Physics
drorzel | February 5, 2016A long-ish stretch of time, but I was basically offline for a bunch of that because I needed to finish a chapter I was asked to contribute to an academic book. So there are only four physics posts from Forbes to promote this time:
-- 'The Expanse' Is A Rare Sci-Fi Show That Gets Simulated Gravity Right: Another post on the SyFy adaptation of "James S. A. Corey"'s books, talking about a nifty bit of visual effects that nods at the Coriolis force you'd see on a rotating space station.
-- What Is The Quantum Pigeonhole Principle And Why Is It Weird?: A paper published in the Proceedings of the…
esiegel | February 3, 2016"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
Neutron stars are some of the most extreme objects in the Universe: a ball of neutrons a few kilometers in diameter, but with more mass than the entire Sun in them. Their magnetic…
drorzel | February 2, 2016This one was a whole bunch of work for one smallish shot...
So, in past rounds of "science-y things with my fancy camera," I looked at the effect of ISO settings and apertures. This time out, I wanted to look at something moving, and the way that it blurs with increasing exposure time.
My initial thought was to try to take pictures of a falling ball, but it's too hard to get that to work consistently without setting up some kind of electronic trigger, and I wasn't willing to do that. But, of course, a swinging pendulum will always be in a relatively narrow range of positions, making it a…
esiegel | February 2, 2016"I like cappuccino, actually. But even a bad cup of coffee is better than no coffee at all." -David Lynch
Particularly in the dead of winter, most of us enjoy a hot drink, whether it's coffee, tea, hot chocolate or soup. But if that drink is too hot, your options for cooling it down are unsatisfying: wait for the room to cool it, which takes forever, drop an ice cube in, which waters down your drink, or blow on it.
Image credit: Wikimedia Commons user Pdbailey, who created this image and placed it in the public domain. The speed distribution is qualitatively the same for liquids as it is for…
esiegel | January 30, 2016“Go then, there are other worlds than these.” -Stephen King, The Dark Tower
When you think about the Multiverse, everyone thinks about the Universe beyond what's accessible to us. But whether you think about more Universe like our own, multiple Universe that are disconnected from ours, an infinite number of parallel Universes, where possibly multiple copies of identical "yous" are entangled, or where the laws of physics are different from our own depends on what type of Multiverse you're talking about.
Image credit: Bock et al. (2006, astro-ph/0604101); modifications by me.
As it turns…
drorzel | January 25, 2016One of the things about being a physicist that makes it tough to have any sensible work-life balance is that I'm constantly seeing little things and thinking "Oooh! Physics!" then getting distracted from what I'm actually supposed to be doing. Take, for example, our bathroom sink.
I have noticed, from time to time, a weird effect where the stream of water coming out of the faucet, which normally is fairly straight, will spread out when the water level in the container below gets close to the faucet. This turns out to be damnably difficult to replicate, though, and I've spent more time than I…
drorzel | January 22, 2016The Center for Quantum Technologies is running a "Quantum Shorts" contest, where they solicited short stories exploring some aspect of quantum physics. They cut their large number of applicants down to two short-lists of ten, one for the "Open" category, and one for the "Youth" category. They'll be giving out a "People's Choice Award" based on Internet voting, so you can go over there and vote for your favorite.
There are also judged prizes, and I'm serving as a judge for the "Youth" category (and already sent in my rankings), so it would be inappropriate for me to plug any particular stories…
esiegel | January 22, 2016“Our knowledge of physics only takes us back so far. Before this instant of cosmic time, all the laws of physics or chemistry are as evanescent as rings of smoke.” -Joe Silk
When people use the word theory colloquially, they use it to mean an "idea" or a "possibility" that could conceivably be at play. But a scientific theory has a much more stringent set of things it must accomplish: it must encompass all the successes of the previously leading theory, it must make successful predictions for phenomena that the leading theory cannot make, and it must predict additional, novel phenomena that…
esiegel | January 21, 2016"Science, however, gives me the feeling of steady progress: I am convinced that theoretical physics is actual philosophy. It has revolutionized fundamental concepts, e.g., about space and time (relativity), about causality (quantum theory), and about substance and matter (atomistics), and it has taught us new methods of thinking (complementarity) which are applicable far beyond physics." -Max Born
The farther away we look in the Universe, the farther back in time we look as well, since light has a finite speed. But if a galaxy's light takes a million years to reach you, that galaxy is going…
esiegel | January 20, 2016"Any fool can criticize, condemn and complain - and most fools do." -Benjamin Franklin
The history of science is rife with stories of cases where a person or team, usually with a lot of clout, reached a conclusion that seemed incontrovertible. When that occurs, we often find that subsequent measurements agree with that conclusion, even if that conclusion later turns out to be wrong.
Recommended speed of light values over time. Adapted from Henrion & Fischhoff (1986).
This was the case for measurements of the speed of light and for the various masses of fundamental and composite…
esiegel | January 17, 2016"To know that we know what we know, and to know that we do not know what we do not know, that is true knowledge." -Nicolaus Copernicus
As we peel back the layers of information deeper and deeper into the Universe's history, we uncover progressively more knowledge about how everything we know today came to be. The discovery of distant galaxies and their redshifts led to expanding Universe, which led to the Big Bang and the discovery of very early phases like the cosmic microwave background and big bang nucleosynthesis.
After the Universe’s atoms become neutral, not only did the photons cease…
esiegel | January 9, 2016"In this first testing ground of the atomic bomb I have seen the most terrible and frightening desolation in four years of war. It makes a blitzed Pacific island seem like an Eden. The damage is far greater than photographs can show." -Wilfred Burchett
The news has been aflame with reports that North Korea detonated a hydrogen bomb on January 6th, greatly expanding its nuclear capabilities with their fourth nuclear test and the potential to carry out a devastating strike against either South Korea or, if they're more ambitious, the United States.
Image credit: TV screenshot of CNN’s The…
esiegel | January 7, 2016“The paradigm of physics — with its interplay of data, theory and prediction — is the most powerful in science.” -Geoffrey West
Cosmic inflation, our earliest theory of the Universe and the phenomenon that sets up the Big Bang, didn't just explain a number of puzzles, but made a slew of new predictions for the Universe. In the subsequent 35 years, five of the six have been confirmed, with only primordial gravitational waves left to go.
Image credit: NASA / WMAP science team.
Inflation predicts that they could be large or small, but based on the simplest classes of models and the measured…
esiegel | December 31, 2015“If you see an antimatter version of yourself running towards you, think twice before embracing.” –J. Richard Gott III
Everywhere we look in the Universe, we find that planets, stars, galaxies, and even the gas between them are all made of matter and not antimatter. Yet as far as we know, the laws of nature are symmetric between matter and antimatter: you can't create or destroy one without the other.
Image credit: Karen Teramura, UHIfA / NASA.
This question -- why the Universe is full of matter and not antimatter -- is one of the greatest unsolved problems in theoretical physics. Yet it's…
esiegel | December 26, 2015“This whole Santa Claus thing just doesn't make sense. Why all the secrecy? Why all the mystery?
If the guy exists why doesn't he ever show himself and prove it?
And if he doesn't exist what's the meaning of all this?” -Calvin, via Bill Watterson
This is our last comments of the week for 2015, and Starts With A Bang can't wait for the new year! All the great things we've worked so hard for this year promise to bring about an even better one in 2016. But that said, there's still more science for this year! This past week saw the following:
When a photon gets redshifted, where does its energy…
esiegel | December 23, 2015"As of now, string theorists have no explanation of why there are three large dimensions as well as time, and the other dimensions are microscopic. Proposals about that have been all over the map." -Edward Witten
Earlier this month, a conference was held devoted to the question of whether untestable scientific ideas like string theory and the multiverse are actually science or not. While many opinions were stated and no one changed their mind, the answer is apparent: unless you're willing to change the definition of science to include 'this thing that isn't science,' then no, string theory is…
esiegel | December 22, 2015"I often feel a discomfort, a kind of embarrassment, when I explain elementary-particle physics to laypeople. It all seems so arbitrary - the ridiculous collection of fundamental particles, the lack of pattern to their masses." -Leonard Susskind
When it comes to physics, there are a tremendous number of unsolved problems that seem to mandate the existence of a new particle. These include the dark matter problem, the matter-antimatter asymmetry problem, the massive neutrino problem and the strong-CP problem. Moreover, these particles required cannot be part of the Standard Model: they must lie…
drorzel | December 22, 2015A couple of weeks ago, I gave a talk at TEDxAlbany on how quantum physics manifests in everyday life. I posted the approximate text back then, but TEDx has now put up the video:
So, if you've been wondering what it sounded like live, well, now you can see...
esiegel | December 20, 2015"Our family was too strange and weird for even Santa Claus to come visit... Santa, who was jolly - but, let's face it, he was also very judgmental." -Julia Sweeney
Everyone loves to point out the holes in the Santa Claus theory. After all, how could one person with a sled, powered by eight flying reindeer, deliver presents in one night to hundreds of millions of households all over the world? And yet, every Christmas morning, children wake up to find they did, in fact, get a visit from Santa.
Image credit: Wikimedia Commons user Glogger, of the Santa Claus parade in Toronto, 2007.…
esiegel | December 17, 2015
“I just think too many nice things have happened in string theory for it to be all wrong. Humans do not understand it very well, but I just don’t believe there is a big cosmic conspiracy that created this incredible thing that has nothing to do with the real world.” -Edward Witten
String theory is often touted as the best option for physics beyond the Standard Model, and for unifying gravity with quantum theory. No one disputes the need for a quantum theory of gravity, as general relativity is woefully insufficient for describing gravitational fields at extremely small distances.
Image…