Hey Colin, the point is that,------ it Vibrates, isn't that good enough fer 
you?  Hope you are keepin those strings vibrating up there!  Jim  WA6EKS
-----Original Message----- 
From: Colin McDonald
Sent: Saturday, February 13, 2016 1:04 AM
To: [log in to unmask]
Subject: Re: interesting email about Gravitational waves

yes, but the question is, does it vibrate at 8hz, or 432hz?

73
Colin, V A6BKX
-----Original Message----- 
From: Jim Gammon
Sent: Friday, February 12, 2016 9:18 PM
To: [log in to unmask]
Subject: interesting email about Gravitational waves

Got this from a ham friend yesterday.
Gravitational Waves Exist: The Inside Story of How Scientists Finally Found
Them
By Nicola Twilley

Just over a billion years ago, many millions of galaxies from here, a pair
of black holes collided. They had been circling each other for aeons, in a
sort of mating dance, gathering pace with each orbit, hurtling closer and
closer. By the time they were a few hundred miles apart, they were whipping
around at nearly the speed of light, releasing great shudders of
gravitational energy. Space and time became distorted, like water at a
rolling boil. In the fraction of a second that it took for the black holes
to finally merge, they radiated a hundred times more energy than all the
stars in the universe combined. They formed a new black hole, sixty-two
times as heavy as our sun and almost as wide across as the state of Maine.
As it smoothed itself out, assuming the shape of a slightly flattened
sphere, a few last quivers of energy escaped. Then space and time became
silent again.




The waves rippled outward in every direction, weakening as they went. On
Earth, dinosaurs arose, evolved, and went extinct. The waves kept going.
About fifty thousand years ago, they entered our own Milky Way galaxy, just
as Homo sapiens were beginning to replace our Neanderthal cousins as the
planet’s dominant species of ape. A hundred years ago, Albert 
Einstein,
one
of the more advanced members of the species, predicted the waves’
existence,
inspiring decades of speculation and fruitless searching. Twenty-two years
ago, construction began on an enormous detector, the Laser Interferometer
Gravitational-Wave Observatory (LIGO). Then, on September 14, 2015, at just
before eleven in the morning, Central European Time, the waves reached
Earth. Marco Drago, a thirty-two-year-old Italian postdoctoral student and a
member of the LIGO Scientific Collaboration, was the first person to notice
them. He was sitting in front of his computer at the Albert Einstein
Institute, in Hannover, Germany, viewing the LIGO data remotely. The waves
appeared on his screen as a compressed squiggle, but the most exquisite ears
in the universe, attuned to vibrations of less than a trillionth of an inch,
would have heard what astronomers call a chirp—a faint whooping from 
low
to
high. This morning, in a press conference in Washington, D.C., the LIGO team
announced that the signal constitutes the first direct observation of
gravitational waves.




When Drago saw the signal, he was stunned. “It was difficult to 
understand
what to do,” he told me. He informed a colleague, who had the presence 
of
mind to call the LIGO operations room, in Livingston, Louisiana. Word began
to circulate among the thousand or so scientists involved in the project. In
California, David Reitze, the executive director of the LIGO Laboratory, saw
his daughter off to school and went to his office, at Caltech, where he was
greeted by a barrage of messages. “I don’t remember exactly 
what I
said,” he
told me. “It was along these lines: ‘Holy shit, what is 
this?’ ”
Vicky
Kalogera, a professor of physics and astronomy at Northwestern University,
was in meetings all day, and didn’t hear the news until dinnertime. 
“My
husband asked me to set the table,” she said. “I was completely 
ignoring
him, skimming through all these weird e-mails and thinking, What is going
on?” Rainer Weiss, the eighty-three-year-old physicist who first 
suggested
building LIGO, in 1972, was on vacation in Maine. He logged on, saw the
signal, and yelled “My God!” loudly enough that his wife and 
adult son
came
running.




The collaborators began the arduous process of double-, triple-, and
quadruple-checking their data. “We’re saying that we made a 
measurement
that
is about a thousandth the diameter of a proton, that tells us about two
black holes that merged over a billion years ago,” Reitze said. “That 
is
a
pretty extraordinary claim and it needs extraordinary evidence.” In 
the
meantime, the LIGO scientists were sworn to absolute secrecy. As rumors of
the finding spread, from late September through this week, media excitement
spiked; there were rumblings about a Nobel Prize. But the collaborators gave
anyone who asked about it an abbreviated version of the truth—that 
they
were
still analyzing data and had nothing to announce. Kalogera hadn’t 
even
told
her husband.




LIGO consists of two facilities, separated by nearly nineteen hundred
miles—about a three-and-a-half-hour flight on a passenger jet, but a
journey
of less than ten ten-thousandths of a second for a gravitational wave. The
detector in Livingston, Louisiana, sits on swampland east of Baton Rouge,
surrounded by a commercial pine forest; the one in Hanford, Washington, is
on the southwestern edge of the most contaminated nuclear site in the United
States, amid desert sagebrush, tumbleweed, and decommissioned reactors. At
both locations, a pair of concrete pipes some twelve feet tall stretch at
right angles into the distance, so that from high above the facilities
resemble carpenter’s squares. The pipes are so long—nearly two 
and a
half
miles—that they have to be raised from the ground by a yard at each 
end,
to
keep them lying flat as Earth curves beneath them.




LIGO is part of a larger effort to explore one of the more elusive
implications of Einstein’s general theory of relativity. The theory, 
put
simply, states that space and time curve in the presence of mass, and that
this curvature produces the effect known as gravity. When two black holes
orbit each other, they stretch and squeeze space-time like children running
in circles on a trampoline, creating vibrations that travel to the very
edge; these vibrations are gravitational waves. They pass through us all the
time, from sources across the universe, but because gravity is so much
weaker than the other fundamental forces of nature—electromagnetism, 
for
instance, or the interactions that bind an atom together—we never 
sense
them. Einstein thought it highly unlikely that they would ever be detected.
He twice declared them nonexistent, reversing and then re-reversing his own
prediction. A skeptical contemporary noted that the waves seemed to
“propagate at the speed of thought.”




Nearly five decades passed before someone set about building an instrument
to detect gravitational waves. The first person to try was an engineering
professor at the University of Maryland, College Park, named Joe Weber. He
called his device the resonant bar antenna. Weber believed that an aluminum
cylinder could be made to work like a bell, amplifying the feeble strike of
a gravitational wave. When a wave hit the cylinder, it would vibrate very
slightly, and sensors around its circumference would translate the ringing
into an electrical signal. To make sure he wasn’t detecting the 
vibrations
of passing trucks or minor earthquakes, Weber developed several safeguards:
he suspended his bars in a vacuum, and he ran two of them at a time, in
separate locations—one on the campus of the University of Maryland, 
and
one
at Argonne National Laboratory, near Chicago. If both bars rang in the same
way within a fraction of a second of each other, he concluded, the cause
might be a gravitational wave.




In June of 1969, Weber announced that his bars had registered something.
Physicists and the media were thrilled; the Times reported that “a new
chapter in man’s observation of the universe has been opened.” 
Soon,
Weber
started reporting signals on a daily basis. But doubt spread as other
laboratories built bars that failed to match his results. By 1974, many had
concluded that Weber was mistaken. (He continued to claim new detections
until his death, in 2000.)




Weber’s legacy shaped the field that he established. It created a
poisonous
perception that gravitational-wave hunters, as Weiss put it, are “all
liars
and not careful, and God knows what.” That perception was reinforced 
in
2014, when scientists at BICEP2, a telescope near the South Pole, detected
what seemed to be gravitational radiation left over from the Big Bang; the
signal was real, but it turned out to be a product of cosmic dust. Weber
also left behind a group of researchers who were motivated by their
inability to reproduce his results. Weiss, frustrated by the difficulty of
teaching Weber’s work to his undergraduates at the Massachusetts 
Institute
of Technology, began designing what would become LIGO. “I 
couldn’t
understand what Weber was up to,” he said in an oral history conducted 
by
Caltech in 2000. “I didn’t think it was right. So I decided I 
would go
at it
myself.”




In the search for gravitational waves, “most of the action takes place 
on
the phone,” Fred Raab, the head of LIGO’s Hanford site, told 
me. There
are
weekly meetings to discuss data and fortnightly meetings to discuss
coördination between the two detectors, with collaborators in Australia,
India, Germany, the United Kingdom, and elsewhere. “When these people 
wake
up in the middle of the night dreaming, they’re dreaming about the
detector,” Raab said. “That’s how intimate they have to 
be with it,”
he
explained, to be able to make the fantastically complex instrument that
Weiss conceived actually work.




Weiss’s detection method was altogether different from 
Weber’s. His
first
insight was to make the observatory “L”-shaped. Picture two 
people lying
on
the floor, their heads touching, their bodies forming a right angle. When a
gravitational wave passes through them, one person will grow taller while
the other shrinks; a moment later, the opposite will happen. As the wave
expands space-time in one direction, it necessarily compresses it in the
other. Weiss’s instrument would gauge the difference between these 
two
fluctuating lengths, and it would do so on a gigantic scale, using miles of
steel tubing. “I wasn’t going to be detecting anything on my
tabletop,” he
said.




To achieve the necessary precision of measurement, Weiss suggested using
light as a ruler. He imagined putting a laser in the crook of the “L.”
It
would send a beam down the length of each tube, which a mirror at the other
end would reflect back. The speed of light in a vacuum is constant, so as
long as the tubes were cleared of air and other particles the beams would
recombine at the crook in synchrony—unless a gravitational wave 
happened
to
pass through. In that case, the distance between the mirrors and the laser
would change slightly. Since one beam would now be covering a shorter
distance than its twin, they would no longer be in lockstep by the time they
got back. The greater the mismatch, the stronger the wave. Such an
instrument would need to be thousands of times more sensitive than any
previous device, and it would require delicate tuning in order to extract a
signal of vanishing weakness from the planet’s omnipresent din.




Weiss wrote up his design in the spring of 1972, as part of his
laboratory’s
quarterly progress report. The article never appeared in a scientific
journal—it was an idea, not an experiment—but according to Kip 
Thorne,
an
emeritus professor at Caltech who is perhaps best known for his work on the
movie “Interstellar,” “it is one of the greatest papers 
ever
written.”
Thorne doesn’t recall reading Weiss’s report until later. 
“If I had
read it,
I had certainly not understood it,” he said. Indeed, Thorne’s 
landmark
textbook on gravitational theory, co-authored with Charles Misner and John
Wheeler and first published in 1973, contained a student exercise designed
to demonstrate the impracticability of measuring gravitational waves with
lasers. “I turned around on that pretty quickly,” he told me.




Thorne’s conversion occurred in a hotel room in Washington, D.C., in 
1975.
Weiss had invited him to speak to a panel of NASA scientists. The evening
before the meeting, the two men got to talking. “I don’t 
remember how it
happened, but we shared the hotel room that night,” Weiss said. They 
sat
at
a tiny table, filling sheet after sheet of paper with sketches and
equations. Thorne, who was raised Mormon, drank Dr Pepper; Weiss smoked a
corncob pipe stuffed with Three Nuns tobacco. “There are not that many
people in the world that you can talk to like that, where both of you have
been thinking about the same thing for years,” Weiss said. By the time
Thorne got back to his own room, the sky was turning pink.




At M.I.T., Weiss had begun assembling a small prototype detector with
five-foot arms. But he had trouble getting support from departmental
administrators, and many of his colleagues were also skeptical. One of them,
an influential astrophysicist and relativity expert named Phillip Morrison,
was firmly of the opinion that black holes did not exist—a viewpoint 
that
many of his contemporaries shared, given the paucity of observational data.
Since black holes were some of the only cosmic phenomena that could
theoretically emit gravitational waves of significant size, Morrison
believed that Weiss’s instrument had nothing to find. Thorne had more
success: by 1981, there was a prototype under way at Caltech, with arms a
hundred and thirty-one feet long. A Scottish physicist named Ronald Drever
oversaw its construction, improving on Weiss’s design in the process.




In 1990, after years of studies, reports, presentations, and committee
meetings, Weiss, Thorne, and Drever persuaded the National Science
Foundation to fund the construction of LIGO. The project would cost two
hundred and seventy-two million dollars, more than any N.S.F.-backed
experiment before or since. “That started a huge fight,” Weiss 
said.
“The
astronomers were dead-set against it, because they thought it was going to
be the biggest waste of money that ever happened.” Many scientists 
were
concerned that LIGO would sap money from other research. Rich Isaacson, a
program officer at the N.S.F. at the time, was instrumental in getting the
observatory off the ground. “He and the National Science Foundation 
stuck
with us and took this enormous risk,” Weiss said.




“It never should have been built,” Isaacson told me. “It 
was a couple
of
maniacs running around, with no signal ever having been discovered, talking
about pushing vacuum technology and laser technology and materials
technology and seismic isolation and feedback systems orders of magnitude
beyond the current state of the art, using materials that hadn’t been
invented yet.” But Isaacson had written his Ph.D. thesis on 
gravitational
radiation, and he was a firm believer in LIGO’s theoretical 
underpinnings.
“I was a mole for the gravitational-wave community inside the 
N.S.F.,”
he
said.




In their proposal, the LIGO team warned that their initial design was
unlikely to detect anything. Nonetheless, they argued, an imperfect
observatory had to be built in order to understand how to make a better one.
“There was every reason to imagine this was going to fail,” 
Isaacson
said.
He persuaded the N.S.F. that, even if no signal was registered during the
first phase, the advances in precision measurement that came out of it would
likely be worth the investment. Ground was broken in early 1994.




It took years to make the most sensitive instrument in history insensitive
to everything that is not a gravitational wave. Emptying the tubes of air
demanded forty days of pumping. The result was one of the purest vacuums
ever created on Earth, a trillionth as dense as the atmosphere at sea level.
Still, the sources of interference were almost beyond reckoning—the 
motion
of the wind in Hanford, or of the ocean in Livingston; imperfections in the
laser light as a result of fluctuations in the power grid; the jittering of
individual atoms within the mirrors; distant lightning storms. All can
obscure or be mistaken for a gravitational wave, and each source had to be
eliminated or controlled for. One of LIGO’s systems responds to 
minuscule
seismic tremors by activating a damping system that pushes on the mirrors
with exactly the right counterforce to keep them steady; another monitors
for disruptive sounds from passing cars, airplanes, or wolves.




“There are ten thousand other tiny things, and I really mean ten
thousand,”
Weiss said. “And every single one needs to be working correctly so 
that
nothing interferes with the signal.” When his colleagues make 
adjustments
to
the observatory’s interior components, they must set up a portable 
clean
room, sterilize their tools, and don what they call bunny 
suits—full-body
protective gear—lest a skin cell or a particle of dust accidentally 
settle
on the sparkling optical hardware.




The first iteration of the observatory—Initial LIGO, as the team now 
calls
it—was up and running in 2001. During the next nine years, the 
scientists
measured and refined their instruments’ performance and improved 
their
data-analysis algorithms. In the meantime, they used the prototype at
Caltech and a facility in Germany to develop ever more sensitive mirror,
laser, and seismic-isolation technology. In 2010, the detectors were taken
offline for a five-year, two-hundred-million-dollar upgrade. They are now so
well shielded that when the facilities manager at the Hanford site revs his
Harley next to the control room, the scientist monitoring the
gravitational-wave channel sees nothing. (A test of this scenario is
memorialized in the logbook as “Bubba Roars Off on a Motor 
Cycle.”) The
observatory’s second iteration, Advanced LIGO, should eventually be
capable
of surveying a volume of space that is more than a thousand times greater
than its predecessor’s.




Some of the most painstaking work took place on the mirrors, which, Reitze
said, are the best in the world “by far.” Each is a little more 
than a
foot
wide, weighs nearly ninety pounds, and is polished to within a
hundred-millionth of an inch of a perfect sphere. (They cost almost half a
million dollars apiece.) At first, the mirrors were suspended from loops of
steel wire. For the upgrade, they were attached instead to a system of
pendulums, which insulated them even further from seismic tremors. They
dangle from fibres of fused silica—glass, basically—which, 
although
strong
enough to bear the weight of the mirrors, shatter at the slightest
provocation. “We did have one incident where a screw fell and pinged 
one,
and it just went poof,” Anamaria Effler, a former operations 
specialist at
the Hanford site, told me. The advantage of the fibres is their purity,
according to Jim Hough, of the University of Glasgow. “You know how, 
when
you flick a whiskey glass, it will ring beautifully?” he asked. “Fused
silica is even better than a whiskey glass—it is like plucking a 
string on
a
violin.” The note is so thin that it is possible for LIGO’s
signal-processing software to screen it out—another source of 
interference
eliminated.




Preparing Advanced LIGO took longer than expected, so the new and improved
instrument’s start date was pushed back a few days, to September 18, 
2015.
Weiss was called in from Boston a week prior to try to track down the source
of some radio-frequency interference. “I get there and I was 
horrified,”
he
said. “It was everywhere.” He recommended a weeklong program of 
repairs
to
address the issue, but the project’s directors refused to delay the 
start
of
the first observing run any longer. “Thank God they didn’t let 
me do
it,”
Weiss said. “I would have had the whole goddamn thing offline when the
signal came in.”




On Sunday, September 13th, Effler spent the day at the Livingston site with
a colleague, finishing a battery of last-minute tests. “We yelled, we
vibrated things with shakers, we tapped on things, we introduced magnetic
radiation, we did all kinds of things,” she said. “And, of 
course,
everything was taking longer than it was supposed to.” At four in the
morning, with one test still left to do—a simulation of a truck 
driver
hitting his brakes nearby—they decided to pack it in. They drove 
home,
leaving the instrument to gather data in peace. The signal arrived not long
after, at 4:50 A.M. local time, passing through the two detectors within
seven milliseconds of each other. It was four days before the start of
Advanced LIGO’s first official run.




The fact that gravitational waves were detected so early prompted confusion
and disbelief. “I had told everyone that we wouldn’t see 
anything until
2017
or 2018,” Reitze said. Janna Levin, a professor of astrophysics at 
Barnard
College and Columbia University, who is not a member of the LIGO Scientific
Collaboration, was equally surprised. “When the rumors started, I was
like,
Come on!” she said. “They only just got it locked!” The 
signal,
moreover,
was almost too perfect. “Most of us thought that, when we ever saw 
such a
thing, it would be something that you would need many, many computers and
calculations to drag out of the noise,” Weiss said. Many of his 
colleagues
assumed that the signal was some kind of test.




The LIGO team includes a small group of people whose job is to create blind
injections—bogus evidence of a gravitational wave—as a way of 
keeping
the
scientists on their toes. Although everyone knew who the four people in that
group were, “we didn’t know what, when, or whether,” 
Gabriela
González, the
collaboration’s spokeswoman, said. During Initial LIGO’s final 
run, in
2010,
the detectors picked up what appeared to be a strong signal. The scientists
analyzed it intensively for six months, concluding that it was a
gravitational wave from somewhere in the constellation of Canis Major. Just
before they submitted their results for publication, however, they learned
that the signal was a fake.




This time through, the blind-injection group swore that they had nothing to
do with the signal. Marco Drago thought that their denials might also be
part of the test, but Reitze, himself a member of the quartet, had a
different concern. “My worry was—and you can file this under 
the fact
that
we are just paranoid cautious about making a false claim—could 
somebody
have
done this maliciously?” he said. “Could somebody have somehow 
faked a
signal
in our detector that we didn’t know about?” Reitze, Weiss, 
González,
and a
handful of others considered who, if anyone, was familiar enough with both
the apparatus and the algorithms to have spoofed the system and covered his
or her tracks. There were only four candidates, and none of them had a
plausible motive. “We grilled those guys,” Weiss said. “And 
no, they
didn’t
do it.” Ultimately, he said, “We accepted that the most 
economical
explanation was that it really is a black-hole pair.”




Subgroups within the LIGO Scientific Collaboration set about validating
every aspect of the detection. They reviewed how the instruments had been
calibrated, took their software code apart line by line, and compiled a list
of possible environmental disturbances, from oscillations in the ionosphere
to earthquakes in the Pacific Rim. (“There was a very large lightning
strike
in Africa at about the same time,” Stan Whitcomb, LIGO’s chief
scientist,
told me. “But our magnetometers showed that it didn’t create 
enough of a
disturbance to cause this event.”) Eventually, they confirmed that the
detection met the statistical threshold of five sigma, the gold standard for
declaring a discovery in physics. This meant that there was a probability of
only one in 3.5 million that the signal was spotted by chance.




The September 14th detection, now officially known as GW150914, has already
yielded a handful of significant astrophysical findings. To begin with, it
represents the first observational evidence that black-hole pairs exist.
Until now, they had existed only in theory, since by definition they swallow
all light in their vicinity, rendering themselves invisible to conventional
telescopes. Gravitational waves are the only information known to be capable
of escaping a black hole’s crushing gravity.




The LIGO scientists have extracted an astonishing amount from the signal,
including the masses of the black holes that produced it, their orbital
speed, and the precise moment at which their surfaces touched. They are
substantially heavier than expected, a surprise that, if confirmed by future
observations, may help to explain how the mysterious supermassive black
holes at the heart of many galaxies are formed. The team has also been able
to quantify what is known as the ringdown—the three bursts of energy 
that
the new, larger black hole gave off as it became spherical. “Seeing 
the
ringdown is spectacular,” Levin said. It offers confirmation of one of
relativity theory’s most important predictions about black 
holes—namely,
that they radiate away imperfections in the form of gravitational waves
after they coalesce.




The detection also proves that Einstein was right about yet another aspect
of the physical universe. Although his theory deals with gravity, it has
primarily been tested in our solar system, a place with a notably weak
gravitational regime. “You think Earth’s gravity is really 
something
when
you’re climbing the stairs,” Weiss said. “But, as far as 
physics goes,
it is
a pipsqueak, infinitesimal, tiny little effect.” Near a black hole,
however,
gravity becomes the strongest force in the universe, capable of tearing
atoms apart. Einstein predicted as much in 1916, and the LIGO results
suggest that his equations align almost perfectly with real-world
observation. “How could he have ever known this?” Weiss asked. 
“I
would love
to present him with the data that I saw that morning, to see his 
face.”




Since the September 14th detection, LIGO has continued to observe candidate
signals, although none are quite as dramatic as the first event. “The
reason
we are making all this fuss is because of the big guy,” Weiss said. 
“But
we’re
very happy that there are other, smaller ones, because it says this is not
some unique, crazy, cuckoo effect.”




Virtually everything that is known about the universe has come to scientists
by way of the electromagnetic spectrum. Four hundred years ago, Galileo
began exploring the realm of visible light with his telescope. Since then,
astronomers have pushed their instruments further. They have learned to see
in radio waves and microwaves, in infrared and ultraviolet, in X-rays and
gamma rays, revealing the birth of stars in the Carina Nebula and the
eruption of geysers on Saturn’s eighth moon, pinpointing the center 
of the
Milky Way and the locations of Earth-like planets around us. But more than
ninety-five per cent of the universe remains imperceptible to traditional
astronomy. Gravitational waves may not illuminate the so-called dark energy
that is thought to make up the majority of that obscurity, but they will
enable us to survey space and time as we never have before. “This is a
completely new kind of telescope,” Reitze said. “And that means 
we have
an
entirely new kind of astronomy to explore.” If what we witnessed 
before
was
a silent movie, Levin said, gravitational waves turn our universe into a
talkie.




As it happens, the particular frequencies of the waves that LIGO can detect
fall within the range of human hearing, between about thirty-five and two
hundred and fifty hertz. The chirp was much too quiet to hear by the time it
reached Earth, and LIGO was capable of capturing only two-tenths of a second
of the black holes’ multibillion-year merger, but with some minimal 
audio
processing the event sounds like a glissando. “Use the back of your
fingers,
the nails, and just run them along the piano from the lowest A up to middle
C, and you’ve got the whole signal,” Weiss said.




Different celestial sources emit their own sorts of gravitational waves,
which means that LIGO and its successors could end up hearing something like
a cosmic orchestra. “The binary neutron stars are like the 
piccolos,”
Reitze
said. Isolated spinning pulsars, he added, might make a monochromatic
“ding”
like a triangle, and black holes would fill in the string section, running
from double bass on up, depending on their mass. LIGO, he said, will only
ever be able to detect violins and violas; waves from supermassive black
holes, like the one at the center of the Milky Way, will have to await
future detectors, with different sensitivities.




Several such detectors are in the planning stages or under construction,
including the Einstein Telescope, a European project whose underground arms
will be more than twice the length of LIGO’s, and a space-based
constellation of three instruments called eLISA. (The European Space Agency,
with support from NASA, launched a pathfinder mission in December.) Other
detectors are already up and running, including the BICEP2 telescope, which,
despite its initial false alarm, may still detect the echoes of
gravitational waves from even further back in the universe’s history.
Reitze’s
hope, he told me, is that the chirp will motivate more investment in the
field.




Advanced LIGO’s first observing run came to an end on January 12th. 
Effler
and the rest of the commissioning team have since begun another round of
improvements. The observatory is inching toward its maximum sensitivity;
within two or three years, it may well register events on a daily basis,
capturing more data in the process. It will come online again by late
summer, listening even more closely to a celestial soundtrack that we have
barely imagined. “We are opening up a window on the universe so 
radically
different from all previous windows that we are pretty ignorant about
what’s
going to come through,” Thorne said. “There are just bound to be 
big
surprises.”