Copasetic Flow

Summary Callibrtion of the NaI gamma ray detector has begun.  A mistake in the gain and treshold settings made it appear as if the dectector might not be working properly as it gave the same energy spectrum with and without a Cesium 137 source present.  Once the gain and threshold were properly set what appeared to be good spectra were recorde. New to the lab book?  Scroll to the bottom for background on the experiment. Using the Photomultiplier Tube power supply First, turn on the lever switch labeled “Power” on the lower left hand side fo the box.  Make sure to wit fo rhte “Stdby Reset” panel light to illuminate before switching on the “High Voltage” lever switch To turn on the QVT,  switch on the power switch on the NIM Bin supply on the far right hand side of the bin. Clearing the QVT To clear the contents of the QVT, hold the start/stop switch in the stop position while toggling the clear switch. picture 1 and 2 are the fron...

Penrose created visually appealing and conceptually utilitarian conformal maps of spacetime including the point at infinity for general relativity. Penrose published his first articles on diagrams with his dad, L.S. Penrose.  The article cited an M.C. Escher exhibit Penrose attended in 1954 Roger Penrose wrote over 20 books and articles referencing Escher.  You can find them all on Google Scholar When Penrose and Penrose published their first article citing Escher’s work, he hadn’t created his woodcuts of the hyperbolic plane which illustrate a conformal infinity.  By 1962 when the first Penrose diagram, (a conformal map with infinity), appears, Escher had, (1959). Escher’s woodcut is included in Penrose’s book “The Road to Reality”, and is very similar in form to Penrose’s first published conformal map of the point at infinity in spacetime. There’s an entire collection ...

Imagine living thousands of years ago in ancient Sumeria as a mathematician.  Your medium for storing infomration is cuneiform on clay tablets.  As you work, you stamp each equation into wet clay by making wedge shaped marks using the blunt end of a reed to make a finished document that looks like this (picture 1)[1] When your instructor tells you to investigate the properties of a table of let's say, a hundred numbers or so, you might sigh in resignation, and plan on having results by sometime next week. With the advent of paper and pencil, things become much easier.  There's still lots of work to be done, but the recording of the information so that it can be viewed and worked with is, comparatively speaking, a piece of cake. Finally, though, the computer comes along and getting a table of 100 numbers is more like playing.  With  +The SageMathCloud   the 100 number task suggested in the +Mathematical Association of America  video below...

+Jonah Miller  is currently working on a multi-part series of articles on how computers work.  In one of the installmetns he mentioned the good old triode vacuum tube with a cathode, plate, and grid.  That brings up the subject of today's post, the grid dip meter, (GDM).  If you wandered over here from the ham radio practice tests [1], and you want the shortest answer possible, then click here, or scroll down the page.  If you want more information, read on: The grid Dip meter schematic is shown in picture 1. The main purpose of the circuit, at least for amateur radio operators, is to determine the resonant frequency of some other circuit or device, (like an antenna).  Let's say you've built you're latest radio and you'd like to get all the power you can from the driving finals, into the antenna.  To do that, you'd like to make sure that the antenna resonates at the same frequency you'd like to send and receive at.  If the antenna resonate...

I spent most of yesterday travelling between Austin and College Station, but I did manage to get a little bit of research in.  I'm looking for other experiments related to Hirsch's theories we can do in conjunction to the search for H-rays.  One of the measurable predictions of Hirsch's theory is a change in the coefficient of sliding friction when a material enters it's superconducting state. All about friction [6] New to the lab book?  Scroll to the bottom for background and a summary of the experiment. Hirsch mentions [1] that a finding of reduced friction in superconductors might be evidence in support of his hole theory of superconductivity. Furthermore, the electronic layer outside the surface is likely to affect the friction properties of the superconductor, by providing a ‘lubricating layer’ on top of which another material would slide. As a matter of fact, an abrupt drop in sliding friction between a lead surface and solid nitrogen has be...

The Alcubierre drive works, (theoretically), by warping space 'downwards' in front of a spaceship and 'upwards' behind it, (picture 1). The net effect is that the spaceship always feels like it's free-falling through space.  We have to be careful not to let the spaceship approach either the upward or downward walls of the curved space shown above.  In these regions, gravity due to the curvature of space is changing rapidly, and will cause uneven forces, known as tidal forces, on different portions of the spaceship that can cause it to break apart.  That's where Alcubierre's tophat function comes in.  The tophat is the input to the operation that describes how space is warped by the drive.  It's nice, flat top becomes the flat area in the middle of the warp shown above where the spaceship can safely rest. In case you weren't there, here's the description of the tophhat function I provided in the last post on the Alcubierre drive [1], (s...

Lab Book 2014_06_20     Hamilton Carter New to the lab book?  Scroll to the bottom for background and a summary of the experiment. Pulling the Dewar from the Table The spray Styrofoam was shaved off the Dewar this morning revealing that the Dewar had originally been installed on a piece of regular Styrofoam and the spray coating was added later The plan is to peel away as much of the spray foam as is practicable, and then do a two person lift of the Dewar out of the table.  The Dewar will be immediately placed in a padded box. The Dewar was successfully removed!  Next, I’ll remove the shelf and put the magnet in place.  There’s one cooling tube that was knocked off the magnet as it turns out, so that will have to be fixed. Vacuum Pump Down! The leak detector vacuum pump appears to be broken.  The reading on it is a much worse vacuum than from the auxiliary one on the lower shelf of the cart ...