NSF’s LIGO Detects Gravitational Waves

LIGO Detects Gravitational Waves

An artist’s impression of gravitational waves generated by binary neutron stars.

Using the Laser Interferometer Gravitational-Wave Observatory (LIGO), the National Science Foundation has detected gravitational waves.

Albert Einstein predicted the existence of gravitational waves in his general theory of relativity a century ago, and scientists have been attempting to detect them for 50 years. Einstein pictured these waves as ripples in the fabric of space-time produced by massive, accelerating bodies, such as black holes orbiting each other. Scientists are interested in observing and characterizing these waves to learn more about the sources producing them and about gravity itself.

The LIGO detections represent a much-awaited first step toward opening a whole new branch of astrophysics. Nearly everything we know about the universe comes from detecting and analyzing light in all its forms across the electromagnetic spectrum – radio, infrared, visible, ultraviolet, X-rays and gamma rays. The study of gravitational waves opens a new window on the universe, one that scientists expect will provide key information that will complement what we can learn through electromagnetic radiation.

Just as in other areas of astronomy, astronomers need both ground-based and space-based observatories to take full advantage of this new window. LIGO is sensitive to gravitational waves within the range of 10 to 1,000 cycles per second (10 to 1,000 Hz). A space-based system would be able to detect waves at much lower frequencies, from 0.0001 to 0.1 Hz, and detect different types of sources. NASA is working closely with the European Space Agency (ESA) to develop a concept for a space-based gravitational wave observatory.


This movie shows a simulation of the merger of two black holes and the resulting emission of gravitational radiation. The colored fields represent a component of the curvature of space-time. The outer sheets (red) correspond directly to outgoing gravitational radiation, which was recently detected by the NSF’s LIGO observatories.

ESA is currently leading the LISA Pathfinder mission, launched last December and now in its commissioning phase, to demonstrate technologies that could be used for a future space-based gravitational wave observatory. NASA contributed its ST-7 Disturbance Reduction System to the payload as part of that demonstration.

NASA missions are searching the sky for fleeting X-ray and gamma-ray signals from LIGO events. Detecting the light emitted by a gravitational wave source would enable a much deeper understanding of the event than through either technique alone.

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Source: Francis Reddy, NASA’s Goddard Space Flight Center

3 Comments on "NSF’s LIGO Detects Gravitational Waves"

  1. Madanagopal.V.C. | February 12, 2016 at 10:41 pm | Reply

    The four fields of nature in the grand unification theory are 1)electromagnetic waves mediated by force particles ‘photons’ 2)electro weak forces mediated by ‘W+,W-and Z Bosons’3)Gravitational forces said to be propagated by gravitational waves mediated by gravitons ?? and 4) Strong nuclear forces mediated by ‘gluons’.Apart from these there is also ‘Higgs Field’ all over the Universe which is mediated by ‘Higgs Bosons’. All of these forces are travelling at the velocity of light’c’ at the most and may be dampened by matter intervening so that light travels at a lesser speed in a thick medium like glass or air. Severe dampening happens to nuclear forces and gluons, and also gravitational waves and electro weak forces. Only light ,X-ray and Gamma rays travel freely in the cosmos.Of these we have already detected electromagnetic waves of all sort and photons of all sort from light to X-ray and gamma ray photons. Electro-weak forces and W Bosons have been detected. Nuclear field and gluons were detected. Only gravitational field and gravitons were there to be detected and today’s ACIEVEMENT IN TRACING GRAVITATIONAL WAVES is remarkable discovery of the century. Gravitational field is detected and ‘gravitons’ are yet to be detected. Similarly Higgs field is not detected but “Higgs Boson” is detected. Gravity travels in the open vacuum by stretching the ‘four dimensional space’ and the strength is lower and lower at great distances BUT IT IS STILL TRUE AND THAT IS WHAT NOW ESTABLISHED. LOUIS dE BROGLIE has already studied about matter waves and even you and me have got matter waves corresponding to our mass and the wavelength is extremely short and only in case of matter like ‘electrons’, the wave is detectable and is made use of in electron microscope. All forces and energy waves which are dampened by MATTER are indeed attracted by GRAVITY. These force particles are very energetic only near the origin of the field and severely weak as distance moved by. Thus very weak signal of the two black holes merging sending out very strong gravitational waves are detected by extremely high standard instrument where even 1/10000 width of the nucleus of the atom displacement is also detected. Still Dark Matter and Dark Energy is also there to be detected in a wide detail. neutrinos are detected and where the neutrinos are stored finally is not detected, Similarly the empty space is itself a miracle to be solved. You can read my article on space analysis I and space analysis II, by googling ‘vcmadan2’ in my article ‘Science Frontiers- a Probe by Madan. Thank You.

  2. I’ve been watching Kip Thorn on this for ca. thirty years. Great to see it happen.

  3. Madanagopal.V.C. | February 25, 2016 at 5:50 am | Reply

    A little more explanation which I would like to add to discovery of gravitational waves. ACTION AT A DISTANT POINT requires every field in this universe should have a force particle to act on the distant object and a medium called ETHER is discounted in science today. The strength of the field at a point is dependent on these force particles which wanes as distance increases. In electromagnetic waves the force particles are called photons .These photons are corpuscular in nature and it may carry very very very little mass whatsoever since it is attracted by dark matter in the Universe to split the light in kaleidoscopic form. Newton’s gravitational laws say that the force between any two ‘particles’ is directly proportional to the product of the ‘masses’ and inversely proportional to the ‘square of the distance’ between them. The Dark Matter of billion times heavier than ordinary planetary matter is bound to attract these light corpuscles. To attract or disperse these force particles and in this case still not discovered ‘Gravitons’ either the mass of ejection should be very high or the attracting body should be very high. In this case our Earth is just a peanut in the universe in the mass consideration and hence we target only the Black Holes which send out the ripples which are good enough to be detected. In future these LIGO experiments will detect all the powerful black holes in the universe which are colliding with each other. The ripple waves exist only for few nano seconds since these waves are very short to be detected and feeble in all other gravitational bodies.

    ANOTHER POINT OF EXPLANATION is on the space time continuum. You
    forget the space to be only three dimensional. If you add multiple dimensions, say the trajectory between two points in space , having a geometrically linear distance ‘r’ and a spiralling distance between the same two points as ‘R’ you can solve the mystery of variable RANGE OF FORCE OF ATTRACTION which are extremely small in case of ‘gluons’ of the STRONG FORCES OF quarks of the atom, gravitational forces of the heavenly bodies which becomes very weak at a very short distance ( for earth it is only 6000 kms) a bit more and more in other forces of ‘electro-weak forces’ and finally very large in case of electro magnetic waves like light, x-rays , gamma rays, heat etc. In the last case the distance is almost ‘r’ which is the linear distance, and in other cases the real distance is 1000 times and million times more than the actual ‘r’ and thus “R” is large which obeys the law of inverse squares and tapers the field strength very rapidly at nano distances itself. Only when electrons or gluons and W Bosons are very close to each other the forces can be felt. For gravity it is also small in range but only in this case the other product m1 and m2 of two masses can vary astronomically in space because of planets , galaxies, and Black Matter, which can make a sure dent in the space-time continuum and thus can be detected.

    If you increase the distance virtually to ‘R’ between two space points a paradox arises in the time of travel by light between two points and since they reach the same point at the maximum velocity ‘c’ permissible ,now that we can either consider the light speed to increase more than ‘c’ in the spiralling path of the fourth dimension or we can assume the time of travel to be dilated to get the same quotient ‘c’. Time dilatation is there in the Einstein’s relativistic equation contraction of length. Now you get a solution for constant maximum velocity ‘c’ in space. You keep the ‘c’ constant and alter the ‘time’ and ‘length’ relativestically in space
    according to Einstein. Thank You.

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