Exaggerated Effects of Gravitational Waves on Earth LIGO Lab Caltech : MIT 2016-02-11 | Gravitational waves stretch and squeeze the fabric of space and time on very minuscule scales; visually exaggerating these effects reveals how Earth is squeezed and stretched. Gravitational waves are generated when massive objects, such as pairs of black holes, accelerate through space and time. On September 14, 2015, LIGO became the first instrument on Earth to detect these waves, in this instance originating from the collision of two black holes more than a billion light-years away. LIGO detectors were able to measure the stretching and squeezing of space -- caused by the passage of these gravitational waves -- with a precision equivalent to 1/1000th the diameter of a proton. That's like measuring the distance to the nearest star down to a precision level of just a fraction of the thickness of a human hair.Image credit: LIGO/R. Hurt
Ripples in Spacetime Pond LIGO Lab Caltech : MIT 2016-06-15 | This artist's animation shows the merger of two black holes and the gravitational waves that ripple outward during the event. The black holes—which represent those detected by LIGO on Dec. 26, 2015—were 14 and 8 times the mass of the sun, until they merged, forming a single black hole 21 times the sun's mass. One solar mass was converted to gravitational waves. In reality, the area near the black holes would appear highly warped, and the gravitational waves would be difficult to see directly.Credit: LIGO/T. Pyle
Comparing Chirps from Black Holes LIGO Lab Caltech : MIT 2016-06-15 | The best-fit models of LIGO’s gravitational-wave signals are converted into sounds. The first sound is from modeled gravitational waves detected by LIGO on Dec. 26, 2015, when two black holes merged. This is then compared to the first-ever gravitational waves detected by LIGO on Sept. 14, 2015, when two higher-mass black holes merged. This sequence is repeated. The pitch of both signals is then increased, allowing them to be heard more easily, and this sequence is also repeated.Animation credit: LIGO
LIGO: The First Observation of Gravitational Waves LIGO Lab Caltech : MIT 2016-02-12 | On September 14, 2015, LIGO observed ripples in the fabric of spacetime. This video narrative tells the story of the science behind that important detection.Credit: Caltech
LIGO: Opening a New Window Onto the Universe LIGO Lab Caltech : MIT 2016-02-12 | This video narrative tells the story of the history and legacy of LIGO from the genesis of the idea to the detection in September 2015.Credit: Caltech Strategic Communications and Caltech AMT
Two Black Holes Merge into One LIGO Lab Caltech : MIT 2016-02-11 | A computer simulation shows the collision of two black holes, a tremendously powerful event detected for the first time ever by the Laser Interferometer Gravitational-Wave Observatory, or LIGO. LIGO detected gravitational waves, or ripples in space and time generated as the black holes spiraled in toward each other, collided, and merged. This simulation shows how the merger would appear to our eyes if we could somehow travel in a spaceship for a closer look. It was created by solving equations from Albert Einstein's general theory of relativity using the LIGO data.The two merging black holes are each roughly 30 times the mass of the sun, with one slightly larger than the other. Time has been slowed down by a factor of about 100. The event took place 1.3 billion years ago. The stars appear warped due to the incredibly strong gravity of the black holes. The black holes warp space and time, and this causes light from the stars to curve around the black holes in a process called gravitational lensing. The ring around the black holes, known as an Einstein ring, arises from the light of all the stars in a small region behind the holes, where gravitational lensing has smeared their images into a ring. The gravitational waves themselves would not be seen by a human near the black holes and so do not show in this video, with one important exception. The gravitational waves that are traveling outward toward the small region behind the black holes disturb that region’s stellar images in the Einstein ring, causing them to slosh around, even long after the collision. The gravitational waves traveling in other directions cause weaker, and shorter-lived sloshing, everywhere outside the ring.This simulation was created by the multi-university SXS (Simulating eXtreme Spacetimes) project. For more information, visit http://www.black-holes.org. Image credit: SXS
Zooming into an Atom (Annotated) LIGO Lab Caltech : MIT 2016-02-11 | On September 14, 2015, LIGO became the first instrument to detect gravitational waves on Earth. When two black holes, each about 30 times more massive than our sun merged, they generated gravitational waves—ripples in space and time. More than a billion years later, those waves reached LIGO's detectors, causing the distance between its mirrors—separated by 4 kilometers—to change by roughly 1/1000th the diameter of a proton. This animation zooms in on the proton of a hydrogen atom. The movement of the proton shows the tiny changes measured by LIGO.Image credit: LIGO/T. Pyle
The Sound of Two Black Holes Colliding LIGO Lab Caltech : MIT 2016-02-11 | Gravitational waves sent out from a pair of colliding black holes have been converted to sound waves, as heard in this animation. On September 14, 2015, LIGO observed gravitational waves from the merger of two black holes, each about 30 times the mass of our sun. The incredibly powerful event, which released 50 times more energy than all the stars in the observable universe, lasted only fractions of a second. In the first two runs of the animation, the sound-wave frequencies exactly match the frequencies of the gravitational waves. The second two runs of the animation play the sounds again at higher frequencies that better fit the human hearing range. The animation ends by playing the original frequencies again twice.As the black holes spiral closer and closer in together, the frequency of the gravitational waves increases. Scientists call these sounds "chirps," because some events that generate gravitation waves would sound like a bird's chirp. Image credit: LIGO
Spiraling Black Holes LIGO Lab Caltech : MIT 2016-02-11 | A computer simulation of gravitational waves from merging black holes, based on data acquired Sept. 14, 2015 by the LIGO detectors. Our universe's three-dimensional space is shown as a two-dimensional surface, with one dimension removed. The black holes’ strong gravity curves the space near them into funnel shapes. As the black holes spiral together and merge into one, gravitational waves ripple outward. The movie is shown in slow motion, about 40 times slower than real time. This video is based on a computer simulation by the multi-university SXS (Simulating eXtreme Spacetimes) project. For more information, visit http://www.black-holes.org. Image credit: SXS
Most Precise Ruler Ever Constructed LIGO Lab Caltech : MIT 2016-02-11 | This animation illustrates how the twin observatories of LIGO work. One observatory is in Hanford, Washington, the other in Livingston, Louisiana. Each houses a large-scale interferometer, a device that uses the interference of two beams of laser light to make the most precise distance measurements in the world.The animation begins with a simplified depiction of the LIGO instrument. A laser beam of light is generated and directed toward a beam splitter, which splits it into two separate and equal beams. The light beams then travel perpendicularly to a distant mirror, with each arm of the device being 4 kilometers in length. The mirrors reflect the light back to the beam splitter, repeating this process 200 times.When gravitational waves pass through this device, they cause the length of the two arms to alternately stretch and squeeze by infinitesimal amounts, tremendously exaggerated here for visibility. This movement causes the light beam that hits the detector to flicker.The second half of the animation explains the flickering, and this is where light interference comes into play. After the two beams reflect off the mirrors, they meet at the beam splitter, where the light is recombined in a process called interference. Normally, when no gravitational waves are present, the distance between the beam splitter and the mirror is precisely controlled so that the light waves are kept out of phase with each other and cancel each other out. The result is that no light hits the detectors.But when gravitational waves pass through the system, the distance between the end mirrors and the beam splitter lengthen in one arm and at the same time shorten in the other arm in such a way that the light waves from the two arms go in and out of phase with each other. When the light waves are in phase with each other, they add together constructively and produce a bright beam that illuminates the detectors. When they are out of phase, they cancel each other out and there is no signal. Thus, the gravitational waves from a major cosmic event, like the merger of two black holes, will cause the signal to flicker, as seen here.By digitizing and recording the specific patterns of signals that hit the LIGO detectors, researchers can then analyze what they see and compare the data to computer models of predicted gravitational wave signals.The effects of the gravitational waves on the LIGO instrument have been vastly exaggerated in this video to demonstrate how it works. In reality, the changes in the lengths of the instrument's arms is only 1/1000th the size of a proton. Other characteristics of LIGO, such as the exquisite stability of its mirrors, also contribute to its ability to precisely measures distances. In fact, LIGO can be thought of as the most precise "ruler" in the world.Image credit: LIGO/T. Pyle
Black Hole Waves Simulation LIGO Lab Caltech : MIT 2016-02-11 | This simulation depicts the birth, 1.3 billion years ago, of the gravitational waves discovered by LIGO on September 14, 2015. The waves are generated by two black holes that spiral around each other, then collide and merge. In the bright green regions, the waves stretch space; in the dark green regions, they squeeze space. As the black holes approach each other, the waves get stronger and the separation between them gets shorter, giving rise to what scientists refer to as a "chirp." The two black holes collide and merge into a new black hole, bringing the waves to a crescendo. The newborn black hole vibrates briefly, then becomes quiet and stops generating waves. The waves all depart from the black hole’s vicinity, traveling out into the universe, carrying news of the black holes’ collision.This video is based on a computer simulation by the multi-university SXS (Simulating eXtreme Spacetimes) project. For more information, visit http://www.black-holes.org. Image credit: SXS
Warped Space and Time Around Colliding Black Holes LIGO Lab Caltech : MIT 2016-02-11 | This computer simulation shows the warping of space and time around two colliding black holes observed by LIGO on September 14, 2015. LIGO detected gravitational waves generated by this black hole merger—humanity's first contact with gravitational waves and black-hole collisions. Gravitational waves are ripples in the shape of space and flow of time.The colored surface is the space of our universe, as viewed from a hypothetical, flat, higher-dimensional universe, in which our own universe is embedded. Our universe looks like a warped two-dimensional sheet because one of its three space dimensions has been removed. Around each black hole, space bends downward in a funnel shape, a warping produced by the black hole's huge mass.Near the black holes, the colors depict the rate at which time flows. In the green regions outside the holes, time flows at its normal rate. In the yellow regions, it is slowed by 20 or 30 percent. In the red regions, time is hugely slowed. Far from the holes, the blue and purple bands depict outgoing gravitational waves, produced by the black holes' orbital movement and collision.Our universe's space, as seen from the hypothetical higher-dimensional universe, is dragged into motion by the orbital movement of the black holes, and by their gravity and by their spins. This motion of space is depicted by silver arrows, and it causes the plane of the orbit to precess gradually, as seen in the video.The upper left numbers show time, as measured by a hypothetical person near the black holes (but not so near that time is warped). The bottom portion of the movie shows the waveform, or wave shape, of the emitted gravitational waves.The gravitational waves carry away energy, causing the black holes to spiral inward and collide. The movie switches to slow motion as the collision nears, and is paused at the moment the black holes' surfaces (their "horizons") touch. At the pause, space is enormously distorted. After the pause, again seen in slow motion, the shapes of space and time oscillate briefly but wildly, and then settle down into the quiescent state of a merged black hole. Returning to fast motion, we see the gravitational waves from the collision, propagating out into the universe.The collision and wild oscillations constitute a "storm" in the fabric of space and time—an enormously powerful but brief storm. During the storm, the power output in gravitational waves is far greater than the luminosity of all the stars in our observable universe put together. In other words, this collision of two black holes, each the size of a large city on Earth, is the most powerful explosion that astronomers have ever seen, aside from our universe's birth in the Big Bang.This simulation was created by the SXS (Simulating eXtreme Spacetimes) Project (http://www.black-holes.org).Credit: SXS
Journey of a Gravitational Wave LIGO Lab Caltech : MIT 2016-02-11 | LIGO scientist David Reitze takes us on a 1.3 billion year journey that begins with the violent merger of two black holes in the distant universe. The event produced gravitational waves, tiny ripples in the fabric of space and time, which LIGO detected on September 14, 2015, as they passed Earth.Image credit: LIGO/SXS/R.Hurt and T. Pyle
Zooming into an Atom LIGO Lab Caltech : MIT 2016-02-11 | On September 14, 2015, LIGO became the first instrument to detect gravitational waves on Earth. When two black holes, each about 30 times more massive than our sun merged, they generated gravitational waves—ripples in space and time. More than a billion years later, those waves reached LIGO's detectors, causing the distance between its mirrors—separated by 4 kilometers—to change by roughly 1/1000th the diameter of a proton. This animation zooms in on the proton of a hydrogen atom. The movement of the proton shows the tiny changes measured by LIGO.Image credit: LIGO/T. Pyle
What did the Caltech LIGO team expect ahead of this observation? LIGO Lab Caltech : MIT 2016-02-11 | On August 13, 2015, we asked experimentalists and theorists on the Caltech LIGO team what they expected to find during Observation Run 1. Just one month later, on September 14, both detectors picked up the unmistakeable signature of two merging black holes - the first direct detection of gravitational waves.More information: http://ligo.caltech.eduFilmed at the LIGO Gravitational Wave Q&A on August 13, 2015Tolman/Bacher House, CaltechModerator: Christina OchoaPanelists: Kip Thorne, Sarah Gossan, Rana AdhikariProduced by Academic Media TechnologiesEditing and animation by Meg RosenburgLocation provided by the Keck Institute for Space Studies
Direct Detection of Gravitational Waves: What Does That Mean? LIGO Lab Caltech : MIT 2015-11-02 | Advanced LIGO is searching for gravitational waves - what will it find, and what will it mean? Caltech LIGO scientists Kip Thorne, Sarah Gossan, and Rana Adhikari answer your questions.More information: http://ligo.caltech.eduFilmed at the LIGO Gravitational Wave Q&A on August 13, 2015Tolman/Bacher House, CaltechModerator: Christina OchoaPanelists: Kip Thorne, Sarah Gossan, Rana AdhikariProduced by Academic Media TechnologiesEditing and animation by Meg RosenburgLocation provided by the Keck Institute for Space StudiesMusic by Vinny Falcone
What Types of Sources Cause Gravitational Waves? LIGO Lab Caltech : MIT 2015-10-26 | Advanced LIGO is searching for gravitational waves - what will it find, and what will it mean? Caltech LIGO scientists Kip Thorne, Sarah Gossan, and Rana Adhikari answer your questions.More information: http://ligo.caltech.eduFilmed at the LIGO Gravitational Wave Q&A on August 13, 2015Tolman/Bacher House, CaltechModerator: Christina OchoaPanelists: Kip Thorne, Sarah Gossan, Rana AdhikariProduced by Academic Media TechnologiesEditing and animation by Meg RosenburgLocation provided by the Keck Institute for Space StudiesMusic by Vinny Falcone
What are Gravitational Waves? LIGO Lab Caltech : MIT 2015-10-19 | Advanced LIGO is searching for gravitational waves - what will it find, and what will it mean? Caltech LIGO scientists Kip Thorne, Sarah Gossan, and Rana Adhikari answer your questions.More information: http://ligo.caltech.eduFilmed at the LIGO Gravitational Wave Q&A on August 13, 2015Tolman/Bacher House, CaltechModerator: Christina OchoaPanelists: Kip Thorne, Sarah Gossan, Rana AdhikariProduced by Academic Media TechnologiesEditing and animation by Meg RosenburgLocation provided by the Keck Institute for Space StudiesMusic by Vinny Falcone
