Physics

“The more clearly we can focus our attention on the wonders and realities of the universe about us, the less taste we shall have for destruction.” -Rachel Carson The idea that the spatial fabric of the Universe itself is expanding, and that’s what’s behind the observed relationship between redshift and distance has long been controversial, and also long-misunderstood. After all, if more distant objects appear to recede more quickly, couldn’t there be a different explanation, like an explosion that flung many things outward? As it turns out, this isn’t a mere difference in interpretation,…
"Despite its name, the big bang theory is not really a theory of a bang at all. It is really only a theory of the aftermath of a bang." -Alan Guth Did the Universe begin with the Big Bang? When we discovered the cosmic microwave background, and its properties matched exactly the prediction of the Big Bang theory, it was a watershed moment for cosmology. For the first time, we had uncovered the origins to the entire Universe, having learned where all of this came from at long last. Emerging from a hot, dense, expanding, and cooling state, the matter-and-radiation-filled early Universe gave…
"In terms of weapons, the best disarmament tool so far is nuclear energy. We have been taking down the Russian warheads, turning it into electricity. 10 percent of American electricity comes from decommissioned warheads." -Stewart Brand Arguably the greatest advance of humanity — and the cause of the greatest increase in our quality of life — in the past few centuries has been the widespread availability of electrical energy. It powers our homes, our industries, our automobiles, our places of business and more. Our world runs on energy, with the world using upwards of 155,000 TeraWatt-hours…
“There’s something about sitting alone in the dark that reminds you how big the world really is, and how far apart we all are. The stars look like they’re so close, you could reach out and touch them. But you can’t. Sometimes things look a lot closer than they are.” -Kami Garcia When we consider things like molecules, atoms, or even protons and neutrons, they all have finite, measurable sizes. Yet the fundamental particles that they’re made out of, like quarks, electrons, and gluons, are all inherently points, with no physical size to them at all. Why, then, does every composite particle not…
“The bedrock nature of space and time and the unification of cosmos and quantum are surely among science’s great ‘open frontiers.’ These are parts of the intellectual map where we’re still groping for the truth – where, in the fashion of ancient cartographers, we must still inscribe ‘here be dragons.'” -Martin Rees Inside the nuclear furnace of the Sun, protons and other atomic nuclei are compressed together into a tiny region of space, where the incredible temperatures and energies try to overcome the repulsive forces of their electric charges. At a maximum temperature of 15 million K, and…
"The physicist is like someone who’s watching people playing chess and, after watching a few games, he may have worked out what the moves in the game are. But understanding the rules is just a trivial preliminary on the long route from being a novice to being a grand master. So even if we understand all the laws of physics, then exploring their consequences in the everyday world where complex structures can exist is a far more daunting task, and that’s an inexhaustible one I'm sure." -Martin Rees It’s all too easy to take a look at a prediction that’s about something yet unproven and dismiss…
"Hurricane Katrina overwhelmed levees and exploded the conventional wisdom about a shared American prosperity, exposing a group of people so poor they didn't have $50 for a bus ticket out of town. If we want to learn something from this disaster, the lesson ought to be: America's poor deserve better than this." -Michael Eric Dyson Hurricane Irma has, as of this morning, knocked out power to more than 6 million, caused the evacuation of millions more, and has caused flooding and extreme wind damage across hundreds of miles across Florida, Georgia, Alabama and Mississippi. When Irma first made…
"We have to understand the ubiquity of energy in everything we do. Energy is core to our economy and it brings with it environmental challenges, and it's core to our security challenges." -Ernest Moniz In 1953, then-President Eisenhower, in the aftermath of World War II and with rising tensions between the USA and the Soviet Union resulting in a nuclear arms race, began the “Atoms For Peace” plan. The idea was that all nations should be able to reap the benefits of nuclear power, while simultaneously keeping the world safe from nuclear war. While the same ingredients can be used for both…
“That's a misconception, Lennie. The sky is everywhere, it begins at your feet.” -Jandy Nelson There are all sorts of explanations that people give for why the sky is blue. Some say that it’s because of the fact that oxygen is a light blue gas. Others contend that the sky reflects the blue ocean, giving it a comparably blue color. Still others place the blame on sunlight itself, alleging that it’s naturally slightly blue in color. All of these science-y sounding explanations, compelling though they might be, are way off the mark. If they were correct, after all, you wouldn’t have reds during…
"I'd rather fight 100 structure fires than a wildfire. With a structure fire you know where your flames are, but in the woods it can move anywhere; it can come right up behind you." -Tom Watson On September 2nd, a group of teenagers were lighting fireworks in the Columbia Gorge near Eagle Creek. They would light them and attempt to throw them into the river, playing a game of "let’s try to almost-but-not-quite commit devastating arson.” Guess how that game ended? With a catastrophic wildfire that, four days later, now engulfs over 10,000 acres, forcing the evacuation of thousands of people,…
"The sun is a miasma Of incandescent plasma The sun's not simply made out of gas No, no, no The sun is a quagmire It's not made of fire Forget what you've been told in the past" -They Might Be Giants Ask anyone where the Sun (or any star) gets its energy from, and most people will correctly answer “nuclear fusion.” But if you ask what’s getting fused, most people -- including most scientists -- will tell you that the Sun fuses hydrogen into helium, and that’s what powers it. It’s true that the Sun uses hydrogen as its initial fuel, and that helium-4 is indeed the end product, but the…
Another month, another set of blog posts. This one includes the highest traffic I think I've ever seen for a post, including the one that started me on the path to a book deal: -- The ALPHA Experiment Records Another First In Measuring Antihydrogen: The good folks trapping antimatter at CERN have now measured the hyperfine spectrum of hydrogen, which is a good excuse to explain what that is and why it matters. -- 7 Suggestions For Succeeding In Science In College: It's the time of year when lots of people give unsolicited advice to the college-bound, and who am I to buck that trend? -- How To…
"For although it is certainly true that quantitative measurements are of great importance, it is a grave error to suppose that the whole of experimental physics can be brought under this heading." -Hendrik Casimir Ever since we first discovered that the expansion of the Universe is accelerating, scientists have puzzles as to what’s causing it. Although we’ve measured it precisely and concluded that it’s uniform, static in time, and equivalent in its form to a cosmological constant, we still don’t know why it exists. Moreover, any attempts to calculate what its magnitude should be give…
"It’s becoming clear that in a sense the cosmos provides the only laboratory where sufficiently extreme conditions are ever achieved to test new ideas on particle physics. The energies in the Big Bang were far higher than we can ever achieve on Earth. So by looking at evidence for the Big Bang, and by studying things like neutron stars, we are in effect learning something about fundamental physics." -Martin Rees Two years ago, advanced LIGO turned on, and in that brief time, it’s already revealed a number of gravitational wave events. All of them, to no one’s surprise, have been merging black…
"The hurricane flooded me out of a lot of memorabilia, but it can't flood out the memories." -Tom Dempsey As I write this, the gulf coast is currently being battered by Hurricane Harvey, with a few locations already having accumulated more than three feet of rainfall. This storm shows no signs of letting up anytime soon, as it's forecast to remain roughly where it is for days to come. This is being billed as a 500-year-storm, but the truth is far scarier and more sobering: this should be exactly what you'd expect for a city located where Houston is. The new rainfall scale created by the…
"Imagination makes us aware of limitless possibilities. How many of us haven't pondered the concept of infinity or imagined the possibility of time travel? In one of her poems, Emily Bronte likens imagination to a constant companion, but I prefer to think of it as a built-in entertainment system." -Alexandra Adornetto The dream of futuristic technologies and what they might enable us to do -- travel back in time, create artificial gravity, traverse the stars, create unlimited energy -- are some of the best goals science can aspire to. While a great many of the technologies we’ve envisioned…
"North Korea has taught a great lesson to all the countries in the world, especially the rogue countries of dictatorships or whatever: if you don't want to be invaded by America, get some nuclear weapons." -Michael Moore Last year, North Korea claimed to have obtained the technology to create a nuclear fusion bomb: the most destructive weapon humanity has ever engineered. This year, they’re threatening to use them, against either South Korea or the United States, depending on the moment in question. Yet these grandiose claims are questionable, and not merely because of the questionable source…
"Presently thought to be the most powerful explosions in nature... their sources have only recently been localized by observations of associated afterglows in X-rays, visible light, and radio waves, delayed in that order." -Richard Matzner, on the dictionary entry for Gamma Ray Burst It seems like an eternity ago, but it’s been under two years since LIGO first began the science run that would first detect merging black holes. Their latest scientific data run is scheduled to end in just two days, and thus far, they’ve announced a total of three black hole-black hole merger discoveries, along…
“Maybe that is our mistake: maybe there are no particle positions and velocities, but only waves. It is just that we try to fit the waves to our preconceived ideas of positions and velocities. The resulting mismatch is the cause of the apparent unpredictability.” -Stephen Hawking So, you’ve got a black hole in the Universe, and you want to know what happens next. The space around it is curved due to the presence of the central mass, with greater curvature occurring closer to the center. There’s an event horizon, a location from which light cannot escape. And there’s the quantum nature of the…
"We live in a moment of history where change is so speeded up that we begin to see the present only when it is already disappearing." -R. D. Laing This coming Monday, tens of millions of people will gather to watch the total solar eclipse that will go coast-to-coast across the continental United States. Total solar eclipses like this happen, on average, about once every 18 months, due to the frequency of alignment as well as the Moon’s apparent angular size. At present, about 40% of all solar eclipses are total eclipses, with annular eclipses making up 50% and hybrid eclipses the other 10%.…