Laser Sound

This project is based on the Make Controller I picked up at Maker Faire. It plays tones controlled by the interruption of laser beams. The laser beams are from Laser Levels, and the MacBook software is implemented in the Processing environment.

Details here.

CUDA GPGPU on MacBook Pro Laptop

I've ported my pthread generic and CUDA GPGPU real-time ray tracers to Mac OS X running on a MacBook Pro laptop. It has a 2.4GHz Intel Core 2 Duo processor and a NVIDIA GeForce 9600M GT graphics processor. The Performance for 1 and 2 software threads is comparable to my older Linux desktop, and the CUDA is within a factor of 3 of the desktop graphics card.

Threads    Frames Per Second
1           8.5
2          17.4
GPU        16.7

TxtView Application for Android

I've written a simple Android application for viewing .txt files from Project Gutenberg. It is still under development.

APK and source available here.

Three Key Concepts, and Their Application

• Occam's Razor
  "the explanation of any phenomenon should make as few assumptions as possible, eliminating those that make no difference in the observable predictions of the explanatory hypothesis or theory"
  


• Falsifiability
  "the logical possibility that an assertion can be shown false by an observation or a physical experiment"
  


• Uniformitarianism
  "the assumption that the natural processes operating in the past are the same as those that can be observed operating in the present"
  

These three concepts form part of the bedrock of the Western scientific method. When taken seriously, they help refute most supernatural claims. Science asserts that physical law has been constant over the time frames of the evolution of life on Earth, the evolution of man, and the development of civilization.

While we cannot travel into the past to directly witness historical events, we can examine evidence that has been (or should have been) left behind. We can also closely examine contemporaries, in both our own and other cultures, making similar claims. In the case of current supernatural claims, not one has held up to scientific examination.

Psychology carefully avoids making judgments about the truth of supernatural claims, instead focusing the individuals ability to function within their local social group. In Western society today we still see individuals making supernatural claims very similar to those we read in ancient texts. Sometimes they are recognized as mentally ill, but this does not stop others from believing and following them. From this it is easy to assume ancient, pre-scientific peoples were even more credulous.

This leaves one with several options on how to partition one's world-view. One extreme is to assert that many contemporary supernatural claims, from many traditions, are all true. A more moderate position is that the world was different two to four thousand years ago, and that supernatural claims from that time period were true. Of course these positions are often subdivided where claims within one tradition are uniformly true while the others are false (or misguided interpretations of events actually powered by the one true source).

The simplest Occam's-Razor explanation is to take a Uniformitarian position and assert that all supernatural claims for all time are purely based in psychology.

Galapagos

From Galapagos October 2008

Did the First Giraffe Have a Navel, Revisited

In an earlier post I asked, "Did the First Giraffe Have a Navel?". Turns out this is an old question:

These authors seem no more startled at a miraculous act of creation than at an ordinary birth. But do they really believe that at innumerable periods in the earth's history certain elemental atoms have been commanded suddenly to flash into living tissues? Do they believe that at each supposed act of creation one individual or many were produced? Were all the infinitely numerous kinds of animals and plants created as eggs or seed, or as full grown? and in the case of mammals, were they created bearing the false marks of nourishment from the mother's womb? The Origin of Species, By Charles Darwin (1859)

Citations and Uses of Ray Tracer Code

The real-time ray tracing code I wrote for PS3 Cell and CUDA GPGPU is being used by others. David Yuen's group at the Department of Geology and Geophysics and Minnesota Supercomputing Institute at the University of Minnesota used my PS3 code as the starting point for tsunami modeling. From their IEEE Vis 2007 poster session Use of Ray Tracing Techniques on Tsunami Simulation Data with the PlayStation® 3:

"This poster will discuss how we have used the PlayStation® 3’s cell processor to implement and employ parallelized visualization, through the form of ray tracing techniques, on tsunami data. By adapting Eric Rollins’ ray tracing package, we were able to implement his ray casting techniques on triangles. This allowed us to triangulate our tsunami datasets, stored as [x, y, height] data, and feed the triangulated data into the program. We rendered 4000 triangle objects from the data and applied a colormap based on each triangle’s height value. Finally, we displayed the generated image."

They also published a paper Experiments in scientific computation on the PlayStation 3 in the Springer journal Visual Geosciences. This PowerPoint presentation shows images from my and their work.

Other students are trying CUDA GPGPU ray tracing. Michael Allgyer (DOC) cited my work in his masters thesis proposal. Umut Erturk asked me about PS3 versus GPGPU for his thesis. Others are trying to get my CUDA code working on windows.