NASA Uses Gravitational Wave Detector Prototype to Detect ‘Space Mosquito’ Splats

Artist impression of ESA LISA Pathfinder in interplanetary space (ESA)

Imagine speeding down the highway and plowing into an unfortunate swarm of mosquitoes. Now imagine that you had the ability to precisely measure the mass of each mosquito, the speed at which it was traveling and the direction it was going before it exploded over your windscreen.

Granted, the technology to accomplish that probably isn’t feasible in such an uncontrolled environment. Factors such as vibration from the car’s motor and tires on the road, plus wind and air turbulence will completely drown out any “splat” from a minuscule insect’s body, rendering any signal difficult to decipher from noise.

But move your hypothetical “car and mosquitoes” into space — as silly as that may sound — and things become a lot less noisy. And now NASA is measuring its own special kind of “mosquito splat” signal by using a rather unlikely space experiment.

The European LISA Pathfinder spacecraft is a proof of concept mission that’s currently in space, orbiting a region of gravitational stability between the Earth and the sun — called the L1 point located a million miles away. The spacecraft was launched there in late 2015 to carry out precision tests of instruments that will eventually be used in the space-based gravitational wave detector eLISA. Inside the payload is a miniaturized laser interferometer system that measures the distance between two test masses.

When launched in 2034, eLISA (which stands for Evolved Laser Interferometer Space Antenna) will see three spacecraft, orbiting the sun at the L1 point, firing ultra-precise lasers at one another as part of a space-based gravitational wave detector. Now we actually know gravitational waves exist — after the US-based Laser Interferometer Gravitational-wave Observatory (or LIGO) detected the space-time ripples created after the collisions of black holes — excitement is building that we might, one day, be able to measure other phenomena, such as the ultra-low frequency gravitational waves that were created during the Big Bang.

But the only way we can do this is to send stunningly precise interferometers into space, away from our vibration-filled atmosphere to stand a chance of detecting some of the faintest space-time rumbles in our cosmos that would otherwise be drowned out by a passing delivery truck or windy day. And LISA Pathfinder is currently out there, testing a tiny laser interferometer in a near-perfect gravitational free-fall, making the slightest of slight adjustments with its “ultra-precise micro-propulsion system.”

Although LISA Pathfinder is a test (albeit a history-making test of incredible engineering ingenuity), NASA thinks that it could actually be used as an observatory in its own right; not for hunting gravitational waves, but for detecting comet dust.

Like our mosquito-windscreen analogy, spacecraft get hit by tiny particles all the time, and LISA Pathfinder is no exception. These micrometeoroides come from eons of evaporating comets and colliding asteroids. Although measuring less than the size of a grain of sand, these tiny particles zip around interplanetary space at astonishing speeds — well over 22,000 miles per hour (that’s 22 times faster than a hyper-velocity rifle round) — and can damage spacecraft over time, slowly eroding unprotected hardware.

Therefore, it would be nice if we could create a map of regions in the solar system that contain lots of these particles so we can be better prepared to face the risk. Although models of solar system evolution help and we can estimate the distribution of these particles, they’ve only ever been measured near Earth, so it would be advantageous to find the “ground truth” and measure them directly from another, unexplored region of the solar system.

This is where LISA Pathfinder comes in.

As the spacecraft gets hit by these minuscule particles, although they are tiny, their high speed ensures they pack a measurable punch. As scientists want the test weights inside the spacecraft to be completely shielded from any external force — whether that’s radiation pressure from the sun or marauding micro-space rocks — the spacecraft has been engineered to be an ultra-precise container that carefully adjusts its orientation an exact amount to directly counter these external forces (hence the “ultra-precise micro-propulsion system”).

lisa-pathfinder
When LISA Pathfinder is struck by space dust, it compensates with its ultra-precise micro-thrusters (ESA/NASA)

This bit is pretty awesome: Whenever these tiny space particles hit the spacecraft, it compensates for the impact and that compensation is registered as a “blip” in the telemetry being beamed back to Earth. After careful analysis of the various data streams, researchers are learning a surprising amount of information about these micrometeoroides — such as their mass, speed, direction of travel and even their possible origin! — all for the ultimate goal of getting to know the tiny pieces of junk that whiz around space.

“Every time microscopic dust strikes LISA Pathfinder, its thrusters null out the small amount of momentum transferred to the spacecraft,” said Diego Janches, of NASA’s Goddard Space Flight Center in Greenbelt, Md. “We can turn that around and use the thruster firings to learn more about the impacting particles. One team’s noise becomes another team’s data.”

So, it turns out that you can precisely measure a mosquito impact on your car’s windshield — so long as that “mosquito” is a particle of space dust and your “car” is a spacecraft a million miles from Earth.

NASA put together a great video, watch it:

Aside: So it turned out that I inadvertently tested the “car-mosquito” hypothesis when driving home from Las Vegas — though some of these were a lot bigger than mosquitoes…

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A Powerful Galactic Explosion Has Been Detected — and Astronomers Aren’t Sure What Caused It

NASA/CXC/Pontifical Catholic Univ./F.Bauer et al.

A long time ago in a galaxy far, far away…

NASA’s Chandra X-ray Observatory has detected a mysterious explosion in deep space and, although astronomers have some suspected causes for the incredibly powerful event, there’s a possibility that it could be something we’ve never witnessed before.

The signal is the deepest X-ray source ever recorded and it appears to be related to a galaxy located approximately 10.7 billion light-years away (it therefore happened 10.7 billion years ago, when the universe was only three billion years old). Over the course of only a few minutes in October 2014, this event produced a thousand times more energy than all the stars in its galaxy. Before that time, there were no X-rays originating from this location and there’s been nothing since.

The explosion occurred in a region of sky called the Chandra Deep Field-South (CDF-S) — the event was therefore designated “CDF-S XT1” — and archived observations of that part of the sky by the NASA/ESA Hubble Space Telescope and NASA’s Spitzer space telescope revealed that it originated from within a faint, small galaxy.

“Ever since discovering this source, we’ve been struggling to understand its origin,” said Franz Bauer of the Pontifical Catholic University of Chile in Santiago, Chile, in a statement. “It’s like we have a jigsaw puzzle but we don’t have all of the pieces.”

One possibility is that we could be looking at the effects of a huge stellar explosion, known as a gamma-ray burst (GRB). GRBs are caused when a massive star implodes and blasts powerful gamma-rays as intense beams from its poles — think super-sized supernova on acid. They can also be caused by cataclysmic collisions between two neutron stars or a neutron star and black holes. Should one of those beams be directed at Earth, over 10.7 billion light-years of travel, the gamma-ray radiation would have dispersed and arrived here at a lower, X-ray energy, possibly explaining CDF-S XT1.

Alternatively, the signal may have been caused by the rapid destruction of a white dwarf star falling into a black hole. Alas, none of these explanations fully fit the observation and it could, actually, be a new phenomenon.

“We may have observed a completely new type of cataclysmic event,” said Kevin Schawinski, of ETH Zurich in Switzerland. “Whatever it is, a lot more observations are needed to work out what we’re seeing.”

So, in short, watch this space.

The research will be published in the June edition of the journal Monthly Notices of the Royal Astronomical Society and is available online.

Plasma ‘Soup’ May Have Allowed Ancient Black Holes to Beef up to Supermassive Proportions

How ancient supermassive black holes grew so big so quickly is one of the biggest mysteries hanging over astronomy — but now researchers think they know how these behemoths packed on the pounds.

John Wise, Georgia Tech

Supermassive black holes are the most extreme objects in the universe. They can grow to billions of solar masses and live in the centers of the majority of galaxies. Their extreme gravities are legendary and have the overwhelming power to switch galactic star formation on and off.

But as our techniques have become more advanced, allowing us to look farther back in time and deeper into the distant universe, astronomers have found these black hole behemoths lurking, some of which are hundreds of millions to billions of solar masses. This doesn’t make much sense; if these objects slowly grow by swallowing cosmic dust, gas, stars and planets, how did they have time only a few hundred million years after the Big Bang to pack on all those pounds?

Well, when the universe was young, it was a very different place. Closely-packed baby galaxies generated huge quantities of radiation and this radiation had a powerful influence over star formation processes in neighboring galaxies. It is thought that massive starburst galaxies (i.e. a galaxy that is dominated by stellar birth) could produce so much radiation that they would, literally, snuff-out star formation in neighboring galaxies.

Stars form in vast clouds of cooling molecular hydrogen and, when star birth reigns supreme in a galaxy, black holes have a hard time accreting matter to bulk up — these newly-formed stars are able to escape the black hole’s gravitational grasp. But in the ancient universe, should a galaxy that is filled with molecular hydrogen be situated too close to a massive, highly radiating galaxy, these clouds of molecular hydrogen could be broken down, creating clouds of ionized hydrogen plasma — stuff that isn’t so great for star formation. And this material can be rapidly consumed by a black hole.

According to computer simulations of these primordial galaxies of hydrogen plasma, if any black hole is present in the center of that galaxy, it will feed off this plasma “soup” at an astonishingly fast rate. These simulations are described in a study published in the journal Nature Astronomy.

“The collapse of the galaxy and the formation of a million-solar-mass black hole takes 100,000 years — a blip in cosmic time,” said astronomer Zoltan Haiman, of Columbia University, New York. “A few hundred-million years later, it has grown into a billion-solar-mass supermassive black hole. This is much faster than we expected.”

But for these molecular hydrogen clouds to be broken down, the neighboring galaxy needs to be at just the right distance to “cook” its galactic neighbor, according to simulations that were run for several days on a supercomputer.

“The nearby galaxy can’t be too close, or too far away, and like the Goldilocks principle, too hot or too cold,” said astrophysicist John Wise, of the Georgia Institute of Technology.

The researchers now hope to use NASA’s James Webb Space Telescope, which is scheduled for launch next year, to look back to this era of rapid black hole formation, with hopes of actually seeing these black hole feeding processes in action. Should observations agree with these simulations, we may finally have some understanding of how these black hole behemoths grew so big so quickly.

“Understanding how supermassive black holes form tells us how galaxies, including our own, form and evolve, and ultimately, tells us more about the universe in which we live,” added postdoctoral researcher John Regan, of Dublin City University, Ireland.

This Black Hole Keeps Its Own White Dwarf ‘Pet’

The most compact star-black hole binary has been discovered, but the star seems to be perfectly happy whirling around the massive singularity twice an hour.

Credits: X-ray: NASA/CXC/University of Alberta/A.Bahramian et al.; Illustration: NASA/CXC/M.Weiss

A star in the globular cluster of 47 Tucanae is living on the edge of oblivion.

Located near a stellar-mass black hole at only 2.5 times the Earth-moon distance, the white dwarf appears to be in a stable orbit, but it’s still paying the price for being so intimate with its gravitational master. As observed by NASA’s Chandra X-ray Observatory and NuSTAR space telescope, plus the Australia Telescope Compact Array, gas is being pulled from the white dwarf, which then spirals into the black hole’s super-heated accretion disk.

47 Tucanae is located in our galaxy, around 14,800 light-years from Earth.

Eventually, the white dwarf will become so depleted of plasma that it will turn into some kind of exotic planetary-mass body or it will simply evaporate away. But one thing does appear certain, the white dwarf will remain in orbit and isn’t likely to get swallowed by the black hole whole any time soon.

“This white dwarf is so close to the black hole that material is being pulled away from the star and dumped onto a disk of matter around the black hole before falling in,” said Arash Bahramian, of the University of Alberta (Canada) and Michigan State University. “Luckily for this star, we don’t think it will follow this path into oblivion, but instead will stay in orbit.” Bahramian is the lead author of the study to be published in the journal Monthly Notices of the Royal Astronomical Society.

It was long thought that globular clusters were bad locations to find black holes, but the 2015 discovery of the binary system — called “X9” — generating quantities of radio waves inside 47 Tucanae piqued astronomers’ interest. Follow-up studies revealed fluctuating X-ray emissions with a period of around 28 minutes — the approximate orbital period of the white dwarf around the black hole.

So, how did the white dwarf become the pet of this black hole?

The leading theory is that the black hole collided with an old red giant star. In this scenario, the black hole would have quickly ripped away the bloated star’s outer layers, leaving a tiny stellar remnant — a white dwarf — in its wake. The white dwarf then became the black hole’s gravitational captive, forever trapped in its gravitational grasp. Its orbit would have become more and more compact as the system generated gravitational waves (i.e. ripples in space-time), radiating orbital energy away, shrinking its orbital distance to the configuration that it is in today.

It is now hoped that more binary systems of this kind will be found, perhaps revealing that globular clusters are in fact very good places to find black holes enslaving other stars.

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.

So it Could be a ‘Supervoid’ That’s Causing the Mysterious CMB ‘Cold Spot’

Only last month I recorded a DNews video about the awesome possibilities of the “Cold Spot” that sits ominously in the cosmic microwave background (CMB) anisotropy maps (anisotropies = teenie tiny temperature variations in the CMB).

I still hold onto the hope that this anomalous low temperature region is being caused by a neighboring parallel universe squishing up against our own. But evidence is mounting for there actually being a vast low density region — known as a “supervoid” — between us and that Cold Spot.

And that’s crappy news for my dreams of cosmologists finding bona fide observational clues of the multiverse hypothesis any time soon. The Cold Spot could just be the frigid fingerprint of this supervoid etched into our observations of the CMB.

But as this supervoid could be as wide as 1.8 billion light-years, this discovery is still crazy cool — the supervoid could be the newest candidate for the largest structure ever discovered in the universe. Suck it, Sloan Great Wall.

Read more about this new research published today in the Monthly Notices of the Royal Astronomical Society in my Discovery News blog.

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%

Some Galaxies Die Young… Others Recycle

Some galaxies undergo a rapid star formation phase, losing stellar gases to intergalactic space, others choose to recycle, thereby extending their star forming lifespans.
Some galaxies undergo a rapid star formation phase, losing stellar gases to intergalactic space, others choose to recycle, thereby extending their star forming lifespans (NASA, ESA, and A. Feild (STScI))

It sounds like an over-hyped public service announcement: If you don’t recycle, you’ll die a premature death.

But in the case of galaxies, according to three new Science papers based on Hubble Space Telescope data, this is a reality. Should a galaxy “go green,” reusing waste stellar gas contained within huge halos situated outside their visible disks, they will fuel future star-birth cycles, prolonging their lifespans.

Sadly for “starburst” galaxies — galaxies that undergo rapid star generation over very short time periods — they care little for recycling, resulting in an untimely death.

Using data from Hubble’s Cosmic Origins Spectrograph (COS), three teams studied 40 galaxies (including the Milky Way) and discovered vast halos of waste stellar gases. Contained within these spherical reservoirs — extending up to 450,000 light-years from their bright disks of stars — light elements such as hydrogen and helium were found to be laced with heavier elements like carbon, oxygen, nitrogen and neon. There’s only one place these heavy elements could have come from: fusion processes in the cores of stars and supernovae.

Interestingly, the quantity of heavy elements contained within the newly-discovered halos is similar to what is contained in the interstellar gases within the galaxies themselves.

“There’s as much heavy elements out in the halos of the galaxies as there is in their interstellar medium, that is what shocked us.” said Jason Tumlinson, an astronomer for the Space Telescope Science Institute in Baltimore, Md., in an interview for my Discovery News article “Galaxies That Don’t Recycle Live Hard, Die Young.”

But these heavy elements are stored in halos outside the galaxies; how the heck did it get there?

According to the researchers, powerful stellar winds jetting into intergalactic space have been observed, transporting the heavy elements with them. But there’s a catch. If the outflow is too strong, waste stellar gases are ejected from the galaxies completely. Unfortunately for one sub-set of galaxies, powerful stellar outflows come naturally.

Starburst galaxies rapidly generate stars, ejecting speedy streams of stellar waste gas. Some of these streams have been clocked traveling at 2 million miles per hour, escaping from the galaxy forever. In the case of a starbust galaxy, a “recycling halo” cannot be re-supplied — future star birth is therefore killed off.

“We found the James Dean or Amy Winehouse of that population, you know, the galaxies that lived fast and died young,” Tumlinson pointed out. “(Todd) Tripp’s team studied that in their paper.”

“That paper used a galaxy that is known as a ‘post-star burst galaxy’ and its spectrum showed that it had a very robust star burst (phase),” he continued. “It was one of those live fast, die young galaxies.”

Although fascinating, one idea struck me the hardest. On asking Tumlinson to speculate on how galactic recycling of stellar material may impact us, he said:

“Your body is 70 percent water and every water molecule has an oxygen atom in it. The theorists say the recycling time (in the Milky Way’s halo) is approximately a billion years, so that means — potentially — that some of the material (oxygen) inside your body has cycled in and out of the galaxy ten times in the history of the galaxy. At least once, maybe up to ten times.”

As Carl Sagan famously said: “We’re made of star stuff;” perhaps this should be rephrased to: “We’re made of recycled star stuff.”

Publications:

M87’s Obese Black Hole: A Step Closer to the Event Horizon Telescope

The black hole lurking inside galaxy M87 has a mass of 6.6 billion suns, according to today's announcement (NASA)

Fresh from the Department Of I Really Shouldn’t Have Eaten That Last Binary, astronomers attending the American Astronomical Society meeting in Seattle, Wash., have announced a supermassive black hole residing inside the nearby galaxy M87 has a weight problem.

In fact, this galactic behemoth is obese.

With a mass of 6.6 billion suns, it is the biggest black hole in our cosmic neighborhood. “It’s almost on top of us, relatively speaking. Fifty million light-years — that’s our backyard effectively. To have one so large, that’s kind of extreme,” astronomer Karl Gebhardt, with the University of Texas at Austin, told Discovery News. The black hole’s mass was arrived at after Gebhardt’s team tracked the motions of the stars near the black hole using the Gemini North telescope in Hawaii. By analyzing the stars’ orbits, the mass of the black hole could be calculated.

Although it’s been known for some time that M87’s black hole might be slightly on the heavy side, 6.6 billion solar masses exceeds previous estimates.

Previously on Astroengine, I’ve discussed the exciting possibility of imaging a black hole’s event horizon. Radio astronomers have even modeled what they might see should a collection of telescopes participate in event horizon astronomy. Naturally, to see the shadow of an event horizon, the black hole a) needs to be massive, and b) relatively close. The first nearby supermassive black hole that comes to mind is our very own Sagittarius A* (Sag. A*) that camps out in the middle of the Milky Way. That would be a good place to point our first event horizon telescope, right?

Think again. Even before astronomers were able to pinpoint M87’s black hole mass, in 2009, researchers from the Max Planck Institute and University of Texas had estimated M87’s mass to be 6.4 billion suns. Although M87 is a whopping 2,000 times further away from Earth than Sag. A*, due to its mass, the M87 supermassive black hole event horizon shadow should appear bigger in the sky than Sag. A*’s. Today’s announcement is bound to stimulate efforts in the quest to directly image a black hole’s event horizon for the first time.

“Right now we have no evidence that an object is a black hole. Within a few years, we might be able to image the shadow of the event horizon,” Gebhardt added.

For more on today’s news, read Irene Klotz’s report on Discovery News: “Obese Black Hole Lurks in Our Cosmic Backyard

Holographic Universe: Fermilab to Probe Smallest Space-Time Scales

Conceptual design of the Fermilab holometer (Fermilab)
Conceptual design of the Fermilab holometer (Fermilab)

During the hunt for the predicted ripples in space-time — known as gravitational waves — physicists stumbled across a rather puzzling phenomenon. Last year, I reported about the findings of scientists using the GEO600 experiment in Germany. Although the hi-tech piece of kit hadn’t turned up evidence for the gravitational waves it was seeking, it did turn up a lot of noise.

Before we can understand what this “noise” is, we need to understand how equipment designed to look for the space-time ripples caused by collisions between black holes and supernova explosions.

Gravitational wave detectors are incredibly sensitive to the tiniest change in distance. For example, the GEO600 experiment can detect a fluctuation of an atomic radius over a distance from the Earth to the Sun. This is achieved by firing a laser down a 600 meter long tube where it is split, reflected and directed into an interferometer. The interferometer can detect the tiny phase shifts in the two beams of light predicted to occur should a gravitational wave pass through our local volume of space. This wave is theorized to slightly change the distance between physical objects. Should GEO600 detect a phase change, it could be indicative of a slight change in distance, thus the passage of a gravitational wave.

While looking out for a gravitational wave signal, scientists at GEO600 noticed something bizarre. There was inexplicable static in the results they were gathering. After canceling out all artificial sources of the noise, they called in the help of Fermilab’s Craig Hogan to see if his expertise of the quantum world help shed light on this anomalous noise. His response was as baffling as it was mind-blowing. “It looks like GEO600 is being buffeted by the microscopic quantum convulsions of space-time,” Hogan said.

Come again?

The signal being detected by GEO600 isn’t a noise source that’s been overlooked, Hogan believes GEO600 is seeing quantum fluctuations in the fabric of space-time itself. This is where things start to get a little freaky.

According to Einstein’s view on the universe, space-time should be smooth and continuous. However, this view may need to be modified as space-time may be composed of quantum “points” if Hogan’s theory is correct. At its finest scale, we should be able to probe down the “Planck length” which measures 10-35 meters. But the GEO600 experiment detected noise at scales of less than 10-15 meters.

As it turns out, Hogan thinks that noise at these scales are caused by a holographic projection from the horizon of our universe. A good analogy is to think about how an image becomes more and more blurry or pixelated the more you zoom in on it. The projection starts off at Planck scale lengths at the Universe’s event horizon, but its projection becomes blurry in our local space-time. This hypothesis comes out of black hole research where the information that falls into a black hole is “encoded” in the black hole’s event horizon. For the holographic universe to hold true, information must be encoded in the outermost reaches of the Universe and it is projected into our 3 dimensional world.

But how can this hypothesis be tested? We need to boost the resolution of a gravitational wave detector-type of kit. Enter the “Holometer.”

Currently under construction in Fermilab, the Holometer (meaning holographic interferometer) will delve deep into this quantum realm at smaller scales than the GEO600 experiment. If Hogan’s idea is correct, the Holometer should detect this quantum noise in the fabric of space-time, throwing our whole perception of the Universe into a spin.

For more on this intriguing experiment, read the Symmety Magazine article “Hogan’s holometer: Testing the hypothesis of a holographic universe.”