Starts With A Bang podcast

Is there intelligent life out there in the Universe beyond planet Earth? If so, are they technologically advances, can they hear us, and are they broadcasting in ways that we could possibly detect them? In the absence of their arrival on Earth, you might think that there's no surefire way to know. But the scientists working hard on SETI, the Search for ExtraTerrestrial Intelligence, sure are trying their best. By listening to the Universe at large (and our galaxy in particular), they're hoping to uncover the answer to perhaps the ultimate question: whether there's a civilization out there that humanity might hope to make contact with, and that could perhaps be our ally in uncovering the great mysteries of the Universe. I'm so pleased to welcome astronomer and senior scientist at the SETI Institute, Seth Shostak, onto this edition of the Starts With A Bang Podcast!

In 2017, the incredible happened: for the first time in history, we were able to identify an object passing through our Solar System that originated from outside of it! Interstellar interloper 'Oumuamua was originally designated as a comet, then as an asteroid, and then as a new class of object: one of interstellar origin. It's a fascinating object that's the first of its kind, and much has been said about its composition, properties, and possible nature. But, unfortunately, the most famous of those "nature" discussions was from Schmuel Baily and Avi Loeb of Harvard, claiming that it could be due to aliens. Is that plausible? Is that even science? My guest for this edition is astrophysicist Paul Matt Sutter, author of the new book Your Place In The Universe, and we have an almost-hour-long discussion that goes to some fantastic and unexpected places. You won't want to miss it! Find Paul online on Twitter https://twitter.com/PaulMattSutter, Video: http://www.pmsutter.com/shows/askaspaceman/, Book: Your Place In The Universe https://amzn.to/2DCysNj.

Our Solar System formed some 4.6 billion years ago from a molecular cloud that collapsed. Our proto-Sun formed along with a protoplanetary disk that eventually evolved into the Solar System we have today, complete with the inner, rocky planets, an asteroid belt, the gas giants and their moons and ringed systems, and then the outer Solar System. Those outer regions sure are interesting, and it's only over the past 3 decades we've really started to learn about them in earnest. I had the opportunity to speak with outer Solar System specialist Michele Bannister, and she agreed to be this month's guest on our podcast. Oh, did an exciting discussion ensure, and we've got over an hour of knowledge for you! What's the status on how the Solar System formed, on Planet Nine and its alternatives, and what the prospects are for taking the next major steps? Find out on this edition of the Starts With A Bang podcast! Find Michele here at her current research location: https://pure.qub.ac.uk/portal/en/persons/michele-bannister(c83612a1-80b4-4f78-a9f2-85efe0347d3a).html And on Twitter @astrokiwi: https://twitter.com/astrokiwi?lang=en

I'm so pleased to welcome Dr. Erin MacDonald to the Starts With A Bang podcast, as we discuss the future of Gravitational Wave astronomy. From pulsars to merging black holes, to kilonovae to hopes of observing gravitational wave signatures from the earliest moments of the Universe, we cover a whole lot of astrophysics, cosmology, and experimental hopes for the near future in this burgeoning new field of astronomy. The future of gravitational wave science is so bright, even without the collection of any light. Come learn all about it today! Find Dr. Erin MacDonald online here: Website: www.erinpmacdonald.com YouTube: www.youtube.com/c/erinmacdonald

There's been a lot of speculative ideas put forth about the Multiverse, and I dare say that a great many of them are nothing more than wishful thinking. But that doesn't mean the Multiverse itself is ill-motivated at all. Rather, if you take two of our best theories that have been well-confirmed in a wide variety of different ways, you're going to find that you arrive at a bizarre but unavoidable picture: one of an inflating spacetime, eternal to the future, where regions that look like our Universe, complete with a hot Big Bang, are spawned continuously. The evidence might not be there, observably, to confirm or deny the existence of a Multiverse. But as a theoretical consequence, it certainly has a motivation that's far stronger than practically anyone realizes. Here's the cosmic story.

The Universe, today, is expanding and cooling, as the volume of the Universe increases while the number of particles within it remains constant. If you extrapolate forwards in time, the Universe gets sparser, less dense, and closer to being completely empty. But if you extrapolate back in time instead, the Universe gets hotter, denser, and smaller in volume. Eventually, if you didn't stop yourself, you'd go all the way back to a state of infinite density, where all the matter was packed into a single point: a singularity. This was where, when it was first formulated, the idea of a Big Bang singularity came from, and the idea that space and time had a beginning. Yet we no longer believe that to be true! Why not? Come find out on this edition of the Starts With A Bang podcast!

Have you ever wondered what's out there in the Universe, on the largest scales, beyond what we can even observe? Or what lies down below the tiniest distance scales we've ever probed? Is there a smallest fundamental length scale in the Universe, like the Planck scale, or can we go down even farther? Is space discrete or continuous? And is the Universe fundamentally blurred; can we even distinguish? Thinking about the limits of space, on both small and large scales, is a mind-bending game to play, but we're up to the challenge on this latest edition of the Starts With A Bang podcast!

There are three very different ways humanity is searching for alien life beyond Earth. We can directly search the various planets and moons in our Solar System for past or present biological signatures simply by sending decontaminated probes, and looking for the evidence in situ. We can indirectly look at distant worlds around other stars, searching for the characteristic changes to the atmosphere and surface that life would bring. And, most optimistically, we can search for intelligent signatures created, perhaps willfully, by a technologically advanced alien species. These are our three hopes for finding alien life, and we're actively pursuing all three. Here's how the different searches work, along with some speculation about what we're likely to find, and what motivates us to look!

There are some incredibly big questions that humanity has been asking about the Universe since we first began looking upwards: what is the Universe like, how did it get to be this way, where did it all come from, and what is its eventual fate? There were huge advances that were needed in order to answer these questions, such as understanding what the Universe was made of, how fast it was expanding, and what the laws governing it were. But once we know that, not only can we answer these questions, but we can do it with a single equation. It's known as the First Friedmann equation, and I call it the most important equation in the Universe. Find out why on this edition of the Starts With A Bang podcast!

In memory of Stephen Hawking's life, I've decided to share the physics behind his greatest discovery: Hawking radiation. For a long time, in the context of relativity, we thought that black holes were static, unchanging objects defined only by their mass, charge, and angular momentum. A number of developments led us to understand that black holes needed to have entropy, temperature, and therefore, they needed to radiate. But Hawking was the one to put that puzzle together, and describe the physics of the radiation and its consequences for black holes. It goes much further than that, with the famed (and still unresolved) black hole information paradox arising from his work. Who will be the ones who take the next great leap? Come learn what we know and where the frontiers are on this special edition of the Starts With A Bang podcast!

When you fall inside the event horizon of a black hole, there's no escaping, no matter what you do or how you accelerate. Even if you travel at the Universe's speed limit, the speed of light, there's simply no way to get any closer to the exit. Instead, scientists say, you have no choice but to fall inevitably towards the singularity at the center. But why must you arrive at a singularity? Couldn't you wind up at some degenerate object instead? We don't think so, and here's the science behind why. Find out what's at the center of a black hole today!

A simple, innocent question that I received had me thinking for days about how to answer it. The question? "If humans were made in God's image, whose image were aliens made in?" There's so much to say from a science perspective about how humans were made, and how aliens might be made, that I couldn't resist giving it my absolute best! Do you agree? Comment below!

Ever wonder about the biggest questions that there are? You know the ones I mean: about what is the Universe, where does it come from, and what is its fate? For millennia, these were questions for poets, philosophers, and theologians. Yet, despite all the "answers" that they offered, there was no way to test or verify whether they were correct. Enter science. After countless lifetimes struggling mightily with these, we have the answers, and they're spectacular. What do we know? How do we know it? And why is science so powerful at giving these answers? Find out, on this latest edition of the Starts With A Bang podcast!

Ever dream of traveling back in time? According to all the laws of special relativity, all you can do is travel forwards through time, controlling your rate by controlling your motion through space. But in General Relativity, the curvature of spacetime allows you to play with those rules a little more flexibly. You can make it back in time, but you still can't kill your own grandpa before your parents were conceived. Find out why on this edition of the Starts With A Bang podcast! Video version (for the first time): https://www.youtube.com/watch?v=PhCxtdxa8nI

Our current best theories describing the Universe, general relativity for gravity, quantum field theory for electromagnetism and the nuclear forces, do a fantastic job independently and together. But there are fundamental questions that go unanswered if we take these as the final answers. What happens to the gravitational field of an electron passing through a double slit? What happens to the information on a black hole's surface when it decays? And what happens close by a gravitational singularity? Without a quantum theory of gravity, we can't know. Yet we're on a path to try and figure it out! Where are we, and how far do we have to go? Find out, on this edition of the Starts With A Bang podcast!