Science Walrus

ikenbot:

Supermassive Black Hole at Work

Image Credit: NASA, S. Gezari (The Johns Hopkins University), and J. Guillochon (University of California, Santa Cruz)

Back in 2010, astronomers witnessed an explosion of light from a star that was obliterated by a supermassive black hole. This is an accurate computer simulation of the event that took place.

thenewenlightenmentage:

Like attracts like?

Everything you thought you knew about electrostatics is probably wrong.

Make two metal spheres positively electrically charged, bring them close together, and what happens? They’ll repel one another, because like charges repel – right?

Wrong. According to physicist John Lekner at the Victoria University of Wellington in New Zealand, they will most probably attract one another, violating the intuitions of basic physics. The counterintuitive result was published today in the Proceedings of the Royal Society A¹.

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quantumaniac:

Earth Will One Day See a Second Sun

Betelgeuse, a red supergiant star located in the Orion constellation, about 640 light-years away from Earth - is preparing to explode via a supernova. When it does, the Earth will have a front-row seat; in fact, the explosion will be so bright that Earth will seem to briefly have two suns in the sky. 

Betelgeuse is one of the brightest and largest stars in our immediate galactic neighborhood - if you dropped it in our Solar System, it would extend all the way out to Jupiter, leaving Earth completely engulfed. In stellar terms, it’s predicted to explode in the very near future. Of course, the conversion from stellar to human terms is pretty extreme, as Betelgeuse is predicted to explode anytime in the next million years.

But still, whether the explosion occurs in 2011 or 1002011 (give or take 640 years for the light to reach Earth), it’s going to make for one of the most unforgettable light shows in our planet’s history. For a few weeks, the supernova will be so bright that there will appear to be two stars in the sky, and night will be indistinguishable from day for much of that time. So don’t count on getting a lot of sleep when Betelgeuse explodes, because the only sensible thing for the world to do will be to throw a weeks-long global supernova party.

Physicist Brad Carter explains what Earth (and hopefully humanity) can look forward to:

“This is the final hurrah for the star. It goes bang, it explodes, it lights up - we’ll have incredible brightness for a brief period of time for a couple of weeks and then over the coming months it begins to fade and then eventually it will be very hard to see at all.”

Although there’ll be no missing the explosion, Carter points out that the vast majority of material shot out from the supernova will pass by Earth completely unnoticed:

“When a star goes bang, the first we will observe of it is a rain of tiny particles called neutrinos. They will flood through the Earth and bizarrely enough, even though the supernova we see visually will light up the night sky, 99 per cent of the energy in the supernova is released in these particles that will come through our bodies and through the Earth with absolutely no harm whatsoever.”

In any event, the Betelgeuse explosion will likely be the most dramatic supernova Earth ever witnesses - well, unless our Sun eventually explodes and destroys our planet, which would probably leave Betelgeuse the runner-up.

quantumaniac: Peter Higgs Born on May 29th, 1929 - Peter Higgs is best known for his proposal of the Higgs mechanism. Currently he serves as Professor emeritus at the University of Edinburgh.  Higgs’ proposal says that particles were massless when the universe began, and acquired mass a fraction of a second later when interacting with the so-called Higgs field. He postulated that this field permeates all of space, and gives all elementary subatomic particles that interact with it their mass. The Higgs field is thought to interact and cause all of the mass in quarks and leptons, but only causes a tiny portion of the masses of other subatomic particles, such as protons and neutrons. In these larger particles, gluons that bind the quarks together to form them create most of the mass.

See how none of that makes sense or is cohesive? LOL@HIGGSFIELD

(Source: quantumaniac)

Researchers in the Netherlands have now produced quasiparticles that act like Majorana fermions: electrically-neutral particles that are their own antiparticles, such that if two collide, they annihilate. The existence of Majorana fermions was first predicted in the 1930s, but no individual particles are known to behave that way. V. Mourik et al. found a quasiparticle version by constructing a very thin wire—a nanowire—of semiconductor material and connected it to a superconductor. The specific electronic properties of the hybrid system gave rise to a pair of zero-velocity quasiparticles at two positions in the nanowire, and these showed behavior consistent with Majorana fermions. Some researchers suggest that quasiparticles of this type would be very useful in quantum computing applications. (via Elusive Majorana fermions may be lurking in a cold nanowire)

quantumaniac:

Cherenkov Radiation

Don’t diss my bro Einstein quite yet - nothing can surpass the speed of light in a vacuum, 300,000 km a second. However, light obviously does not always travel through a vacuum, and its speed varies depending on the medium through which it travels. For example, photons travel about 25 percent slower in water than in a vacuum. Fun fact: the slowest light has ever been recorded is about 17 meters per second. (Technically light has been brought to a complete stop, but this isn’t technically ‘moving.’) 

In certain mediums, different objects can travel faster than light, including particles in a nuclear reactor. When particles travel faster than light in a certain medium, a blue glow arises - known as Cherenkov radiation. This can be thought of as the light equivalent of a sonic boom. 

In order for Cherenkov radiation to be emitted, the particles passing through the medium traveling faster than light must be charged - because these charged particles polarize the molecules of the medium; water molecules, for example. Although first predicted by English polymath Oliver Heaviside around 1888, the effect is named after Russian physicist  Pavel Alekseyevich Cherenkov, the 1958 Nobel Prize winner who was the first to study it thoroughly. 

unknownskywalker:

Since Tumblr does not have a graphic for NASA posts in the dashboard (as they do with Wired, Wikipedia and others), I propose they use this logo to identify sources that point to NASA websites.

It just makes sense.

jtotheizzoe:

Today’s Google doodle celebrates the birthday of Heinrich Hertz, who proved the existence of electromagnetic waves. 

It occurs to me that this is an accomplishment whose scale is often overlooked. Without Hertz, we wouldn’t have wi-fi, iPhones, radio, Kinect, remote controls for our TVs or really anything that sends a signal to something else.