Einstein - the man who started to take us out of the matrix (part 3): there are gravitational waves!

On February 11, 2016 They announced Physicists from the LIGO laboratory in the USA for further confirmation of Einstein's theory of relativity. Three months after the world celebrated the centenary of the publication of Einstein's theory of general relativity, one of the masterpieces of the human race, comes the news of the discovery of one of Einstein's last predictions that has yet to be confirmed, the direct discovery of gravitational waves. Less than a year later, in October 2017, She announced The Nobel Committee in Stockholm that physicists Rainer Weiss, Barry Barish and Kip Thorne are the winners of the 2017 Nobel Prize in Physics for their work in the field of gravitational waves and their discoveries. So what are gravitational waves and what is their great importance to our understanding of the matrix we live in? 

the article Appeared For the first time on Nir Lahav's blog "Free and Happy"

See previous parts of the series:

• Einstein - the man who started to take us out of the matrix (part 1)
• Einstein - the man who started to take us out of the matrix (part 2)

About five years ago I started writing a series of articles about the "matrix" we live in according to Einstein's theory of relativity, this is the third part of the series (The first part, Part Two). Albert Einstein showed us that the reality we live in is completely different from what we thought and that science not only explains our everyday world but expands it and reveals to us the secrets of the true reality we live in. We, in our day-to-day life, have the feeling that we more or less understand where we live and what the laws that govern nature, but after Einstein it is clear that reality really surpasses any imagination and we actually have no idea what reality is as it is. With the help of physics we slowly discover the laws that govern our real reality. The understandings, and the technologies that follow them, change our perceptions about ourselves and about our position in the universe. Gravitational waves and the theory of relativity reveal to us what is the infrastructure of the universe on which we live, a sort of "matrix" within which our universe is located. Like in the movie "The Matrix", Einstein gave us the red ball, the one that takes you out of the illusion into the real reality and maybe, following these physical understandings, we too can get out of it?

בThe first part I presented one of the key insights of the special theory of relativity that Einstein published in 1905. Not only are time and length not absolute but relative (different people can measure, for example, how long a certain phenomenon took place and each will measure that the phenomenon took place for a different time and both are right), but also, It turns out that time does not flow from the past, through the present to the future, but is a fourth dimension. Another direction that cannot be seen and in which all times, past, present and future exist simultaneously. Everything we have done and everything we will do already exists in him. Therefore, in principle it is possible to try and change our progress along the direction of time and thus reach the future faster or move back to the past. who knows? It may be that in the future we will be able to develop a time machine and do this.

The matrix we live in is called space-time and is the infrastructure of our universe. We are "drawn" on the space-time surface and therefore have three spatial dimensions and one temporal dimension. If we were not part of this space-time, we would not have these four dimensions. We have existence only because we are part of space-time in a similar way to a balloon on which people and stars are drawn. Just as the drawings on the balloon have no meaning outside the front of the balloon, so we have no meaning outside of space-time, and just as the people drawn on the surface of the balloon can only move on the surface of the balloon and cannot see what is outside the front of the balloon, so we also cannot know if there is anything else outside of space. The time we are "stuck" in. It is therefore the matrix of our universe.

Another amazing conclusion that arises from the special theory of relativity is related to the understanding of the essence of matter. After Einstein linked physical dimensions (length, width and height) with time (fourth dimension) he had to redevelop all the Newtonian physics that had been known until then for 300 years. When now there are four dimensions to consider and not three. As a result, new previously unknown relationships emerged between seemingly unrelated physical quantities. The best known example of such a relationship is the most famous equation, not only of Einstein, but in all of science, the equation E=MC2

(E- energy, M- mass, C- speed of light). Einstein links here between mass and energy (because the speed of light cannot change, it is a constant quantity in the theory of relativity. In the equation, it plays the role of a constant that is multiplied by the mass. It is a kind of conversion ratio of how to go from units of mass to units of energy, similar to the conversion ratio of how to go from dollars to pesos Chilean for example. To go from units of mass, such as kilograms, to units of energy, for example joules, you need to multiply the mass by the speed of light squared). For the first time in physics we understood something profound about the essence of matter and the essence of mass. Newton defined a quantity that he called mass, without any explanation of what this mass is and where it comes from. Now the theory of relativity reveals to us that mass is actually another type of energy, rest energy. Energy that matter always has, regardless of whether it is moving or at rest. As there is motion energy or heat energy now there is another type called rest energy which is the mass of the body. Just as one type of energy can be converted into another type of energy, so it is possible to convert mass into kinetic energy or heat energy. This is the process that happens in an atomic bomb or the core of the sun. It is also possible to convert energy into rest energy, for example a photon, which is a massless particle of light, if it is very energetic when it is swallowed by a block of lead it will turn into particles with mass. This is how Einstein unites two seemingly different concepts, mass and energy into one concept. This discovery was so unexpected and amazing that, according to the story, after Einstein proved this connection he got dizzy and had to rest for a few days at home due to excitement.

Schools still teach that there is a law of conservation of matter and a law of conservation of energy, but since the days of special relativity (more than a century!) we know that this is not true. Mass can "disappear", turn into energy. The only thing left is the law of conservation of energy. Einstein's sensational insight is that everything is energy and matter is also just another type of energy. This conclusion can be interpreted in a positive way of unity and connection between us and all the objects that exist in nature, we are all energy. But the human race immediately preferred to develop a horrific bomb based on this incredible conclusion. Forty years after the publication of Private Relativity, the US develops the first atomic bomb and drops two bombs on Japan, bringing about its surrender and ending World War II.

בPart Two In the series I presented Einstein's theory of general relativity. According to which space-time is a real physical entity just like matter and energy. It turns out that there is an interplay between matter and energy and space-time. We are not just characters drawn on it, we also influence its shape. The more mass a substance has (or more precisely the greater mass-energy density) the more it distorts the four dimensional space-time around it!

The interesting thing is that a curved space-time causes the material "drawn" in it to move in curved lines so that two bodies that are in its environment will start to approach each other as if they are exerting a force of attraction between each other. Einstein realized that actually there is no such thing as gravity but there is a mass that distorts the space-time around it and therefore bodies seem to attract each other in this environment. Einstein "abolished" gravity as a real force, in its place is geometry. Geometry of a curved space in which parallel lines approach each other until they finally meet. The more mass a body has, the more it distorts its space-time and the space-time around it and we will see it as if there is a stronger gravitational force there. One of the strange results that comes out of this insight is that there can be stars with such a large mass that they will distort the space-time around them infinitely and essentially tear the space-time (or the matrix) they are in! A kind of holes in space - time, we call these strange stars black holes. This prediction of black holes was confirmed in the middle of the 20th century and today we know of the existence of many black holes.

Einstein's theory of general relativity was already confirmed inMany experiments And our GPS devices work well thanks to it. But one of Einstein's predictions was not finally verified until the results of the last experiment, this is the phenomenon of gravitational waves. According to the theory of general relativity, gravity is actually space-time that has been curved (just like a straight surface that has been curved into a sphere, only that space-time is four-dimensional and is curved into a four-dimensional sphere). One of the solutions to the equations of relativity shows that space-time can vibrate cyclically like a wave. It is a gravitational wave, a sort of cyclical distortion of space-time that progresses along space. We are used to waves moving on the surface of water or in the air, but in this case it is a wave created due to the curvature of space-time itself. Gravitational waves are very weak and therefore difficult to measure, the experiment of the LIGO team is the first experiment in which they managed to directly measure gravitational waves. How do we even know if a gravitational wave is passing through here? When we measure the area where the gravity wave passes, we will find that the space there stretches in a certain direction and contracts in the perpendicular direction, then the direction that was stretched will contract, while the direction that contracted will stretch. If the wave stands in the same spatial area, we will see that this phenomenon is cyclical:

So, in order to detect a gravitational wave, you have to measure a kind of ruler from a distance and see that it suddenly shortens. The problem is that gravitational waves are very weak. The size, for example, of the gravitational wave they were able to measure with the help of LIGO is smaller than the size of a single atom. That's why it took so many years to build the detectors. The truth is that there were previous discoveries according to which the physicists already knew quite clearly that there were gravitational waves even before the direct discovery. As early as 1974, physicists Essel Hulse and Joseph Taylor measured indirect evidence of gravitational waves. They tested a system of two neutron stars orbiting each other. Neutron stars are very very massive stars and because they are so massive and revolved very close to each other, according to general relativity, they are supposed to create gravitational waves. Indeed, when the team of scientists measured how fast these stars rotate around each other, they found that their rotation speed increases over time. This means that instead of rotating around each other at a constant distance, these pair of stars are getting closer to each other while rotating and therefore their rotation speed increases as they get closer:

But why does this happen? Why do neutron stars get closer to each other? The explanation is that they lose energy over time and therefore get closer to each other due to the force of attraction between them. But, why do they lose energy over time? As we understood from special relativity there is a law of conservation of energy. If they lose energy, that means it had to be transformed into another form of energy. So where did she go?
For gravitational waves, of course!

According to the mass and the distance between the neutrino stars, the team of physicists checked what should happen to the neutron stars, according to the theory of general relativity, when they emit gravitational waves. The prediction of the theory of general relativity and the findings from the measurements of the neutrino stars matched each other very precisely!
The team of scientists was awarded the Nobel Prize in Physics in 1993 for this indirect confirmation that gravitational waves exist.

But, with all due respect to this indirect discovery (and there is respect!) this is still only an indirect confirmation and not a measurement of the gravitational wave itself. Another 40 years or so had to pass until last year's experiment to measure the gravitational waves themselves. How did they measure these tiny gravitational waves? As we have already said, when a gravitational wave passes the space-time warps in such a way that the bar will shorten and lengthen as the wave passes through. If you place rulers tilted at ninety degrees, when one of the rulers lengthens the other will contract and vice versa, the detectors work on this principle. The problem is that the differences are on the order of an atom over distances of many millions of kilometers, and any truck that passes by the detector may cause a false alarm. A sufficiently precise laser measurement technology had to be developed to overcome all these technical problems:

The discovery was made possible through the sensitive experimental facilities built especially for this purpose, called LIGO - an acronym for "Laser Interferometer Gravitational-Wave Observatory". Over a thousand researchers from twenty countries are partners in the project, who "together succeeded in realizing a 50-year vision", according to the award committee. Gravitational waves were measured in the project's two experimental facilities, which are far from each other. One at a site near Hanford in Washington State, and the other in Linston, Louisiana. The pair of detectors was activated in August 2015 for two months, and produced findings on which the discovery was based. They managed to measure two different gravitational waves, each gravitational wave was detected in the two different experimental facilities. Since the discovery, another team has managed to measure a third gravitational wave and once again confirm the presence of gravitational waves. The events that created these three gravitational waves are not the rotation of neutron stars but the rotation and violent collision of two black holes. Thus, by the way, we received another confirmation for the existence of black holes. This collision occurred 1.3 billion years ago. These black holes were very massive, much more than neutron stars. One black hole had a mass of 29 times the mass of our sun, and two had a mass of 36 times the mass of the sun! Due to the strong curvature they create, the black holes rotated and approached each other, twisting around each other until they crashed and created a new black hole, which melted 62 times the mass of the sun:

In the video: The collision of massive black holes creates gravitational waves (represented by the vibration of space).

Notice something strange happened here, the masses of the colliding black holes do not add up to the mass of the new black hole after the collision. The new black hole has a smaller mass than the masses of the two black holes that created it! Where did the mass go?

For those who followed the article, the answer is already clear. As we saw from the special theory of relativity, mass is another type of energy and it can be transformed into other forms of energy. Indeed, when two black holes collide, general relativity predicts that some of their mass will be converted into energy that will be released in the form of gravitational waves. The missing gap - three times the mass of the sun turned into gravitational waves that warped space-time and progressed through it for over a billion years until we measured them on Earth with the help of special antennas.

I think it's really amazing to understand the universe and these huge sizes in this way. As the years pass since the publication of the theory of relativity, we manage to confirm more and more the amazing conclusion that space-time is something real. Here we have once again confirmed the existence of black holes, they are the holes in space-time and the periodic fluctuations that move across space-time - gravitational waves. Space - our four-dimensional time is so real that it can be a medium for waves just like the air can be a medium for sound waves.

But, not only did the theory of relativity and the reality of space - four-dimensional time receive additional experimental confirmation, but now we have discovered another way in which the universe can be seen. If until today we could measure the universe with the help of light waves (electromagnetic waves), now we can see the universe not with the help of light waves but with the help of gravitational waves!

To date we have known two basic types of waves, sound waves and light waves. We use both to see. With the help of the sonar and ultrasound technologies, we see with the help of sound waves, and with the help of materials that are sensitive to different frequencies of light waves, we can see the universe with the help of visible light, X-rays, microwaves, ultraviolet, infrared and gamma waves. With the help of light waves we communicate instantly with anywhere around the world. Cell phones, radios and televisions transmit their information using different frequencies of light waves. Light waves at different frequencies opened up new worlds and new knowledge about reality. We have expanded our perception of reality from the visible light we perceive with our eyes towards frequencies that were blocked from our sight. Suddenly we discovered that there is a whole world of sights that can only be seen with the help of other light frequencies, such as seeing bones inside the body with the help of X-ray waves or seeing the remains of the big bang, in which the universe was created, with the help of very low light frequencies. But this whole rich world still relies on only one wave form, on light waves. We have now been able to expand our vision. We have pushed the boundaries beyond light waves and sound waves towards a completely new wave form, gravity waves. The vibration of space-time itself. We still have no idea what we will discover when the technology develops further and we can explore the universe with these gravitational waves. According to the wealth that opened up to us when we discovered how to see frequencies of light beyond the frequency of visible light, we are probably about to discover an even more wonderful and mysterious universe than we understand today.

Kip Thoren, one of the prize winners and founders of the project, described when the discovery was announced in 2016: "Space was as quiet as the Pacific Ocean and then suddenly a 'storm' - a collision of black holes, which lasted only 20 milliseconds. In that brief moment, 50 times more energy was created than all the stars in the universe combined. It's taking three stars - each the size of the sun - and turning them in an instant into pure energy. Gravitational waves are so different from light waves. I am convinced that more great surprises are in store for us in the exploration of the universe."

Because they are waves, they have a frequency. The physicists at the LIGO laboratory converted the frequencies of the gravitational waves into the frequencies of sound waves that we can hear! Low frequencies sound like bass and high frequencies sound like treble. Want to hear?

This is how the gravitational waves that reached us from the collision of the two black holes sound about a billion years ago!

And finally, Kip Thorne is not only a Nobel Prize-winning physicist, he also combines science with art. Already in the eighties he helped the astrophysicist Carl Sagan in writing a science fiction book called Contact (which became an excellent film in 1999). For the story, Thorne developed the theme of wormholes, another solution of the theory of general relativity with the help of which one can instantly jump from one place in space-time to another place very far away in space and time. A few years ago, the director Christopher Nolan, also asked for help from Kip Thorne for his movie "Interstellar". Again Thorne agreed and calculated for them how a black hole should look when approached. Here is the result of the calculations:

See more on the subject on the science website:

• Nobel Prize in Physics for the discovery of gravitational waves
• "The winners of the Nobel Prize in Physics were themselves surprised by the strength of the signal of the first gravitational wave event"
• A collaboration between three observatories resulted in another discovery of gravitational waves (September 2017)
• A new detector will determine the origin of gravitational waves
• Proof of Einstein's theory of general relativity: "The discovery of gravitational waves opens a new window to the universe"
• Einstein's mistakes
• A third gravitational wave event has been discovered; Confirms the existence of a new type of black holes