Gravitationswellen und Co.: Wie wir den Kosmos enträtseln (Ganze Folge) | Quarks

1.3 billion years ago a spectacular event occurred: two black holes began to orbit each other, first slowly and then increasingly faster. The huge collision creates gravitational waves. A completely new window opens to the universe. Sometimes starry nights pass and then you go out and see thousands of stars that give me a feeling of anger. What we see with the naked eye is only a small section of the universe. Our universe, due to its unimaginable size, has always increased. questions about what is out there, where we come from, apart from a few thousand points, humans have not been able to see much for thousands of years, only telescopes bring us closer to the stars, especially the Hubble space telescope, with it we see what is hidden behind the bright spots of the night sky, we see the wonderful world, the Milky Way of our home galaxy, strange sculptures and strange nebulae, clouds of gas driven by solar winds that spread between the stars of our galaxy, but we see much more with Hubble than we look at.

Far away in intergalactic space, in a small section of the sky, we discover details that we see here. Not just individual stars but entire galaxies, countless in the universe and each galaxy, an island in infinite space, shines with the light of billions of suns. According to telescopes, we know that galaxies are moving away from each other and that the universe is expanding, but we also encounter limits. Most of the universe is invisible to our telescopes, but that's exactly what's changing. New signals reach us. From the darkness of the universe some speak of the beginning of a new era.

This discrete signal, which can also be heard, this vub, is a scientific sensation of a real sensation of the century, why it is the first time that it is called that. Gravitational waves have been detected, what exactly they are when we explain to you in this program, but it must be made clear that it is the first time that you have new signals with which you have a new vision of the universe and this signal that was demonstrated here on Earth in 2015 , but its story begins much earlier. 13 billion years ago, very far from Earth, two black holes orbit each other.

They are enormous masses and move around each other at lightning speed, thus causing space-time. When black holes collide, oscillate and generate gravitational waves, the most violent ones are created and propagate through space on Earth. Scientists like Karsten Danzmann have been trying to measure this type of gravitational waves since the 1970s. The two black holes collide with the Earth in vain. And finally researchers measure a signal and even make it audible. The scientist is skeptical. Not all of us believed it was real. For a long time we realize that something really big has just happened. For me, very slowly, I would say two weeks passed until I was ready to admit that this really could be a milestone in astronomy for which Karsten Danzmann's American colleagues even received the prize.

Nobel Prize in Physics in 2017. Of course, not yet. On the contrary, he is starting to drink. Our research is not about proving that gravitational waves exist. Nobody doubted it, but to open a new one. window, developing a new tool, exploring the universe This is the beginning In the coming months, in a new type of astronomy, researchers measure four more gravitational waves from black holes and even manage to locate the origin of the signals in the sky. Although imprecise, researchers are lucky: in the cosmic area of ​​only 130 million light years, two neutron stars are merging. Everything looks similar to the orbit of two black holes.

They approach each other more slowly and are composed of visible matter. Eventually, neutron stars collide with each other and spew extremely hot matter to Earth. At the same time, violent gravitational waves are recorded. According to several detectors, the signal is much weaker than that of black holes. The greenish line barely stands out from the background noise, but it takes more than 100 seconds because we were able to listen for a long time. the sky with such precision, this warning was sent to the optical astronomers and they immediately said yes, we will look there too and then there was no way to stop 70 more telescopes and then they also observed this small galaxy without the direction given by them.

Gravitational waves would be like looking for a needle in a haystack, but after a few minutes telescopes can see the bright remains of neutron stars. For the first time, you can see how the debris cloud slowly cools and becomes increasingly redder. reveals an old mystery how heavy elements like gold arose in the universe optical observations solar cartridges the fusion of stars came to us in the spectra showed that a large blast furnace was created in which enormous quantities of gold were now baked and other heavy elements We know that gold is coming. Gravitational waves answer many questions at the speed of light and almost without disturbances.

They spread throughout the universe and could solve even bigger puzzles. At first, gravitational waves. We will receive more signals, but we will also receive other signals and it will all be really exciting. Which we don't even think about today, I personally would like to listen to the Big Bang at some point and that will do while I'm at it. I am still alive. The search for gravitational waves continues. If the search for gravitational waves is successful, it would be an astronomical revolution because we would gain insight into the part of the cosmos that until now has been hidden because it does not emit. any light, that was almost 20 years ago and how great are the times we live in because gravitational waves have been discovered, it will surely be a while until the Big Bang can also be heard through gravitational waves.

More on this later, but. At least since the collision of neutron stars, as you saw in the article, you notice that there is a new possibility for astronomers. Now, why is the special thing about gravitational waves that they measure something completely different than previous telescopes? because when we look into space first we see light or there are also radio waves, the jungle but you would only see the things, that is very impressive, but if something else appears, that is, the noise that you hear here, then you realize that there is much more hidden there, if you listen carefully you will see, for example, what is exactly. bonds are gravitational waves a man described them to us a long time ago 100 years ago he threw old physics down the drain albert einstein published a new theory of gravity space and time go together he says that the revolutionary idea of ​​gravity is none other thing that a curvature of this space-time A stone designs modern physics and revolutionizes our image of the universe.

Compare space-time to a cloth. All bodies curve this fabric. The heavier the body, the more the sun becomes. so much so that the earth is forced to orbit around the sun. Einstein's new image has consequences. The light from a star will go straight. If the fabric is flat. The light has to pass close to the Sun. It will be deflected. Einstein calculates how much. It is incredibly small but measurable Einstein dares to predict a solar eclipse says he could do it Astronomers measure the bending of light In 1919, astronomers around the world attempted to disprove a stone.

They observed stars close to the sun and took photographs. Something incredible happened. Einstein was right. The starlight was bent and exactly as a stone calculated. This is the first test of his new theory and has additional consequences because, according to Einstein, all moving masses must have a special type of waves in their hands. Einstein passing through the lungs of space-time like in a lake Gravitational waves The faster something moves, the stronger the gravitational waves are. This is what astronomers have been looking for for 100 years, calculates a stone. Because these circles in space-time. They must be incredibly small and we remain skeptical as to whether they can ever be measured.

Gravitational waves can be thought of as a compression of space-time and are produced when very large masses move, for example black holes and neutron stars. They go through the universe and also collide with our earth, for example, and here there is also a compression and one that here seems relatively large but the effect is as small as it is tiny. I would like to show you that, but that's why I. I have to immerse myself in the microcosm, that is, in the world of the very small, what you see here is the lightest element, that is, hydrogen, which consists of a nucleus and an electron of millimeters, now we worry about the length changes and for it.

You have to immerse this hydrogen atom in the center of the nucleus, the so-called proton, and the length changes measured here are approximately one thousandth of the diameter of the proton, as a layman on board says, that is small, so small. Actually, it's difficult. to measure it, but it is a success and I saw how everything works. This long tube in no man's land is the most precise ruler people have ever built. I traveled to the world's largest gravitational wave detector, to Laico, to. for example, an hour's drive from new orleans scott logically is a vacuum engineer and inspects regularly and even with the slightest delay the whole experiment would have to stop for months he told me a long tube which is one of our precious measuring distances in This tube they have created a unique vacuum of 10 to the door minus 9 incredible so it has to be very tight here yes here is the weld seam it worked perfectly over the entire distance of four kilometers that is a lot the scientists used a laser to measure the Gravitational waves laser beams must move as freely as possible, which is why a vacuum is necessary in their path.

The Leiko measurement principle is that a laser beam is divided into two identical beams that travel a measuring path of four kilometers. The longer it is, the more precise the signal is. The rays reflect and overlap. A gravitational wave causes them to reach a tiny length. The change also changes the superposition pattern and this is recorded by the photodetector, although 100 years ago Albert Einstein still doubted whether it was gravitational. The waves could even be measured, but researchers have continued to improve the sensitivity of the detector. So much technology, so much effort. To measure such a small signal, length changes of a billionth of a billionth of a meter are now recorded.

In the laser room, all employees not only have to wear laser glasses, but must also be completely covered. Every flake of skin, every hair would contaminate the beam path and therefore the measurement would be unusable. Experts control the control elements to stabilize the reader. From here, the laser beam is directed to the measuring section. Scientists want to capture a small signal from the universe and, in the middle of the noisy earth, in the control room they try to filter out the loud background noise of our lives. Knowing if gravitational waves would arrive at this time, they could be detected, yes, we could measure them, and despite all the interference signals on Earth, that's all the other activities.

We have tens of thousands of other sources of noise on our Earth, so. We can distinguish them from gravitational waves, we record them there on the monitors. This is an earthquake. We have seismographs that measure the movement of the Earth's surface, but we not only have to use it for earthquakes, we also have to have people. These blue curves show us that someone is walking outside. of our facilities. We also have to detect ocean waves in the Gulf of Mexico like those that hit the coast and then there is human activity here. Here we measure what the people of our region have done within.

The last six hours they were sleeping most of the time, then they waited and then they went to work. Sometimes we even see a train, all the annoying noises that gravitational waves could overlay are in an audible frequency range, so we always try. Creating the place on earth the greatest concert hall in the world for a pin to drop, this silent installation in Louisiana's no man's land has answered one of the most fundamental physics questions there is. Gravitational waves, an interferometer like this is a fascinating tool. instrument and I would like to explain the principle again here, so here you can see the following in the fog, there is a laser here, a semi-transparent mirror and the laser beam is now divided.

In the end there is a mirror here and there and in. At that moment the steel is working. I'll show it here again a little bit more and then here you can see what is also called an interference pattern, that is, the superimposed laser beams form a pattern and this pattern, due to the superposition. , it is extremely sensitive, so if I, for example, press it lightly against a mirror, if you press it, you will notice that the pattern changes,In other words, this instrument is very sensitive when it comes to changes in length and this is a mini interferometer, so to speak, everything is available in a very large size, which is what we saw with Diego with a leg longer than at least minus 4 kilometers and so now you can see small changes in the length and the pattern of this interference pattern changes.

This is what we see here when the two black holes orbit each other, then there is a back and forth and when they get closer they merge with each other and also a very characteristic wave pattern, we have all heard it. It sounds very harsh, it works similarly with neutron stars that merge gradually, so everything takes longer, or with a supernova, that is, a stellar explosion, which also sends gravitational forces and here the corresponding characteristic. The signal you then receive is more like a signal where at the moment there are three big detectors that are connected to each other on earth, but in the future they plan to make everything really big and in space and that brings us to the project Lisa Si todo Si it's going well, Lisa should go live in 2034 and the thighs will be longer here.

We are no longer a few kilometers but approximately a million kilometers and scientists are already excited because with this they could perhaps address the biggest mystery of the disease. Everything, Professor, I have the Big Bang recreated this is not how it works the Big Bang certainly was not an explosion as we imagine it an explosion explodes in a room in the Big Bang there was no place but come on, I'll show you how. the universe really arose where we end up here we are where From a purely physical point of view, the universe does not yet exist in absolute nothingness.

According to our theory, there is no space, no time and certainly no matter. Physicists can calculate quite well what happened after the Big Bang, but we know nothing about the moment of the Big Bang, why the universe. So we know nothing, we have no idea, so it would be conceivable that there could be another universe before the Big Bang. It is conceivable that there are many others besides our universe, even with life, but these are all just theories, there is no evidence, even if it seems absurd. Most physicists today assume that the universe came into being. nothing There is no universe before the Big Bang and no one outside the universe in this nothing arose at the beginning, only here it is tiny.

According to our calculations, the universe at the beginning was so small that it was billions. times in a host atomic nucleus of 48 100 trillion trillion graves everything that exists today in the universe is compressed into this tiny point that was inflation in a fraction of a second the universe becomes trillions of millions of times larger than matter It is distributed throughout all of space, then the universe grows again more slowly and from this primordial soup the first particles of light and matter are formed up to the moon, all the matter that today makes up our Milky Way is almost in a cup of coffee.

There are not even atomic nuclei. Only after a few minutes does it cool enough for them to form. You really don't see anything in the universe. There is a dense fog in which light particles from atomic nuclei and free electrons collide and do not leave the place. for a total of 380,000 years live for 380,000 years yes yes but then the universe expanded and cooled so much that I combined the matter particles into complete atoms now the light particles have room to go straight fly from everywhere to everywhere is God these rays can still be measured today throughout the universe, the dullest and coldest waves in the world, making it the strongest evidence for our big bang model of the expanding universe.

We can measure this cosmic background radiation everywhere today, I mean, if you want, I want a map of the universe and you can see that there is this radiation everywhere, there are slight fluctuations, so to speak, it's a little bit of the residual heat of the big bang, but the important thing is that it was created about 380,000 years later. the big bang, what happened before that, we do not know that the Universe was so dense that normal electromagnetic waves could not pass through it, but that is the great hope that with the help of gravitational waves more can be discovered, i.e. , understand exactly what happened or, for example, how much energy was released during the Big Bang.

So, there are many things to discover. Gravitational waves are, so to speak, a new window to the universe, but if you look at it, the. The simple question of what our universe really consists of is not so easy to answer because it is made up of more than just bright stars, my colleague Adrian Flight now brings us the stars of the sky and I should say from the suitcase that I have here in this suitcase. everything we need for our universe, at least as we know it today, and of course all in a handy miniature format, the building instructions, which we'll need later.

First of all, the stars are in our construction kit. They are packed very close together. In a clear box, the number of stars is almost unbelievable. In total, there are about 10,000 billion stars in the universe. For example, planets, moons, asteroids, comets, and even black holes are made of heavy elements. Ultimately, only 0.3 per thousand of the entire universe. The most important thing is something completely different: free gas, which is gas that has not yet condensed into a star. It is composed mainly of hydrogen, but also contains a small amount of helium. There are also neutrinos, they are tiny particles that are needed to build matter.

They are invisible and hardly react with other particles. However, they are extremely numerous and without them we would not be able to see the fascinating things that the Universe cannot see. Light particles or, as experts say, photons, small intermediate balances, these are now all the known components that we need for our universe; in reality, free gas makes up the majority of it. Our Milky Way can be formed from these components, for example. you need about 300 billion stars and 150 billion planets plus a few billion mouths and a lot of asteroids a wave of gaseous neutrinos and a pinch of photons looks cool now all that was left was to spin it doesn't really work because there is still something Something very crucial is missing: dark matter is invisible, but it influences how normal matter is distributed and moves, but it is not clear what this dark matter consists of and, although we are on the topic of ambiguity, there is an even bigger mystery: dark energy, we have no idea. what it consists of we only know that dark energy is responsible for the fact that the universe or space itself is expanding faster and faster and it makes up the majority of our universe, more than 70 percent and now I really have everything together that our universe It is, again, the Milky Way, this time, but in reality, 100,000 light years away.

The diameter for us now is only one meter and, by the way, here we are. Our Milky Way is, of course, just one of many galaxies in the world. The next really big galaxy has a bit of a way to go. In the space between there are hardly any stars but there is a lot of gas. The largest and most famous galaxy near us is the two and a half-year-old Andromeda galaxy. Millions of light years from us it is time to close. I already have a big room, but there isn't enough space here, even for the miniature universe.

The room would have to be as big as the one in Cologne. Up to Berlin, 470 kilometers on each side and of course at the same altitude, the around 100 billion galaxies have enough space. The result is a huge sponge-like structure, because the galaxies are not evenly distributed, but rather clustered together. a huge pile of energy and matter that we have not yet fully understood, a little gas, a few stars and a pinch of heavy elements, as well as our Earth, if there is a second suitcase somewhere or if there are many, This is something incredible, because most of what is there cannot be seen outside, about 95 percent, so with a telescope, for example, you cannot directly observe the dark matter invisible in the camera.

Direct observations, only about gravitational effects on other celestial bodies, do you know what there is more? Now we have to find out what exactly dark matter is, so far science has barely any idea about it and this is exactly where gravitational waves are found. Interesting, for example, there is a theory that says that this mysterious dark matter may be nothing more than medium-sized black holes and that is a bit of a conclusion from previous measurements of gravitational waves because there are obviously many more of these black ones. holes than is supposed, what we know today about these black holes we owe above all to one man.

His world is formulas and equations. Stephen Hawkins' thought revolves around the cosmos. With all the stars and galaxies of it, from the beginning he wanted to penetrate deeper and deeper. Only a few have come as close to this secret as he has. I remember returning from London at night. Lanterns were turned off at midnight to save money, I say. In the night sky like never before. Before, with the Milky Way passing through it, the Milky Way is made up of more than 200 billion stars like our Sun, huge balls of gas made of hydrogen held together by gravity, the pressure inside is so high that the hydrogen ignites and the stars shine normally.

The star burns most of its life Hydrogen runs out The star collapses due to its own gravity A supernova occurs A stellar explosion The star is only three times heavier than our sun The collapse is so violent that a black hole is created Therefore, black holes are dormant everywhere. In our Milky Way there is a black hole of more than four million solar masses in the center of our Milky Way. Hundreds of stars dancing around this black hole like clockwork reveal its position. Astronomers have precisely measured the orbits of each star. So use the law of gravity to calculate the exact position, that the cross marked in red is exactly here, the black hole can only be seen with bright telescopes, you can't see anything, not even the slightest.

A black hole has a very defined edge. The attraction is so strong that the light can no longer escape. Black holes are invisible to our eyes and telescopes, they can only be discovered indirectly when they eat entire stars. That's what physicists thought until Hawking discovered that black holes reveal. To my surprise, I discovered that a black hole should actually emit particles and that radio astronomers are constantly searching for this particle radiation. Worldwide Hawking has shown you a way to find black holes in space. Otherwise, black holes only reveal themselves indirectly, for example when they swallow whole stars and then emit measurable radiation.

Yes, a black hole is not visible by definition, it is simply black, but with gravitational waves it is possible. It is the first time we have detected black holes directly and in a few decades we will probably have a map of the universe with black holes. Anyway, I'm pretty sure about that. I think it's great, yeah. Humans are specks. of dust in the universe We trust ourselves and investigate the cosmos and I am convinced that we will not be left without questions For a long time people believed that the celestial bodies were superior beings with their own history and will or were developed by bd.

But some Egyptians and Babylonians also developed them. Exact models of celestial bodies in circular orbits already existed, but it was only with Aristotle in ancient Greece that science was finally established. Planets are physical objects that orbit around the Earth and not around the Earth. Sun, leading to the assumption that the complex individual motions of the planets were the only way to explain observations in the night sky. Nicholas Copernicus put an end to the astronomical chaos around 1700 years later. Finally the idea that the Sun is in the center prevailed. However, here the solar system was still limited by a spherical shell in which the fixed stars were supposed to be located.

Giordano Bruno later explained that there are no fixed star spheres, that the universe is infinite and has many worlds. He was condemned as a heretic by the church in 1600 and burned the improved In the following centuries, observational technology demonstrated that our solar system is actually little more than a speck of dust in the universe. Georgi Kurhalle Maitre stated at the beginning of the 20th century that space is expanding. The redshift of distant galaxies The expansion of space attracts light waves The length and power he wanted Metro had the idea of ​​reversing cosmic expansion and came to the conclusion that the universe began in a kind of primordial atom. founder of the big bang theory for decades it was believed that the universe would collapse due to gravity after many billions of years and in the big bang new ones are created again and again but the expansion is not slow but faster until the moment the facts. nowIt is speculative that the many worlds model has been circulating since the late 50's here many universes exist in parallel with different natural laws it is also difficult to imagine models in which our four dimensional spacetime is on a plane that exists with others orbits in an eleven-dimensional space Nothing can be seen from Earth and if multidimensionality and higher dimensions will ever be demonstrated.

Let's see if there are still many unsolved mysteries in the universe. It is impressive when you look into space and then realize how small and sometimes insignificant our everyday conflicts and problems are. You start to put yourself in perspective and I think that's quite healing sometimes. That's all for today and, as always, they stay. We faithfully recommend each other, bye.