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Did Time Start at the Big Bang?

July 18, 2019 / / 0 Comments

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Our universe started with the big bang. But only for the right definition of “our universe”. And of “started” for that matter. In fact, probably the Big Bang is nothing like what you were taught.
A hundred years ago we discovered the beginning of the universe. Observations of the retreating galaxies by Edwin Hubble and Vesto Slipher, combined with Einstein’s then-brand-new general theory of relativity, revealed that our universe is expanding. And if we reverse that expansion far enough – mathematically, purely according to Einstein’s equations, it seems inevitable that all space and mass and energy should once have been compacted into an infinitesimally small point – a singularity. It’s often said that the universe started with this singularity, and the Big Bang is thought of as the explosive expansion that followed. And before the Big Bang singularity? Well, they say there was no “before”, because time and space simply didn’t exist. If you think you’ve managed to get your head around that bizarre notion then I have bad news. That picture is wrong. At least, according to pretty much every serious physicist who studies the subject. The good news is that the truth is way cooler, at least as far as we understand it.

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Hosted by Matt O’Dowd
Written by Matt O’Dowd
Graphics by Leonardo Scholzer
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

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Vinnie Falco

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Hank S
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Matthew
Matthew O’Connor
Syed Ansar

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Tim Jones
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The Quantum Internet

July 15, 2019 / / 0 Comments

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When we finally have a quantum internet you’ll be able to simultaneously like and dislike this video. But we don’t. So I hope you like it. The world is widely regarded as being well and truly into the digital age, also called the information age. No longer are economies and industries solely characterised by the physical goods they produce, and in fact some of the largest companies in the world produce no physical goods at all: digital information is a commodity in its own right. As discussed in a previous episode, this worldwide digital economy is fundamentally reliant on certain cryptographic processes. Currently these processes work in the realm of classical cryptography, but one day soon this may not be enough and so quantum cryptographic methods and algorithms are being developed. However, it’s one thing to design a protocol, it’s something else entirely to build a system to support it. To understand what needs to be done we need to get to the foundations of quantum mechanics – we need to talk about quantum information theory.

Hosted by Matt O’Dowd
Written by Graeme Gossel and Matt O’Dowd
Graphics by Leonardo Scholzer
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

Big Bang Supporters:

Anton Lifshits
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Juan Benet
Justin Lloyd
Morgan Hough

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Vinnie Falco

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Donal Botkin
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Hank S
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Matthew O’Connor
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Thorium and the Future of Nuclear Energy

July 1, 2019 / / 0 Comments

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Energy too cheap to meter – that was the promise of nuclear power in the 1950s, at least according to Lewis Strauss chairman of the Atomic Energy Commission. That promise has not come to pass – but with some incredible new technologies, perhaps it still could. The question is – should it?

Hosted by Matt O’Dowd
Written by Matt O’Dowd
Graphics by Leonardo Scholzer
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

If we want to convert mass into energy, fission gives the most bang for our buck. Unfortunately that “bang” can be literal. Use of nuclear energy may risk the proliferation of nuclear weaponry, and there’s also the problem of nuclear waste, and the specter of horrible accidents. This last one was painted in terrifying detail in the recent dramatization of the Chernobyl disaster. Nuclear reactors sound scary because the disasters are pretty epic. However the reality is that far, far more people die from straight up air pollution due to coal-fired power plants than ever died in a nuclear reactor accident. In fact the radioactivity around coal-fired plants is also higher due to the trace but completely uncontained radioactive products of coal burning.

But the most compelling attraction is that nuclear power doesn’t directly produce carbon emissions. In fact nuclear power may be our most sure path to reducing carbon emissions and halting climate change. But can we do nuclear power safely enough? There are modern ideas – including the much-hyped thorium reactor – that suggest maybe we can. Before we can understand those we’ll need to review how nuclear reactors work.

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The Quasar from The Beginning of Time | STELLAR

June 20, 2019 / / 0 Comments

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Check out Physics Girl visit LIGO to see where they discovered Gravitational Waves
https://youtu.be/jtp71NT0GNg

Recently, the oldest quasar ever seen was discovered by the Gemini North telescope in Hawaii, the Magellan Telescopes at Las Campanas Observatory in Chile, as well as the Large Binocular Telescope in Arizona. In this first episode of the PBS DS mini-series, STELLAR, Matt travels to the top of Mauna Kea to visit the Gemini North telescope and see just how they found this ancient Quasar and it’s massive black hole.

Stellar is a brand new miniseries done in collaboration with Dianna Cowern from @Physics Girl and Joe Hanson from @It’s Okay To Be Smart Over six episodes we travel to some of the world’s most important telescopes, go inside amazing space research centers, and talk with brilliant scientists. Next up, Dianna from Physics Girl visits LIGO observatory in Washington that detected the very first gravitational waves. Then Joe Hanson visits one of the telescopes that was part of world spanning Event Horizon Telescope.

You’ll be able to see future episodes on the Physics Girl and It’s Okay to be Smart YouTube channels, as well as the PBS Digital Studios Facebook page.

Stellar is a part of the PBS Summer of Space. There will be lots of awesome space-related content all summer long on PBS. See what’s happening at https://www.pbs.org/summer-of-space/

#SummerOfSpacePBS #astrophysics #space

Special Thanks to Joy Pollard and Gemini Observatory for all their help making this episode.

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Hosted by Matt O’Dowd
Written by: Sophia Chen, Matt O’Dowd, Andrew Kornhaber, Eric Brown
Directed by: Eric Brown and Andrew Kornhaber
Producer: Randa Eid
Director of Photography: Eric Brouse
Sound: Tobi Nova
Production Assistant: Anna Bosketti
Editing: Pavel Ezrohi
Graphics: Murilo Lopes
Assistant Editing: Daniel Sircar
Produced By: Kornhaber Brown

How Black Holes Kill Galaxies

June 17, 2019 / / 0 Comments

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Black holes are really only dangerous if you get too close. Ha, who am I kidding. It turns out they may be responsible for ending star formation across the entire universe.

Hosted by Matt O’Dowd
Written by Matt O’Dowd
Graphics by Leonardo Scholzer
Directed by Andrew Kornhaber
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When we first realized that black holes could have masses of millions or even billions of times that of the sun, it came as a bit of a shock. They were discovered as the driving force behind quasars, where matter is heated to extreme incandescence before its plunge into vast black holes. But if that weren’t enough, we soon realized that every single decent-sized galaxy contains such a supermassive black hole. By the beginning of the 21st century it became clear that black holes and the galaxies that contain them are very closely connected. The bigger the galaxy, the bigger its supermassive black hole. That might not sound surprising. What was weird was how closely they were connected. There’s a tight correlation between the mass the central black hole and the mass of the stars in the galactic bulge – that’s the central ball-like part of a spiral galaxy, or the entirety of an elliptical galaxy, and every bulge contains a supermassive black hole around one-one-thousandth its mass. And there’s an even tighter relationship between the black hole mass and the speed that stars are moving in their random orbits within the galactic bulge – the so-called stellar velocity dispersion – which itself depends of the total mass of the galaxy, including dark matter.

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The Alchemy of Neutron Star Collisions

June 6, 2019 / / 0 Comments

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Carl Sagan’s famous words: “We are star stuff” refers to a mind-blowing idea – that most atomic nuclei in our bodies were created in the nuclear furnace and the explosive deaths of stars that lived in the ancient universe. In recent years it’s become clear that the truth is even more mind-blowing. Many heavy elements – includes most precious metals – were produced in an even more spectacular event: the collision of neutron stars. In fact, according to a recent study most of the Earth’s supply of these elements was created in a single neutron star merger that took place near our Sun’s birth nebula 80 million years ago before Earth formed.

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#theuniverse #astrophyics #spacetime

Hosted by Matt O’Dowd
Written by Matt O’Dowd
Graphics by Leonardo Scholzer
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

When I was in astrophysicist school they taught us that all of the elements of the periodic table between carbon and iron were produced in onion shells by nuclear fusion in the cores of very massive stars during the last phases of their lives. And that the elements heavier than iron were synthesized in the following supernova explosion. That latter process is well understood – the star’s dead core collapses and protons are converted to neutrons. The surrounding shells ricochet outwards, along with a layer of the iron and nickel core. The latter is blasted by a wave of neutrons, which get rammed into the escaping nuclei. Some of those captured neutrons convert back to protons and so elements all the way up the periodic table can be made. This is the rapid neutron capture or r-process. The rapid part is because neutrons are captured faster than nuclei can decay, making it possible to build very heavy nuclei.

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The Cosmic Dark Ages

May 16, 2019 / / 0 Comments

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We live in the stelliferous era. Somewhere between 10 and 1000 billion trillion stars fill the observable universe with light. But there was a time before the first star ignited. A time we call the cosmic dark ages.

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https://youtu.be/vNaEBbFbvcY

#theuniverse #astrophyics #spacetime

Hosted by Matt O’Dowd
Written by Matt O’Dowd
Graphics by Aaron Havley
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

In astronomy we study things that are very far away. It’s a powerful challenge because even the brightest objects are almost impossibly faint when you view them from the other side of the universe. But there’s an up side. If the light from some space object took billions of years to get to us then we see that object as it was billions of years ago. In this way we can peer back in time and literally see the past in motion. In fact we’re able to see some of the first stars and galaxies to ever form. But if we look beyond, both in distance and in time, there is … nothing. Darkness. For the hundred million years or so between the formation of the first atom and the formation of the first star there were no light sources in the universe. These were the cosmic dark ages. It’s a period of cosmic history rarely discussed because it’s hellishly difficult to observe. Fortunately scientists are devilishly clever. So what do we know about the time before stars?

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Why Quantum Computing Requires Quantum Cryptography

May 9, 2019 / / 0 Comments

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Quantum computing is cool, but you know what would be extra awesome – a quantum internet. In fact if we want the first we’ll need the latter. And the first step to the quantum internet is quantum cryptography.

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#cryptography #quantumcomputing #spacetime

Hosted by Matt O’Dowd
Written by Graeme Gossel and Matt O’Dowd
Graphics by Leonardo Wille
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

Quantum theory may seem like an obscure subject of questionable relevance to the average person. But in fact much of our technological world depends on our understanding of the quantum properties of the subatomic universe. And soon, perhaps very soon, we’ll be interacting with the weirdness of quantum mechanics even more directly – with the coming of quantum computing and the quantum internet. Quantum computing is a topic that’s that has been well covered, so we’re going to be talking about the quantum internet. Specifically quantum cryptography and quantum key distribution – the foundations of the prospective quantum internet. We may come back to quantum computer in detail – but for now let me show you why their advent will demand a quantum internet.

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Anton Lifshits
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Vinnie Falco

Hypernova Supporters:

Antoine Brugier
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Hank S
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kkm
Mark Heising
Matthew
Matthew O’Connor

Gamma Ray Burst Supporters:

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Antonio Ruiz
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James Flowers
James Quintero
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John Pollock
Jonah
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Mark Vasile
Nathan Hitchings
Nick Virtue
Paul Rose
Ratfeast
Ryan Jones
Scott Gossett
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Tim Stephani
Tommy Mogensen
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سلطان الخليفي

The Real Science of the EHT Black Hole

May 1, 2019 / / 0 Comments

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How do you take a picture of a black hole and what can we learn from it? Our first ever actual bona fide photo of a black hole, made by the Event Horizon Telescope and revealed to the world in a press conference on April 10th. Since then it’s got plenty of coverage, because … I mean look at it. It’s a freaking black hole. It’s black, it’s holey, it’s everything we hoped it would be. Now that the giddiness has subsided and I personally have stopped spending hours on end staring at a black spot, we can take a breath and actually look at the real science here and discuss exactly how a picture like this could be taken and what we can learn from it.

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https://youtu.be/vNaEBbFbvcY

#Blackhole #astrophysics #spacetime

Hosted by Matt O’Dowd
Written by Matt O’Dowd
Graphics by Murilo Ceasar Lopes
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

So, how do you take a picture of a black hole? The beast in question is the supermassive black hole in the center of this – the M87 elliptical galaxy. It has an estimated mass of several billion times that of the Sun, which gives it an event horizon larger than the solar system. M87 is 53 million light years away, so resolving that black hole is equivalent to resolving a grain of stand on the beach in LA – if you’re standing in New York. By comparison, the Hubble Space Telescope would struggle to see a large watermelon over that distance.

Big Bang:
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Tambe Barsbay
Vinnie Falco

Hypernova:
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Chuck zegar
Danton Spivey
Donal Botkin
Edmund Fokschaner
Hank S
John Hofmann
Jordan Young
Joseph Salomone
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Mark Heising
Matthew
Matthew O’Connor

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No Dark Matter = Proof of Dark Matter?

April 24, 2019 / / 0 Comments

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We’ve been failing to detect dark matter for decades. Finally, the latest failure to detect dark matter may have actually proved its existence. One of these is true: either most of the matter in the universe is invisible and formed of something not explained by modern particle physics OR our understanding of gravity is completely broken. The debate over which is true has raged for decades, but may finally have been resolved in an unlikely way: the proof that dark matter exists, and really is an exotic, unknown substance, may have come from the discovery of two galaxies that appear to have no dark matter at all. Today on Space Time Journal Club we’ll look at the papers that reveal this discovery:

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#darkmatter #astrophysics #spacetime

Hosted by Matt O’Dowd
Written by Matt O’Dowd
Graphics by Kurtis Ross
Directed by Andrew Kornhaber
Produced By: Kornhaber Brown

The effect of dark matter was first noticed in 1933, when the legendary Swiss astrophysicist Fritz Zwicky noticed that the galaxies in the Coma cluster were moving too quickly to remain gravitationally bound within that cluster. He guessed the presence of “dunkle m aterie” – a dark matter invisible to his telescope but whose gravitational effect held the cluster together. As with many of Zwicky’s predictions – like the existence of neutron stars and gravitational lensing – this wasn’t taken seriously until decades later. The hunt for dark matter began in earnest after the early 70s when Vera Ruben, discovered that the rotation rates of spiral galaxies were too fast given the mass of their visible stars alone. They should throw themselves to pieces spinning that quickly – that is, unless, a gravitational force of unseen origin was holding them together.

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chuck zegar
Danton Spivey
Donal Botkin
Edmund Fokschaner
John Hofmann
Jordan Young
Joseph Salomone
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Matthew O’Connor

Thanks to our Patreon Gamma Ray Burst Supporters:

Adrien Moyneux
Alexander Lazerev
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Carlo Mogavero
Daniel Lyons
David Behtala
Dustan Jones
Geoffrey Short
James Flowers
James Quintero
John Funai
John Pollock
Jonah
Joseph Dillman

Joseph Emison
Josh Thomas
Kevin Warne
Kyle Hofer
Malte Ubl
Mark Vasile
Nathan Hitchings
Nicholas Rose
Nick Virtue
Ratfeast
Ryan Jones
Scott Gossett
Sigurd Ruud Frivik
Tim Crookham
Tim Stephani
Tommy Mogensen
Yurii Konovaliuk
سلطان الخليفي