This Is Why NASA’s Space Station Bose-Einstein Experiment Will Be so Cool

An instrument capable of cooling matter to a smidgen above absolute zero is being readied for launch to the International Space Station, possibly uncovering new physics and answering some of our biggest cosmological questions.

NASA

This summer, a rather interesting experiment will arrive at the International Space Station. Called the Cold Atom Laboratory (CAL), this boxy instrument will be able to chill material down to unimaginably low temperatures — so low that it will become the coldest place in the known universe.*

At a temperature of a billionth of a degree above absolute zero, CAL will investigate a state of matter that cannot exist in nature. This strange state is known as a Bose-Einstein condensate (or BEC), which possesses qualities that, quite frankly, don’t make a lot of sense.

When a gas is sufficiently cooled and the subatomic particles (bosons) drop to their lowest energy state, “normal” physics start to break down and quantum mechanics — the physics that governs the smallest scales — starts to manifest itself throughout a material (on a macroscopic scale). When this occurs, a BEC is possible. And it’s weird.

BECs act as a “superfluid,” which means it has zero viscosity. Early experiments on supercooled helium-4 exhibited this trait, causing confusion at the time when this mysterious fluid was observed flowing up, against the force of gravity, and over the sides of its containing beaker. Now we are able to cool gases to sufficiently low temperatures, this superfluid trait dominates and gases move as one, apparently coherent, mass.

So far, BEC experiments have only been carried out in a gravitational environment and can only be observed for a very short period of time as gravity continually pulls the BEC particles to the bottom of its container, thereby limiting its stability. But remove gravity from the equation and we enter a brand new observational regime with the potential for brand new insights to fundamental physics, and this is why NASA built CAL — humanity’s first microgravity BEC laboratory that could unlock some of the universe’s biggest mysteries.

CAL works by trapping the BEC in magnetic containment and lasers will be used to cancel out energy in the gas, thereby cooling it (pictured top). The gas will then be further cooled through evaporative cooling (using a radio frequency “knife”) and adiabatic expansion. When sufficiently cooled, experiments can be carried out on the BEC — the first time a BEC has been tested in space. (The technical details behind CAL’s technology can be found on the experiment’s website.)

“Studying these hyper-cold atoms could reshape our understanding of matter and the fundamental nature of gravity,” said Robert Thompson, CAL Project Scientist from NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif., in a statement. “The experiments we’ll do with the Cold Atom Lab will give us insight into gravity and dark energy — some of the most pervasive forces in the universe.”

It is hoped that BECs will be observable inside CAL for five to twenty seconds and the ultra-low temperature technologies developed will allow for future experiments that could contain stable BECs for hundreds of times longer.

CAL isn’t a pure physics curiosity, even if it is pretty awesome just to observe quantum physics manifest itself across an entire mass of particles (in free-fall, no less). Producing stable BECs could have technical applications, such as in quantum computer development and improving the precision of quantum clocks. In addition, creating a stable BEC in a lab setting could, quite literally, give us new eyes on fundamental universal mysteries. Lower temperatures means more stability and more stability means boosted sensor precision. Astronomy is all about precision, so the spin-off technologies from the techniques developed in CAL could usher in a new generation of ultra-sensitive telescopes and detectors that could, ultimately, reveal the mechanisms behind dark energy and dark matter.

“Like a new lens in Galileo’s first telescope, the ultra-sensitive cold atoms in the Cold Atom Lab have the potential to unlock many mysteries beyond the frontiers of known physics,” said Kamal Oudrhiri, CAL deputy project manager also at JPL.

CAL is set for launch on a SpaceX resupply mission to the International Space Station in August and I can’t wait to see what new physics the instrument might uncover.

*Assuming there are no other intelligent lifeforms also playing with supercooled matter elsewhere in the universe, of course.

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We Are The 4.9%

The AMS attached to the space station's exterior (NASA)
The AMS attached to the space station’s exterior (NASA)

This month is Global Astronomy Month (GAM2013) organized by my friends Astronomers Without Borders (AWB). There is a whole host of events going on right this moment to boost astronomy throughout the international community, and as a part of GAM2013, AWB are hosting daily blogs from guest astronomers, writers, physicists and others with a background in space. Today (April 11) was my turn, so I wrote a blog about the fascinating first results to be announced on the International Space Station instrument the Alpha Magnetic Spectrometer — or AMS for short.

Although the AMS’ most recent findings suggest positrons with a signature energy indicative of the annihilation of dark matter — particularly hypothetical weakly interaction massive particles (WIMPS) — it isn’t final proof of dark matter (despite what the tabloid press might’ve told you). But still, it’s exciting and another component of our enduring search for 95.1% of the mass-energy of the universe that is locked in the mysterious and perplexing dark matter and dark energy.

You can read my blog on the AWB website: “Dark Matter: We Are The 4.9%

Unexpectedly Large Black Holes and Dark Matter

The M87 black hole blasts relativistic plumes of gas 5000 ly from the centre of the galaxy (NASA)
The M87 black hole blasts relativistic plumes of gas 5000 ly from the centre of the galaxy (NASA)

I just spent 5 minutes trying to think up a title to this post. I knew what I wanted to say, but the subject is so “out there” I’m not sure if any title would be adequate. As it turns out, the title doesn’t really matter, so I opted for something more descriptive…

So what’s this about? Astronomers think they will be able to “see” a supermassive black hole in a galaxy 55 million light years away? Surely that isn’t possible. Actually, it might be.

When Very Long Baseline Interferometry is King

Back in June, I reported that radio astronomers may be able to use a future network of radio antennae as part of a very long baseline interferometry (VLBI) campaign. With enough observatories, we may be able to resolve the event horizon of the supermassive black hole lurking at the centre of the Milky Way, some 26,000 light years away from the Solar System.

The most exciting thing is that existing sub-millimeter observations of Sgr. A* (the radio source at the centre of our galaxy where the 4 million solar mass black hole lives) suggest there is some kind of active structure surrounding the black hole’s event horizon. If this is the case, a modest 7-antennae VLBI could observe dynamic flares as matter falls into the event horizon.

It would be a phenomenal scientific achievement to see a flare-up after a star is eaten by Sgr. A*, or to see the rotation of a possibly spinning black hole event horizon.

All of this may be a possibility, and through a combination of Sgr. A*’s mass and relatively close proximity to Earth, our galaxy’s supermassive black hole is predicted to have the largest apparent event horizon in the sky.

Or does it?

M87 Might be a Long Way Away, But…

As it turns out, there could be another challenger to Sgr. A*’s “largest apparent event horizon” crown. Sitting in the centre of the active galaxy called M87, 55 million light years away (that’s over 2,000 times further away than Sgr. A*), is a black hole behemoth.

M87’s supermassive black hole consumes vast amounts of matter, spewing jets of gas 5,000 light years from the core of the giant elliptical galaxy. And until now, astronomers have underestimated the size of this monster.

Karl Gebhardt (Univ. of Texas at Austin) and Thomas Jens (Max Planck Institute for Extraterrestrial Physics in Garching, Germany) took another look at M87 and weighed the galaxy by sifting through observational data with a supercomputer model. This new model accounted for the theorized halo of invisible dark matter surrounding M87. This analysis yielded a shocking result; the central supermassive black hole should have a mass of 6.4 billion Suns, double the mass of previous estimates.

Therefore, the M87 black hole is around 1,600 times more massive than our galaxy’s supermassive black hole.

A Measure for Dark Matter?

Now that the M87 black hole is much bigger than previously thought, there’s the tantalizing possibility of using the proposed VLBI to image M87’s black hole as well as Sgr. A*, as they should both have comparable event horizon dimensions when viewed from Earth.

Another possibility also comes to mind. Once an international VLBI is tested and proven to be an “event horizon telescope,” if we are able to measure the size of the M87 black hole, and its mass is confirmed to be in agreement with the Gebhardt-Jens model, perhaps we’ll have one of the first indirect methods to measure the mass of dark matter surrounding a galaxy…

Oh yes, this should be good.

UPDATE! How amiss of me, I forgot to include the best black hole tune ever:

Publication: The Black Hole Mass, Stellar Mass-to-Light Ratio, and Dark Matter Halo in M87, Karl Gebhardt et al 2009 ApJ 700 1690-1701, doi: 10.1088/0004-637X/700/2/1690.
Via: New Scientist

Did Dark Matter Reionize the Universe?

Did dark matter characterize our early Universe?

Immediately after the Big Bang, 13.72 billion (±120 million) years ago, the Universe was filled with energy. Nothing but energy. No protons, electrons, quarks or photons; just energy. Even the fundamental forces of nature (gravity, weak, strong, electromagnetic) were a confused mess and could not be distinguished, but that issue didn’t last for long. 10-43 seconds after the Big Bang the grand unification epoch began, when gravity is thought to have separated from the soup. Shortly after, the strong force separated from the electroweak force in a period called the electroweak epoch.
Continue reading “Did Dark Matter Reionize the Universe?”

New Exotic Particle May Explain Milky Way Gamma-Ray Phenomenon

Chandra observation of Cassiopeia A, a young supernova remnant in our galaxy - a prominent source of high-energy particles (NASA/CXC/MIT/UMass Amherst/M. D. Stage et al.)
Chandra observation of Cassiopeia A, a young supernova remnant in our galaxy - a prominant source of high-energy particles (NASA/CXC/MIT/UMass Amherst/M. D. Stage et al.)

There is something strange happening in the core of the Milky Way. A space observatory measuring the energy and distribution of gamma-rays in the cosmos has made an unexpected (and perplexing) discovery. It would seem there is a very high proportion of gamma-ray photons emanating from our galactic core with a very distinctive signature; they have a precise energy of 511 keV (8×10-14 Joules), and there’s a lot of them. So what could possibly be producing these 511 keV gamma-rays? It turns out, 511 keV is a magic number; it is the exact rest mass energy of a positron (the antimatter particle of the electron). So this is fairly conclusive evidence that positrons are dying (i.e. annihilating) in vast numbers in our galactic nuclei. Still, this is of little help to astrophysicists as there is no known mechanism for producing such high numbers of annihilating positrons. Ideas have been put forward, but there’s a new possibility, involving some new particle physics and some lateral thinking…
Continue reading “New Exotic Particle May Explain Milky Way Gamma-Ray Phenomenon”

Is the Sun a Dark Matter Factory?

Hinode X-ray observation of a solar sigmoid (David McKenzie/Montana State University)
The hypothetical axion is a particle that might help scientists work out where the bulk of dark matter may be held in the Universe. So far, there has been much talk about the search for another type of hypothetical particle, the weakly interacting massive particle (WIMP), and little attention has been paid to the lowly axion. WIMPs are very appealing to scientists as proving they exist will help patch some holes in quantum theory. What’s more, WIMP detectors need to be huge, large volumes of underground caverns filled with hi-tech sensors and cleaning fluid – this makes for a cool funding proposal; think up and grand idea, explain that it will prove our understanding of the Universe and then receive a multi-billion $/£/€ cheque (it’s not quite as easy as that, but there are socioeconomic and political reasons for building such an awesome structure).

So how do you go about finding an axion? Surely this exotic particle will need an even bigger detector, especially as it has zero charge, very low mass and cannot interact via the strong and weak nuclear forces? Actually, a large WIMP-type detector would be useless for axion detection. Fortunately axions have a neat interaction with magnetic fields that can be detected with existing instrumentation. What produces the strongest magnetic field in the Solar System? This is where the Sun can help out…
Continue reading “Is the Sun a Dark Matter Factory?”

Primordial Quark Nuggets Disguised as Near Earth Asteroids?

The HST map of dark matter. Image credit: NASA/HST. Source: BBC

We know that dark matter is difficult to observe… in fact, we can only indirectly observe the stuff. Gravitational lensing and WMAP “Haze” are two possible ways to observe large-scale dark matter, but what about the small-scale stuff? New research suggests that some types of dark matter may be in the form of cold, primordial clumps of elementary particles and there’s a possibility we’ve been accidentally been observing them for years…
Continue reading “Primordial Quark Nuggets Disguised as Near Earth Asteroids?”

Supermassive Black Holes Can’t Swallow Dark Matter

A modelled accretion disk around a black hole. Image credit: Michael Owen, John Blondin (North Carolina State Univ.). Source: http://apod.nasa.gov/apod/ap050312.html

Apparently, black holes and dark matter don’t play well together. Broadly speaking, black holes can be considered to be a significant portion of the “missing mass” in the universe, but dark matter is distinguished as “non-baryonic matter”. It seems that this mysterious non-baryonic matter is being used to explain a huge number of unexplained cosmic mysteries, but in the case of supermassive black holes, dark matter plays a very small role insofar as being used as black hole food…
Continue reading “Supermassive Black Holes Can’t Swallow Dark Matter”

Dark Matter Ain’t So Dark After All: Observing The Mysterious Cosmic Glow with the Wilkinson Microwave Anisotropy Probe

Observations by the WMAP observatory of the cosmic background radiation. Is there Dark Matter out there? Image credit: WMAP Science Team, NASA

The Wilkinson Microwave Anisotropy Probe (WMAP) has observed something rather strange in our galaxy. There appears to be excess microwave radiation being emitted from the space around us, with apparently no explanation. In new research, this microwave excess may be caused by “nuggets” of dark matter, perhaps a few tonnes in mass, radiating some low energy EM waves. Could this be the first evidence of dark matter? If so, this could be a revolutionary method of observing the stuff…
Continue reading “Dark Matter Ain’t So Dark After All: Observing The Mysterious Cosmic Glow with the Wilkinson Microwave Anisotropy Probe”

Large Hadron Collider Could Detect “Unparticles”

Unparticles may have fractal properties. Source: http://en.wikipedia.org/wiki/Image:Complex_fractle_image.png

Understanding the mysterious dark matter in our universe is paramount to cosmologists. Dark matter and dark energy makes up the vast majority of mass in the observable universe. It influences galaxy rotation, galactic clusters and even holds the answer to our universe’s fate. So, it is unsurprising to hear about some outlandish physics behind the possible structure of this concealed mass. A Harvard scientist has now stepped up the plate, publishing his understanding about dark matter, believing the answer may lie in a type of material that has a mass, but doesn’t behave like a particle. “Unparticles” may also be detected by the high energy particle accelerator, the Large Hadron Detector (LHD) at CERN going online in a few weeks time. High energy physics is about to get stranger than it already is… [more]