- Thinking with 50,000 Volts of electricity - Twitter combined with Tesla Coil -
- Masters of their Center of Mass -
- Bose-Einstein Condensates, pt. 3 -
- Bose-Einstein Condensates, pt. 2 -
- Bose-Einstein Condensates, pt. 1 -
- A smooth spiral tool path for high speed machining of 2D pockets? -
- The Future Of My Cameras -
- Working with Light -
- Dancing Volvox: Hydrodynamic Bound States of Swimming Algae -
- High-Resolution Probing of Cellular Force Transmission -
- Planet imaging - focusing methods -
Month: April 2009
A Noux65 from Bangkok
Phanchita Supasirithanawat (www.rcsails.com) from Bangkok Thailand sent me these pictures of a down-scaled Noux design built to the RG65 rules. It's called a Noux65.
There is a video here http://www.rcsails.com/noux65.htm
Mad Max comes to Finland
Riku and Lasse from the Turku-area IOM-fleet are proud new owners of Jeff Byerley designed Mad Max IOMs. These are the very first boats to come out of Mike Clifton's moulds in the UK. Note black main-boom, I hear it's about 10% faster than the standard aluminum-colored one!
Links - April 19, 2009
- Photo Animation Goodness -
- The Geometry of Sound -
- Talent = 10,000 Hours + Luck -
- Canon EOS 50D Review -
- Canon EOS 5D Mark II Review -
- Canon EOS 500D / Digital Rebel T1i Preview -
- Kick Your Ass with Science -
- Suggested Caption: This new machining technique gives you the ability to utilize the entire flute length of the cutting tool, saving both time and money -
- Scallop bisectors -
- Learning Physics Through Open Courses -
- Brownian motion and how to run a lottery (or a bank) -
- How cells decide -
3930m of Jogging
Nokia Sports Tracker can be used on my N95 to keep track of speed, distance, time etc.
This is a 3930m run which took 26min 13s (average speed 9,0 km/h).
Links - April 12, 2009
- Vital Browser Addition: Readability -
- 04/10/09 PHD comic: 'Single keystroke' -
- World’s Most Interesting Bookstores -
- Super-resolution orientation estimation and localization of fluorescent dipoles using 3-D steerable filters -
- 04/08/09 PHD comic: 'Lao-Tze' -
- The Hubble Space Telescope’s Greatest Images -
- A Closer Look at YouTube EDU -
- Golden Gate Bridge Time Lapse Video via Google Street View -
- What Happened to my Laptop -
- Beta release: emc 2.3.0beta2 -
- jukumagic -
MicroMagic 2009 ranking 3
The third ranking race of the year gathered 8 boats just outside Carusel in central Helsinki.
OpenFOAM 1.5 on Ubuntu 8.10
Although we have a general idea of how low Reynolds number foils, bulbs, and rudders should look like, we thought it would be fun to do some Colorful Fluid Dynamics to test different airfoils and configurations. It's likely that we will pick a well-known airfoil for the first set of foils and bulb for the Pikanto project, but if anything comes out of this computational analysis then cnc-machining new moulds is not a problem.
There are a lot of CFD software packages out there, some expensive and some hugely expensive. The most well known open-source alternative seems to be OpenFOAM. It's not as easy to use as the fancy commercial ones, but it's well supported by both academic and industrial users, and it's free! Some installation notes, mostly for myself, on how I installed Ubuntu 8.10 and OpenFOAM 1.5.
- download 64-bit Ubuntu 8.10 iso-file and burn to CD (8.04 did not want to boot on my Q9300 cpu machine, probably a motherboard conflict?)
- install Ubuntu as normal, run suggested updates (286 of them actually!)
- for OpenFOAM I roughly followed instructions from here: https://help.ubuntu.com/community/OpenFOAM
- download all the .gtgz files from here. Rename them to just .tgz so Ubuntu knows how to extract them
- run the bashrc magic with '. $HOME/OpenFOAM/OpenFOAM-1.5/etc/bashrc' followed by 'source ~/.bashrc'
- now in OpenFOAM-1.5/bin we can try './foamInstallationTest' which errors out because it doesn't find ssh or rsh (these are only needed for remote installations or cluster-calculations or similar I think)
- to make foamInstallationTest happy, install ssh: sudo apt-get install ssh
- now foamInstallationTest reports that all systems are go.
- paraFoam which is used for pre- and post-processing needs QT. I'm not sure which packages exactly are required, but mine started working after installing 'libqtcore4', 'libqt4-assistant', 'libqtgui4' and all of their dependencies. (I did this with the synaptic package manager)
- Ready!
Try running the tutorial cases in e.g. ~/OpenFOAM/OpenFOAM-1.5/tutorials/icoFoam/cavity. This tutorial is explained in the docs here. Everything is set up already, so you only have to run blockMesh to generate the mesh, then icoFoam to do the actual calculation, and then visualize with paraFoam.
Mirror mount
The mirror is now parabolized to better than 1/18-wave RMS, so we are assembling the telescope to star-test it prior aluminizing the mirror. If and when everything looks OK through the scope we will send the mirror to be aluminized.
We came up with this mirror holder out of ca 20mm thick oak board. There are three M8 screws that support the mirror cell. Springs push it upwards, and the wing-nuts used for collimation pull down. It's all going to be attached to the wooden tube by three L-brackets.