The Physics of Scary Sounds
From PBS Digital Studios, and with an obvious sendup to Rod Serling of Twilight Zone fame, host Joe Hanson explores the connection between sounds, scary or otherwise, and human physiology.
Zeno’s Paradox, specifically the one about a race between Achilles and a tortoise (rabbit, hare), has annoyed me for years, because so many folks casually dismiss it as a simple mathematical limit issue, i.e., “the infinite step process takes a finite amount of time, so stop with the Zeno’s Paradox bit already!”
As Dr. Grime, above, points out, excellently, how can an infinite process have a last step, so how can it terminate in a finite amount of time, or more to the physics side of the question, can space, or equivalently time, be subdivided an infinite number of times?
I would submit that Zeno’s Paradox strongly suggests that space and time cannot be infinitely subdivided, that they must be quantized. Of course, suggesting this immediately runs up against the problem of Heisenberg’s Uncertainty Principle, which does not state that space cannot be infinitely subdivided, only that the description of the motion of a particle becomes increasingly meaningless, because the tolerance for a particle’s momentum blows up the more we localize it in space.
My vote is for quantization of both space and time as a reasonable explanation for Zeno’s Achilles and Tortoise Paradox, namely that a finite number of minimum sized steps allows Achilles to pass the tortoise in a finite amount of time.
A similar issue that pops up is whether space and time have fundamental meaning, or whether the truly fundamental measurable variable is motion. We are conditioned to think of motion as derivative of space and time, but I have come to the opposite conclusion, that we infer time’s passage, and the immediacy of space, by the observation of motion.
In the course of reading the remarkable non-fiction classic and pulitzer prize winning book “The Swerve”, author Stephen Greenblatt remarks that the famous and possibly crazy Dominican monk Giordano Bruno probably met the English mathematician and scientist Thomas Harriot, who among other things 1) first drew the surface of the Moon, 2) first viewed and drew sunspots, 3) discovered (contemporaneously with Galileo) the four main moons of Jupiter, 4) proposed (contemporaneously with Kepler) that planetary orbits are elliptical, not circular, 5) discovered the Law of Refraction (twenty years before Snell), and 6) first introduce negative (or imaginary) square roots into algebra.
What Harriot didn’t do was publish any of his findings!
Recently, a wordsmith friend of mine objected to my saying “an hypothesis”. He said it sounded funny. We don’t say “an hotel”, or “an hypodermic needle”, so why am I saying “an hypothesis”?
After extensive research (OK, I googled it), I found that there is a somewhat spirited debate about “a” versus “an” when used with hypothesis, with about 70% saying that “a” is correct, and about 30% saying that “an” is correct.
There was also a pdf document I found from Duke’s biology department that listed the elements of a scientific hypothesis.
I asked my physics colleagues what they thought, and while there was a mixed response, the small sampled preponderance was towards “an”. This leads me to conclude that science professionals use “an” and everyone else (who cares) uses “a”.
Anyways, here’s my physics based definition of “an hypothesis”: An hypothesis is a scientifically vetted tentative explanation of a physical phenomenon. An hypothesis must be proven by experiment in order to become a scientific theory, law or principle. An hypothesis must be falsifiable, if in fact it is false.
Phil Plait Goes Berserk, and Me Too
From The Guardian we learn from senior trump adviser Bob Walker that Drumpf intends to remove all climate research from NASA’s mission, because such research is “politicized science.” Phil Plait of Bad Astronomy on the Salon website has absolutely ripped Drumpf and his weany post-truth “adviser” a new one on this subject, and I’m glad, because the science community cannot take this lying down.
Fortunately, the GOES-R satellite was launched on November 18th (see video above), so I don’t think the Orange One can recall it. The GOES-R satellite is one of four weather satellites expected to cost roughly 11 billion dollars over 20 years.
Make America Great Again, my ass.
Here’s a nice video about the GOES-R satellite, and why it is absolutely necessary for NASA, NOAA and the world to have it: