A physics-based puzzle game in which you have to guide your character to the goal by cutting wooden objects and joints.
Category Archives: Physics
Dude, It's Physics
The Physics of Surfing (Part One: Dropping In)
[P]addling by itself doesn’t get you into the wave, because you actually cannot paddle as fast as the wave is moving, and you need to match the speed of the wave if you want to ride with it. In order to catch up to that wave speed, it’s necessary to use the gravitational potential energy of the wave. The trick is to obtain sufficient speed by paddling that, as the wave travels under you, your board begins to fall down the face. As you drop down the front of the wave, the gravitational potential energy you gain is converted into kinetic energy. Soon you are travelling as fast as the wave. In fact, if you continue to drop to the bottom of the wave, you’ll be moving faster than the wave — and if you don’t cut into the face, you might temporarily outrun it.
Say "Cheese"
Ultrafast Lasers Show Snapshot Of Electrons In Action
In a paper to appear in the Oct. 30 issue of Science Express, the online version of the journal Science, the CU team describes how they shot a molecule of dinitrogen tetraoxide, or N2O4, with a short burst of laser light to induce very large oscillations within the molecule. They then used a second laser to produce an X-ray, which was used to map the electron energy levels of the molecule, and most importantly, to understand how these electron energy levels rearrange as the molecule changes its shape, according to Kapteyn.
1/Problem
Optics basics: Inverse problems at Skulls in the Stars.
Plenty of other techniques exist for measuring the internal structure of objects, using a variety of different types of waves. Magnetic resonance imaging (MRI) subjects a patient to an intense magnetic field, and makes an image by measuring the radio waves emitted when the field is suddenly switched. Ultrasound imaging uses ultrasonic waves to probe the soft tissues of the human body, and is used in mammography.
Each of these techniques is quite different in its range of application, but all require nontrivial mathematical techniques to reconstruct an image from the raw scattered wave data. These mathematical techniques are broadly grouped into a class of problems known as inverse problems, and I thought it would be worth an optics basics post to discuss inverse problems, their common features, and the challenges in solving them.
Grab Your ACME Umbrella
Space station trash plunging to Earth
NASA and the U.S. Space Surveillance Network are tracking the object — a 1,400-pound (635-kilogram) tank of toxic ammonia coolant thrown from the international space station — to make sure it does not endanger people on Earth. Exactly where the tank will inevitably fall is currently unknown, though it is expected to re-enter Earth’s atmosphere Sunday afternoon or later that evening, NASA officials said.
The umbrella won’t help, of course. Just ask Wile E. Coyote.
Pollin', Pollin', Pollin', Rawhide!
Don’t try to understand this
Just knock, ring and canvass
Soon we’ll be votin’ high and wide
Obama Takes Lead in Galactic Polls
M83, known sometimes as the “Southern Pinwheel”, is a more complicated case, as its electoral votes are divided following Interstellar Congressional districts. The rural regions continue to hold out for McCain, with disaffected liberals in the more tech-heavy globular clusters opting to vote Nader in protest.
I've Seen Fire, and I've Seen Rainbow
The Fire Rainbow: An Astonishing and Rare Marvel of Nature
To name it properly, a fire rainbow is a circumhorizontal arc. It is also known as a circumhorizon arc but whichever you chose, scientists (and aficionados) call it a CHA. It is given its name because it looks as if a rainbow has spontaneously combusted as it made its way across the sky.
Contrast with the circumzenithal arc (upside-down rainbow)
Nanograffiti
More atomic force microscope writing. (Like spelling out ‘IBM’)
‘Atomic pen’ writes with individual atoms
An Osaka University research team has demonstrated an “atomic pen” that can inscribe nano-sized text on metal by manipulating individual atoms on the surface.
According to the researchers, whose results appear in the October 17 edition of Science magazine, the atomic pen is built on a previous discovery that silicon atoms at the tip of an atomic force microscope probe will interchange with the tin atoms in the surface of a semiconductor sample when in close proximity.
Zombie Water
Mysterious ‘dead water’ effect caught on film
Research has already shown that dead water occurs when an area of water consists of two or more layers of water with different salinity, and hence density – for example, when fresh water from a melting glacier forms a relatively thin layer on top of denser seawater. Waves that form in the hidden layer can slow the boat with no visible trace.
Now French scientists recreating that scenario in a lab tank have revealed new detail of the phenomenon and even captured the effect on video. The work will help scientists to better understand dead water and the behaviour of stratified sea patches.
All Right, Mr. DeMille, I'm Ready for my Close-Up
Saturn’s tiny, icy moon Enceladus has recently been visited by NASA’s Cassini orbiter on several very close approaches – once coming within a mere 25 kilometers (15 miles) of the surface. Scientists are learning a great deal about this curious little moon. Only about 500 kilometers wide (310 miles), it is very active, emitting internal heat, churning its surface, and – through cryovolcanism – ejecting masses of microscopic ice particles into Saturnian orbit. Cassini has been orbiting Saturn for over 4 years now, and has provided some amazing views of tiny Enceladus, some collected here. Another close flyby is scheduled for Halloween, October 31st. (26 photos total)