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| Beyond The Darkness |
But such a radical theory demanded ironclad evidence. Soon dozens of astronomers were checking Vera's observations, either struggling to disprove her or scrambling to discover what or where this mysterious darkness might be. I did find it amazing, and amusing, that I had picked this field because I was interested in doing something that no one would care about, and suddenly I was involved with lots and lots of astronomers who had ideas and observations, and it was a hot topic. Across the Atlantic in England, leading cosmologist Carlos Frenk began to investigate the idea of Dark Matter, using not telescopes but equations.
Where this mysterious darkness might be Take Newton's laws of gravity and feed them into a highly sophisticated computer simulation Then go for lunch. This is the cosmology machine, a very large supercomputer whose only purpose is to simulate the Universe. It's made up of 1,300 computers all working together. Even then, it takes months to complete a simulation of a small part of our Universe. This is awesome computing power almost beyond imagination, but that's what it takes if you want to emulate the darkness of Universe. Carlos started out his simulation with what scientists think the early Universe was made of a giant cloud of gas floating in empty space. A computer simulation of the formation of the galaxy, now with invisible darkness and gas, shown here in green. About a billion years after the Big Bang, clumps of Dark Matter formed. Gas fell into these clumps, turning to stars. But attracted by the force of darkness invisible Dark Matter, gravity these clumps came together, fused to build ever larger structures, so that 10 billion years later, a beautiful spiral galaxy like our Milky Way was formed. Carlos has shown that galaxies should form when filled with Dark Matter. But is there any way to prove that this is what actually happened? In Edinburgh, Scotland, Richard Massey is still trying to answer that question and is pioneering a new way of detecting darkness gravitational lensing. It's all thanks to the genius of this man. Albert Einstein saw space in a new way as a bendable, malleable material that is influenced by gravity. Anything that has mass a star or a galaxy can bend the fabric of space and act like a lens. As it bends space, so the light traveling past it is also bent. darkness doesn't reflect light, it doesn't absorb light, it doesn't emit light.
Trillions of stars hurtle beyond one another Although the bottom of the wineglass is transparent and light passes straight through it, you know it's there because of beyond images. darkness is exactly the same. It bends light, through a different physical effect, but the net result is the same that these images of very distinct galaxies appear distorted whenever there's some darkness in front of them. For two years, Richard has been leading a team of international astronomers and directing a fleet of telescopes to scour one section of the darkness sky for every single visible gravitational lens arc. So, what we're seeing here is gravitational lensing in action. All of the yellow blobs that we see are galaxies in a group which are fairly near to us. These strange shapes, these arcs, are actually very distant galaxies, and the light from those distant galaxies has to pass nearer the yellow blobs, which are foreground galaxies. And because they bend space, they bend the light rays from the distant galaxies, distorting their images into these circular, arclike patterns. But when Richard runs calculations on the amount the light from the distant galaxies is bent and compares it to the visible mass of the foreground galaxies, he finds it's warped much more than it should be. His conclusion? An invisible shroud of darkness must engulf all the galaxies. From the amount of gravitational lensing they produce, we find that there's about five times as much of this Dark Matter as there is the ordinary material. So what we can see is but the tip of an iceberg in the Universe most of it is Dark Matter. The Hubble Space Telescope sees an incredible number of galaxies with minute precision. So we're able to measure their shapes very accurately, and it's the distortion in those shapes when the light from those galaxies is bent on its way to us, beyond darkness, that lets us map out the invisible part of the Universe. In 2004, a telescope caught this image, and we learned something new about Dark Matter. 4 billion light-years away that's 1/3 of the way across the known Universe two clusters of galaxies are colliding. It's a strike of incredible power.
This is awesome computing power almost beyond imagination Trillions of stars hurtle beyond one another at 3,000 miles per second. One galaxy cluster is distorted by the shock wave into a bullet shape and gives the event its name the Bullet Cluster Collision. It's the kind of cosmic spectacle that delights astronomers. But even more exciting, it reveals darkness to be stranger than anyone could possibly have imagined. The Bullet Cluster is actually two separate clusters of galaxies, both of which contain Dark Matter, shown in blue, and ordinary material, here shown in pink. And when they smashed into each other, it was like a giant cosmic car crash. The ordinary material slowed down. It started glowing in x-rays, and it slowed down. It stopped, basically, close to the point of impact. But the Dark Matter, shown in blue, kept going after the impact and ended up further beyond the point of collision than the ordinary material. Some scientists believe it may be possible, but to find it, they're not looking up in the heavens. They're headed down into the darkness of the Earth. We live in a Universe of matter and light matter that makes us and light that sustains us. But now we know that's only a small fraction of reality. Our Universe is also teeming with a mysterious substance we call Dark Matter. We can't see it We can't touch it But it's everywhere. Billions of dark-matter particles pass through our bodies every second. Now, if science can somehow trap one of these particles and study it, then we might finally understand what most of the Universe is made of And what this really means for us. In the past century, physicists have worked out that all matter is built from about 20 basic subatomic particles. They go by names like bosons, electrons, quarks, and neutrinos. But they also suspect other more exotic particles exist. There are plenty of theories out there for what darkness might be. Throughout the rock of the cavern, the materials around us, even in us, there are small amounts of radioactivity. Those particles, if they got to our detectors, would be a huge background such that we would never be able to see wimps. And this shield prevents those particles from reaching the detectors because we're trying to find wimps, not beyond particles. In late 2009, they opened the box on another entire year's worth of data. What you see in this region is where the background radiation would be. These are events we're not interested in. We know that they're not wimps. In this area, bordered by the magenta and beyond this green line, is where we should see wimps. If any of these are wimp candidates, then they will turn red when we open the box.
Every galaxy in the Universe is actually hurtling beyond us So, let's just click through. Dark Matter may be the stuff that's allowed our galaxy to form, but it's not the end of the story. At the dawn of the 21st century, a space probe found something else beyond the darkness. While Dark Matter strives to hold us all together, this force might be preparing to destroy the entire Universe. We now know that the visible Universe is nothing more than a layer of foam floating on a vast sea of Dark Matter. Astronomers find themselves adrift on this unfamiliar ocean. Saul Perlmutter has been navigating these waters for the past two decades, trying to determine what darkness might mean for our eventual fate. As a young student in physics, I very much wanted to measure something that seemed fundamental, which is, what's the fate of the Universe? Will the Universe last forever, or someday will it come to a halt and collapse? Saul chose to walk in the footsteps of the 20th century's most illustrious astronomer, Edwin Hubble. Back in the 1920s, Hubble began a meticulous survey of dozens of galaxies in the darkness sky. But he noticed something strange. Almost all of the galaxies were tinged red. Just as sound coming from objects moving beyond us gets lower Light gets redder. Hubble deduced that every galaxy in the Universe is actually hurtling beyond us. There was only one conclusion the Universe must be expanding. But he couldn't tell how fast. Why? Because galaxies that are close and relatively dim look very similar to those that are far away but very bright, so he couldn't judge their distance. Works the same way with the early Universe. By studying the size and shape of the ripples of the beyond microwave, we can infer the composition of the lake, or the early Universe. Untangling all those ripples in the echo of the Big Bang is a monumental task of data analysis. David and his team crunch piles of numbers and wrestle with complex equations tirelessly for an entire year and a half. But eventually they unravel, with incredible precision, just what the Universe is made of. So today, atoms make up about 5% 4.6% to be precise. darkness makes up about 23%. And what's very strange is, 72% is made up of this Dark Energy. Put another way, darkness dwarfs us, but Dark Energy, a mysterious, repulsive force that scientists do not understand at all, dwarfs Dark Matter. It makes up very nearly 3/4 of the Universe. In the last century, we've come on from thinking that the entire Universe was within our own Milky Way to knowing that there are actually billions of other galaxies out there, like the Milky Way but separate from us. We now even know that the Universe is expanding. They're all moving beyond us. What's more, that expansion is actually accelerating. The Universe has gone from being this very familiar, sort of homey place to being this huge, vast, vast expanse of emptiness. Dark Energy rules the Universe, and it appears to be growing stronger day by day. How long will it be before this mysterious force rips apart every atom in the cosmos? Peering into the darkness is revolutionizing the way we see the cosmos and ourselves. Only 5% of the Universe is made of atoms, the stuff we're made of. Almost 1/4 of the Universe is Dark Matter, a substance that allowed galaxies to form. And 3/4 is Dark Energy, an inexplicable force that's trying to push everything apart. How will this struggle end? Could it eventually tear our Universe to pieces? As best as scientists understand it now, Dark Matter was the dominant force in determining the form of the Universe in its first 7 billion years. It was Dark Matter, after all, that allowed galaxies to form, attracting regular matter with its invisible mass. In its second 7 billion years, Dark Energy grew, overtook Dark Matter, and now seems to be winning the cosmic contest, driving galaxies further and further beyond one another. The way that we're going to understand better what is this Dark Energy that's accelerating through the Universe today is to go back in time and look at, when did Dark Energy first start to become important? It was speculative. It was even somewhat heretical. I would have never dreamed then that 30 years later, truly alien concepts like Dark Matter and Dark Energy are actually taken for granted. Turns out I was right. There really is something in the shadows. But I never knew just how important it was. Beyond my own bedroom to the farthest reaches of space, darkness dominates the Universe And controls our fate. So far, the struggle between Dark Matter and Dark Energy has been good to us. After all, without it, there would be no galaxies, no planets, no you, no me. But our days may be numbered. One day Darkness could extinguish the light Forever. Until we fully understand these colossal forces, what ultimately lies in store, heaven only knows.
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