Name: How to Build the Universe
Uploaded: undefined
Duration: undefined

NOVA

Carlisle Companies

Viking

NOVA Science Trust Logo

<div class="rich-text">A how-to guide for anyone planning to build a universe.
</div>

A how-to guide for anyone planning to build a universe.

How to Build the Universe

<div class="rich-text">A how-to guide for anyone planning to build a universe.</div>

Physics & Math

<div class="rich-text"><h3>
 How to Build the Universe
</h3>

 Aug. 17, 2017



 Greg Kestin:
 
 Last time, I took everything in the known universe out of this box and put it on the table. Wait, where are the black holes? These are always so hard to find. Okay, everything in the known universe. And in this video what I’m going to do is I’m going to show you how to put it together because, let’s be honest, nobody reads the manual.


 Let’s start with a galaxy. You see how there are a bunch of small, stellar mass black holes and then this one supermassive black hole? Let’s take the supermassive black hole and put it right there. That’s going to be the center of our galaxy.



Check out stars at the center of the milky way, they’re zooming around a huge invisible object…probably a supermassive black hole.


All right, let’s put in the stars. I’m going to build this a little bit like our galaxy, so let’s start with the red stars and fill it up with about 100 billion of those. Then we have our yellow and orange-ish stars, and that’s about 20 billion. And then we’re going to put in — just sprinkle a few billion blue and white dwarfs in there. And then we’re going to take our small black holes and we’ll just sprinkle them in — and that’s about 100 million of those. Now, this is looking good. Let’s tweak a few of these, and then let’s spin it up.


You’ll notice around the edges the stars aren’t moving quite as quickly as you’re used to from your everyday experience with galaxies. And, actually, let me try something. I’m just gonna see how much this… So, it feels a little light. It feels like about 60 billion times the mass of the sun, so that’s a little light. Okay, I think I know how to solve both our spinning star problem and the weight. Let’s put in some dark matter. So, let’s just spray that. Now, you’ll notice that we have this spherical halo of dark matter that we sprayed in there, and — let’s spin it up a little bit faster so the stars don’t fall in. If you simulate it, you’ll see that if you build your galaxy with a dark matter halo, the increased gravity will let the stars around the edge move faster, just like a real galaxy.


We have our galaxy. But you’ll want to put together the entire universe. Now, I’m not going to put together the entire universe, because that’s an infinite number of galaxies and this is just a tutorial. I’ll let you handle that. I’ll just put together the entire observable universe, because that’s only about 2 trillion galaxies. Let’s go ahead and do that.


I think it’s ready.


The observable universe. I thought, since it’s about 13.8 billion years old, it would be about 13.8 billion light years across. But, if we look at it, it seems like, yeah, it’s about 46 billion light years across. Bigger than I thought. That’s the opposite of what happened when I ordered my computer.


You can tell this universe is old because it’s filled with cosmic webs — made of galaxies. But if we look at a younger universe, it’s mostly a sea of hydrogen with a star here or there.


Okay, back to our universe. Now don’t forget, you need to water it so it can grow and expand. And what you need for that is some dark energy. Wherever you look in the universe, there’s dark energy, and it’s causing the expansion of the universe to accelerate. Now, that’s a little bit better. It’s growing, expanding. If you hold onto it, for, say, 10 billion years, it’ll approximately double in size. Now, that is a good investment.


What do I think of the universe? Well, it’s nice. It has the perfect properties for life, it’s a little bit sparkly… It’s sort of a rip-off because most of it's empty space. Also, it doesn’t really hold up well over time. After a while it turns into mostly holes — just black holes and almost nothing else. And even those disintegrate after long enough. So I’m gonna go ahead and give this three stars.


Oh, what? Oh, no!

</div>

United States

Northern Mariana Islands

Puerto Rico

American Samoa

Guam

U.S. Virgin Islands

U.S. Minor Outlying Islands

US & Territories

Colossal explosions shake a remote corner of the Siberian tundra, leaving behind massive craters. In Alaska, a huge lake erupts with bubbles of inflammable gas. Scientists are discovering that these mystifying phenomena add up to a ticking time bomb, as long-frozen permafrost melts and releases vast amounts of methane, a potent greenhouse gas. What are the implications of these dramatic developments in the Arctic? Scientists and local communities alike are struggling to grasp the scale of the methane threat and what it means for our climate future. (Premiered February 2, 2022)

In the Arctic, enormous releases of methane, a potent greenhouse gas, threaten the climate.

Arctic Sinkholes

The top half of Jupiter in blue and green against a night sky

A composite image of Jupiter using images captured by the James Webb Space Telescope. Image Credit: NASA, ESA, CSA, Jupiter ERS Team; image processing by Judy Schmidt.

Explore the cosmos, delve into ancient history, and follow an extreme rescue with NOVA’s most-watched documentaries released in 2022.

NOVA’s most popular science documentaries of 2022

Four bright orange loops brand off of a dark blue blob

A transmission electron micrograph of HIV-1 virus particles (orange) replicating from the plasma membrane of an infected H9 T cell. Credit: NIAID, Flickr

Scientists have cured a handful of people of HIV by piggybacking on treatments they received for blood cancer. But does that bring a widespread cure any closer?

Transcript

Credits

Support Provided By