universe as we know it, once an outcome has occurred, there’s no going back. Once you open a bag of potato chips, you can never return that bag to its unopened state; the air molecules from inside and outside have already mixed with one another, even if you reseal it. Once you cut down a tree, you can never return the tree to the state it was in prior to you cutting it down. Even on a quantum level, once you measure a particle’s spin, you can never return it to its pre-measurement state. We have only the one Universe that we inhabit, and while future events do not yet have determinate outcomes, past events all do.

But what if there were copies of our Universe out there, far beyond the limits of what’s observable or measurable, that were identical to our own? Would it be possible for different outcomes to have occurred in those Universes, and what would that mean for a variety of systems: quantum particles, trees and potato chip bags, or even entire human beings? That’s what Danny Porter wants to know, writing in to ask:

“If the universe is infinite, and string theory suggests…

The laws of physics aren’t changing. But the Earth’s conditions are different than what they used to be, and so are hurricanes as a result.

Here in our Universe, there’s a formula for understanding how any physical phenomenon works. If we can come to know the fundamental rules governing any physical system, and if those rules remain constant over time, then we can input the parameters that we have at any moment and evolve that system forwards in time, allowing us to predict its future behavior. These laws enable certain phenomena to arise as long as specific physical conditions are met:

• gravitation and orbital parameters determine the tides,
• solar ejecta and the magnetic connection between the Earth and Sun determine the aurorae,
• and the interface between Earth’s windy atmosphere and the warm ocean waters determine the formation and properties of hurricanes.

The specifics of whatever conditions are in place at any moment in time help determine things — like frequency and intensity — of any such physical phenomenon.

For chaotic systems like hurricanes, there’s inevitably going to be a certain amount of variation and…

Hydrogen emission lines have never been seen earlier than 550 million years after the Big Bang. So why does JADES-GS-z13-1-LA have one?

Ever since its launch, JWST has revealed the cosmos in unprecedented light.

The widespread discovery of early, bright, ubiquitous galaxies puzzled many.

Years of research was needed before we understood why they were so numerous.

However, a new mystery has just arisen with detailed measurements of a new, ultra-distant galaxy.

Known as JADES-GS-z13-1-LA, it appears typical of very distant galaxies in many ways.

Although a great many unidentified sights have been seen in the skies, none have conclusively demonstrated the presence of aliens. So far.

Whenever we’re outside on a clear, starry night, our eyes are inexorably, almost irresistibly, drawn skyward, as if we can’t help ourselves from pondering and contemplating the great expanse of space that lies above us, separated only by our thin atmosphere. Yet within that atmosphere, many sights appear that often confound us: streaks of lights, sometimes flashing and sometimes steady, sometimes colored and sometimes white, frequently appearing to move at angle that make it difficult to know precisely what the nature of this object is or how far away it truly is from us. Most of these phenomena turn out to have mundane explanations, but for a few of them, their presence remains unexplained.

Could these hard-to-identify objects, normally called an unidentified aerial phenomenon (UAP) or an unidentified flying object (UFO), be signs of something beyond what modern science has the ability to explain? Could they even, potentially, be the result of activity by intelligent extraterrestrials? We shouldn’t let our imaginations run wild; we should figure out how to answer these questions scientifically…

The observation that everything we know is made out of matter and not antimatter is one of nature’s greatest puzzles. Will we ever solve it?

Here in our Universe, there are some cosmic puzzles that loom very large, casting a grand veil of uncertainty over our attempts to understand all of reality. Some of the biggest ones include:

• Why does the Universe obey the rules that it does, as opposed to any other rules?
• Why do the fundamental constants have the values that they do, rather than any other values that they could have taken on?
• Why do the particles of the Standard Model have the masses that they’re observed to have, and why are neutrinos massive at all?
• Why do we have dark matter and dark energy, and what, exactly, are these mysterious forms of energy that have eluded direct detection so far?

Yet there’s one enormous question, of importance on cosmic scales as well as to those who study nature at an elementary level, that often gets overlooked: why is our Universe, and everything in it, predominantly composed of normal matter, and not of antimatter? We’ve learned a whole slew of lessons about the Universe — what makes it…

The mass that gravitates and the mass that resists motion are, somehow, the same mass. But even Einstein didn’t know why this is so.

Here in our Universe, we don’t have just one different kind of mass that objects can possess. Instead, there are different types of mass that arise in different contexts. If you want to accelerate a mass — i.e., to change its motion — you’re interested in its inertial mass, or the mass that resists changes to its otherwise constant motion. (This is also the “m” in Newton’s famous equation, F = ma.) If you want to know how much gravity an object causes, you need to know its gravitational mass, or the total amount of gravitational energy that causes the fabric of spacetime to curve. And, although it seems unrelated, there’s also the rest mass that all massive objects possess: the “m” in Einstein’s most famous equation, E = mc².

Even though there’s no fundamental reason that these different types of mass should be equivalent to one another, it’s an idea that has been around for a long time. It was suspected by Newton hundreds of years ago, and the first very strict tests were performed by physicist Loránd Eötvös from the 1880s through the 1920s, for whom the famed Eötvös experiment is named. But, at…

The “little red dots” were touted as being too massive, too early, for cosmology to explain. With new knowledge, everything adds up.

It’s hard to believe, but it was only two years ago, in the summer of 2022, that the very first science images from the James Webb Space Telescope (JWST) were unveiled to the world. Although they revealed remarkable details about newly forming planets, young stellar systems, exoplanets, stars with debris disks, galaxies, and much, much more, the greatest surprise came when looking to the greatest distances of all. Out there, amidst the deepest cosmic depths ever probed, were an unexpected population of galaxies — in large numbers — that were incredibly distant, red in color, point-like in size, and yet were still bright enough to be easily detected by JWST’s instruments.

These objects, known colloquially as “little red dots,” presented a challenge for modern cosmology. We already had a very precise picture of what the ingredients in our Universe were: a mix of dark energy, dark matter, normal matter, and a tiny bit of radiation, and we already knew how old the Universe was and how we expected structure to form within it. So why were there so many of these bright objects appearing at such early…