Category: physics


11 pm // After procrastinating all day, now I truly enjoyed the enlightening moment of realizing that a catenary has the form of cosh(x). Loving the beauty of theoretical mechanics.

Wolfgang Paul Was A Great Physicist, Not A Typ…

Wolfgang Paul Was A Great Physicist, Not A Typo Of ‘Wolfgang Pauli’

“Yet recognition almost escaped Paul entirely. Upon his retirement, where he became Professor Emeritus, the University took his office away and moved him to a janitor’s closet in the basement. Despite all of his contributions to the University of Bonn (including singlehandedly getting 100% of the funding for the 500 MeV synchrotron and getting it built there) and to physics over the years, he never complained about it.

Yet when Stockholm called, everything changed. They moved him back out of the basement and into his former office, where he continued his work until the end of his days. Of course, posthumously, CERN chose him as one of the physicists to honor with a street all his own. It still exists today, and I assure you, it isn’t a typo.”

Did you ever see the movie Office Space, where “Michael Bolton” refuses to change his name, go by “Mike,” or do anything that would distinguish himself from the much-more-famous singer with the same name? When confronted about it, his response was, “why should I change? He’s the one who sucks.”

Well, now imagine that you’re a physicist pushing the frontiers of our fundamental knowledge, developing new methods of manipulating particles in our Universe. You’re a hero at your University, a legend in your country, and you’ll go on to win a Nobel Prize. Yet your name is just one letter shy of a much more famous physicist, and you’re forever thought of as a typo of their name.

This is the not-quite-tragic story of Wolfgang Paul, who you should definitely remember as much more than a typo. His quip to Pauli, upon meeting him, is the best nerd joke you’ll read all year.

What do you think of who is behind with their …

What do you think of who is behind with their studies?? Like have you ever had friends or colleagues struggling and taking longer that normal?? I had problem with my studies because of dyslexia and I’m older than anyone else also depression and these kind of fields are so competitive and I feel always judged and hopeless and just old and with no real possibilities…. congratulations on your phd :))

Let me tell ya, I know many people who didn’t complete their studies within the ‘normal’ amount of years. In physics, I would say those who did were a minority. I myself finished my studies two years later than I was supposed to. Still got into a PhD. It’s true, it’s an insanely competitive field and it’s never easy. But I think you have to keep in mind that the science world is a bit different than undergrad/graduate courses, being older doesn’t really matter. What matters is the quality of your work. And comparing yourself to others won’t be very helpful to you. I lost one year due to depression, another to laziness and procrastination (and self doubt, and all of that). I think what got me through is what my high school math teacher once said to me: “the drop will dig into the rock”. Do all you can, but do it. Best of luck!


Did Time Have A Beginning?

Did Time Have A Beginning?

“Even though we can trace our cosmic history all the way back to the earliest stages of the hot Big Bang, that isn’t enough to answer the question of how (or if) time began. Going even earlier, to the end-stages of cosmic inflation, we can learn how the Big Bang was set up and began, but we have no observable information about what occurred prior to that. The final fraction-of-a-second of inflation is where our knowledge ends.

Thousands of years after we laid out the three major possibilities for how time began — as having always existed, as having begun a finite duration ago in the past, or as being a cyclical entity — we are no closer to a definitive answer. Whether time is finite, infinite, or cyclical is not a question that we have enough information within our observable Universe to answer. Unless we figure out a new way to gain information about this deep, existential question, the answer may forever be beyond the limits of what is knowable.”

If you didn’t know anything about the Universe, you might intuit three possibilities for how time originated. Either it had a beginning a finite duration ago, or it existed for an eternity into the past, or it is cyclical in nature, with no beginning, end, or true delineation between past and future. But we have lots of physical evidence today. We know about the Big Bang and what its limits are. We know about cosmic inflation, which preceded and set up the Big Bang. And we know about dark energy, which determines the fate of our Universe.

With everything we know, what can we say about whether time had a beginning or not? Not enough, unfortunately, but the possibilities remain tantalizing. Find out what we do and don’t know today!


Does Particle Physics Have A Future On Earth?

Does Particle Physics Have A Future On Earth?

“Will it be successful? Regardless of what we find, that answer is unequivocally yes. In experimental physics, success does not equate to finding something, as some might erroneously believe. Instead, success means knowing something, post-experiment, that you did not know before you did the experiment. To push beyond the presently known frontiers, we’d ideally want both a lepton and a proton collider, at the highest energies and collision rates we can achieve.

There is no doubt that new technologies and spinoffs will come from whichever collider or colliders come next, but that’s not why we do it. We are after the deepest secrets of nature, the ones that will remain elusive even after the Large Hadron Collider finishes. We have the technical capabilities, the personnel, and the expertise to build it right at our fingertips. All we need is the political and financial will, as a civilization, to seek the ultimate truths about nature.”

With the discovery of the Higgs boson and nothing else at the LHC, many physicists are legitimately entertaining what’s been called the “nightmare scenario,” where no new particles exist beyond the Standard Model that can be discovered by terrestrial colliders. But it isn’t a foregone conclusion that there aren’t such particles, and there are two generic types of plan for how we might find any new particles that do exist beyond the LHC’s reach. If the experimental particle physics community comes together to develop a single, coherent proposal for their future, we could probe the frontiers of nature as never before.

Does particle physics have a future on Earth? It should, and here’s what I would recommend they choose if they have the political and financial will to do so.

Ask Ethan: What’s It Like When You Fall …

Ask Ethan: What’s It Like When You Fall Into A Black Hole?

“[W]hat is it like to be/fall inside a rotating black hole? This is not observable, but calculable… I have talked with various people who have done these calculations, but I am getting old and keep forgetting things.”

I get a lot of questions that people submit for Ask Ethan, but only rarely do they come to me from other scientists who tower above me in the field. This week’s question, from Event Horizon Telescope scientist extraordinaire Heino Falcke, asks me to help him visualize what it would look like if you fell into a black hole. Not just any black hole, mind you, but a realistic, rotating black hole. There’s really only one person on Earth who understands this well enough: Andrew Hamilton, who has devoted the last 15 years of his life to figuring out what it looks like and what it means when this actually happens.

So what did I do? I went and met Andrew, interviewed him, read his papers, and used his simulations to give everyone the best answer I could. I hope you love it, and I hope (even moreso) that I got it right!

This Is Why It’s Meaningless That Dark M…

This Is Why It’s Meaningless That Dark Matter Experiments Haven’t Found Anything

“To date, the direct detection efforts having to do with dark matter have come up empty. There are no interaction signals we’ve observed that require dark matter to explain them, or that aren’t consistent with Standard Model-only particles in our Universe. Direct detection efforts can disfavor or constrain specific dark matter particles or scenarios, but does not affect the enormous suite of indirect, astrophysical evidence that leaves dark matter as the only viable explanation.

Many people are working tirelessly on alternatives, but unless they’re misrepresenting the facts about dark matter (and some do exactly that), they have an enormous suite of evidence they’re required to explain. When it comes to looking for the great cosmic unknowns, we might get lucky, and that’s why we try. But absence of evidence is not evidence of absence. When it comes to dark matter, don’t let yourself be fooled.”

If dark matter is so successful, then why haven’t we directly detected the particles that make it up yet? Doesn’t the failure of all these experiments attempting to directly detect dark matter point to a failure of the dark matter hypothesis.

Not at all, and if you think that, you’d better learn the difference between model-dependent and model-independent tests. Here’s where you’ll want to start.

This Little-Known Quantum Rule Makes Our Exist…

This Little-Known Quantum Rule Makes Our Existence Possible

“If we didn’t have the Pauli Exclusion Principle to prevent multiple fermions from having the same quantum state, our Universe would be extremely different. Every atom would have almost identical properties to hydrogen, making the possible structures we could form extremely simplistic. White dwarf stars and neutron stars, held up in our Universe by the degeneracy pressure provided by the Pauli Exclusion Principle, would collapse into black holes. And, most horrifically, carbon-based organic compounds — the building blocks of all life as we know it — would be an impossibility for us.

The Pauli Exclusion Principle isn’t the first thing we think of when we think of the quantum rules that govern reality, but it should be. Without quantum uncertainty or wave-particle duality, our Universe would be different, but life could still exist. Without Pauli’s vital rule, however, hydrogen-like bonds would be as complex as it could get.”

When you think of quantum mechanics, you probably think of all the usual suspects. Wave/particle duality. The double slit experiment. Photons and electrons interfering with themselves. Schrodinger’s cat. The inherent uncertainty, due to Heisenberg’s principle, of knowing two physical quantities (like position and momentum or energy and time) simultaneously. But it’s the Pauli exclusion principle that tops them all in terms of giving us the chemical-rich Universe we have today. The elements are all different from one another, and Pauli’s exclusion rule explains why.

Come get the story behind the underappreciated quantum rule that makes our existence possible!