The influence of gravitational waves. Einstein was right: gravitational waves exist. Theory in simple terms

Just a few hours ago, news arrived that had been long awaited in the scientific world. A group of scientists from several countries working as part of the international LIGO Scientific Collaboration project say that using several detector observatories they were able to detect gravitational waves in laboratory conditions.

They are analyzing data coming from two laser interferometer gravitational-wave observatories (Laser Interferometer Gravitational-Wave Observatory - LIGO), located in the states of Louisiana and Washington in the United States.

As stated at the LIGO project press conference, gravitational waves were detected on September 14, 2015, first at one observatory, and then 7 milliseconds later at another.

Based on the analysis of the data obtained, which was carried out by scientists from many countries, including Russia, it was found that the gravitational wave was caused by the collision of two black holes with a mass of 29 and 36 times the mass of the Sun. After that, they merged into one large black hole.

This happened 1.3 billion years ago. The signal came to Earth from the direction of the Magellanic Cloud constellation.

Sergei Popov (astrophysicist at the Sternberg State Astronomical Institute of Moscow State University) explained what gravitational waves are and why it is so important to measure them.

Modern theories of gravity are geometric theories of gravity, more or less everything from the theory of relativity. The geometric properties of space affect the movement of bodies or objects such as a light beam. And vice versa - the distribution of energy (this is the same as mass in space) affects the geometric properties of space. This is very cool, because it’s easy to visualize - this whole elastic plane lined in a box has some physical meaning, although, of course, it’s not all so literal.

Physicists use the word "metric". A metric is something that describes the geometric properties of space. And here we have bodies moving with acceleration. The simplest thing is to rotate the cucumber. It is important that it is not, for example, a ball or a flattened disk. It is easy to imagine that when such a cucumber spins on an elastic plane, ripples will run from it. Imagine that you are standing somewhere, and a cucumber turns one end towards you, then the other. It affects space and time in different ways, a gravitational wave runs.

So, a gravitational wave is a ripple running along the space-time metric.

Beads in space

This is a fundamental property of our basic understanding of how gravity works, and people have been wanting to test it for a hundred years. They want to make sure that there is an effect and that it is visible in the laboratory. This was seen in nature about three decades ago. How should gravitational waves manifest themselves in everyday life?

The easiest way to illustrate this is this: if you throw beads in space so that they lie in a circle, and when a gravitational wave passes perpendicular to their plane, they will begin to turn into an ellipse, compressed first in one direction, then in the other. The point is that the space around them will be disturbed, and they will feel it.

"G" on Earth

People do something like this, only not in space, but on Earth.

Mirrors in the shape of the letter “g” [referring to the American LIGO observatories] hang at a distance of four kilometers from each other.

Laser beams are running - this is an interferometer, a well-understood thing. Modern technologies make it possible to measure fantastically small effects. It’s still not that I don’t believe it, I believe it, but I just can’t wrap my head around it - the displacement of mirrors hanging at a distance of four kilometers from each other is less than the size of an atomic nucleus. This is small even compared to the wavelength of this laser. This was the catch: gravity is the weakest interaction, and therefore the displacements are very small.

It took a very long time, people have been trying to do this since the 1970s, they have spent their lives searching for gravitational waves. And now only technical capabilities make it possible to register a gravitational wave in laboratory conditions, that is, it came here and the mirrors shifted.

Direction

Within a year, if everything goes well, there will already be three detectors operating in the world. Three detectors are very important, because these things are very bad at determining the direction of the signal. In much the same way as we are bad at determining the direction of a source by ear. “A sound from somewhere on the right” - these detectors sense something like this. But if three people stand at a distance from each other, and one hears a sound from the right, another from the left, and the third from behind, then we can very accurately determine the direction of the sound. The more detectors there are, the more they are scattered around the globe, the more accurately we will be able to determine the direction to the source, and then astronomy will begin.

After all, the ultimate goal is not only to confirm the general theory of relativity, but also to obtain new astronomical knowledge. Just imagine that there is a black hole weighing ten solar masses. And it collides with another black hole weighing ten solar masses. The collision occurs at the speed of light. Energy breakthrough. This is true. There is a fantastic amount of it. And there’s no way... It’s just ripples of space and time. I would say that detecting the merger of two black holes will be the strongest evidence for a long time that black holes are more or less the black holes we think they are.

Let's go through the issues and phenomena that it could reveal.

Do black holes really exist?

The signal expected from the LIGO announcement may have been produced by two merging black holes. Such events are the most energetic ones known; the strength of the gravitational waves emitted by them can briefly outshine all the stars in the observable universe combined. Merging black holes are also quite easy to interpret from their very pure gravitational waves.

A black hole merger occurs when two black holes spiral around each other, emitting energy in the form of gravitational waves. These waves have a characteristic sound (chirp) that can be used to measure the mass of these two objects. After this, black holes usually merge.

“Imagine two soap bubbles that come so close that they form one bubble. The larger bubble is deformed,” says Tybalt Damour, a gravitational theorist at the Institute of Advanced Scientific Research near Paris. The final black hole will be perfectly spherical, but must first emit predictable types of gravitational waves.

One of the most important scientific consequences of detecting a black hole merger will be the confirmation of the existence of black holes - at least perfectly round objects consisting of pure, empty, curved space-time, as predicted by general relativity. Another consequence is that the merger is proceeding as scientists predicted. Astronomers have a lot of indirect evidence of this phenomenon, but so far these have been observations of stars and superheated gas in the orbit of black holes, and not the black holes themselves.

“The scientific community, including myself, doesn’t like black holes. We take them for granted, says France Pretorius, a general relativity simulation specialist at Princeton University in New Jersey. “But when we think about how amazing this prediction is, we need some truly amazing proof.”

Do gravitational waves travel at the speed of light?

When scientists start comparing LIGO observations with those from other telescopes, the first thing they check is whether the signal arrived at the same time. Physicists believe that gravity is transmitted by graviton particles, the gravitational analogue of photons. If, like photons, these particles have no mass, then gravitational waves will travel at the speed of light, matching the prediction of the speed of gravitational waves in classical relativity. (Their speed may be affected by the accelerating expansion of the Universe, but this should be evident at distances significantly greater than those covered by LIGO).

It is quite possible, however, that gravitons have a small mass, which means that gravitational waves will move at a speed less than light. So, for example, if LIGO and Virgo detect gravitational waves and find that the waves arrived on Earth after cosmic event-related gamma rays, this could have life-changing consequences for fundamental physics.

Is space-time made of cosmic strings?

An even stranger discovery could occur if bursts of gravitational waves are found emanating from “cosmic strings.” These hypothetical defects in the curvature of spacetime, which may or may not be related to string theories, should be infinitely thin, but stretched to cosmic distances. Scientists predict that cosmic strings, if they exist, may accidentally bend; if the string were to bend, it would cause a gravitational surge that detectors like LIGO or Virgo could measure.

Can neutron stars be lumpy?

Neutron stars are the remains of large stars that collapsed under their own weight and became so dense that electrons and protons began to fuse into neutrons. Scientists have little understanding of the physics of neutron holes, but gravitational waves could tell us a lot about them. For example, the intense gravity on their surface causes neutron stars to become almost perfectly spherical. But some scientists have suggested that there may also be "mountains" - a few millimeters high - that make these dense objects, no more than 10 kilometers in diameter, slightly asymmetrical. Neutron stars typically spin very quickly, so the asymmetric distribution of mass will warp spacetime and produce a persistent gravitational wave signal in the shape of a sine wave, slowing the star's rotation and emitting energy.

Pairs of neutron stars that orbit each other also produce a constant signal. Like black holes, these stars move in a spiral and eventually merge with a characteristic sound. But its specificity differs from the specificity of the sound of black holes.

Why do stars explode?

Black holes and neutron stars form when massive stars stop shining and collapse in on themselves. Astrophysicists think this process underlies all common types of Type II supernova explosions. Simulations of such supernovae have not yet shown what causes them to ignite, but listening to the gravitational wave bursts emitted by a real supernova is thought to provide an answer. Depending on what the burst waves look like, how loud they are, how often they occur, and how they correlate with the supernovae being tracked by electromagnetic telescopes, this data could help rule out a bunch of existing models.

How fast is the Universe expanding?

The expansion of the Universe means that distant objects that move away from our galaxy appear redder than they really are because the light they emit is stretched as they move. Cosmologists estimate the rate of expansion of the Universe by comparing the redshift of galaxies with how far away they are from us. But this distance is usually estimated from the brightness of Type Ia supernovae, and this technique leaves a lot of uncertainties.

If several gravitational wave detectors around the world detect signals from the merger of the same neutron stars, together they can absolutely accurately estimate the volume of the signal, and therefore the distance at which the merger occurred. They will also be able to estimate the direction, and with it, identify the galaxy in which the event occurred. By comparing the redshift of this galaxy with the distance to the merging stars, it is possible to obtain an independent rate of cosmic expansion, perhaps more accurate than current methods allow.

Gravitational waves - artist's rendering

Gravitational waves are disturbances of the space-time metric that break away from the source and propagate like waves (the so-called “space-time ripples”).

In general relativity and in most other modern theories of gravity, gravitational waves are generated by the motion of massive bodies with variable acceleration. Gravitational waves propagate freely in space at the speed of light. Due to the relative weakness of gravitational forces (compared to others), these waves have a very small magnitude, which is difficult to register.

Polarized gravitational wave

Gravitational waves are predicted by the general theory of relativity (GR), and many others. They were first directly detected in September 2015 by two twin detectors, which detected gravitational waves likely resulting from the merger of two to form a single, more massive, rotating black hole. Indirect evidence of their existence has been known since the 1970s - General Relativity predicts the rate of convergence of close systems due to the loss of energy due to the emission of gravitational waves, which coincides with observations. Direct registration of gravitational waves and their use to determine the parameters of astrophysical processes is an important task of modern physics and astronomy.

Within the framework of general relativity, gravitational waves are described by solutions of wave-type Einstein equations, which represent a perturbation of the space-time metric moving at the speed of light (in the linear approximation). The manifestation of this disturbance should be, in particular, a periodic change in the distance between two freely falling (that is, not influenced by any forces) test masses. Amplitude h gravitational wave is a dimensionless quantity - a relative change in distance. The predicted maximum amplitudes of gravitational waves from astrophysical objects (for example, compact binary systems) and phenomena (explosions, mergers, captures by black holes, etc.) when measured are very small ( h=10 −18 -10 −23). A weak (linear) gravitational wave, according to the general theory of relativity, transfers energy and momentum, moves at the speed of light, is transverse, quadrupole and is described by two independent components located at an angle of 45° to each other (has two directions of polarization).

Different theories predict the speed of propagation of gravitational waves differently. In general relativity, it is equal to the speed of light (in the linear approximation). In other theories of gravity, it can take any value, including infinity. According to the first registration of gravitational waves, their dispersion turned out to be compatible with a massless graviton, and the speed was estimated to be equal to the speed of light.

Generation of gravitational waves

A system of two neutron stars creates ripples in spacetime

A gravitational wave is emitted by any matter moving with asymmetric acceleration. For a wave of significant amplitude to occur, an extremely large mass of the emitter and/or enormous accelerations are required; the amplitude of the gravitational wave is directly proportional first derivative of acceleration and the mass of the generator, that is ~ . However, if an object is moving at an accelerated rate, this means that some force is acting on it from another object. In turn, this other object experiences the opposite effect (according to Newton’s 3rd law), and it turns out that m 1 a 1 = − m 2 a 2 . It turns out that two objects emit gravitational waves only in pairs, and as a result of interference they are mutually canceled out almost completely. Therefore, gravitational radiation in the general theory of relativity always has the multipole character of at least quadrupole radiation. In addition, for non-relativistic emitters in the expression for the radiation intensity there is a small parameter where is the gravitational radius of the emitter, r- its characteristic size, T- characteristic period of movement, c- speed of light in vacuum.

The strongest sources of gravitational waves are:

• colliding (giant masses, very small accelerations),
• gravitational collapse of a binary system of compact objects (colossal accelerations with a fairly large mass). As a special and most interesting case - the merger of neutron stars. In such a system, the gravitational-wave luminosity is close to the maximum Planck luminosity possible in nature.

Gravitational waves emitted by a two-body system

Two bodies moving in circular orbits around a common center of mass

Two gravitationally bound bodies with masses m 1 and m 2, moving non-relativistically ( v << c) in circular orbits around their common center of mass at a distance r from each other, emit gravitational waves of the following energy, on average over the period:

As a result, the system loses energy, which leads to the convergence of bodies, that is, to a decrease in the distance between them. Speed ​​of approach of bodies:

For the Solar System, for example, the greatest gravitational radiation is produced by the subsystem and. The power of this radiation is approximately 5 kilowatts. Thus, the energy lost by the Solar System to gravitational radiation per year is completely negligible compared to the characteristic kinetic energy of bodies.

Gravitational collapse of a binary system

Any double star, when its components rotate around a common center of mass, loses energy (as assumed - due to the emission of gravitational waves) and, in the end, merges together. But for ordinary, non-compact, double stars, this process takes a very long time, much longer than the present age. If a compact binary system consists of a pair of neutron stars, black holes, or a combination of both, then the merger can occur within several million years. First, the objects come closer together, and their period of revolution decreases. Then, at the final stage, a collision and asymmetric gravitational collapse occurs. This process lasts a fraction of a second, and during this time energy is lost into gravitational radiation, which, according to some estimates, amounts to more than 50% of the mass of the system.

Basic exact solutions of Einstein's equations for gravitational waves

Bondi-Pirani-Robinson body waves

These waves are described by a metric of the form . If we introduce a variable and a function, then from the general relativity equations we obtain the equation

Takeno Metric

has the form , -functions satisfy the same equation.

Rosen metric

Where to satisfy

Perez metric

Wherein

Cylindrical Einstein-Rosen waves

In cylindrical coordinates, such waves have the form and are executed

Registration of gravitational waves

Registration of gravitational waves is quite difficult due to the weakness of the latter (small distortion of the metric). The devices for registering them are gravitational wave detectors. Attempts to detect gravitational waves have been made since the late 1960s. Gravitational waves of detectable amplitude are born during the collapse of a binary. Similar events occur in the surrounding area approximately once a decade.

On the other hand, the general theory of relativity predicts the acceleration of the mutual rotation of binary stars due to the loss of energy due to the emission of gravitational waves, and this effect is reliably recorded in several known systems of binary compact objects (in particular, pulsars with compact companions). In 1993, “for the discovery of a new type of pulsar, which provided new opportunities in the study of gravity” to the discoverers of the first double pulsar PSR B1913+16, Russell Hulse and Joseph Taylor Jr. was awarded the Nobel Prize in Physics. The acceleration of rotation observed in this system completely coincides with the predictions of general relativity for the emission of gravitational waves. The same phenomenon was recorded in several other cases: for the pulsars PSR J0737-3039, PSR J0437-4715, SDSS J065133.338+284423.37 (usually abbreviated J0651) and the system of binary RX J0806. For example, the distance between the two components A and B of the first binary star of the two pulsars PSR J0737-3039 decreases by about 2.5 inches (6.35 cm) per day due to energy loss to gravitational waves, and this occurs in agreement with general relativity . All these data are interpreted as indirect confirmation of the existence of gravitational waves.

According to estimates, the strongest and most frequent sources of gravitational waves for gravitational telescopes and antennas are catastrophes associated with the collapse of binary systems in nearby galaxies. It is expected that in the near future several similar events per year will be recorded on improved gravitational detectors, distorting the metric in the vicinity by 10 −21 -10 −23 . The first observations of an optical-metric parametric resonance signal, which makes it possible to detect the effect of gravitational waves from periodic sources such as a close binary on the radiation of cosmic masers, may have been obtained at the radio astronomical observatory of the Russian Academy of Sciences, Pushchino.

Another possibility of detecting the background of gravitational waves filling the Universe is high-precision timing of distant pulsars - analysis of the arrival time of their pulses, which characteristically changes under the influence of gravitational waves passing through the space between the Earth and the pulsar. Estimates for 2013 indicate that timing accuracy needs to be improved by approximately one order of magnitude to detect background waves from multiple sources in our Universe, a task that could be accomplished before the end of the decade.

According to modern concepts, our Universe is filled with relic gravitational waves that appeared in the first moments after. Their registration will make it possible to obtain information about the processes at the beginning of the birth of the Universe. On March 17, 2014 at 20:00 Moscow time at the Harvard-Smithsonian Center for Astrophysics, an American group of researchers working on the BICEP 2 project announced the detection of non-zero tensor disturbances in the early Universe by the polarization of the cosmic microwave background radiation, which is also the discovery of these relict gravitational waves . However, almost immediately this result was disputed, since, as it turned out, the contribution was not properly taken into account. One of the authors, J. M. Kovats ( Kovac J.M.), admitted that “the participants and science journalists were a bit hasty in interpreting and reporting the data from the BICEP2 experiment.”

Experimental confirmation of the existence

The first recorded gravitational wave signal. On the left is data from the detector in Hanford (H1), on the right - in Livingston (L1). Time is counted from September 14, 2015, 09:50:45 UTC. To visualize the signal, it is filtered with a frequency filter with a passband of 35-350 Hertz to suppress large fluctuations outside the high sensitivity range of the detectors; band-stop filters were also used to suppress the noise of the installations themselves. Top row: voltages h in the detectors. GW150914 first arrived at L1 and 6 9 +0 5 −0 4 ms later to H1; For visual comparison, data from H1 are shown in the L1 plot in reversed and time-shifted form (to account for the relative orientation of the detectors). Second row: voltages h from the gravitational wave signal, passed through the same 35-350 Hz bandpass filter. The solid line is the result of numerical relativity for a system with parameters compatible with those found based on the study of the GW150914 signal, obtained by two independent codes with a resulting match of 99.9. The gray thick lines are the 90% confidence regions of the waveform reconstructed from the detector data by two different methods. The dark gray line models the expected signals from the merger of black holes, the light gray line does not use astrophysical models, but represents the signal as a linear combination of sinusoidal-Gaussian wavelets. The reconstructions overlap by 94%. Third row: Residual errors after extracting the filtered prediction of the numerical relativity signal from the filtered signal of the detectors. Bottom row: A representation of the voltage frequency map, showing the increase in the dominant frequency of the signal over time.

February 11, 2016 by the LIGO and VIRGO collaborations. A merger signal of two black holes with an amplitude at maximum of about 10 −21 was recorded on September 14, 2015 at 9:51 UTC by two LIGO detectors in Hanford and Livingston, 7 milliseconds apart, in the region of maximum signal amplitude (0.2 seconds) combined the signal-to-noise ratio was 24:1. The signal was designated GW150914. The shape of the signal matches the prediction of general relativity for the merger of two black holes with masses of 36 and 29 solar masses; the resulting black hole should have a mass of 62 solar and a rotation parameter a= 0.67. The distance to the source is about 1.3 billion, the energy emitted in tenths of a second in the merger is the equivalent of about 3 solar masses.

Story

The history of the term “gravitational wave” itself, the theoretical and experimental search for these waves, as well as their use for studying phenomena inaccessible to other methods.

• 1900 - Lorentz suggested that gravity “...can spread at a speed no greater than the speed of light”;
• 1905 - Poincaré first introduced the term gravitational wave (onde gravifique). Poincaré, on a qualitative level, removed the established objections of Laplace and showed that the corrections associated with gravitational waves to the generally accepted Newtonian laws of gravity of order cancel, thus the assumption of the existence of gravitational waves does not contradict observations;
• 1916 - Einstein showed that, within the framework of general relativity, a mechanical system will transfer energy to gravitational waves and, roughly speaking, any rotation relative to fixed stars must sooner or later stop, although, of course, under normal conditions, energy losses of the order of magnitude are negligible and practically not measurable (in In this work, he also mistakenly believed that a mechanical system that constantly maintains spherical symmetry can emit gravitational waves);
• 1918 - Einstein derived a quadrupole formula in which the emission of gravitational waves turns out to be an effect of order , thereby correcting the error in his previous work (an error remained in the coefficient, the wave energy is 2 times less);
• 1923 - Eddington - questioned the physical reality of gravitational waves "...propagating...at the speed of thought." In 1934, when preparing the Russian translation of his monograph “The Theory of Relativity,” Eddington added several chapters, including chapters with two options for calculating energy losses by a rotating rod, but noted that the methods used for approximate calculations of general relativity, in his opinion, are not applicable to gravitationally bound systems , so doubts remain;
• 1937 - Einstein, together with Rosen, investigated cylindrical wave solutions to the exact equations of the gravitational field. During the course of these studies, they began to doubt that gravitational waves may be an artifact of approximate solutions of the general relativity equations (correspondence regarding a review of the article “Do gravitational waves exist?” by Einstein and Rosen is known). Later, he found an error in his reasoning; the final version of the article with fundamental changes was published in the Journal of the Franklin Institute;
• 1957 - Herman Bondi and Richard Feynman proposed the “beaded cane” thought experiment in which they substantiated the existence of physical consequences of gravitational waves in general relativity;
• 1962 - Vladislav Pustovoit and Mikhail Herzenstein described the principles of using interferometers to detect long-wave gravitational waves;
• 1964 - Philip Peters and John Matthew theoretically described gravitational waves emitted by binary systems;
• 1969 - Joseph Weber, founder of gravitational wave astronomy, reports the detection of gravitational waves using a resonant detector - a mechanical gravitational antenna. These reports give rise to a rapid growth of work in this direction, in particular, Rainier Weiss, one of the founders of the LIGO project, began experiments at that time. To date (2015), no one has been able to obtain reliable confirmation of these events;
• 1978 - Joseph Taylor reported the detection of gravitational radiation in the binary pulsar system PSR B1913+16. Joseph Taylor and Russell Hulse's research earned them the 1993 Nobel Prize in Physics. As of early 2015, three post-Keplerian parameters, including period reduction due to gravitational wave emission, had been measured for at least 8 such systems;
• 2002 - Sergey Kopeikin and Edward Fomalont used ultra-long-baseline radio wave interferometry to measure the deflection of light in the gravitational field of Jupiter in dynamics, which for a certain class of hypothetical extensions of general relativity makes it possible to estimate the speed of gravity - the difference from the speed of light should not exceed 20% (this interpretation does not generally accepted);
• 2006 - the international team of Martha Bourgay (Parkes Observatory, Australia) reported significantly more accurate confirmation of general relativity and its correspondence to the magnitude of gravitational wave radiation in the system of two pulsars PSR J0737-3039A/B;
• 2014 - Astronomers at the Harvard-Smithsonian Center for Astrophysics (BICEP) reported the detection of primordial gravitational waves while measuring fluctuations in the cosmic microwave background radiation. At the moment (2016), the detected fluctuations are considered not to be of relict origin, but are explained by the emission of dust in the Galaxy;
• 2016 - international LIGO team reported the detection of the gravitational wave transit event GW150914. For the first time, direct observation of interacting massive bodies in ultra-strong gravitational fields with ultra-high relative velocities (< 1,2 × R s , v/c >0.5), which made it possible to verify the correctness of general relativity with an accuracy of several post-Newtonian terms of high orders. The measured dispersion of gravitational waves does not contradict previously made measurements of the dispersion and upper bound on the mass of a hypothetical graviton (< 1,2 × 10 −22 эВ), если он в некотором гипотетическом расширении ОТО будет существовать.

Gravitational waves, theoretically predicted by Einstein back in 1917, are still awaiting their discoverer.

At the end of 1969, University of Maryland physics professor Joseph Weber made a sensational statement. He announced that he had discovered gravitational waves coming to Earth from the depths of space. Until that time, no scientist had made such claims, and the very possibility of detecting such waves was considered far from obvious. However, Weber was known as an authority in his field, and therefore his colleagues took his message very seriously.

However, disappointment soon set in. The amplitudes of the waves allegedly recorded by Weber were millions of times higher than the theoretical value. Weber argued that these waves came from the center of our Galaxy, obscured by dust clouds, about which little was then known. Astrophysicists have suggested that a gigantic black hole is hiding there, which annually devours thousands of stars and throws out part of the absorbed energy in the form of gravitational radiation, and astronomers began a futile search for more obvious traces of this cosmic cannibalism (it has now been proven that there really is a black hole there, but it leads behave quite decently). Physicists from the USA, USSR, France, Germany, England and Italy began experiments on detectors of the same type - and achieved nothing.

Scientists still don’t know what to attribute the strange readings from Weber’s instruments. However, his efforts were not in vain, although gravitational waves have still not been detected. Several installations to search for them have already been built or are being built, and in ten years such detectors will be launched into space. It is quite possible that in the not too distant future, gravitational radiation will become as observable a physical reality as electromagnetic oscillations. Unfortunately, Joseph Weber will no longer know this - he died in September 2000.

What are gravitational waves

It is often said that gravitational waves are disturbances of the gravitational field propagating in space. This definition is correct, but incomplete. According to the general theory of relativity, gravity arises due to the curvature of the space-time continuum. Gravity waves are fluctuations of the space-time metric, which manifest themselves as fluctuations in the gravitational field, so they are often figuratively called space-time ripples. Gravitational waves were theoretically predicted in 1917 by Albert Einstein. No one doubts their existence, but gravitational waves are still waiting for their discoverer.

The source of gravitational waves is any movement of material bodies that leads to a non-uniform change in the force of gravity in the surrounding space. A body moving at a constant speed does not radiate anything, since the nature of its gravitational field does not change. To emit gravitational waves, accelerations are necessary, but not just any acceleration. A cylinder that rotates around its axis of symmetry experiences acceleration, but its gravitational field remains uniform and gravitational waves do not arise. But if you spin this cylinder around a different axis, the field will begin to oscillate, and gravitational waves will run from the cylinder in all directions.

This conclusion applies to any body (or system of bodies) that is asymmetrical about the axis of rotation (in such cases the body is said to have a quadrupole moment). A mass system whose quadrupole moment changes with time always emits gravitational waves.

Basic properties of gravitational waves

Astrophysicists suggest that it is the radiation of gravitational waves, taking away energy, that limits the speed of rotation of a massive pulsar when absorbing matter from a neighboring star.

Gravity beacons of space

Gravitational radiation from terrestrial sources is extremely weak. A steel column weighing 10,000 tons, suspended from the center in a horizontal plane and spun around a vertical axis up to 600 rpm, emits a power of approximately 10 -24 W. Therefore, the only hope of detecting gravitational waves is to find a cosmic source of gravitational radiation.

In this regard, close double stars are very promising. The reason is simple: the power of gravitational radiation of such a system grows in inverse proportion to the fifth power of its diameter. It is even better if the trajectories of the stars are very elongated, since this increases the rate of change of the quadrupole moment. It is quite good if the binary system consists of neutron stars or black holes. Such systems are similar to gravitational beacons in space - their radiation is periodic.

There are also “pulse” sources in space that generate short but extremely powerful gravitational bursts. This happens when a massive star collapses before a supernova explosion. However, the star's deformation must be asymmetric, otherwise the radiation will not occur. During collapse, gravitational waves can carry away up to 10% of the total energy of the star! The power of gravitational radiation in this case is about 10 50 W. Even more energy is released during the merger of neutron stars, here the peak power reaches 10 52 W. An excellent source of radiation is the collision of black holes: their masses can exceed the masses of neutron stars by billions of times.

Another source of gravitational waves is cosmological inflation. Immediately after the Big Bang, the Universe began to expand extremely quickly, and in less than 10 -34 seconds its diameter increased from 10 -33 cm to its macroscopic size. This process immeasurably strengthened the gravitational waves that existed before it began, and their descendants persist to this day.

Indirect confirmations

The first evidence of the existence of gravitational waves comes from the work of American radio astronomer Joseph Taylor and his student Russell Hulse. In 1974, they discovered a pair of neutron stars orbiting each other (a radio-emitting pulsar with a silent companion). The pulsar rotated around its axis with a stable angular velocity (which is not always the case) and therefore served as an extremely accurate clock. This feature made it possible to measure the masses of both stars and determine the nature of their orbital motion. It turned out that the orbital period of this binary system (about 3 hours 45 minutes) is reduced by 70 μs annually. This value agrees well with the solutions of the equations of the general theory of relativity, which describe the loss of energy of a stellar pair due to gravitational radiation (however, the collision of these stars will not happen soon, after 300 million years). In 1993, Taylor and Hulse were awarded the Nobel Prize for this discovery.

Gravity wave antennas

How to detect gravitational waves experimentally? Weber used meter-long solid aluminum cylinders with piezoelectric sensors at the ends as detectors. They were isolated with maximum care from external mechanical influences in a vacuum chamber. Weber installed two of these cylinders in a bunker under the University of Maryland golf course, and one at Argonne National Laboratory.

The idea of ​​the experiment is simple. Space is compressed and stretched under the influence of gravitational waves. Thanks to this, the cylinder vibrates in the longitudinal direction, acting as a gravitational wave antenna, and piezoelectric crystals convert the vibrations into electrical signals. Any passage of cosmic gravitational waves almost simultaneously affects detectors separated by a thousand kilometers, which makes it possible to filter gravitational impulses from various types of noise.

Weber's sensors were able to detect displacements of the ends of the cylinder equal to only 10 -15 of its length - in this case 10 -13 cm. It was precisely such fluctuations that Weber was able to detect, which he first reported in 1959 on the pages Physical Review Letters. All attempts to repeat these results have been futile. Weber's data also contradicts the theory, which practically does not allow us to expect relative displacements above 10 -18 (and values ​​​​less than 10 -20 are much more likely). It is possible that Weber made a mistake when statistically processing the results. The first attempt to experimentally detect gravitational radiation ended in failure.

Subsequently, gravitational wave antennas were significantly improved. In 1967, American physicist Bill Fairbank proposed cooling them in liquid helium. This not only made it possible to get rid of most of the thermal noise, but also opened up the possibility of using SQUIDs (superconducting quantum interferometers), the most accurate ultra-sensitive magnetometers. The implementation of this idea turned out to be fraught with many technical difficulties, and Fairbank himself did not live to see it. By the early 1980s, physicists from Stanford University had built an installation with a sensitivity of 10 -18, but no waves were detected. Now in a number of countries there are ultra-cryogenic vibration detectors of gravitational waves operating at temperatures only tenths and hundredths of a degree above absolute zero. This is, for example, the AURIGA installation in Padua. The antenna for it is a three-meter cylinder made of aluminum-magnesium alloy, the diameter of which is 60 cm and the weight is 2.3 tons. It is suspended in a vacuum chamber cooled to 0.1 K. Its shocks (with a frequency of about 1000 Hz) are transmitted to an auxiliary resonator weighing 1 kg, which vibrates with the same frequency, but with a much larger amplitude. These vibrations are recorded by measuring equipment and analyzed using a computer. The sensitivity of the AURIGA complex is about 10 -20 -10 -21.

Interferometers

Another method for detecting gravitational waves is based on the abandonment of massive resonators in favor of light rays. It was first proposed by Soviet physicists Mikhail Herzenstein and Vladislav Pustovoit in 1962, and two years later by Weber. In the early 1970s, an employee of the corporation's research laboratory Hughes Aircraft Robert Forward (a former Weber graduate student, later a very famous science fiction writer) built the first such detector with quite decent sensitivity. At the same time, Massachusetts Institute of Technology (MIT) professor Rainer Weiss performed a very deep theoretical analysis of the possibilities of recording gravitational waves using optical methods.

These methods involve the use of analogues of the device with which 125 years ago physicist Albert Michelson proved that the speed of light is strictly the same in all directions. In this installation, a Michelson interferometer, a beam of light hits a translucent plate and is divided into two mutually perpendicular beams, which are reflected from mirrors located at the same distance from the plate. Then the beams merge again and fall on the screen, where an interference pattern appears (light and dark stripes and lines). If the speed of light depends on its direction, then when the entire installation is rotated, this picture should change; if not, it should remain the same as before.

The gravitational wave interference detector works in a similar way. A passing wave deforms space and changes the length of each arm of the interferometer (the path along which light travels from the splitter to the mirror), stretching one arm and compressing the other. The interference pattern changes, and this can be registered. But this is not easy: if the expected relative change in the length of the arms of the interferometer is 10 -20, then with a tabletop size of the device (like Michelson's) it results in oscillations with an amplitude of the order of 10 -18 cm. For comparison: visible light waves are 10 trillion times longer! You can increase the length of the shoulders to several kilometers, but problems will still remain. The laser light source must be both powerful and stable in frequency, the mirrors must be perfectly flat and perfectly reflective, the vacuum in the pipes through which the light travels must be as deep as possible, and the mechanical stabilization of the entire system must be truly perfect. In short, a gravitational wave interference detector is an expensive and bulky device.

Today the largest installation of this kind is the American LIGO complex (Light Interferometer Gravitational Waves Observatory). It consists of two observatories, one of which is located on the Pacific coast of the United States, and the other near the Gulf of Mexico. Measurements are made using three interferometers (two in Washington state, one in Louisiana) with four-kilometer-long arms. The installation is equipped with mirror light accumulators, which increase its sensitivity. “Since November 2005, all three of our interferometers have been operating normally,” LIGO complex representative Peter Solson, a professor of physics at Syracuse University, told Popular Mechanics. - We constantly exchange data with other observatories trying to detect gravitational waves with a frequency of tens and hundreds of hertz, which arose during the most powerful supernova explosions and mergers of neutron stars and black holes. The German interferometer GEO 600 (arm length - 600 m), located 25 km from Hannover, is now in operation. The 300-meter Japanese TAMA instrument is currently being upgraded. The three-kilometer Virgo detector near Pisa will join the effort in early 2007, and at frequencies below 50 Hz it will be able to surpass LIGO. Installations with ultracryogenic resonators operate with increasing efficiency, although their sensitivity is still somewhat less than ours.”

Prospects

What does the near future hold for gravitational wave detection methods? Professor Rainer Weiss told Popular Mechanics about this: “In a few years, more powerful lasers and more advanced detectors will be installed in the observatories of the LIGO complex, which will lead to a 15-fold increase in sensitivity. Now it is 10 -21 (at frequencies of about 100 Hz), and after modernization it will exceed 10 -22. The upgraded complex, Advanced LIGO, will increase the depth of penetration into space by 15 times. Moscow State University professor Vladimir Braginsky, one of the pioneers in the study of gravitational waves, is actively involved in this project.

The launch of the LISA space interferometer is planned for the middle of the next decade ( Laser Interferometer Space Antenna) with an arm length of 5 million kilometers, it is a joint project of NASA and the European Space Agency. The sensitivity of this observatory will be hundreds of times higher than the capabilities of ground-based instruments. It is primarily designed to search for low-frequency (10 -4 -10 -1 Hz) gravitational waves, which cannot be detected on the Earth's surface due to atmospheric and seismic interference. Such waves are emitted by double star systems, quite typical inhabitants of the Cosmos. LISA will also be able to detect gravitational waves generated when ordinary stars are absorbed by black holes. But to detect relict gravitational waves that carry information about the state of matter in the first moments after the Big Bang, more advanced space instruments will most likely be required. Such an installation Big Bang Observer, is currently being discussed, but it is unlikely that it will be created and launched earlier than in 30-40 years.”

Valentin Nikolaevich Rudenko shares the story of his visit to the city of Cascina (Italy), where he spent a week on the then just built “gravitational antenna” - the Michelson optical interferometer. On the way to the destination, the taxi driver asks why the installation was built. “People here think it’s for talking to God,” the driver admits.

– What are gravitational waves?

– A gravitational wave is one of the “carriers of astrophysical information.” There are visible channels of astrophysical information; telescopes play a special role in “distant vision”. Astronomers have also mastered low-frequency channels - microwave and infrared, and high-frequency channels - X-ray and gamma. In addition to electromagnetic radiation, we can detect streams of particles from Space. For this purpose, neutrino telescopes are used - large-sized detectors of cosmic neutrinos - particles that weakly interact with matter and are therefore difficult to register. Almost all theoretically predicted and laboratory-studied types of “carriers of astrophysical information” have been reliably mastered in practice. The exception was gravity - the weakest interaction in the microcosm and the most powerful force in the macrocosm.

Gravity is geometry. Gravitational waves are geometric waves, that is, waves that change the geometric characteristics of space when they pass through that space. Roughly speaking, these are waves that deform space. Strain is the relative change in the distance between two points. Gravitational radiation differs from all other types of radiation precisely in that it is geometric.

– Did Einstein predict gravitational waves?

– Formally, it is believed that gravitational waves were predicted by Einstein as one of the consequences of his general theory of relativity, but in fact their existence becomes obvious already in the special theory of relativity.

The theory of relativity suggests that due to gravitational attraction, gravitational collapse is possible, that is, the contraction of an object as a result of collapse, roughly speaking, to a point. Then the gravity is so strong that light cannot even escape from it, so such an object is figuratively called a black hole.

– What is the peculiarity of gravitational interaction?

A feature of gravitational interaction is the principle of equivalence. According to it, the dynamic response of a test body in a gravitational field does not depend on the mass of this body. Simply put, all bodies fall with the same acceleration.

Gravitational interaction is the weakest we know today.

– Who was the first to try to catch a gravitational wave?

– The gravitational wave experiment was first conducted by Joseph Weber from the University of Maryland (USA). He created a gravitational detector, which is now kept in the Smithsonian Museum in Washington. In 1968-1972, Joe Weber conducted a series of observations on a pair of spatially separated detectors, trying to isolate cases of "coincidences". The coincidence technique is borrowed from nuclear physics. The low statistical significance of the gravitational signals obtained by Weber caused a critical attitude towards the results of the experiment: there was no confidence that gravitational waves had been detected. Subsequently, scientists tried to increase the sensitivity of Weber-type detectors. It took 45 years to develop a detector whose sensitivity was adequate to the astrophysical forecast.

During the start of the experiment, many other experiments took place before fixation; impulses were recorded during this period, but their intensity was too low.

– Why was the signal fixation not announced immediately?

– Gravitational waves were recorded back in September 2015. But even if a coincidence was recorded, before announcing it, it is necessary to prove that it is not accidental. The signal taken from any antenna always contains noise bursts (short-term bursts), and one of them can accidentally occur simultaneously with a noise burst on another antenna. It is possible to prove that the coincidence did not occur by chance only with the help of statistical estimates.

– Why are discoveries in the field of gravitational waves so important?

– The ability to register the relict gravitational background and measure its characteristics, such as density, temperature, etc., allows us to approach the beginning of the universe.

What's attractive is that gravitational radiation is difficult to detect because it interacts very weakly with matter. But, thanks to this same property, it passes without absorption from the objects most distant from us with the most mysterious, from the point of view of matter, properties.

We can say that gravitational radiation passes without distortion. The most ambitious goal is to study the gravitational radiation that was separated from the primordial matter in the Big Bang Theory, which was created at the creation of the Universe.

– Does the discovery of gravitational waves rule out quantum theory?

The theory of gravity assumes the existence of gravitational collapse, that is, the contraction of massive objects to a point. At the same time, the quantum theory developed by the Copenhagen School suggests that, thanks to the uncertainty principle, it is impossible to simultaneously indicate exactly such parameters as the coordinate, speed and momentum of a body. There is an uncertainty principle here; it is impossible to determine the exact trajectory, because the trajectory is both a coordinate and a speed, etc. It is only possible to determine a certain conditional confidence corridor within the limits of this error, which is associated with the principles of uncertainty. Quantum theory categorically denies the possibility of point objects, but describes them in a statistically probabilistic manner: it does not specifically indicate coordinates, but indicates the probability that it has certain coordinates.

The question of unifying quantum theory and the theory of gravity is one of the fundamental questions of creating a unified field theory.

They continue to work on it now, and the words “quantum gravity” mean a completely advanced area of ​​science, the border of knowledge and ignorance, where all theorists in the world are now working.

– What can the discovery bring in the future?

Gravitational waves must inevitably form the foundation of modern science as one of the components of our knowledge. They play a significant role in the evolution of the Universe and with the help of these waves the Universe should be studied. The discovery contributes to the general development of science and culture.

If you decide to go beyond the scope of today's science, then it is permissible to imagine gravitational telecommunication lines, jet devices using gravitational radiation, gravitational-wave introscopy devices.

– Do gravitational waves have anything to do with extrasensory perception and telepathy?

Dont Have. The described effects are the effects of the quantum world, the effects of optics.

Interviewed by Anna Utkina

Yesterday, the world was shocked by a sensation: scientists finally discovered gravitational waves, the existence of which Einstein predicted a hundred years ago. This is a breakthrough. Distortion of space-time (these are gravitational waves - now we’ll explain what’s what) was discovered at the LIGO observatory, and one of its founders is - who do you think? - Kip Thorne, author of the book.

We tell you why the discovery of gravitational waves is so important, what Mark Zuckerberg said and, of course, share the story from the first person. Kip Thorne, like no one else, knows how the project works, what makes it unusual and what significance LIGO has for humanity. Yes, yes, everything is so serious.

Discovery of gravitational waves

The scientific world will forever remember the date February 11, 2016. On this day, participants in the LIGO project announced: after so many futile attempts, gravitational waves had been found. This is reality. In fact, they were discovered a little earlier: in September 2015, but yesterday the discovery was officially recognized. The Guardian believes that scientists will certainly receive the Nobel Prize in Physics.

The cause of gravitational waves is the collision of two black holes, which occurred already... a billion light years from Earth. Can you imagine how huge our Universe is! Since black holes are very massive bodies, they send ripples through space-time, distorting it slightly. So waves appear, similar to those that spread from a stone thrown into the water.

This is how you can imagine gravitational waves coming to the Earth, for example, from a wormhole. Drawing from the book “Interstellar. Science behind the scenes"

The resulting vibrations were converted into sound. Interestingly, the signal from gravitational waves arrives at approximately the same frequency as our speech. So we can hear with our own ears how black holes collide. Listen to what gravitational waves sound like.

And guess what? More recently, black holes are not structured as previously thought. But there was no evidence at all that they exist in principle. And now there is. Black holes really “live” in the Universe.

This is what scientists believe a catastrophe looks like—a merger of black holes.

On February 11, a grandiose conference took place, which brought together more than a thousand scientists from 15 countries. Russian scientists were also present. And, of course, there was Kip Thorne. “This discovery is the beginning of an amazing, magnificent quest for people: the search and exploration of the curved side of the Universe - objects and phenomena created from distorted space-time. Black hole collisions and gravitational waves are our first remarkable examples,” said Kip Thorne.

The search for gravitational waves has been one of the main problems in physics. Now they have been found. And Einstein's genius is confirmed again.

In October, we interviewed Sergei Popov, a Russian astrophysicist and famous popularizer of science. He looked like he was looking into water! In the fall: “It seems to me that we are now on the threshold of new discoveries, which is primarily associated with the work of the LIGO and VIRGO gravitational wave detectors (Kip Thorne made a major contribution to the creation of the LIGO project).” Amazing, right?

Gravitational waves, wave detectors and LIGO

Well, now for a little physics. For those who really want to understand what gravitational waves are. Here's an artistic depiction of the tendex lines of two black holes orbiting each other, counterclockwise, and then colliding. Tendex lines generate tidal gravity. Go ahead. The lines, which emanate from the two points furthest apart from each other on the surfaces of a pair of black holes, stretch everything in their path, including the artist’s friend in the drawing. The lines emanating from the collision area compress everything.

As the holes rotate around one another, they carry along their tendex lines, which resemble streams of water from a spinning sprinkler on a lawn. In the picture from the book “Interstellar. Science behind the scenes" - a pair of black holes that collide, rotating around each other counterclockwise, and their tendex lines.

Black holes merge into one big hole; it is deformed and rotates counterclockwise, dragging tendex lines with it. A stationary observer far from the hole will feel vibrations as the tendex lines pass through him: stretching, then compression, then stretching - the tendex lines have become a gravitational wave. As the waves propagate, the black hole's deformation gradually decreases, and the waves also weaken.

When these waves reach the Earth, they look like the one shown at the top of the figure below. They stretch in one direction and compress in the other. The extensions and compressions oscillate (from red right-left, to blue right-left, to red right-left, etc.) as the waves pass through the detector at the bottom of the figure.

Gravitational waves passing through the LIGO detector.

The detector consists of four large mirrors (40 kilograms, 34 centimeters in diameter), which are attached to the ends of two perpendicular pipes, called detector arms. Tendex lines of gravitational waves stretch one arm, while compressing the second, and then, on the contrary, compress the first and stretch the second. And so again and again. As the length of the arms changes periodically, the mirrors shift relative to each other, and these displacements are tracked using laser beams in a way called interferometry. Hence the name LIGO: Laser Interferometer Gravitational-Wave Observatory.

LIGO control center, from where they send commands to the detector and monitor the received signals. LIGO's gravity detectors are located in Hanford, Washington, and Livingston, Louisiana. Photo from the book “Interstellar. Science behind the scenes"

Now LIGO is an international project involving 900 scientists from different countries, with headquarters located at the California Institute of Technology.

The Curved Side of the Universe

Black holes, wormholes, singularities, gravitational anomalies and higher order dimensions are associated with curvatures of space and time. That's why Kip Thorne calls them "the twisted side of the universe." Humanity still has very little experimental and observational data from the curved side of the Universe. This is why we pay so much attention to gravitational waves: they are made of curved space and provide the most accessible way for us to explore the curved side.

Imagine if you only saw the ocean when it was calm. You wouldn't know about currents, whirlpools and storm waves. This is reminiscent of our current knowledge of the curvature of space and time.

We know almost nothing about how curved space and curved time behave "in a storm" - when the shape of space fluctuates violently and when the speed of time fluctuates. This is an incredibly alluring frontier of knowledge. Scientist John Wheeler coined the term "geometrodynamics" for these changes.

Of particular interest in the field of geometrodynamics is the collision of two black holes.

Collision of two non-rotating black holes. Model from the book “Interstellar. Science behind the scenes"

The picture above shows the moment when two black holes collide. Just such an event allowed scientists to record gravitational waves. This model is built for non-rotating black holes. Top: orbits and shadows of holes, as seen from our Universe. Middle: curved space and time, view from the bulk (multidimensional hyperspace); The arrows show how space is involved in movement, and the changing colors show how time is bent. Bottom: The shape of the emitted gravitational waves.

Gravitational waves from the Big Bang

Over to Kip Thorne. “In 1975, Leonid Grischuk, my good friend from Russia, made a sensational statement. He said that at the moment of the Big Bang, many gravitational waves arose, and the mechanism of their origin (previously unknown) was as follows: quantum fluctuations (random fluctuations - editor's note) gravitational fields during the Big Bang were greatly enhanced by the initial expansion of the Universe and thus became the original gravitational waves. These waves, if detected, could tell us what happened at the birth of our Universe."

If scientists find the primordial gravitational waves, we will know how the Universe began.

People have solved far all the mysteries of the Universe. There's more to come.

In subsequent years, as our understanding of the Big Bang improved, it became obvious that these primordial waves must be strong at wavelengths commensurate with the size of the visible Universe, that is, at lengths of billions of light years. Can you imagine how much this is?.. And at the wavelengths that LIGO detectors cover (hundreds and thousands of kilometers), the waves will most likely be too weak to be recognized.

Jamie Bock's team built the BICEP2 apparatus, with which the trace of the original gravitational waves was discovered. The device located at the North Pole is shown here during twilight, which occurs there only twice a year.

BICEP2 device. Image from the book Interstellar. Science behind the scenes"

It is surrounded by shields that shield the device from radiation from the surrounding ice cover. In the upper right corner there is a trace discovered in the cosmic microwave background radiation - a polarization pattern. Electric field lines are directed along short light strokes.

Trace of the beginning of the universe

In the early nineties, cosmologists realized that these gravitational waves, billions of light years long, must have left a unique trace in the electromagnetic waves that fill the Universe - the so-called cosmic microwave background, or cosmic microwave background radiation. This began the search for the Holy Grail. After all, if we detect this trace and deduce from it the properties of the original gravitational waves, we can find out how the Universe was born.

In March 2014, while Kip Thorne was writing this book, the team of Jamie Bok, a cosmologist at Caltech whose office is next door to Thorne's, finally discovered this trace in the cosmic microwave background radiation.

This is an absolutely amazing discovery, but there is one controversial point: the trace found by Jamie's team could have been caused by something other than gravitational waves.

If a trace of the gravitational waves that arose during the Big Bang is indeed found, it means that a cosmological discovery has occurred on a level that happens perhaps once every half century. It gives you a chance to touch the events that occurred a trillionth of a trillionth of a trillionth of a second after the birth of the Universe.

This discovery confirms theories that the expansion of the Universe at that moment was extremely fast, in the slang of cosmologists - inflationary fast. And heralds the advent of a new era in cosmology.

Gravitational waves and Interstellar

Yesterday, at a conference on the discovery of gravitational waves, Valery Mitrofanov, head of the Moscow LIGO collaboration of scientists, which includes 8 scientists from Moscow State University, noted that the plot of the film “Interstellar,” although fantastic, is not so far from reality. And all because Kip Thorne was the scientific consultant. Thorne himself expressed hope that he believes in future manned flights to a black hole. They may not happen as soon as we would like, but today it is much more real than it was before.

The day is not too far off when people will leave the confines of our galaxy.

The event stirred the minds of millions of people. The notorious Mark Zuckerberg wrote: “The discovery of gravitational waves is the biggest discovery in modern science. Albert Einstein is one of my heroes, which is why I took the discovery so personally. A century ago, within the framework of the General Theory of Relativity (GTR), he predicted the existence of gravitational waves. But they are so small to detect that it has come to look for them in the origins of events such as the Big Bang, stellar explosions and black hole collisions. When scientists analyze the data obtained, a completely new view of space will open before us. And perhaps this will shed light on the origin of the Universe, the birth and development of black holes. It is very inspiring to think about how many lives and efforts have gone into unveiling this mystery of the Universe. This breakthrough was made possible thanks to the talent of brilliant scientists and engineers, people of different nationalities, as well as the latest computer technologies that have appeared only recently. Congratulations to everyone involved. Einstein would be proud of you."

This is the speech. And this is a person who is simply interested in science. One can imagine what a storm of emotions overwhelmed the scientists who contributed to the discovery. It seems we have witnessed a new era, friends. This is amazing.

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