Here is a 2014 note on the derivation of Lorentz transformation without any a priori assumption about the velocity of light.
I just wrote a few functions to manipulate quaternions. They are available here.
Using the above, I wrote a program to construct fractal objects like the von Koch curve but in three dimension. Here is an example of the successive iterations for the construction of fractal dimension 2.
This is essentially unrelated but I wrote a bunch of functions to write postscript files. They are in this tar file and permit to easily produce a postscript document such as this one.
Since 2005 I have been working at investigating the potential and approaches of a return to to stellar intensity interferometry. This project is now taken over by Nolan Matthews under the direction of David Kieda but I still like to give a hand when I can.
Here is a tar file with the SII Monte-Carlo simulation code written by Janvida Rou. The paper is submitted to MNRAS I will post it as soon as it is accepted.
Here is the 2012 honors thesis on SII Monte-Carlo simulation presented by Janvida Rou and here is an essay on the application of the HBT in particles physics she wrote for an assignment in the introduction to particle and nuclear physics class she took in 2011
Paper by Paul Nunez on Imaging capabilities with a large intensity interferometer
Deployment of Star Base Utah with two 3m telescopes as a Air Cherenkov and Intensity Interferometry instrumentation test bed.
For many years (from the time of my PhD until 2012) I worked in the field of Gamma ray
astronomy (here for an interactive sky map) with VERITAS. Here is
an animated stereo-scopic view of a few selected
events recorded with the three first VERITAS telescopes (pictures of telescope 4 under moonlight [1][2]).
2009 colloquium at the univesrity of Utah: pptx or pdf
GrISU(tah) a simulation package for Atmospheric Cherenkov cosmic ray detectors.
FROGS is a suite of functions to implement the shower image template analysis of atmospheric cherenkov data.
Paper on Haar wavelets as a tool for the statistical characterization of
variability, Astroparticle Physics 34 (2011) 871 (Ryan Price)
We worked on the optical calibration of the VERITAS
telescopes using Rayleigh scattered LASER light
pulse. We had a first test run in May 2005,
a preliminary analysis is
presented at the 29th ICRC. Our most recent paper on this topic is available here. This effort has been somewhat abandonned because of the setup being impractical but we are in the process of resurecting it now (2011).
SGARFACE the Short GAmma Rar
Front Air Cherenkov Experiment (in search for ultra short gamma ray burst)
described in a paper in Astroparticle Physics. The result of the search for primordial black holes with SGARFACE is presented here
The data acquisition of SGARFACE is a c program I wrote with a threaded TCP/IP socket server as in the prototype server.c (Makefile). The control interface is a TclTk TCP/IP client script as in the prototype client.wish I find this an easy way to remotly control hardware from a graphical interface easy to develop.
I made this minisky a while ago. If you have ideas to improve it, let me know. When putting this together with kids, I like to use Stellarium to show the constellations and how the sky, the Sun and the Moon turn.
This equatorial sundial is fun to put together with elementary school kids and it brings up good discussions on cardinal directions, time, latitude and longitude, the motion of the Earth around the Sun...
This sundial is more complicated and works better with middle school students. It is shown assembled here. It includes the equation of time correction and the seasonal change of the height of the Sun. It is designed for Salt-Lake-City. If you would like me to send you a version of it for your own location, just send me your latitude and longitude.
With this "astrolabe" (assembled), you can measure the latitude by pointing at polarus. In the day time you can measure the height of your school building by applying triangle geometry (with trigonometry or using this template). I would like to see if we could use it to measure the height of clouds... With this activity, you get to talk about similar triangles, angles, the Pythagorean theorem, trigonometry,...
Here are the slides of a presentation on the history of the measurements of the speed of light. People (high school kids and adults) seem to like it. I believe it can be done with younger students if associated with some demos. The "lecture" covers historical aspects, measurements of time and distance, electromagnetism, relativity. Many other elements could easily be added.
![[1]](telescopemoon1.jpg){kind=link}
![[2]](telescopemoon2.jpg){kind=link}
