Posts Tagged ‘Physics’
With an eye to the digestive challenges that many readers will likely be facing tomorrow, (R)D will be on holiday hiatus, to resume on Black Friday… In the meantime, a Thanksgiving gift: Mark Twain’s “Hunting the Deceitful Turkey.”
When I was a boy my uncle and his big boys hunted with the rifle, the youngest boy Fred and I with a shotgun—a small single-barrelled shotgun which was properly suited to our size and strength; it was not much heavier than a broom. We carried it turn about, half an hour at a time…
Readers will find links here to download the full story (as a pdf) or to read online at the Library of America’s site… and will realize that the real gift here is the link on that page to subscribe to their wonderful “Story of the Week” list– a free, downloadable short story, like this one, selected each week from the extraordinary trove of treasures in their stock. The perfect post-prandial pleasure!
As we prepare to loosen our belts, we might send safe and satisfied birthday greetings to Jesse Ernest Wilkins, Jr.; he was born on this date in 1923. The youngest ever undergraduate at the University of Chicago when he was admitted at the age of 13, he went on to earn his doctorate there, and thus to become the first African-American PhD in mathematics. He went on to earn both Masters and PhD degrees in mechanical engineering at NYU.
Wilkins was involved in the Manhattan Project during World War II, then developed mathematical models to calculate the amount of gamma radiation absorbed by any given material (a technique of calculating radiative absorption still widely used among researcher in space and nuclear science). He then developed the radiation shielding used against the gamma radiation emitted during electron decay of the Sun and other nuclear sources.
Your correspondent, for one, will be using that shielding in his oven tomorrow.
What happens when an immovable object encounters an unstoppable force? MinutePhysics explains…
Email readers, click here
As we acclimate ourselves to anticlimax, we might send ethereal birthday greetings to Edward Williams Morley; he was born on this date in 1838. A chemist by training, Morley is best remembered for his collaboration with physicist Albert Michelson at (what is now) Case Western Reserve University, where both taught. They attempted to detect the relative motion of matter through the stationary luminiferous aether (“aether wind”– the medium required, scientists then believed, for the transmission of light). On their first attempt, they found nothing; they tried again, with more sensitive equipment, and again found nothing.
The Michelson-Morley Experiment, as it’s now known, has been called both the most famous and the most important failed experiment of all time: because the aether couldn’t be detected, scientists had to contemplate the possibility that it didn’t exist… thus, the Michelson-Morley Experiment kicked off the Second Scientific Revolution– initiating the line of research that eventually led to special relativity (in which a stationary aether concept has no role).
[Here's a candidate for the "experiment with surprising results" that might herald the Third Scientific Revolution...]
On the heels of yesterday’s film recommendation, another… albeit somewhat different: Stanford physics professor, Leonard Susskind, one of the fathers of string theory, articulator of the Holographic Principle, and explainer of the Megaverse, has a gift for making science accessible… a gift that is on display in this lecture, “Demystifying the Higgs Boson“:
(email readers, click here)
As we say “ahh,” we might spare a thought for Pierre de Fermat; he died on this date in 1665. With Descartes, one of the two great mathematicians of the first half of the Seventeenth Century, Fermat made a wide range of contributions (that advanced, among other fronts, the development of Calculus) and is regarded as the Father of Number Theory. But he is best remembered as the author of Fermat’s Last Theorem.* Fermat had written the theorem, in 1637, in the margin of a copy of Diophantus’ Arithmetica– but went on to say that, while he had a proof, it was too large to fit in the margin. He never got around to committing his proof to writing; so mathematicians started, from the time of his death, to try to derive one. While the the theorem was demonstrated for a small number of cases early on, a complete proof became the “white whale” of math, eluding its pursuers until 1995, when Andrew Wiles finally published a proof.
* the assertion that no three positive integers a, b, and c can satisfy the equation an + bn = cn for any integer value of n greater than two
For years both scientists and science fiction writers have suggested that a sufficiently advanced civilisation could– and thus would– create a simulated universe. And since simulations beget simulations (within simulations, within simulations, etc., etc.), there would ultimately be many more simulated universes than real ones… meaning that it would be more likely than not that any one universe– say, ours– is artificial.
First, some background. The problem with all simulations is that the laws of physics, which appear continuous, have to be superimposed onto a discrete three dimensional lattice which advances in steps of time.
The question that Beane and co ask is whether the lattice spacing imposes any kind of limitation on the physical processes we see in the universe. They examine, in particular, high energy processes, which probe smaller regions of space as they get more energetic
What they find is interesting. They say that the lattice spacing imposes a fundamental limit on the energy that particles can have. That’s because nothing can exist that is smaller than the lattice itself.
So if our cosmos is merely a simulation, there ought to be a cut off in the spectrum of high energy particles.
It turns out there is exactly this kind of cut off in the energy of cosmic ray particles, a limit known as the Greisen–Zatsepin–Kuzmin or GZK cut off.
This cut-off has been well studied and comes about because high energy particles interact with the cosmic microwave background and so lose energy as they travel long distances.
But Beane and co calculate that the lattice spacing imposes some additional features on the spectrum. “The most striking feature…is that the angular distribution of the highest energy components would exhibit cubic symmetry in the rest frame of the lattice, deviating signiﬁcantly from isotropy,” they say.
In other words, the cosmic rays would travel preferentially along the axes of the lattice, so we wouldn’t see them equally in all directions.
That’s a measurement we could do now with current technology. Finding the effect would be equivalent to being able to to ‘see’ the orientation of lattice on which our universe is simulated…
Read the whole mind-blowing story (including some comforting caveats) at “The Measurement That Would Reveal The Universe As A Computer Simulation” (and find Beane’s paper here).
As we wonder if there’s a “reset” button, we might spare a thought for the extraordinary Erwin Rudolf Josef Alexander Schrödinger; he died on this date in 1961. A physicist best remembered in his field for his contributions to the development of quantum mechanics (e.g., the Schrödinger equation), and more generally for his “Schrödinger’s cat“ thought experiment– a critique of the Copenhagen interpretation of quantum mechanics– he also wrote on philosophy and theoretical biology. Indeed, both James Watson, and independently, Francis Crick, co-discoverers of the structure of DNA, credited Schrödinger’s What is Life? (1944), with its theoretical description of how the storage of genetic information might work, as an inspiration.
It seems plain and self-evident, yet it needs to be said: the isolated knowledge obtained by a group of specialists in a narrow field has in itself no value whatsoever, but only in its synthesis with all the rest of knowledge and only inasmuch as it really contributes in this synthesis toward answering the demand, “Who are we?”
- from Science and Humanism, 1951
… to photos…
… readers will find the backstories to these gaffes and myriad others at Poynter’s “The best (and worst) media errors and corrections of 2012.”
Special Bonus: Jim Romenesko’s Headline of the Year: “Maneater: Hall Bitten by Oates.”
As we fixate on fact-checking, we might recall that this is the birthday of quantum physics: it was on this date in 1900 that Max Planck published his study of the effect of radiation on a “blackbody” substance, demonstrating that in certain situations energy exhibits the characteristics of physical matter– something unthinkable at the time– and suggesting that energy exists in discrete packets, which he called “quanta”… thus laying the foundation on which he, Einstein, Bohr, Schrodinger, Dirac, and others built our modern understanding of physics.