Meet The Universe’s First-Ever Supermass…

Meet The Universe’s First-Ever Supermassive Binary Black Holes

“In 1891, the object OJ 287, 3.5 billion light years distant and a blazar itself, optically bursted. Every 11-12 years since, it’s produced another burst, recently discovered to have two, narrowly-separated peaks. Its central, supermassive black hole is 18 billion solar masses, one of the largest known in the Universe. This periodic double-burst arises from a 100-150 million solar mass black hole punching through the primary’s accretion disk.”

The big problem with black holes is that, well, they’re so dark. They don’t emit any detectable light of their own, so we have to rely on indirect, secondary signals to infer their existence. That usually arises in the form of radio and X-ray radiation from matter that gets accelerated by the black hole’s extreme gravity, as well as from the magnetic fields that an accretion disk around the black hole can create. The radiation can form jets, and when a jet points at our eyes, we see a blazar. Well, the system OJ 287 has a periodic blazar that flares in a double-burst every 11-12 years, indicative of a large, supermassive black hole orbiting an even more massive behemoth, punching through the accretion disk twice with every orbit.

Come meet OJ 287, first found to burst way back in 1891, and still one of only two supermassive black hole binaries known in the Universe!

Ask Ethan: How Do We Know The Age Of The Solar…

Ask Ethan: How Do We Know The Age Of The Solar System?

“How do we know the age of our solar system? […] I have a loose grasp on the concept of dating the time elapsed since a rock was liquid, but 4.5 Billion years is roughly how long ago Theia hit proto-Earth liquefying a massive amount of everything. […] How do we know we’re actually dating the solar system and not just finding dozens of ways to date the Theia collision?”

You’ve probably heard the estimates before: that the Earth, the Sun, and the rest of the Solar System are all about 4.5 or 4.6 billion years old. But why be so imprecise? We don’t have to be! In fact, we know that there are slight variations, and based on the fact that we think that the Earth-Moon system formed from a giant impact tens of millions of years after the rest of the Solar System did, we shouldn’t get the same answer for everything! It turns out that we’ve now advanced to the point where we can actually give answers that are extremely accurate: the Earth-Moon system should be 4.51 billion years old; the oldest meteorites show an age for the rest of the Solar System of 4.568 billion years, and the Sun may be a little older at 4.6 billion years.

How do we know? The science of radioactive decay holds the answer, and it’s a lot more complex, but a lot more well-understood, than you might think!

Mars Opportunity And Spirit Rovers Could Have …

Mars Opportunity And Spirit Rovers Could Have Lived Practically Forever With One Tiny Change

“If one extra piece of equipment, such as a compressed air blower aboard a robotic arm, were installed, dusty solar panels could be cleaned at will. Hunkering down to survive a dust storm, even one that blocked 100% of the light, wouldn’t be catastrophic so long as the rovers had enough power stored in their batteries to control and operate the blower mechanism. Had that been in place, Spirit could have saved itself from its 2010 fate, and Opportunity wouldn’t be in the danger it’s in now, in the midst of the enormous dust storm it’s experiencing. Still, even though hindsight is 20/20, it’s pretty hard to be sad about two missions that overachieved beyond anyone’s expectations. But for next time, it’s an invaluable lesson: if you can protect yourself from Martian dust accumulation, you could potentially live forever. At least, if you’re a rover on Mars.”

If a dust storm blots out the Sun, then we shall rove in the shade, says the brave Mars rover. But for a rover like Opportunity, which relies on solar panels, this is a lousy, battery-draining strategy that would be its death knell. Despite the fact that it’s lasted for over 5,000 Martian days and roved for over 45 kilometers, this single large dust storm that it’s caught it could be its absolute end. Unless a natural cleaning event occurs, its panels may be so dust-covered as to be useless, which is how Spirit, its twin, met its demise in 2010. Although the rover has far exceeded its expectations, if it were built with the capability of actively addressing the dust accumulation problem, both Spirit and Opportunity could have lived, practically, forever.

Here are the options for the tiny changes that could have been made that would have kept them alive indefinitely. Go, little rover, go!

Are Space And Time Quantized? Maybe Not, Says …

Are Space And Time Quantized? Maybe Not, Says Science

“Incredibly, there may actually be a way to test whether there is a smallest length scale or not. Three years before he died, physicist Jacob Bekenstein put forth a brilliant idea for an experiment where a single photon would pass through a crystal, causing it to move by a slight amount. Because photons can be tuned in energy (continuously) and crystals can be very massive compared to a photon’s momentum, it ought to be possible to detect whether the “steps” that the crystal moves in are discrete or continuous. With a low-enough energy photon, if space is quantized, the crystal would either move a single quantum step or not at all.”

When it comes to the Universe, everything that’s in it appears to be quantum. All the particles, radiation, and interactions we know of are quantized, and can be expressed in terms of discrete packets of energy. Not everything, however, goes in steps. Photons can take on any energy at all, not just a set of discrete values. Put an electron in a conducting band, and its position can take on a set of continuous (not discrete) values. And so then there’s the big question: what about space and time? Are they quantized? Are they discrete? Or might they be continuous, even if there’s a fundamental quantum theory of gravity.

Surprisingly, space and time don’t need to be discrete, but they might be! Here’s what the science has to say so far.

The Surprising Reason Why Neutron Stars Don&rs…

The Surprising Reason Why Neutron Stars Don’t All Collapse To Form Black Holes

“The measurements of the enormous pressure inside the proton, as well as the distribution of that pressure, show us what’s responsible for preventing the collapse of neutron stars. It’s the internal pressure inside each proton and neutron, arising from the strong force, that holds up neutron stars when white dwarfs have long given out. Determining exactly where that mass threshold is just got a great boost. Rather than solely relying on astrophysical observations, the experimental side of nuclear physics may provide the guidepost we need to theoretically understand where the limits of neutron stars actually lie.”

If you take a large, massive collection of matter and compress it down into a small space, it’s going to attempt to form a black hole. The only thing that can stop it is some sort of internal pressure that pushes back. For stars, that’s thermal, radiation pressure. For white dwarfs, that’s the quantum degeneracy pressure from the electrons. And for neutron stars, there’s quantum degeneracy pressure between the neutrons (or quarks) themselves. Only, if that last case were the only factor at play, neutron stars wouldn’t be able to get more massive than white dwarfs, and there’s strong evidence that they can reach almost twice the Chandrasekhar mass limit of 1.4 solar masses. Instead, there must be a big contribution from the internal pressure each the individual nucleon to resist collapse.

For the first time, we’ve measured that pressure distribution inside the proton, paving the way to understanding why massive neutron stars don’t all form black holes.

Is Theoretical Physics Wasting Our Best Living…

Is Theoretical Physics Wasting Our Best Living Minds On Nonsense?

“The book is a wild, deep, thought-provoking read that would make any reasonable person in the field who’s still capable of introspection doubt themselves. No one likes confronting the possibility of having wasted their lives chasing a phantasm of an idea, but that’s what being a theorist is all about. You see a few pieces of an incomplete puzzle and guess what the full picture truly is; most times, you’re wrong. Perhaps, in these cases, all our guesses have been wrong. In my favorite exchange, she interviews Steven Weinberg, who draws on his vast experience in physics to explain why naturalness arguments are good guides for theoretical physicists. But he only manages to convince us that they were good ideas for the classes of problems they previously succeeded at solving. There’s no guarantee they’ll be good guideposts for the current problems; in fact, they demonstrably have not been.”

There are a slew of brilliant ideas in physics that have now become the dominant, accepted theory of what describes reality: the Standard Model. the Big Bang, General Relativity, etc. These theories are, in many ways, beautiful. They have an elegant mathematical structure, they have strong predictive power, and most importantly, they match reality. It’s that last criteria that separates them from other beautiful theories that have fallen by the wayside, such as the beautiful (but incorrect) Sakata Model. theory of Technicolor, Steady-State Model, and more. Without the experimental evidence to support them, however, are we wrongly investing our energy, intellect, and resources into beautiful, promising dead-ends? In particular, are supersymmetry, grand unification, string theory, and the multiverse exactly those dead-ends, and is following them the reason (or a symptom of) why progress has been so scarce in recent decades?

Come learn about naturalness, this possibility, and why you should buy Sabine Hossenfelder’s new book, Lost In Math, to learn more!

Remnants Of Our Solar System’s Formation Found…

Remnants Of Our Solar System’s Formation Found In Our Interplanetary Dust

“Our naive picture of a disk that gets very hot, fragments, and cools to then form planets may be hopelessly oversimplified. Instead, we’ve learned that it may actually be cold, outer material that holds the key to our planetary backyard. If the conclusions of the Ishii et al. paper stand the test of time, we may have just revolutionized our understanding of how all planetary systems come into being.”

How did Earth (and the other planets) form? According to conventional wisdom, a molecular cloud collapsed, formed a protoplanetary disk, funneled material into the center, and gave birth to a star. This star then blew off the gas and light elements from the inner Solar System, with the planets we have today representing the survivors from these hot, early stages. Only, what if that picture weren’t correct after all? What if the material that gave rise to our (and other) worlds wasn’t forged in an inferno, but in a colder, more distant environment that only fell into the inner reaches at a later time?

The way to decide would be to identify and examine material left over from these early stages of Solar System formation in enough detail. For the first time, we’ve done exactly that. Don’t miss the results!

New Stars Turn Galaxies Pink, Even Though Ther…

New Stars Turn Galaxies Pink, Even Though There Are No ‘Pink Stars’

“New star-forming regions produce lots of ultraviolet light, which ionizes atoms by kicking electrons off of their nuclei.

These electrons then find other nuclei, creating neutral atoms again, eventually cascading down through its energy levels.

Hydrogen is the most common element in the Universe, and the strongest visible light-emitting transition is at 656.3 nanometers.

The combination of this red emission line — known as the Balmer alpha (or Hα) line — with white starlight adds up to pink.”

When you look through a telescope’s eyepiece at a distant galaxy, it will always appear white to you. That’s because, on average, starlight is white, and your eyes are more sensitive to white light than any color in particular. But with the advent of a CCD camera, collecting individual photons one-at-a-time, you can more accurately gauge an astronomical object’s natural color. Even though new stars are predominantly blue in color, star-forming regions and galaxies appear pink. The problem compounds itself when you realize there isn’t any such thing as a pink star! And yet, there’s a straightforward physical explanation for what we see.

It’s a combination of ultraviolet radiation, white starlight, and the physics of hydrogen atoms that turn galaxies pink. Find out how, with some incredible  visuals, today!

Ask Ethan: If Mass Curves Spacetime, How Does …

Ask Ethan: If Mass Curves Spacetime, How Does It Un-Curve Again?

“We are taught that mass warps spacetime, and the curvature of spacetime around mass explains gravity – so that an object in orbit around Earth, for example, is actually going in a straight line through curved spacetime. Ok, that makes sense, but when mass (like the Earth) moves through spacetime and bends it, why does spacetime not stay bent? What mechanism un-warps that area of spacetime as the mass moves on?”

You’ve very likely heard that according to Einstein, matter tells spacetime how to curve, and that curved spacetime tells matter how to move. This is true, but then why doesn’t spacetime remain curved when a mass that was once there is no longer present? Does something cause space to snap back to its prior, un-bent position? As it turns out, we need to think pretty hard about General Relativity to get this right in the first place at all. It isn’t just the locations and magnitudes of masses that determine how objects move through space, but a series of subtle effects that must all be added together to get it right. When we do, we find out that uncurving this space actually results in gravitational radiation: ripples in space that have been observed and confirmed.

The deciding results are actually decades old, and were indirect evidence for gravitational waves long before LIGO. Come get the answer today!

Sorry, Methane And ‘Organics’ On M…

Sorry, Methane And ‘Organics’ On Mars Are Not Evidence For Life

“In 2020, two next-generation rovers will launch: ESA’s ExoMars and NASA’s Mars 2020. Instead of indirect inferences and possibilities, we’ll actually be able to understand whether the origin of these molecules is geological or biological in nature. It’s important to keep an open mind and let science, rather than our hopes or fears, decide the answer. The evidence is building, and we’re finally gaining a more robust picture of how, exactly, Mars works.

It’s producing methane seasonally, contains loads of carbon-based compounds, and had a very watery past. But does that all add up to life, past or present? In 2018, the evidence doesn’t say “yes” just yet. But in just a few years, we just might have the answer. In a few years, for the first time, we might finally know if there’s life beyond Earth.”

We use the word “organics” a lot when we talk about life (and molecules) beyond Earth. But while that word may conjure up images of reproducing molecules, new cells, and life, the scientific definition is far more mundane: a molecule containing carbon. That means carbon monoxide and cyanide are organic, even though they may be toxic to life itself. The discovery of seasonally-varying methane on Mars is interesting, but it may be better evidence for something geologically compelling than it is for anything biological. Regardless of how you interpret it, one thing is for certain: everything we’ve found on Mars so far is not yet enough to claim evidence for life.

So we’ll continue to look in new and better ways. But until the deciding evidence comes in, be skeptical. Good science demands it.