Infinity is weird: how big is infinity?
How big is infinity? Most people, though familiar with the general concept of infinity, would probably answer with a simple, question-dodging response of “infinite.” To be fair, the infinite is a really difficult concept to wrap one’s head around, and still causes challenges and puzzles in mathematics to this day.
I don’t want to over-state the case because, actually, I love new gizmos that allow me to browse my music collection through my TV and to photograph the Orion Nebula in mere moments using the unbelievably sensitive ISO25600 setting on my camera. I wouldn’t want to halt the inevitable march of progress even if I could. But I would like to take this opportunity to mark the passing of some dearly loved and enlightening technology that has gone the way of all flesh.
I agree. New technology is amazing , but there’s something to be said about the older analog equipment, where you could tinker in ways that you can’t do anymore.
Cool stuff. I’m from an atomic interferometry background (check out the diffraction gratings I made) so much of the physics part of this is familiar territory.
Pretty crazy, and enjoyable, but I think it falls a little short of insane.
Viewpoint: A SQUID Analog with a Bose-Einstein Condensate
How can an ultracold gas act like a dc-SQUID? The Josephson effect relies on the sinusoidal nature of the relation between the current that flows and the relative phase that exists across the junction. In conventional dc-SQUIDs the flow is an electric current, whereas in BECs it is a mass current, and the relative phase is the difference in phase factors of the wave function on either side of the junction. In these macroscopic quantum systems, the relative phase evolves in time in response to the applied potential differences (voltage difference for superconductors, pressure and temperature differences for superfluid helium, and population difference between the two condensates for BECs). A constant potential difference, for example, leads to a relative phase that increases linearly in time, and through the sinusoidal current-phase relation, this then gives rise to an oscillating current. The nonlinear current-phase relation is a key signature of the leakage and the weak coupling of the two macroscopic wave functions.
The Math Trick Behind MP3s, JPEGs, and Homer Simpson’s Face
You probably use a descendant of Fourier’s idea every day, whether you’re playing an MP3, viewing an image on the web, asking Siri a question, or tuning in to a radio station.
I linked to the drawing of Homer Simpson’s face before, but didn’t explain Fourier series/transforms in as much depth (or as well)
Finding That There’s Nothing to Find
[T]he people working for both of these collaborations have every reason to be proud of their detectors not finding anything. They haven’t failed to find exotic new particles, they’ve shown that there are no exotic particles to find.
Having the front end with some mass in it as an adjustable counterbalance has to make this easier (or even possible)
If you don’t want to build a complex robot that can navigate around obstacles, you make one that can stumble around and bump into them and still work.