Science Blog for the Unwanted

April172013

vanished:

Alan Friedman - HD Photos of the Sun

Beautiful textures of our nearest star.

April32013

the-science-llama:

Particle Collisions Could Create Twin Black Holes at Large Hadron Collider
Back in 2008, physicists repeatedly assured us that a black hole produced by the Large Hadron Collider (LHC) was not going to swallow Earth. But that doesn’t mean they weren’t hoping to make one. Collisions between high energy particles, like the LHC’s protons, could theoretically squeeze enough mass and energy into a small enough space to create a tiny black hole—and making one might be a bit easier than physicists believed. It takes 2.4 times less energy than previously thought to create a black hole from a particle collision, according to a new paper in Physical Review Letters. That’s because when two particles smash into each other, their gravitational pull traps energy at two points on either side of the crash site. If enough energy gets concentrated at those points, it collapses into twin black holes that quickly gobble each other up and merge into one, as seen in the simulation above. Even with the new energy estimates, the chances of making a black hole in a particle accelerator are still vanishingly small. But because spotting one at the relatively low energy of the LHC would be solid experimental evidence for extra dimensions, physicists are keeping their fingers crossed.
Via sciencemag.org

Particle Collisions Could Create Twin Black Holes at Large Hadron Collider

Back in 2008, physicists repeatedly assured us that a black hole produced by the Large Hadron Collider (LHC) was not going to swallow Earth. But that doesn’t mean they weren’t hoping to make one. Collisions between high energy particles, like the LHC’s protons, could theoretically squeeze enough mass and energy into a small enough space to create a tiny black hole—and making one might be a bit easier than physicists believed. It takes 2.4 times less energy than previously thought to create a black hole from a particle collision, according to a new paper in Physical Review Letters. That’s because when two particles smash into each other, their gravitational pull traps energy at two points on either side of the crash site. If enough energy gets concentrated at those points, it collapses into twin black holes that quickly gobble each other up and merge into one, as seen in the simulation above. Even with the new energy estimates, the chances of making a black hole in a particle accelerator are still vanishingly small. But because spotting one at the relatively low energy of the LHC would be solid experimental evidence for extra dimensions, physicists are keeping their fingers crossed.

Via sciencemag.org

(via thescienceofreality)

March42013

The Dumbbell Nebula in Mapped Color

About This Photograph

This image of the Dumbell Nebula is presented in false-color. Red, green and blue channels were assigned to Sulphur-IIm Hydrogen-alpha and Oxygen-III emission lines, respectively. The H-alpha channel was also used for the luminance data.

source (x)

science The Dumbbell Nebula Mapped Color space nebula astrophotography

4PM

sciencenote:

Fatal Contact

By David McDonald and Thomas Hope, Case Western University and Northwestern University

A dendritic cell (left) presents HIV (green) to primary T cells (rigth) in an infectious synapse. HIV is labeled with GFP-Viral Protein R (vpr). Filamentous actin is stained red with phalloidin, and nuclei are stained blue with Dapi. Deconvolved image was captured on a DeltaVision imaging system (API).

February282013

ikenbot:

What Are Little Planet Projections?

We’ve seen these wonderful forms of photographic manipulation many times before on APOD, but how are they done?

Little planets are created by applying a stereographic projection to a spherical panorama. It is possible to seamlessly move from a birds-eye view in the sky to that of a bug on the ground!

Equirectangular panoramas

To generate these images we start with a spherical (equirectangular) panorama. This is an image where the x-axis corresponds to the longitude around a sphere (0-360 degrees) and the y-axis is the latitude (-90 to 90 degrees).

For any longitude or latitude position on a sphere we can retrieve the colour directly from the corresponding x,y coordinates on the panorama image. A proper equirectangular panorama should be twice as wide as tall, e.g. 1024x512 pixels.

Stereographic projection

Stereographic projection is a mapping that projects a sphere onto a plane, as illustrated with the world map below. It is conformal, which means that it preserves angles locally (note the grid lines still cross each other at right angles) although it doesn’t preserve areas or distances.

As we already have the colour of each longitude and latitude point on a sphere from the equirectangular panorama the inverse stereographic projection formulas are used, as described by Mathworld.

Want to give it a try? A few folks have already written tutorials on this emerging art form. You can check out a couple of these tutorials over at flickr here and here, but I’m sure there are many more on the web. Now go on and make a couple of little planets of your own!

Images: [**][**][**][**][**]

Want to submit sky or astro photography to CWL? Head over to the submissions section. If you’ve got some of your own or generally favorite awesome photos you’d like to share with us.. Don’t be shy! If it’s awesome, best believe it will be posted.

(via snapdragonmcfisticuffs)

February222013

jtotheizzoe:

Dinosaurs vs. People

Just stumbled upon a fantastic gallery on WIkipedia of illustrated size comparisons between humans and dinosaurs. So many tiny dino-chickens!

Check them all out here. Lots of them look like the blue waving guy is about to get chomped Jurassic Park “lawyer in the bathroom” style, but that’s probably pretty accurate.

(via Kyle Hill)

January62013

theworstmathematician:

When two bodies orbit around each other in space, we know exactly what happens. The bodies trace out conic sections, they do so in accordance with Kepler’s laws, and that’s it, more or less.

When three or more bodies orbit around each other in space, things can be more complicated. In the general case, no explicit formula for the orbits exists, and we have to rely on numerical simulations. As the first two animations illustrate, these can get messy. (These animations by my friend poulenque.)

Among all these possible orbits, though, there exist some which repeat after some time. These are called n-body choreographies (with n = the number of bodies), small islands of order in a large chaotic space of ways-things-can-be. That’s what all those other animations are. (These animations are by Chris Moore, from here, where he has some others too.)

Most of these are completely unstable, in that the slightest nudge or imbalance in their masses will get amplified until they go flying. However, the one that traces out a figure 8 above is only somewhat unstable, in that (apparently) it will resist small nudges or variations in mass. It is estimated that between 1 and 100 naturally-occurring such figure 8 configurations exist in the entire observable universe.

In all of the animations above except for the second, the masses of all the objects are the same. This is important if you want to wonder about them.

.‿.

(via thescienceofreality)

December312012