Monday, December 21, 2009

How to build a magic rollback can - Short Version

Well the original was kind of long, but it's probably a good step-by-step for kids.
I made a shortened version and ditched the narration. Enjoy

Saturday, December 19, 2009

New Video!

How much gold and silver have been mined in history?
I decided to throw together a video of my last blog post.

Saturday, December 12, 2009

Just how much gold (and other precious metals) has ever been mined?

Gold, while one of the earliest metals known to man, is also among the most rare found on Earth. Other precious metals, such as Silver, and Platinum are also plenty rare. Just how much of these metals has ever been mined? You'd probably be surprised...

Click here for a video!

Gold (Au)

Total mass mined to date = approx 5,770,000,000 oz = 164,000 metric tons
Total value @ $1,115/oz (December, 2009)  = $6,433,550,000,000

Fun fact: That's more than the Gross Domestic Product of Germany and Russia combined! (2008)

How big is 5.77 BILLION oz of gold?
Total volume = 8,480 cubic meters. (@ 19.3 g/cm^3)
That would make a cube of 20.4 meters on each side!

 The Mount Rushmore National Memorial is 18 meters tall.

Friday, December 11, 2009

Total number of astronauts flown to space to increase by 600% within 5-7 years

As of 2009, only 500 people have flown to space. By 2016, that number will be 3,500 thanks to private space tourism.

SpaceShipTwo (legendary aircraft engineer Burt Rutan's follow-up to his 2004 X-Prize-winning SpaceShipOne) was unveiled earlier this week. The spacecraft, launched from a larger aircraft from 60,000 feet will be capable of sending six passengers and two pilots more than 100 km, just past the edge of space for a brief sub-orbital flight after which it glides  gently back to Earth.

SS2 will enter service with billionaire Richard Branson's Virgin Galactic after a battery of ground and flight tests starting around 2011. So far, 300 people have signed up (and paid deposits) for a $200,000 per flight ticket. Though pricey, this is still much less than the $20-30 million paid by space tourists who visit the International Space Station (albeit, their flights are orbital). Branson has stated that within five years, he expects that about 3000 tourists will have flown on his spacecraft. If true, this will mean that the total number of people to have flown into space will have increased by 600%.

For some perspective, between 1961 and 2009, slightly more than 500 people have flown into space. That's it. Many of these people flew multiple missions, so presently there have been a little over 1,100 trips into space. So it's taken a little less than 50 years for a little more than 1000 trips. Branson is hoping to add THREE TIMES as many tourists into space within FIVE years as there has been total trips to space in the past FIFTY.

Sunday, December 6, 2009

Stability Properties of Physical Systems

We can think of a physical system as a subset of the physical universe as a whole. We define what constitutes the system based on what we are interested in analyzing. Anything outside of the system we ignore for analysis except for how it affects the system we're looking at. So for example, your body can be considered as a physical system. The solar-system can be thought of as a physical system. A lagoon can be thought of as a physical system. Even an individual atom can be thought of as a physical system. It all depends on what you want to look at.

Stability properties of a physical system refers to how the system responds to some perturbation; whether the system can recover on its own after being perturbed or whether it goes haywire. Stability analysis helps us to understand what happens when we perturb a system.

Saturday, December 5, 2009


A few years ago for my 'Technology and Engineering in Antiquity' class, the students were given the option of either writing a mid-term test, or submitting a project about some medieval/ancient device that they had built. Due to my aversion to studying, I decided on the latter.

I ended up building a ballista, which is more-or-less just a gigantic crossbow. It wasn't very effective, but at least it worked! You can read about my project at my Medieval War Weapons blog. It includes pictures and several videos of the ballista in action.

Evolution of Hearing

As part of effort to post interesting papers I had written for school on-line, I started a blog devoted to the topic of one such paper: The Evolution of Hearing. In it, I present my paper which traces the evolution of the ear from early fish and amphibians through reptiles and then to mammals. I haven't really been able to find an online resources that sums up how ears first evolved, so this is probably a good general introduction into the topic.

I also created a video presentation which is almost verbatim from the paper. So enjoy either one, both, or none. :)

Paper: The Evolution of Hearing


How NOT to cut glass with scissors!

Back in 2007, there was a video floating around demonstrating how one could cut glass with ordinary scissors provided they do it underwater. Like with all interesting videos on the internet, many people thought it was fake. I myself am not sure, nor do I really care. But after watching the video, I decided to spoof it. So with some really basic special effects (jump-cuts, beet soup, photoshop, sound effects), I threw together my video and uploaded it to

A few months went by when I noticed my video on the front page of Break. Within a day it had amassed over half a million views. Today, it has been viewed 850,000 times. Sheesh!

My parody:

The original:

How to make your own Magic Rollback Can

The Rollback Can is a very simple but fun toy that anyone can make in less than 5 minutes using common household items. It looks like an ordinary can, but when you roll it along a surface, it will roll right back to you. Properly built ones can even roll up a slight incline.

I've put together an instructional video, or you can check out my step-by-step instructional guide. Enjoy!

Friday, December 4, 2009


Welcome to check media! This blog is brand new and under construction but will shortly be host to articles and videos written and created by me. Please check back soon.

In the mean time, take a look at my other blogs:

Evolution of Hearing - Traces the evolution of hearing and ears from early fish and amphibians to modern mammals, with video.

Stability Analysis - A paper explaining how to perform a simple stability analysis from a set of ordinary differential equations, using a numerical simulation. The example in this case is one of the rate of star formation within a model galaxy.

Medieval War Weapons - Documenting the construction of a modern day ballista catapult. Includes videos of test firing.

My YouTube Channel - Where I host all of my videos.