Plus: Rubik’s Cube Ball, Solar-Powered Plane, Scary Engineering Feats and MORE.

What better way to celebrate Nikola Tesla‘s birthday than by watching a 15 ft. tall Tesla coil that shoots sparks as far as 26 feet?

Tesla, born July 10, 1856, was an inventor and a mechanical and electrical engineer who brought the world alternating current, the radio, other works in the field of electromagnetism and electromechanical engineering, and much more. To celebrate his birthday, the Nikola Tesla Inventors Club is hosting a three-day celebration in Philadelphia to “provide an opportunity for Tesla enthusiasts, inventors, scientists and free energy advocates to gather together in solidarity, reflection and exploration.”

Rubik Set to Puzzle Once Again
Thirty-five years after the cube, Erno Rubik is launching a new puzzle that promises to be just as testing as the Rubik’s Cube. The new Rubik’s 360 has some elements of the original design, Rubik says, and will challenge the solver “to use skill, dexterity and logic.”

The original cube was invented in 1974 and still has a cult following. Approximately 15 million units were sold last year.

Are you ready for a new challenge?

Solar-Powered Plane Ready to Fly
The Solar Impulse HB-SIA, the first 100 percent solar-powered plane, was unveiled June 26 and is ready to make its first flight. The Impulse has a 26.5 ft. wingspan but weighs less than a small car. It will travel with an average speed of 43.5 mph at an altitude of 39,300 ft. Using almost 12,000 solar cells, rechargeable batteries and four electric motors, the plane will travel day and night without using an ounce of fuel.

The plane will have a series of test flights over the next two years, and based on those flights, a new plane will be constructed for a round-the-world journey in 2012. The first test flight is scheduled for later this year and a complete night voyage is planned for 2010.

Engineers Defy Physics
In a quest to make more thrilling and scary theme park rides, engineers have pushed the limits of physics to create some of the most frightening experiences one can have in 30 seconds or less. Popular Mechanics put together a list of five of the scariest rides, including this 28-second heart-stopper:

The Kingda Ka is the tallest and fastest roller coaster in the world, launching its passengers up to 128 mph in 3.5 seconds. On one test ride, Popular Mechanics staffers said they lost control of their facial muscles and were rendered weightless for a bit.

Signs Good for Safety and Giggles
Along with all their good intentions, some safety signs and warning signs are also inadvertently funny. Safety Graphic Fun posts numerous funny safety signs for your amusement. A couple of the gems:

Toodles!