Copasetic Flow

The unschooling gang here gets a science lesson a week.  They learn about things like electricity, magnetism, waves, the Doppler effect, and water pressure.  They don’t do any homework or worksheets . The lessons are based on demonstration and play.  They watch the demonstration first, and then they get to play with it, (perhaps a more stern educational type than I might call it experimenting rather than playing).  There are no worksheets, no homework, and no books. People might ask, “Can a kid really learn something without doing some type or rote homework to help them internalize it?”  As with most things unschooling, we’re discovering that the repetition that might be necessary to learn happens not at a desk or at our kitchen table, but instead in the outside world where the 7, 5, and 3 y.o. gang here spend most of their time. Take water pressure for example.  The kids performed a water pressure experiment using milk jugs.  They filled two jugs ...

"Sure," I hear you saying, "Michael Gladych is cool and all, but what does this have to do with the history of physics?" Read on and find out how Gladych reported on the events that would fund Higgs Particle research as well as the relativistic framework that inspired the Alcubierre drive. The same events that inspired Nick Cook's antigravity classic, "The Hunt for Zero Point" The article that brought Mike Gladych to the attention of fringe physics buffs everywhere, “The G-Engines are Coming”, appeared in its first incarnation in the pages of the November, 1956 issue of American Modeler.  The article begins with the bold assertion that nuclear airplanes will be made obsolete—by the artificial control of gravity—before they ever leave the design phase.  It then goes on to state that many aircraft companies were currently engaged in the study of the control of gravitation including: Glenn L. Martin Aircraft Co., Convair, Bell Aircraft, Lear, Inc.,...

One of the kids' friends asked about magnets a few weeks ago.  This led to three weeks worth of play dates on electric circuits, electromagnets, and last but not least, Motors!!!  (It's nice to have a physicist in the family). The motors were amazingly simple to put together, so I’m including the instructions.  Here’s a picture so we have something to talk about. The parts are: • 1 D cell battery • 1 pound of 18 awg magnet wire, (you don’t need the whole pound, but Amazon sells It by the pound… seriously) • 1 piece of cardboard out of the side of a box, • 1 magnet • scotch tape The How Tape the D cell to the cardboard so it can’t move.  Next, cut two 4 inch pieces of magnet wire.  The next step is a bit of work, but use a kitchen knife, or a piece of sandpaper to scrape off the red insulation until you just see bare copper wire.  Place a dime size loop in one end of the wire, and then bend it over at a right angle to the rest of the wir...

In August, there will be a total eclipse of the sun visible over the United States.  No. 1 and her mom, our resident physics professor, turned out this diagram of starlight bending around the sun because the sun's mass curves space.  Can a general relativity experiment be far behind? In other news, metallic ink pens do interesting things under photo filters. The following day, this all inspired No. 1's derivative artwork :)

Given the fascinating history of the author, I was very excited to read the book.  Agnew Hunter Bahnson Jr. is featured in the near sci-fi non-fiction book, "The Philadelphia Experiment".  A wealthy industrialist that fancied himself a potential astronaut, Bahnson funded fringe physics projects, (that's how he landed in The Philadelphia Experiment"), as well as mainstream general relativity research, (he raised the funds to sponsor the Institute for Field Physics at the University of North Carolina Chapel Hill). More on Agnew's history" The book alas, did not live up to the author.  While the story is more interesting if you allow yourself the gratuitous fantasy that Bahnson was dreaming about the ship he himself hoped to build, that's about all the book has to offer.  He had a potentially spectacular female character, a pilot the equal of the book's main character.  Unfortunately, Bahnson squandered her, using only as a romantic prop.  It...

Once again the Eagleworks warp drive is in the news again.  This time purporting to be the subject of a peer reviewed article. Errr, uhhh, where to start. First, these guys have done pretty poor science for a pretty long time. Which is sad, because if it was real, they would have some really cool stuff. Second, the AIAA reference clears up a lot of confusion I had about this announcement. The AIAA hosts an 'advanced propulsion' workshop once a year. By advanced, think... well... scifi. It's not to say that legit researchers don't turn up there, because they do, it's just to say that they're not all legit. The proceedings of this conference are in fact published. Consequently, getting peer-reviewed, and published in this particular conference doesn't infer you're entirely legit. This leaves us with why I don't think their science is entirely legit. I'll ignore all the 'violations of Newton's 2nd law' arguments, since those have b...

D.r Harold Daw In the late 1950’s, my uncle, then a teenager, found himself at odds with the Law in Las Cruces, NM.  Simply put, the police had decided he was, in fact, his brother, wanted for fleeing a drag race in the same car my uncle had just driven home.  Despite his repeated pleas that they were arresting the wrong Carter boy, the police persevered, first handcuffing my uncle, and then shuffling him into the police car.  Unbeknownst to them, the woman who lived across the street from my dad’s family had observed everything.  Turning to her husband, she said Harold, they go the wrong boy!  You go down to the station and help them straighten this out!”  That’s how my uncle found himself riding back to his house in the car of Dr. Harold Daw, head of the New Mexico State University physics department.  The Hot Rod in Question The reason I bring this story up now, isn’t because of its somewhat topical nature in relation to the state of ...

Today’s math fun involves portions of yesterday's, but with a few more steps.  It may also—dare I say it?—involve partitioning!  I might be using the word partitioning in an incorrect way, and if so, then pardons please, (also, please let me know).  The question is, what are the fewest number of coins you need to make change for up to a dollar. Here's how I worked, using an iterative algorithm, (fancy words for: "I'm going to use the same trick over and over").  It was all about granularity of coins, and getting quickly from one amount to the next.  The quickest way, (where quick is defined by using the smallest number of coins), to get to a large amount of change is with large coins.  So, as we move around within 99 cents, the biggest step we can make is with a half dollar. Using yesterday’s method, we can fit one half dollar into 99 cents.  That leaves us with 49 cents left move around in.  The quickest way to make progress within that interva...

Working through the problems in Niven's book on combinatorics, I came across the following one that cleverly introduces least-common-multiples without saying any of those words.  The book asks the following question: How many numbers that are evenly divisible by 11 exist between 1 and 2000?  How many that aren't also evenly divisible by 3?  How many numbers that are evenly divisible by 6, but not by 4 exist between 1 and 2000? The hastily scribbled answer can be seen below, with each of the answers boxed in succession down the screen. By simply dividing 2000 by 11, we find out how many integers between 1 and 2000 are evenly divisible by 11.  In other words, we ask how many multiples of 11 can fit between 1 and 2000.  When we want to eliminate the multiples of 3, that's when the least common multiple comes in.  We already have the answer for all numbers divisible by 11, but how to eliminate those also divisible by 3?  By first asking what number...

Remember when "The New Math" had us all learning set theory in elementary school?  I hated set theory, and had no idea why we were learning it.  This week, years, (ahem, many), year later, I found out what it was all about: Sputnik!  While researching a book in the--as it turns out--aptly named New Mathematical Library, I found the historical link. The NML was a series of books commissioned by the School Math Study Group (SMSG).  A quick dive into Wikipedia turned up the interesting fact that the SMSG was formed after Sputnik flew over.  The US decided we were going to need far more scientists and engineers than we had available.  The solution to the problem back then made logical sense: increase the number of math literate students available.  Hence, the SMSG gave us the NML, a series of excellent books that: "make available to high school students short expository books on various topics not usually covered in the high school curriculum", and the...

I'm in the process of reading Schiff's Gravity Probe B inception paper[1].  Gravity Probe B was the satellite borne experiment that detected the Earth's gravitomagnetic field, but that's not what I'll be talking about today.  This post is more about a math trick/pattern.  It's a mathematical pattern that comes up pretty frequently in physics, so I figured it was worth a few notes here.  The first picture below shows the equation for the torque on a spinning object due to a spherical source of gravity, (like the Earth), with a bit of its attendant explanation by Schiff.  My notes can be seen to the left: The cool part I'm going to focus on today is one of the smallest expressions within the rather ginormous equation 3, (also shown in picture 2): $$\left(\vec{\omega}\cdot\vec{r}\right)\vec{r}/r^2$$ I've run into structures like this in the past and it took me awhile to realize what they did.  Likewise for some of my classmates.  The short versio...

While doing research for an article I'm writing about Janet Tate and her Gravity Probe B experiment[4], I found a few cool things regarding superconductors, frictionless bearings, and the Egg of Columbus experiment this morning. The Egg of Columbus demonstration was first performed by Nicola Tesla in 1893 at the World's Columbian Exposition [1].  Here's a brief video from MIT showing a modern day version of the demonstration[2]: The MIT site[2] describes the apparatus as follows: "A toroid with three different wire windings is connected to 220 VAC 3-phase voltage. The voltage phase of each of the three windings lags 120 degrees behind the next, creating a changing induced magnetic field. The changing field causes metal objects to rotate when placed inside. Motors using this principle are very common. In fact, power lines are often seen in sets of three because they are carrying three phases. For more information on 3-phase voltage," Alfred Leitner made ...

Michael Heiland serendipitously took this phenomenal time lapse video of the pink space cloud reported over Arizona last week on 2/25/2015. The cloud was formed by the Air Force Research Lab's rocket-launched ionospheric research experiment .  The video was taken from Michael's perch on Mount Lemmon northeast of Tucson. Based on the timing of this video showing the appearance of the cloud pretty much coincident with sunrise, the two science questions remain unanswered. Did the substance released in the experiment react chemically with the sparse oxygen in the ionosphere causing a glow in the process, as in the first Smoke Puff experiment back in 1956[2]? Or, was sunlight responsible for ionizing the substance in the same manner as the phosphorous payload released in the Smoke Puff 2 experiment[3]? +Michael Heiland  is a bit of a phenomenon himself.  He became famous for a gorgeous  time lapse video of the Phoenix valley  he made as a high sc...

A pink cloud was reported in the early morning, (pre-sunrise), sky over Arizona on Wednesday [1]. NASA and the DOD soon thereafter took credit for the cloud.  They had launched a rocket into the ionosphere where it released a vapor that created the cloud.  The purpose of the experiment was to study the effects of the vapor on the ionosphere itself.  The article, referenced above from ABC, said: "The experiment, which also involved using ground stations to take measurements of the ionosphere, was intended to develop scientific explanations for ionospheric disturbances and their effects on modern technology, officials said." This has all been done before [2] as it turns out!  In 1956 the Air Force launched two missiles from White Sands Missile Range with payloads of nitric oxide.  The gas released in the ionosphere created a glowing cloud described as being ' yellow-red '[3] in color.  They were studying the ionosphere as well, which, back in 195...

Did you ever wonder if there was any 'real science' behind the subject matter of shows like 'Ancient Aliens'? There is! Yesterday I came across these two articles[1][2] by Dr. Virginia Trimble: UC Irvine astronomy professor and science historian. The first article was written by Dr. Trimble when she was still an undergrad at UCLA. It detailed her calculations showing that the constellation Orion was visible through the 'so called air shaft' of Cheops pyramid when it was constructed. The second article was an excellently written and fun to read review of the a 1979 "Symposium on the Implications of Our Failure to Observe Extraterrestrials " The symposium was attended by luminaries such as Freeman Dyson and Bracewell. Among other topics, there were discussions of how many planets were available that could support life. It gives a nice historical perspective on today's post from John Baez [3] References 1. "Astronomical Investigation Conc...

Work is proceeding on testing the systems that will be used in the experiment.  While the glass Dewar’s silvering blocks gamma radiation in the 22 keV range substantially, it fits nicely inside the yoke magnet whose field can be easily measured.  A temperature gauge was located; vacuum testing was started for the inner Dewar and lid, (including the instrumentation ports.)  Scroll to the bottom for the background of the experiment. All about the temperature gauge Today, just pictures of the gauge.  For an idea of scale, its rectangular footprint is about the size of a nickel.  The four wire sockets on the left are for attaching a four point probe to measure the resistance of the gauge. The Dewar lid with all the attachments The easiest way to seal the Dewar lid was to put the instrumentation stick back in place.  An experimental stage to hold the Pb sample still needs to be designed. Testing the vacuum pump before testing the D...

How a car accident in 1936 turned physicist, David Tressel Griggs, into WWII radar test pilot who ferried other scientists to the European front to capture Nazi atom bomb scientists. Here's what I already knew: Agnew Hunter Bahnson Jr., in a rather indirect manner, provided both the airplane and the test pilot used by MIT's Radiation Lab to test a new WWII technology, radar.  In 1936, Bahnson, who was a resident of a Harvard dormitory, took one of his geophysicist dorm-mates, David Tressel Griggs on a hiking trip through the Caucasus Mountains.  The Caucasus range connects the Black Sea with the Caspian Sea.  Bahnson's and Grigg's hiking trip ended before it even began, however, when Agnew swerved off the road to miss a bicyclist and struck a tree[1].  Griggs narrowly missed losing both of his legs to amputation. Hunter's father had taken out an insurance policy for the trip.  Grigg's used his payment to purchase a Luscombe airplane.  His injured legs ...

Our cosmology course is well under way and it's  a lot of fun so far!  The class direction overall is towards describing the inflationary universe by means of quantum field theory, but this week we're focused on relativity.  We're allowed to work on our homework together, however, I'm spending most of my time in the lab this semester, so I'll be posting my homework notes here.  If you'd like to grab bits and pieces, make suggestions, or contribute, the whole shooting match will also be archived on github . Our first homework contains a problem that involves accelerating reference frames.  The question is, given the transformation between the lab and the accelerating reference frame, figure out if the line element $ds^2$ is preserved.  There are a few interesting aspects to this problem.  First, while the transform looks similar to Rindler coordinates, it's not, (as ar as I can tell.)  Second, looking into Rindler coordinates a bit, they seem to ...

For background on the experiment, please scroll down. We can get a cheap piece of 3/4 inch diameter Pb from Rotometals .  Here are the details 3/4 17.14 per foot Nuclead has the same thing.  Check for purity and price. Also there’s Mayco . Next question, how pure does pure have to be? Pb purity data: The following are reference articles about superconductors.  Each of them describes the purity of the Pb samples used.  The lower bar is set by the RMP article referenced below, as well as one other that mentions the use of ‘commercial’ grade material and the evidence of a transition to a superconducting state for this material.  The final reference from 1886 in the section defines commercial level material to have a quality not lower than 99% pure.  This information is being researched to determine what purity of sample we should use.  It would seem that a higher purity sample will produce fewer unexpected experimental results, as we...

I ran into a rather abstruse question in today's first mechanics recitation.  The question gave the one dimensional position of a particle with respect to time as $x = 10 - 4t + 2t^3$ It then asked for the distance traveled by the particle between t = 0 and t = 2.  The suggested answer, (from the prof in charge of TAs), was to plot the trajectory of the particle, thereby demonstrating the distance and displacement were different.  Here's the plot: The idea is that you can see that the particle travelled form 10 to 8 and then back to 18, so the total distance is more than the displacement from 10 to 18 i.e. 8. The question came up as to how to do this to get the exact answer.  Here goes What we want to do is add up all the small, (read infinitesimal), distances travelled by the particle between time 0 and time 2.  The phrases, 'adding up', and infinitesimal provide the tip off that we'll do an integral, so: Getting to the Integral the ...