2017 Nobel Goes to Gravitational Waves

Three American physicists have received the Nobel Prize in physics for their contributions to the discovery of gravitational waves.

Nobel 2017 to Gravitational Waves

Ranier Weiss (MIT), Kip S. Thorne (Caltech), and Barry C. Barish (Caltech) have been chosen by the Royal Swedish Academy of Sciences for the award thanks to their decisive contributions in the development of the Laser Interferometer Gravitational-Wave Observatory (LIGO) and their observations of gravitational waves.
LIGO

This could have been an exciting day for Albert Einstein — were he alive, of course. The Nobel Prize in physics for 2017 has been awarded to three researchers for their work helping to prove a prediction he made more than 100 years ago, based on his general theory of relativity: the existence of gravitational waves.

Ranier Weiss (MIT), Kip S. Thorne (Caltech), and Barry C. Barish (Caltech) have been chosen by the Royal Swedish Academy of Sciences for the award thanks to their decisive contributions in the development of the Laser Interferometer Gravitational-Wave Observatory (LIGO) and their observations of gravitational waves.

LIGO consists of two L-shaped laser interferometers, each four kilometers in length, located on opposite sides of the United States. When a gravitational wave — a ripple in spacetime produced by an accelerating mass — reaches the instrument, the wobble it creates in the dimensions of spacetime itself produces minuscule variations (on the order of 10-18 meter, or a million trillionth of a meter) in the length of the interferometer. LIGO measures these tiny stretches and squeezes with its extremely sensitive instruments.

The prize has been awarded to Weiss, Thorne, and Barish, but it’s an acknowledgement of the efforts of roughly 1,000 participants of a project that has been almost 50 years in the works, since Weiss first came up with the idea of an interferometer for detecting gravitational waves. After developing a prototype at MIT in the early 1970s, Weiss teamed up in 1976 with Caltech physicist Kip Thorne, who was instrumental in developing physicists’ understanding of gravitational waves.

In 1979 they started working with Scottish experimentalist Ronald Drever (1931–2017) and together founded the LIGO project. Drever, who added key improvements to Weiss’s detector design, might have been the third recipient of this Nobel, if not for his death this year. Barish came onboard as principal investigator after the project started, becoming science director in 1997. He oversaw critical stages of LIGO’s construction and contributed to securing funding for the project.

The Revolution of Gravitational Waves

LIGO’s first detection of gravitational waves happened in September 2015, after years of tuning and refining the instrument. Three more detections came afterwards, the last one announced just a few days ago on September 27th. The latest discovery included observations from the Advanced Virgo detector of the European Gravitational Observatory near Pisa, Italy, which enabled researchers to pinpoint the location of the waves’ source in the sky with much better precision than previously possible.

All four detections so far appear to come from the merger of stellar-mass black holes, objects with the mass of dozens of Suns contained within a couple hundred kilometers, which is less than the distance between Boston and New York. These objects do not emit any kind of electromagnetic radiation. Before LIGO, astrophysicists didn’t know that black holes existed at these masses, or even that they could come in pairs, Weiss said in a press conference a few hours after the award announcement. Weiss also said that many (including him) thought that LIGO would detect neutron stars first, mostly because astronomers already knew they existed in binaries—which made them a better justification to get funding, he joked.

Although LIGO has not yet announced any detection of neutron star mergers, Weiss hinted an announcement may be coming on October 16th (so brace yourselves for more gravitational wave hubbub very soon).

Gravitational waves open an entirely unexplored route for scientists, like developing an entirely new sense to feel their way around. “With these instruments we have opened a new field of astronomy and astrophysics, so the real payoff will be in the future,” Weiss said. “This [gravitational-wave] radiation is caused by accelerating mases and is so penetrating that nothing perturbs its travel to Earth at all, so it will allow us to see new things and look to what we already know in a new way.”

Scientists hope that gravitational waves will bring new insights to many longstanding questions in astrophysics and cosmology. Questions such as how stiff matter is at its most extreme pressures to how heavy elements are made, how black holes and pulsars rotate over long periods of time — and not only when they smash —and even studying the imprint of the inflationary epoch of the universe

The field of gravitational astronomy is just starting, and we are posed to see very exciting developments in the near future. New ground and space-based instruments are already planned and under construction. The Kamioka Gravitational-Wave Detector is being built in Japan, and it will use extremely cold temperatures to reach high levels of sensitivity. In India, another interferometer will join the LIGO and Virgo collaboration, implementing a spare instrument built by the LIGO team. Finally, the first space-based gravitational wave detector, LISA, is scheduled to launch in 2030 by the European Space Agency and NASA.

The future looks bright for gravitational astronomy.

4 thoughts on “2017 Nobel Goes to Gravitational Waves

  1. Graham-Wolf

    Congratulations to all three!

    I have particularly and keenly followed Kip’s stellar career over the decades.
    His academic interchanges (particularly with Stephen Hawking) have been the stuff of legend.
    His (in)famous public wager with Stephen many years ago, is remarkable in itself!

    A dry wit, an amazing sense of humour, and a razor-sharp scientific genious are 3 of Kip’s hallmarks.
    It’s been a long time coming, but finally he’s nailed a Nobel Prize.
    And he’s inspired countless others along the way.
    One of my favourite physicists… right up there with Richard Feynman (another personal favourite).

    Well done, Kip!

    Graham W. Wolf at 46 South, Dunedin N.Z.

  2. xinhangshen

    It is preposterous that Nobel Prize goes to these who claimed to discover “gravitational waves” – ripples of spacetime, while there is nothing called spacetime in nature, not to mention ripples of spacetime. Time is absolute and independent of space. Einstein’s relativity theory has already been disproved both logically and experimentally (see “Challenge to the special theory of relativity”, March 1, 2016 on Physics Essays and a press release “Special Theory of Relativity Has Been Disproved Theoretically” on Eurekalert website: https://www.researchgate.net/deref/https%3A%2F%2Fwww.eurekalert.org%2Fpub_releases%2F2016-03%2Fngpi-tst030116.php ) The problem of Einstein’s relativity is that it has redefined time and space through Lorentz Transformation. The newly defined time is no longer the physical time measured with physical clocks, which can be easily demonstrated by the thought experiment of candle clocks, the symmetric twin paradox, the universal synchronization of GPS clocks, etc.

    Let’s look at a series of vertically standing candles with the same burning rate and moving at different constant horizontal velocities in an inertial reference frame of (x, y, z, t) where x, y, z, t are relativistic positions and time. At any moment t of relativistic time, all candles have the same height H in the reference frame of (x, y, z, t) and the height has been calibrated to physical time as physical clocks. Therefore, we have the simultaneous events of the observation measured in both relativistic time and physical time in the frame of (x, y, z, t): (Candle1, x1, y1, H, t), (candle2, x2, y2, H, t), …, (CandleN, xN, yN, H, t). When these events are observed on anther horizontally moving inertial reference frame (x’, y’, z’, t’), according to special relativity, these events in the reference frame of (x’, y’, z’, t’) can be obtained through Lorentz Transformation: (Candle1, x1′, y1′, H, t1′), (Candle2, x2′, y2′, H, t2′), … , (CandleN, xN’, yN’, H, tN’) where t1′, t2′, …, and tN’ are relativistic times of the events in the frame of (x’, y’, z’, t’). It is seen that these events have different relativistic times after Lorentz Transformation in the frame of (x’, y’, z’, t’), i.e., they are no longer simultaneous measured with relativistic time in the frame of (x’, y’, z’, t’), but the heights of the candles remain the same because the vertical heights here do not experience any Lorentz contraction. Since the heights of the candles are the measures of the physical time, we can see these events still have the same physical time, i.e., they are still simultaneous measured with the physical time. Therefore, the physical time is invariant of inertial reference frames, which is different from relativistic time. As relativistic time is no longer the physical time we measure with physical devices, the description of special relativity is irrelevant to the physical world.

    Now let’s have a look at the symmetric twin paradox. Two twins made separate space travels in the same velocity and acceleration relative to the earth all the time during their entire trips but in opposite directions. According to special relativity, each twin should find the other twin’s clock ticking more slowly than his own clock during the entire trip due to the relative velocity between them because acceleration did not have any effect on kinematic time dilation in special relativity. But when they came back to the earth, they found their clocks had exact the same time because of symmetry. Thus, there is a contradiction which has disproved special relativity. This thought experiment demonstrates that relativistic time is not our physical time and can never be materialized on physical clocks.

    Now let’s look at clocks on the GPS satellites which is thought as one of the strong evidences of Einstein’s relativity. Many physicists claim that clocks on the GPS satellites are corrected according to both special relativity and general relativity. This is not true because the corrections of the atomic clocks on the GPS satellites are absolute changes of the clocks, none of which is relative to a specific observer as claimed by special relativity. After all corrections, the clocks are synchronized not only relative to the ground clocks but also relative to each other, i.e., time is absolute and special relativity is wrong. This is a fact as shown on Wikipedia. But some people still argue that the clocks on the GPS satellites are only synchronized in the earth centered inertial reference frame, and are not synchronized in the reference frames of the GPS satellites. If it were true, then the time difference between a clock on a GPS satellite and a clock on the ground observed in the satellite reference frame would monotonically grow due to their relative velocity while the same clocks observed on the earth centered reference frame were still synchronized. If you corrected the clock on the satellite when the difference became significant, the correction would break the synchronization of the clocks observed in the earth centered frame. That is, there is no way to make such a correction without breaking the synchronization of the clocks observed in the earth centered frame. Therefore, it is wrong to think that the clocks are not synchronized in the satellite frame.

    Hefele-Keating experiment is also considered as another evidence of relativistic effects. It is clear that all the differences of the clocks after flights in Hefele-Keating experiment were absolute (i.e., they were the same no matter whether you observe them on the earth, on the moon or on the space station). But according to relativity, if the clocks were observed on the earth, the two clocks after flights had experienced the equivalent paths of same velocity and same distance in same elevation, and thus should generate the same kinematic time dilation and the same gravitational time dilation, directly contradicting the experimental result. Therefore, the differences of the clocks were nothing to do with the velocities relative to each other or relative to the earth as claimed by relativists, but were the result of the velocities relative to one medium which seems fully dragged by the earth on its surface but partially dragged on the altitude of the airplanes. It is wrong to interpret the differences of the displayed times of the clocks as the results of relativistic effects.

    Experiments show that electrons will emit photons when they are “moving”, but “moving” is relative. All electrons on the earth can be considered “moving” when you observe them on a rocket. Why in a rocket frame don’t you see the electrons emit photons? This clearly points out that it is not the velocity relative to the observer to make an electron emit photons, but it is the velocity relative to “something” to make electrons emit photons. This “something” is aether, the existence of which has been proved in the above paper. Photons are waves of aether which is a compressible viscous fluid filling up the entire visible part of the universe, though its viscosity is very very small. It is the velocity relative to aether that makes an electron emit photons when it moves relative to aether just like a boat on the water which generates waves only when it moves relative to the water.

    The increase of the lives of muons in a circular accelerator or going through the atmosphere are also absolute changes which are the same observed in all reference frames. Actually, all so-called proofs of relativistic effects are just misinterpretations of experiments and observations without exception, and all what relativity describes is irrelevant to physical phenomena, including the speed of light which in special relativity is constant in all inertial reference frames, but which in real physical world still follows Newton’s velocity addition formula (see the paper). That is, time is absolute and space is 3D Euclidean. There is nothing called spacetime continuum in nature, not to mention the ripples of spacetime.

  3. Dileep-Sathe

    I agree with Xinhang Shen, STC is still an enigma after 100 years of discussion. Have we understood Einstein’s STC (Space-Time continuum) completely? This question is pinching my mind ever since I saw the hot debate between a common man and a leader of GR in an international conference in Borivali, Mumbai, MH , India in January 2005 and because, in my opinion, that leader failed in giving a convincing answer to the audience. Read the narration, made by me, in Physics World, 30 November 2015. Actually a quick look at the history of debates on STC, starting from the days of Henri Poincare, Philipp Lenard, Albert Einstein and even the great artiste Charlie Chaplin, one can conclude that our understanding of STC is far from perfect. In 2016, James Owen Weatherall wrote a book, title: Void: the Strange Physics of Nothing (Yale University Press). So a common man’s question can be, How Nothing can have physics, that too strange physics?
    As our understanding of the STC is far from perfect, How can a Common Man / Head of a Funding Agency can believe in the claim that gravitational waves caused ripples on STC or in other words NOTHING? Hence I still believe that discovery of gravitational waves is still based on a shaky footing.

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