Saturday, October 31, 2015

Coffee acoustics

The next video in my series with Cleveland State University has been posted. Suppose that you are in a restaurant when a nearby customer repeatedly taps his spoon against the cup’s interior. The tapping sends sound waves into the water, and the sound waves within a certain range of frequencies build up by constructive interference. Thus, the noise (and your irritation at the repeated tapping) can be significant. If the person then adds powdered coffee (or almost any other type of powder) to the water and continues to tap, the frequency range noticeably shifts and then gradually returns to its initial value. I am so fascinated by the physics of that shift that I have tested it out in every restaurant I have visited. Indeed, maybe that person that so irritated you was me.My video series


Friday, October 30, 2015

November 2015 stories at the Flying Circus of Physics website

November 2015 stories at the main site for The Flying Circus of Physics: (1) Players on a football field are hurt when lightning strikes nearby. For several years I figured that they were hurt by the currents spreading along the ground from the point of the strike. But recently (and in class), I changed my explanation --- I think they were hurt by upward streamers at their heads. (2) Pub trick --- pouring a black and tan, a popular layered beer drink. (3) Coating an egg with black soot and then dropping it into water gives the egg a glimmering edge. How can a black egg become brighter? (4) A rotating, soaked sponge ball sprays water in spiral arms that resemble a spiral galaxy. However, when something is thrown off a rotating object, it must move in a straight line. So, what causes the appearance of spiral arms? More stories are at the FCP Facebook site (open access).

Labels: , , , , ,

Wednesday, September 30, 2015

Flying Circus of Physics October 2015

The October 2015 stories at the main FCP site: (1) Pointy ice drops --- water drops that form peaks at their tops when they freeze and that then form fern-like structures along their sides. (2) Japanese samurai warriors wore large cloth bags on their back when they rode into battle. Were these horo, as they are called, purely for decoration or were they protective devices against the arrows the opponents shot at the warriors? A video reveals the function of the horo. (3) Here is a challenge against all common sense: Drive a nail into the ceiling by juggling hammers beneath it. This juggler manages to do just that in spite of the fact that an object (here a hammer) slows as it moves upward. So, what is his secret? (4) Pub trick: on a card draw arrows pointing left and right. In a pub setting, how can you reverse their directions without touching the card (and, of course, without standing on your head, which would certainly get you thrown out of the pub)? Oh, by the way, I intend to post stories on the Facebook site more frequently. A few days ago I posted a story about how people made an ice merry-go-round in the middle of a lake. It must have been a depressing winter, or maybe they just wanted a project to justify lots of adult beverages.Flying Circus of Physics main site FCP Facebook

Labels: , , ,

Sunday, July 05, 2015

FCP stories for July 2015

The July stories at the main FCP site: (1) sloshing – When you walk with a cup of coffee, why does the coffee tend to slosh out of the cup? When you walk with a mug of beer, why is the sloshing much less? Other examples of sloshing are given, such as the swimming pool on a ship in rough waters, and how to use sloshing to float an initially submerged canoe. (2) Pinhole rifle sites, pinhole glasses, and pinhole selfies. (3) Turkish coffee is brewed in hot sand --- why the sand? (4) Pub trick – balancing a safety pin on the rim of any common drinking glass.
Flying Circus of Physics

Labels: , , ,

Monday, June 01, 2015

June 2015 stories at Flying Circus of Physics

The second episode of my Flying Circus of Physics video series with Cleveland State has now been posted. FCP video series

The June 2015 stories at the main FCP site: (1) The physics of rockfalls, with several dramatic videos. (2) Shooting a laser beam into a reflecting room. (3) The optical illusion of a star sapphire. (3) Pub magic trick of balancing paper currency on a single outstretched finger at one end.

Labels: , ,

Sunday, May 03, 2015

May 2015 stories at FCP + news of my new video series

My new video series
My school (Cleveland State University) and I have started a new video series. Here is a link to the CSU YouTube channel where the first video has been posted. New videos will appear about once a month. If you want to subscribe to the channel so that you know when a new video has been posted, use the subscribe button. This first video shows me dipping my fingers into molten lead (about 750 degrees Fahrenheit).

Main FCP site for May 2015
The May 2015 stories at the main FCP site: (1) tesla coils, with music, including the Doctor Who theme. (2) self-righting of turtles and the toy known as gomboc, which automatically finds its equilibrium point as though it has a mind of its own. (3) a self-pouring teapot that is now a collector’s item – you don’t need to pick it up and tilt it to get a cup of tea. (4) pub trick – a self-righting bottle –  how to get a bottle that lies on its side to stand up (without use your hands in any way).  
FCP main site
my new video series
FCP Facebook

Labels: , , ,

Thursday, April 02, 2015

April 2015 stories at the main FCP site

The April 2015 stories at the main FCP site: (1) I spent many hours trying to work out the operation of this simplistic electric train that only recently appeared on YouTube: Attach magnets at the two ends of a common AA or AAA battery. Insert the assembly (the “train”) into a copper-wire coil. The train shoots through the coil. If you make a loop out of the coil, the train will shoot around the loop for hours. What in the world propels the train? (2) Pour pepper onto salt. Can you then separate the two types of grains? That is the pub challenge this month. (3) Whispering park benches --- a friend whispers at one end of this long bench and you can then clearly hear the words at the far end. This is the park version of the famous whispering gallery of St. Paul’s Cathedral in London. (4) When the flying bombs (V1) were sent into England in World War II, some English pilots were able to disrupt the gyroscopic guidance of the bombs by bring their wing down onto the flying bomb’s wing.
The Flying Circus of Physics

Labels: , , ,