Phuck Yeah Physics
Because chemists can't top the hydrogen bomb.

Because chemists can't top the hydrogen bomb.
  • foobarnacle
  • macmankev

In Search of Antimatter Galaxies

NASA’s space shuttle program is winding down. With only about half a dozen more flights, shuttle crews will put the finishing touches on the International Space Station (ISS), bringing to an end twelve years of unprecedented orbital construction. An act of Congress in 2008 added another flight to the schedule near the end of the program. Currently scheduled for 2010, this extra flight of the shuttle is going to launch a hunt for antimatter galaxies.

The device that does the actual hunting is called the Alpha Magnetic Spectrometer—or AMS for short. It’s a $1.5 billion cosmic ray detector that the shuttle will deliver to the ISS.

In addition to sensing distant galaxies made entirely of antimatter, the AMS will also test leading theories of dark matter, an invisible and mysterious substance that comprises 83 percent of the matter in the universe. And it will search for strangelets, a theoretical form of matter that’s ultra-massive because it contains so-called strange quarks. Better understanding of strangelets will help scientists to study microquasars and tiny, primordial black holes as they evaporate, thus proving whether these small black holes even exist.

All of these exotic phenomena can make their presence known by the ultra-high energy cosmic rays they emit—the type of particles AMS excels in detecting.

“For the first time, AMS will measure very high-energy cosmic rays very accurately,” explains Nobel laureate Samuel Ting.

Antimatter galaxies, dark matter, strangelets—these are just the phenomena that scientists already know about. If history is any guide, the most exciting discoveries will be things that nobody has ever imagined. Just as radio telescopes and infrared telescopes once revealed cosmic phenomena that had been invisible to traditional optical telescopes, AMS will open up another facet of the cosmos for exploration.

“We will be exploring whole new territories,” Ting says. “The possibility for discovery is off the charts.” … “For the first time we could find out what dark matter is made of.”

Simple Explanation for Mysterious Observations

Recently, several astronomical experiments have revealed mysterious components of elementary particles. But up until now, the origin of electrons and positrons is unknown. Is dark matter the actual origin of this radiation, as some physicists speculate?

Now an international team of astrophysicists, including the Bochum junior professor Dr. Julia Becker and the Dortmund physicist Prof. Dr. Dr. Wolfgang Rohde, have found a simple explanation: giant stars, at least fifteen times the mass of our sun, emit elementary particles in a final explosion when they die. The flux of the electrons and positrons calculated on the basis of this theory fits in with the enigmatic signals observed during these astronomical experiments.

Big Bang Briefly

jabinante:

A pretty succinct description of the beginning of time and space.

lastchatwithphontaine: Unveiling the true face of Betelgeuse State of the art observations reveal a vast plume of gas almost as large as our Solar System, and a gigantic bubble boiling on its surface. This artist’s impression includes a scale in terms of the radius of Betelgeuse and the scale of the Solar System. Image: ESO/L. Calçada Betelgeuse rides on the shoulder of the constellation known as Orion the Hunter. At 1,000 times the size of our Sun it is one of the biggest stars known and also one of the most luminous, emitting more light than 100,000 Suns put together. But such mightiness comes at a cost, for Betelgeuse will meet its fate in a spectacular supernova explosion at an age of only a few million years. Giant stars like Betelgeuse shed the equivalent mass of the Earth every year, but the mechanism of how they do so is poorly understood. “We know relatively well how much mass supergiants loose, and how it ends up in the interstellar medium as planetary nebulae,” Pierre Kervella of the Paris Observatory tells Astronomy Now. “However, the mechanism of this mass loss is currently poorly understood, i.e. how physically the material escapes the gravitational field of the star.” rest of the article at astronomynow.com

lastchatwithphontaine:

Unveiling the true face of Betelgeuse

State of the art observations reveal a vast plume of gas almost as large as our Solar System, and a gigantic bubble boiling on its surface. This artist’s impression includes a scale in terms of the radius of Betelgeuse and the scale of the Solar System. Image: ESO/L. Calçada

Betelgeuse rides on the shoulder of the constellation known as Orion the Hunter. At 1,000 times the size of our Sun it is one of the biggest stars known and also one of the most luminous, emitting more light than 100,000 Suns put together. But such mightiness comes at a cost, for Betelgeuse will meet its fate in a spectacular supernova explosion at an age of only a few million years.

Giant stars like Betelgeuse shed the equivalent mass of the Earth every year, but the mechanism of how they do so is poorly understood. “We know relatively well how much mass supergiants loose, and how it ends up in the interstellar medium as planetary nebulae,” Pierre Kervella of the Paris Observatory tells Astronomy Now. “However, the mechanism of this mass loss is currently poorly understood, i.e. how physically the material escapes the gravitational field of the star.”

rest of the article at astronomynow.com

The Largest Black Holes in the Universe (via SpaceRip)

Short documentary on black holes. Quite interesting.

Supermassive Black Holes Collide to Become Even More Super and Massive New X-ray data from NASA’s Chandra X-ray Observatory added to an image previously captured by the Hubble Space Telescope created this amazing composite image of two black holes on the verge of colliding. The two supermassive black holes, which show up as two points of light in the center of the galaxy NGC 6240, are only 3,000 light-years apart. Astronomers think the two will eventually combine into a single, larger black hole. Also combining to make a whole greater than the sum of its parts are the two pieces of this image, shown below. Space photos are often a combination of multiple images and sets of data, designed to bring out the details and beauty of the subject. In this case, Chandra’s X-ray data and Hubble’s optical data come together to create an image so stunning that it looks like it must be an artist’s rendering.

Supermassive Black Holes Collide to Become Even More Super and Massive

New X-ray data from NASA’s Chandra X-ray Observatory added to an image previously captured by the Hubble Space Telescope created this amazing composite image of two black holes on the verge of colliding.

The two supermassive black holes, which show up as two points of light in the center of the galaxy NGC 6240, are only 3,000 light-years apart. Astronomers think the two will eventually combine into a single, larger black hole.

Also combining to make a whole greater than the sum of its parts are the two pieces of this image, shown below. Space photos are often a combination of multiple images and sets of data, designed to bring out the details and beauty of the subject. In this case, Chandra’s X-ray data and Hubble’s optical data come together to create an image so stunning that it looks like it must be an artist’s rendering.

cosmicpower:

So one of my rad followers send me this video today.

Symphony of Science - ‘We Are All Connected’ (ft. Sagan, Feynman, deGrasse Tyson & Bill Nye)

Young galaxies gorge on gas

unknownskywalker:

Stars form from giant gas clouds in galaxies — the star-formation rate, however, has changed over cosmic timescales. In the young universe, many more stars were born. Scientists from the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, together with an international team of astronomers, have found a plausible explanation: A few billion years after the Big Bang normal star-forming galaxies contained five to ten times more cold gas than today, providing more “food” to fuel the star-formation process.

Read article »
Can a Really, Really Fast Spacecraft Turn Into A Black Hole? This question was posed in an Astronomy Cast episode a while back. It offers an interesting thought experiment, although a reasonably definitive answer to the question can be arrived at. Imagine a scenario where a spacecraft gains relativistic mass as it approaches the speed of light, while at the same time its volume is reduced via relativistic length contraction. If these changes can continue towards infinite values (which they can) – it seems you have the perfect recipe for a black hole. Of course, the key word here is relativistic. Back on Earth, it can appear that a spacecraft which is approaching the speed of light, is indeed both gaining mass and shrinking in volume. Also, light from the spacecraft will become increasingly red-shifted – potentially into almost-blackness. This can be partly Doppler effect for a receding spacecraft, but is also partly a time dilation effect where the sub-atomic particles of the spacecraft seem to oscillate slower and hence emit light at lower frequencies. So, back on Earth, ongoing measurements may indicate the spacecraft is becoming more massive, more dense and much darker as its velocity increases. But of course, that’s just back on Earth. If we sent out two such spacecraft flying in formation – they could look across at each other and see that everything was quite normal. The captain might call a red alert when they look back towards Earth and see that it is starting to turn into a black hole – but hopefully the future captains of our starships will have enough knowledge of relativistic physics not to be too concerned. So, one answer to the Astronomy Cast question is that yes, a very fast spacecraft can appear to be almost indistinguishable from a black hole – from a particular frame (or frames) of reference. But it’s never really a black hole. Special relativity allows you to calculate transformations from your proper rest mass (as well as rest length, rest volume, rest density etc) as your relative velocity changes. So, it is possible to find a point of reference where your relativistic mass (length, volume, density etc) seem to mimic the parameters of a black hole. But a real black hole is a different story. Its proper rest parameters are already those of a black hole – indeed you won’t be able to find a point of reference where they aren’t. A real black hole is a real black hole – from any frame of reference. [thanks to]

Can a Really, Really Fast Spacecraft Turn Into A Black Hole?

This question was posed in an Astronomy Cast episode a while back. It offers an interesting thought experiment, although a reasonably definitive answer to the question can be arrived at.

Imagine a scenario where a spacecraft gains relativistic mass as it approaches the speed of light, while at the same time its volume is reduced via relativistic length contraction. If these changes can continue towards infinite values (which they can) – it seems you have the perfect recipe for a black hole.

Of course, the key word here is relativistic. Back on Earth, it can appear that a spacecraft which is approaching the speed of light, is indeed both gaining mass and shrinking in volume. Also, light from the spacecraft will become increasingly red-shifted – potentially into almost-blackness. This can be partly Doppler effect for a receding spacecraft, but is also partly a time dilation effect where the sub-atomic particles of the spacecraft seem to oscillate slower and hence emit light at lower frequencies.

So, back on Earth, ongoing measurements may indicate the spacecraft is becoming more massive, more dense and much darker as its velocity increases. But of course, that’s just back on Earth. If we sent out two such spacecraft flying in formation – they could look across at each other and see that everything was quite normal. The captain might call a red alert when they look back towards Earth and see that it is starting to turn into a black hole – but hopefully the future captains of our starships will have enough knowledge of relativistic physics not to be too concerned.

So, one answer to the Astronomy Cast question is that yes, a very fast spacecraft can appear to be almost indistinguishable from a black hole – from a particular frame (or frames) of reference.

But it’s never really a black hole.

Special relativity allows you to calculate transformations from your proper rest mass (as well as rest length, rest volume, rest density etc) as your relative velocity changes. So, it is possible to find a point of reference where your relativistic mass (length, volume, density etc) seem to mimic the parameters of a black hole.

But a real black hole is a different story. Its proper rest parameters are already those of a black hole – indeed you won’t be able to find a point of reference where they aren’t.

A real black hole is a real black hole – from any frame of reference.

[thanks to]

macmankev:

Brian Cox on Saturn’s rings in BBC’s Wonders of the Solar System: Order Out Of Chaos.