If the universe sprung into existence and then expanded exponentially, you get gravitational waves traveling through space-time. These would fill the universe, a pattern of echoes of the inflation itself. Neil Turok
I think that physics is the most important – indeed the only – means we have of finding out the origins and fundamentals of our universe, and this is what interests me most about it. I believe that as science advances religion necessarily recedes, and this is a process I wish to encourage, because I consider that, on the whole, the influence of religion is malign. William Bowen Bonner
So galaxies must have formed out of that early universe. Professor Michael Strauss
Billions and billions of galaxies. The universe is so vast we can’t even imagine what those numbers mean. But fourteen billion years ago none of it existed. Until the Big Bang. How The Universe Works s1e1: The Big Bang, Discovery 2010
What came before the Big Bang? ibid.
Scientists think it took less than a millionth of a millionth of a millionth of a millionth of a second for the universe to expand from the size of an atom to a tennis ball ... That means it was expanding faster than the speed of light. It’s called Plank Time. ibid.
When the Earth crushes down to just five centimetres across that’s the density of a black hole. It would be about the size of a golf ball, yet weigh the same as the Earth with the same amount of gravity. How the Universe Works s1e2: Black Holes
When massive stars ten times heavier than our sun die gravity crushes them creating a huge explosion. A supernova. But some stars are even bigger than that. These supermassive stars weigh one hundred times more than our sun, and have one hundred times our gravity. When one of these stars dies it sets off the biggest explosion in the universe: a hypernova. And this is the birth of a black hole. ibid.
Black holes are born from dying stars. And most are small. And thirty kilometres across. But now scientists have discovered some black holes are much bigger: they’re called supermassive black holes. They’re the same size as our entire solar system. And one of these monsters lies at the heart of our own galaxy. ibid.
Everything in our galaxy including our own solar system orbits around a supermassive black hole. But the Milky Way is not the only galaxy with a black hole at its centre. There are supermassive black holes at the heart of most galaxies in the universe. The Andromeda Galaxy is our closest neighbour. It circles a supermassive black hole weighing one hundred and forty times more than our sun. ibid.
Quasars blast away huge quantities of gas from the surrounding galaxy. The equivalent of ten Earths every minute. Black holes suck gas in; quasars blow it out. But eventually there’s no gas left to make stars. And the galaxy stops growing. With no gas left to feed on, the quasar jets shrink and die. What’s left is a supermassive black hole at the centre of the galaxy with a lot of infant stars. Just like our Milky Way when it was young. ibid.
What lies at the heart of a black hole? Some scientists believe we could use black holes as a portal with potential to travel across the universe. ibid.
Black holes might even be gateways to other universes. On the other side of a black hole there could even be a Big Bang. ibid.
We live in a galaxy called the Milky Way. An empire with hundreds of billions of stars. There are two hundred billion galaxies in the known universe. Each one unique, enormous and dynamic. How the Universe Works s1e3: Alien Galaxies
The stars in a galaxy are born in clouds of dust and gas called nebulas. ibid.
Our galaxy contains many billions of stars. And around many of them are systems of planets and moons. But for a long time we didn’t know much about galaxies. Just a century ago we thought the Milky Way was all there was. Scientists called it our island universe. For them no other galaxies existed. Then in 1924 astronomer Edwin Hubble changed that thinking. ibid.
Galaxies are big. Really really big. ibid.
Andromeda, our nearest galactic neighbour, is over two hundred thousand light years across. Twice the size of our galaxy. ibid.
They all seem to orbit something at their centre ... a black hole. And not just any sort of black hole: but a supermassive black hole. The meal is gas and stars. And it’s being consumed by the supermassive black hole. But sometimes black holes devour too quickly. And what they’re consuming is discharged back into space as beams of pure energy. It’s called a Quasar. ibid.
When scientists see a quasar blasting from a galaxy they know it has a supermassive black hole. ibid.
A maverick scientist came up with the idea that something else was at work. Back in the 1930s Swiss astronomer Fritz Zwicky wondered why galaxies stayed together in groups. ibid.
It’s clear now that Dark Matter is a vital ingredient of the universe. It’s been working since the dawn of time. And affects everything, everywhere. It triggers the birth of galaxies. And stops them from falling apart. We can’t see it or detect it. Nevertheless, Dark Matter is the master of the universe. ibid.
Each of the filaments is home to millions of galaxy clusters. All bound together by Dark Matter. ibid.
Dark Matter holds together the whole super-structure of the universe. It binds galaxies in clusters. And clusters in super-clusters. All these are locked together in a web of filaments. Without Dark Matter the whole structure of the universe would simply fall apart ... It’s a giant cosmic web. ibid.
Dark Energy has the opposite effect of Dark Matter. Instead of binding galaxies together it pushes them apart. ibid.
Stars: they’re big. They’re hot. And they’re everywhere. Stars rule the universe. Born in violence, dying in epic explosions. They fill the universe with stardust. The building blocks of life. How the Universe Works s1e4: Extreme Stars
Inside a real star fusion continues for billions of years. The reason is simple: size. Fusion at the core of the stars generates the force of a billion nuclear bombs every second. Gravity and fusion are in an epic battle. ibid.
Iron absorbs energy. From the moment a massive star creates iron it only has seconds to live ... In a few seconds supernovas create more energy than our sun ever will. ibid.
The super-dense core is now a neutron star. It’s around thirty kilometres across. And unbelievably heavy. ibid.
Slowly it disintegrates; the star is dead. All that remains is an intensely hot dead core – the red giant has become a white dwarf. ibid.
At the heart of a white dwarf astronomers believe there is a giant crystal of pure diamond. A cosmic diamond thousands of kilometres across. ibid.
This is an exploding star. It’s called a supernova. Supernovas come in different sizes and types; all of them are so bright they can be seen across the universe. But this violent destruction of a star is also the birth of everything we see around us. How the Universe Works s1e5: Supernovas
Really big stars die with a violent explosion called a supernova. They’re so violent if one of them exploded a few dozen light years away, planet Earth would be scorched. ibid.
Our sun won’t become a supernova: it’s too small. ibid.
Supernovas make everything in the universe ... It’s all made of iron from Type 1A supernovas. But the heavier elements in our world – like gold, silver and uranium – come from another type of supernova, a single-star supernova. ibid.
They were super-powerful explosions of high energy radiation called Gamma Ray Bursts. And they were coming from exploding hypernovas. ibid.
Gamma Ray Bursts: They are the brightest thing in the known universe. ibid.
The moment the white dwarf star starts to fuse carbon and oxygen into iron it’s doomed. Suddenly the white dwarf explodes. ibid.
Scientists used to think the expanding universe was slowing down but they couldn’t prove it. Until they found double-star supernovas. Type 1As. They always explode when a white dwarf star reaches exactly 1.4 times the mass of our sun. And their explosions always release exactly the same amount of light. They are the perfect markers to measure distance in space ... But instead they got a huge surprise. ibid.
But pulsars aren’t the strangest thing a supernova can leave behind. When stars thirty times bigger than our sun explode they produce a type of neutron star called a magnetar. Magnetars are even stranger than pulsars and generate powerful magnetic fields. ibid.
Sometimes there’s a corpse. The type of corpse depends on the size of a star. Supernovas from stars more than eight times bigger than our sun leave behind a neutron star. And it’s one of the strangest objects in the universe. ibid.
A teaspoon of neutron star would weigh over ninety million tons. ibid.
Some neutron stars spin so fast they generate huge pulses of energy. Beams of radiation blasting out of the star’s north and south poles. This neutron star is called a pulsar. ibid.
It used to be that the only planets we knew about were the ones that orbit our sun. Now we’ve discovered rocky worlds and gas giants orbiting other stars. And they tell an amazing story. Planets are made everywhere in the same way – they form from the dust and debris left over from the birth of stars. How The Universe Works s1e6: Extreme Planets
No two planets are the same. Each is unique. ibid.