Showing 456 posts tagged video
Watch the miraculous journey of infant sea turtles as these tiny animals run the gauntlet of predators and harsh conditions. Then, in numbers, see how human behavior has made their tough lives even more challenging.
As you may have heard, the asteroid 2012 DA14 silently glided past Earth on Friday, Feb. 15, 2013. Observations using radar have shown it to be an elongated rock about 20 x 40 meters (65 x 130 feet) in size…
It still didn’t get very bright; it was invisible to the naked eye. But with digital cameras and dark skies, snapping pictures of it was a matter of knowing where to aim, something photographer Colin Legg knows very well. From Perth, Australia, he captured this lovely time-lapse video of the asteroid moving past Earth right at the time of closest approach, 19:24 UTC. And he captured more than just DA14; there are some other surprises in the video, too. Make sure to set it to full-screen.
You can see DA14 sliding through the video from top to bottom on the left side of the frame. But right after the video starts, a meteor plummets through the field of view, leaving behind what’s called a persistent train—a trail of vaporized rock that can glow for several minutes.
From Slate’s Bad Astronomy.
A playground ball finds stability in a saddle when the saddle is rotating at the proper speed.
Mechanical analog of a “Paul Trap” particle confinement—a ball is trapped in a time-varying quadrupole gravitational potential. A large saddle shape (attached to a plywood disk) is mounted on a multi-purpose turntable. The saddle shape is essentially a quadrupole gravitational potential. Rotation of this potential subjects the ball to an alternating repulsive and attractive potential, much like the time-varying electric quadrupole potential of a Paul Trap used in trapping single ions or electrons.
The plastic ball used here is about 25 cm in diameter and was purchased at a toy store. The saddle consists of many layers of fiberglass and was hand-made with help from Justin Georgi. The turntable is driven at about 110 rpm with a DC motor. We have observed this ball at this speed remaining stable for over 2 hours.
Wired Science has an incredible gallery of the Best Microscope Videos of 2012, via Nikon’s video competition. We have a few favorites: This is a Bay Scallop Argopecten irradians. (Those blue things are tiny eyes.) And here’s a beating heart display of a Danio rerio (zebrafish).
The above video shows a Limnias melicerta (a rotifer) at 200x:
This microanimal lives in a self-built tube attached to waterplants. We see the rotifer using fast moving cilia to create a vortex. This enables it to sweep in food particles like algae. Inside the organism we can also see a jaw-like structures that grind the food.