Category Archives: Students

Items for students and others, interested in learning about science and engineering and the application of science in our lives. We post many of the general interest items here.

Want to be a Computer Game Programmer?

You need to understand math, physics and more to become a computer game programmer. Things You Need to Know before Interviewing for a Game Programming Position:

You do need to have very good linear algebra skills. If you don’t know what the formula for a dot product is (a dot b = a.x * b.x + a.y * b.y + a.z * b.z ) and what it means geometrically (|a| * |b| * cosine of the angle between a and b), then there’s no chance you can get a job. You need to know how to project a vector onto another vector (a projected onto b = ( a dot b ) / |b|^2 * b) and onto a plane. You need to know what the cross product is (a x b = [a.y * b.z – a.z * b.y, a.z * b.x – a.x * b.z, a.x * b.y – a.y * b.x]) and what it means geometrically (a vector perpendicular to the vectors with a length equal to the sine of the angle between them).

You should be very familiar with all the projectile equations. If you can’t either derive or remember d = v0 * t + 0.5 * a * t^2, you’ll be in trouble when you interview or take a programming test. Any problem that involves a projectile with gravity should be easy for you to solve. Whether the unknown is gravity, launch angle, y velocity, xz velocity, time, distance or any combinations that are solvable, you should have no problems determining the solution. You should also be familiar with momentum and kinetic energy for elastic and inelastic collisions. Drag and friction should be concepts you understand also.

If that all looks like great fun to you, perhaps game programming is the career for you.

$100 Laptop Update

Green $100 Laptop photo

Public can purchase $100 laptop. I am not sure I understand the headline – this seems a more accurate picture of situation: OLPC aims for mass production in third quarter, 2007. At this time the cost each is about $150 and you will have to pay for 2 (you buy one for yourself and one for the developing world). The aim is to reach the $100 price level, but that has not quite been achieved yet.

The first countries to sign up to buying the machine, which is officially dubbed XO, include Brazil, Argentina, Uruguay, Nigeria, Libya, Pakistan and Thailand.

The XO’s software has been designed to work specifically in an educational context. It has built-in wireless networking and video conferencing so that groups of children can work together. The project is also working to ensure that children using the laptop around the world can be in contact.

The project continues to move forward even with the bumps along the road – it is quite an ambitious plan. Take a look at this great story: What kids can learn when you just give them access to a computer.

Related: Official Laptop Site$100 Laptops for the WorldAppropriate Technology

Cheap, Superefficient Solar

Cheap, Superefficient Solar

Technologies collectively known as concentrating photovoltaics are starting to enjoy their day in the sun, thanks to advances in solar cells, which absorb light and convert it into electricity, and the mirror- or lens-based concentrator systems that focus light on them. The technology could soon make solar power as cheap as electricity from the grid.

“I’d much rather make a few square miles of plastic lenses–it would cost me less–than a few square miles of silicon solar cells,” Olson says. Today solar power is still more expensive than electricity from the grid, but concentrator technology has the potential to change this. Indeed, if manufacturers can meet the challenges of ramping up production and selling, distributing, and installing the systems, their prices could easily meet prices for electricity from the grid, says solar-industry analyst Michael Rogol

Related: Large-Scale, Cheap Solar ElectricitySolar Tower Power Generation

Engineering A Cleaner River

I Eat Rubbish:

“I eat rubbish!”, the notice fixed to it claims that it collects 40 tons of rubbish every year; the equivalent of 800,000 plastic bottles. Called a “passive debris collector”, nine of them have been bobbing along the river for the past five years. Each captures tons of floating litter; bottles, cans, and plastic, that otherwise would have flowed out to sea and killed fish and birds. It was initiated by Thames21, an environmental charity…

How Do You Fix an Undersea Cable?

How Do You Fix an Undersea Cable?

A working fiber will transmit those pulses all the way across the ocean, but a broken one will bounce it back from the site of the damage. By measuring the time it takes for the reflections to come back, the engineers can figure out where along the cable they have a problem.

If the faulty part of the cable is less than about 6,500 feet down, the crew will send out a submersible tanklike robot that can move around on the sea floor. A signal can be sent through the cable to guide the robot toward the problem spot. When the robot finds the right place, it grabs ahold of the cable, cuts out the nonworking section, and pulls the loose ends back up to the ship.

A skilled technician or “jointer” splices the glass fibers and uses powerful adhesives to attach the new section of cable to each cut end of the original—a process that can take up to 16 hours. The repaired cable is then lowered back to the seabed on ropes.

Related: Underwater Fiber for the Internet

Help Choose the New PBS Science Program

PBS Science:

Here’s the experiment: Throughout January, PBS will broadcast three new science programs. Only one program will become a regular science series on PBS. We want you to help us decide. Watch the programs on your PBS station or, beginning January 1st, visit the companion sites below to watch each pilot show. Then tell us what you think

Wired Science – “brings WIRED Magazine’s cutting edge vision, stylish design, and irreverent attitude to the screen with breakout ideas, recent discoveries, and the latest innovations”

Science Investigators – “Full of information told through compelling stories, the series is presented by four young, lively hosts armed with the latest gadgets and technology, who make this a science show with attitude for the blog generation.” From WGBH, producers of NOVA

22nd Century – “Science fantasy or futuristic nightmare? 22nd Century takes you to the forefront of technology and hears from people on the cusp of a scientific revolution.”

Floating Windmills: Power at Sea

Floating Windmills (they broke the link – when will sites lean how to obey basic usability practices?):

A demonstration project is currently being planned based on wind turbines with a power generation capacity of 3 megawatt (MW). The windmills will reach 80 meters above the sea’s surface and will have a rotor diameter of about 90 meters.

According to plans, the demonstration project will start operating in 2007. We eventually envision wind turbines with a power capacity of 5 MW and a rotor diameter of approximately 120 meters.

“The future goal is to have large-scale offshore wind parks with up to 200 turbines capable of producing up to 4 terawatt hours (TWh) per year and delivering renewable electricity to both offshore and onshore activities. This goal is far in the future, but if we’re to succeed in 10-15 years, we have to start the work today,” Bech Gjørv says.

For photos see: Offshore Wind Turbine Farms

Related: USA Wind Power CapacityEngineers Save EnergyWind-Powered Water Heater

Effect of People on Other Species

We’ve Seen The Future, And It Is Us:

Human habitation has been, and is increasingly, playing a direct role not only in the extinction of species, but in their evolution. By our own actions, we may be accompanied into the future by ever more diverse pests and pathogens, and may leave behind what we value most—elephants, tigers, and others of the earth’s great megabeasts.

Where we have industrialized agriculture, weeds have evolved to chemically mimic our crops to avoid the herbicide. Insect pests have evolved resistance to DDT and to the pesticides that have followed. We have countered with genetically engineered crops. Already there are insect species resistant to the defenses of those crops. When we add new species of crops, insects in turn rapidly switch to those.

Australian Coal Mining Caused Earthquakes

Coal Mining Causing Earthquakes, Study Says by Richard A. Lovett:

The magnitude-5.6 quake that struck Newcastle, in New South Wales, on December 28, 1989, killed 13 people, injured 160, and caused 3.5 billion U.S. dollars worth of damage. That quake was triggered by changes in tectonic forces caused by 200 years of underground coal mining, according to a study by Christian D. Klose of Columbia University’s Lamont-Doherty Earth Observatory in Palisades, New York.

The removal of millions of tons of coal from the area caused much of the stress that triggered the Newcastle quake, Klose said. But even more significant was groundwater pumping needed to keep the mines from flooding.