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jtotheizzoe:

Common Physics Misconceptions

Isn’t it time that we stop teaching our kids that the Earth is flat? Sure, we can’t exactly jump into special relativity in 8th grade science classes, but surely we can bring physics education into the 20th, or maybe 21st century?

A fine message by Henry from minutephysics, to go along with his open letter to the President on physics education.

Gray Egg Methone

It’s difficult not to think of an egg when looking at Saturn’s moon Methone, seen here during a Cassini flyby of the small moon. The relatively smooth surface adds to the effect created by the oblong shape.

Small moons like Methone are not generally spherical in shape like the larger moons. Their small sizes means that they lack sufficient gravity to pull themselves into a round shape. Scientists think that the elongated shapes of these moons may be a clue to how they formed.

Super-Dense Neutron Star Is Fastest Ever Seen

Astronomers have discovered an ultra-dense star that orbits with a dying stellar companion once every 93 minutes, making it the fastest-orbiting star of its kind.

Image: Credit: NASA/DOE/Fermi LAT Collaboration/AEI

The speedy object, a kind of neutron star called a millisecond pulsar, rockets through space at 8,100 mph (13,000 kph) or more, researchers said. Its lightweight companion — which the “black widow” pulsar is destroying with a barrage of radiation — is faster still, zipping around the system’s common center of mass at 1.7 million mph (2.8 million kph) or so.

The pulsar, known as PSR J1311-3430, and its partner are separated by just 320,000 miles (520,000 kilometers) — about 1.4 times the distance from Earth to the moon — making them the most tightly bound such pair known.

Scientists spotted PSR J1311-3430 after combing through four years’ worth of data collected by NASA’s Fermi Gamma-Ray Space Telescope. The find marks the first time a millisecond pulsar (MSP) has been detected via high-energy gamma rays alone, researchers said.

“The discovery of this first MSP from direct gamma-ray pulsations opens the door to the detection of other extreme binary pulsars,” study lead author Holger Pletsch, of the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Hanover, Germany, told SPACE.com via email.

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Gravity Waves Give Twin Stars Speed Boost, Scientists Say

Two stars circling each other are speeding up in a tell-tale way that scientists attribute to gravitational waves: ripples in the very fabric of space and time.

Image: This illustration shows the gravitational waves thought to be produced by two orbiting white dwarf stars in a binary system called J0651, according to an August 2012 study. Credit: NASA

The stars are dense objects called white dwarfs, which are so close together they take less than 13 minutes to orbit each other. The two white dwarfs, remnants of stars that used to be as big as our sun, are only spread apart by one-third of the distance between the Earth and the moon.

In observing this system, astronomers have made the first measurements in optical light of motions that must be caused by gravitational waves, they said.

“This result marks one of the cleanest and strongest detections of the effect of gravitational waves,” astronomer Warren Brown of the Smithsonian Astrophysical Observatory said in a statement.

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LRG 3-757: Galactic Horseshoe

A gravitationally lensed galaxy

An interesting galaxy has been circled in this NASA/ESA Hubble Space Telescope image. The galaxy — one of a group of galaxies called Luminous Red Galaxies — has an unusually large mass, containing about ten times the mass of the Milky Way. However, it’s actually the blue horseshoe shape that circumscribes the red galaxy that is the real prize in this image.

This blue horseshoe is a distant galaxy that has been magnified and warped into a nearly complete ring by the strong gravitational pull of the massive foreground Luminous Red Galaxy. To see such a so-called Einstein Ring required the fortunate alignment of the foreground and background galaxies, making this object’s nickname “the Cosmic Horseshoe” particularly apt.

Credit: NASA/ESA/Hubble

the-star-stuff:

Gravity Waves

Credit: Henze/NASA

Gravity waves are distortions in the fabric of space-time predicted by Albert Einstein’s theory of general relativity. The gravitational waves travel at the speed of light, but they are so weak that scientists expect to detect only those created during colossal cosmic events, such as black hole mergers like the one shown above. LIGO and LISA are two detectors designed to spot the elusive waves.

jtotheizzoe:

What is Gravity?

I can think of no better way to answer this question than fire and a trebuchet. Thank you, BBC.

(by BBC)

matthen:

Why is it always better to look for shooting stars just before dawn? This shows a simulation of the Earth going on its orbit around the Sun, and encountering the debris from a comet that has passed by. This is precisely what the Earth has been doing for the past couple of days, creating the Perseid meteor shower. The A.M. half of the Earth is at the front of the orbit, and like a car’s front wind shield it picks up a lot of the debris. Have a look out for meteors again tonight! [code] [more]

Cats & Others in Zero G (Gravity) for Science

Cats only land on their feet when they know which way is down. Researchers at the Air Force Aerospace Medical Research Laboratories in Dayton, Ohio sent cats flying in a C-131 jet on a trajectory that gave them 15 seconds of weightlessness. This footage is from an Air Force film called Bioastronautics Research.

View More Animals under Zero G via Wired

Video: U.S. Air Force Aerospace Medical Research Laboratorie