Andromeda Galaxy
Andromeda Galaxy

Cosmic Queries – Galaxies Galore

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About This Episode

What does JWST tell us about galaxy formation? Neil deGrasse Tyson and Chuck Nice answer questions about galaxies, measuring the distance of far away objects, dark matter, primordial galaxies, and more!

How do we determine how far things are from Earth? Learn how stereoscopic vision inspired astrophysicists to discover the distances of far away stars. Learn about Henrietta Leavitt, variable stars, and Hubble’s discovery of the andromeda galaxy. What is parallax? Find out about arcseconds and how Star Wars uses parsec wrong.

Why can we see massive galaxies just after the big bang? We discuss JWST’s primordial galaxies and the definition of dark matter versus dark energy. Why doesn’t dark matter fall into the center of galaxies? How do supermassive black holes get so big? What does this mean for the age of the universe?

We explore redshifting and the nature of the universe’s expansion. What would be necessary technology for aliens to have in order to visit us? Why would aliens be interested in Earth? How has the JWST forever changed our understanding of the universe?

Thanks to our Patrons Will Bailey, Joanie Nelson, Holly Harlin, Terry Eby, Brian Pennington, Dan Dymek, and Alex Florescu for supporting us this week.

NOTE: StarTalk+ Patrons can listen to this entire episode commercial-free.

Transcript

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Coming up on Star Talk, Cosmic Queries, Galaxies galore.

You’re gonna learn about how we get the distances to things in the universe.

And what else is going on with the James Webb Space Telescope?

Messing with our tidy theories of the early universe.

All that and more coming up on Star Talk.

Your place in the universe where science and pop culture collide.

Star Talk begins right now.

This is Star Talk.

Neil deGrasse Tyson here.

You’re a personal astrophysicist.

Co-host Chuck Nice.

Chuck, all right, man, how you doing?

I’m doing great.

How’s it going, Neil?

Yeah, we’re a little overdue for another Cosmic Queries.

Yes.

Which is always a fan favorite.

And apparently today has a topic.

Oh.

So as we’ve been doing a lot of Galactic Gumbo lately.

But this one is Galag-

Galon-ty.

Just grab a bag of-

This one is Galaxies Galore.

So maybe, are they all about galaxies?

Is that what you put them together?

Galaxies are my thing, you know.

Well, me and galaxies go way back.

Let’s hope so.

Well, I’m on the wrong show.

We’re in a lot of trouble.

It was just like, I don’t know what we’re going to do now that they’re asking about galaxies.

I don’t know any.

All right.

So bring it on.

Okay.

Let’s get to it.

Let’s get right to it.

We got Bruce Ryan, who says, greetings, gents.

Who changed his name so that you could pronounce it.

Just thought I would tell you that.

Yes, I’m sure.

And by the way, thank you, Bruce.

Yes.

Actually, I should thank your parents.

He says, greetings, gents.

I’d love to know how you determine how far away stars or even galaxies are from Earth.

And isn’t that distance based on the light we’re seeing now as opposed to the actual distance given the expansion of the universe?

Thanks in advance, Bruce Ryan.

All right.

Well, look at that.

So there are two ways I can answer that.

One is completely lazy.

All right.

All right.

All right.

So I’ll give that answer second.

No, give the lazy answer first.

Really?

I mean, unless it’s just, unless it’s like, yes.

Right.

If it’s that lazy, then…

No, no, no.

The lazy answer is…

Our second StarTalk book published with National Geographic called Cosmic Queries has an entire section on how astronomers find distances to things in the universe.

And it was called the Distance Ladder.

It’s called the Distance Ladder because you figure out the distance to nearby things, and then you step on that rung, and that enables you to then think about distances to the next categories of objects, because the same methods don’t apply at all distances.

So, the objects that are farther away depend on the accuracy of methods and tools you use for closer objects, right on down to the distances to nearby stars and even the planets themselves.

Right, I was going to say, does that apply to the planets?

So, my answer to you is read the damn book.

That’s the lazy answer, read the book.

Yeah, if you get a nice big fat book, it makes a good gift, but there’s an entire set, a lot of energy was put, many, many pages on this.

So, just so you know.

And yes, by the time we get to galaxies, light has been traveling for a great time before it reaches us, but we have other evidence to show that the speed of light has been constant, not only across space, but also through the depths of time.

Otherwise, we would not be getting the right answers to things that are far away, which depend on the light travel time and things like this and how fast they’re moving in the expanding universe.

There’s a lot of interdependent factors there.

So, that’s the easy answer.

But I’ll give you a starter answer to get you ready for when you get the book.

When you get the book.

So, here it is.

So, we have two eyes.

And if you put your two fingers out in front of you, you can have them hit each other every time.

You’re using a stereoscopic vision to make that happen.

If you try that with one eye, put your fingers at arm’s distance and use two eyes and have them connect to each other.

Just do that.

Easy.

Now, bring your hands back in.

Close one eye.

Put your arms out.

Now, try it again.

Oh, my gosh.

First of all, officer, I do not think that this is a fair test.

I’m just saying I have one beer at work, and quite frankly, I…

Wow, that’s amazing.

Yeah, yeah.

So let the record show that Chuck could not have his fingers.

Neither could I.

I close one eye, put my hands back, and I miss it by an inch.

Yeah, it’s so funny.

Four centimeters.

But you have to refresh the…

Right, right.

You can’t leave it.

Refresh your arm.

If you just leave it there, your brain actually makes up the difference and does it for you.

Because you know what you’re trying to do.

Right, so with two eyes, you do it.

Right.

Do it every time.

Bring your hands back in.

Go one eye, do it, and you miss.

Look at that.

So that’s called…

So what we did was…

It’s a method of triangulation.

You have two angles of view.

So in other words, you have one sight line that intersects.

It could be anywhere along the sight line.

If you have two sight lines, those two sight lines intersect at a single point.

Right.

And geometrically, you can know exactly the distance to that object using this method.

So my people are very clever.

Very clever.

We said, let’s do that with the Earth’s orbit.

Right.

Right.

The Earth’s orbit.

Because consider, the farther away something is, the less useful this separation of your eyes will be.

Right.

Think about it.

Right?

If something is a mile away, you can’t use starry vision to get a distance to it.

Exactly.

It’s just far.

Alright?

Stars are far.

So how do you help out the baseline of what would be your eye sockets for something that’s that far away?

You use the entire orbit of the Earth.

Orbit of the Earth around.

Isn’t that something?

That’s so smart.

So like one eye.

It is.

One eye is Earth in June.

The other eye is Earth in December.

So you see them because they’re in two different spots.

It’s your left eye and your white eye.

And then you have a sight line.

And then you look for the points where they come together.

Two different sight lines.

And so here the way this works is.

My God.

That is so simple.

It’s so smart.

My people.

These are my people.

These are my people.

Proud of my people.

Yeah.

So, you get the nearby stars, and it turns out they’re far, but they’re close enough for this method to work.

And here’s what you do.

You take a picture of that star against the background star.

And it’s going to be sitting in front of some pattern.

Then you wait six months.

You take that same picture again, and your sight line on that star has changed, and now it’s sitting slightly in front of a different pattern of star.

Very slightly.

That corresponds to an angle.

And that angle, okay, is one part of that triangle, and we have the base of that triangle, which is the diameter of Earth’s orbit.

Right?

Because it’s not the radius.

It’s the full diameter.

That’s like the diameter between your two eyes.

You do the geometry of this.

We know the distance from Earth to the Sun.

You need that because that’s one of the legs of this triangle.

Before we knew the distance from Earth to the Sun, you could not successfully apply this method because you’d be missing one of the dimensions.

Let’s say you had the wrong measurement here.

That wrong measurement would eke its way into these other measurements and propagate through all of your estimates for the distances to stars in your neighborhood.

Before we knew the Sun was 93 million miles away, the answer to this question was, whoa, you don’t even want to know.

I never thought of giving that answer to questions.

How far is the next star after the Sun?

Whoa, you don’t even want to know.

You don’t even want to know.

So that’s why it’s a ladder because any error at the base level of this would propagate to all other levels.

So now we get the distance to the nearby stars.

Now we hope, well, we made sure one of those stars is like the Sun.

Now we know the luminosity of the Sun.

We’re orbiting the damn thing.

And luminosity is how much energy it’s giving off.

So if I know how much energy it’s giving off, then I start putting it farther and farther away from me.

It gets dimmer, doesn’t it?

Of course, yeah.

If I know what its intrinsic luminosity is, then I can calculate the rate at which it gets dimmer as it moves away from me.

It’s called the inverse square law of light.

So if I find another star like the Sun, spectroscopically I get to say, that star is just like the Sun.

Just like our Sun, right.

And therefore I believe I know its luminosity because I know the Sun’s luminosity.

And look how dim it is.

Based on that, I can now give you the distance to that star with a simple formula.

So then I guess you change it because there are a lot of different stars with different luminosities and some things that aren’t even stars, you know.

Well, right, right.

So that gets me the distance to stars that look like the Sun.

Right, right.

But if I get a triangulated distance to a star that’s not like the Sun.

Like a brown dwarf or something.

Like a brown dwarf or any red giant or whatever.

And I get the triangulated distance.

Now I find another star like that and then I can apply the same method.

Damn.

I know, I know.

That is unbelievable.

I’m telling you right now.

Now you want to know, you know what, you know what I don’t know, when we dunked on this, you ready?

Go ahead.

Okay, recently there’s a satellite called Gaia, G-A-I-A, Gaia, okay?

Google it.

It is a specially tuned satellite designed to get this triangulated distance method to a billion stars.

Because it’s above Earth’s atmosphere, it can measure the tiniest angles with very high precision.

Oh my gosh.

So now we got that.

We’re good.

We good.

We can find these stars in other galaxies and get the distance there.

By the way, that’s what Hubble did.

Hubble said, okay, here’s a star that pulsates.

And it was discovered by Henrietta Leavitt and the women of Harvard College Observatory who were given the, quote, menial work of the laborers of calculating things with stars.

They were called human computers.

Turns out that’s what all the action was.

And modern stellar astrophysics was birthed in the room where it happened.

To quote Hamilton.

In the room where it happened.

All the women, there’s a bunch of women who all did this work while the men stood up in their smoking lounges, believing they were contemplating the universe.

But the real action, with their pipes.

The academics smoked the pipes.

That’s right.

Right, the gangsters, the fat cats smoked the cigars.

Yeah, the fat cats smoked the cigars and academics smoked pipes.

There was a guy I went to school with, he was a philosophy major, and he smoked a pipe.

And I said, I swear to God.

And everybody kind of, people were like, what a pompous pretentious ass.

But then one day I just asked, I was like, dude, seriously, why do you smoke a pipe?

And he had the pipe when I asked him.

And he went, because it makes me look like I’m thinking about something, when actually there’s nothing on my mind.

You got a head.

You got to give it to him.

I was like, 100%, you win.

There’s no comeback on that one.

So, let me end with this Hubble example.

So, Henrietta Leavitt figured out that the rate at which the star pulsates directly correlates with the luminosity of the star.

And again, all you have to do is know the…

What is the luminosity?

It’s the wattage stamped on the light bulb.

And so, if you know that there’s another light bulb with the same wattage, but it looks much dimmer, it’s because it’s farther away.

Because you otherwise can’t see distance in the universe.

The fact that you can’t see distance led legions and generations of people to think that the stars were just points of light on the inside of a dome, on the surface of a dome, leaving them to think that constellations were real things.

They’re scattered in space.

And since you, and they just did any other angle of view on them, they look completely different.

They’re not real things.

They’re completely in your head.

So stars are scattered in space.

So once you knew this, Hubble found one of these variable stars in the Andromeda Nebula.

And he measured its pulsation rate, deduced the luminosity, then calculated its distance, and it was a holy shit moment.

This nebula is not in the Milky Way.

It is way beyond the limits of the Milky Way.

In fact, it’s an entire other galaxy.

The Andromeda Nebula overnight became the Andromeda Galaxy.

Oh snap.

Yes.

All of these galaxies, we didn’t know these were just nebulae.

We just called them nebulae, the fuzzy spiral thing.

Why would we think there’s anything other than our own system?

It’s got a little bit of our ego playing out there.

There’s another island universe out there, an island galaxy.

There it was.

And then that opened up the entire universe.

And that happened between 1926 and 1929.

We’re in the centennial decade of discovering how big the universe really is because of a distance method to determine, a method to determine the distance to this kind of variable star discovered by Henrietta Leavitt in the Harvard College Observatory.

Unbelievable.

There it is.

That’s amazing.

Wait, then, once he got the distance to Andromeda, he could get distances to other galaxies with methods similar.

And then he found out that the galaxies are receding from us.

And the farther away the galaxy is, the faster it’s moving away from us.

Well, if that’s an actual relationship, then you don’t need to separately know the distance.

You just have to measure how fast it’s moving away, which you could do using the Doppler shift.

Just measure the speed moving away from us, and you put it in the Hubble equation and out pops the distance.

So that is the ultimate.

That’s the highest rung of the distance ladder, what’s called the red shift of the object, which was based ultimately on variable stars traceable to nearby galaxies, traceable in our galaxy, traceable to the triangulation method, traceable all the way back to just looking at stereoscopically with your eyes.

Look at that.

That’s amazing.

Well, Bruce, that was an extensive…

I got one more.

Wait, wait, wait, wait, wait.

There can’t be more.

Okay, ready?

Okay, here it is.

Okay.

You can ask if there’s an object where the angle changes by one arc second.

An arc second is one sixtieth of an arc minute.

There’s the angles now, even though it sounds like time.

One sixtieth of an arc minute and an arc minute is one sixtieth of a degree.

That’s how small these angles are.

Right.

Well, that makes sense.

Okay, so we have degrees, minutes, seconds.

So, if there were an object at a distance such that this angle was one arc second.

By the way, you know what we call this angle?

Changing out, we call it a parallax.

Okay.

You might have heard that word before.

Yeah.

The parallax is the angle change in a…

It’s a big deal.

By the way, have you ever been on 3D filmmaking?

Okay, exactly.

They care about that all the time.

The bigger the parallax, the closer your brain puts the object to you.

Your brain uses parallax to judge what’s close and what’s far.

So, and the farther away it is, the lower the parallax.

That’s why the moon follows you when you walk.

Oh, look at that!

Oh!

And here, I thought it was just me.

The moon is so far away from you and your eyes, that you don’t see a change in the angle on it against the background.

So it looks like it follows.

Whereas the trees have very high parallax as you walk by them.

So they have the highest parallax.

The trees across the street have a lower parallax.

Buildings near the horizon.

Okay?

The moon would eventually pass you by if you kept walking for another 300,000 miles, but that’s what you would need to get a big enough angle for that to happen.

All right.

Let me get back to this.

So an object whose parallax is one arc second is at a distance of one parsec.

What?

That’s amazing.

That’s where we get the distance parsec from.

Look at that.

Now, I lied a little.

It’s a little more complicated.

It’s half angle is one arc second, just because that’s how we define it.

The angle that connects to the sun rather than to the full baseline.

But that’s just a geometric factor there.

So you heard parsec used in Star Trek and some other sci-fi movies.

And our boy in Star Wars did the Kessel Run in 12 parsecs, which is profoundly ignorant of what a parsec is.

Because a parsec is a unit of distance, it’s not a unit of time.

And then the apologist got online and said, here, Dr.

Tyson, here’s why he says parsecs.

And it made up some total BS about…

It was a distance…

He found a loop that was shorter, and that’s why he did it in 12 parsecs instead of 15 parsecs.

And I said, all right, I’m staying away from this community of fans.

There’s no…

Because Star Wars is magic.

Let’s be honest.

So that’s the whole…

So I’m sorry, I blew half the time of this episode.

But it was very important.

And it took us, I would say, 60 years to fully develop that distance ladder.

And we’re still improving it.

Oh, by the way, we later would find out that Hubble was using a different kind of variable star than the one Henrietta Leavitt had used.

Uh-huh.

But it still correlated in that way, but it had a different correction factor.

And once they corrected the factor, the size of the universe, was it doubled or halved?

Again, because it was the foundation for the later measurements.

Right.

And so that’s how that uncertainty can creep in to the other measurements.

But there it is.

That’s really cool.

And all of that is in Cosmic Queries.

And a whole section called the Cosmic Distance Ladder.

Look at that.

I guess now you don’t have to buy the book, but you kind of do because you may go through it.

Well, no, you do because you need to go ahead and get that information so that you can have it as a reference.

Yeah, as a reference.

And it’s fully as it’s more organizationally laid out than I could possibly deliver in this.

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All right, this is Mike Parker, another great name.

Another good one, okay.

He says, hello, Dr.

Tyson and Chuck.

Mike from Richmond, Virginia here.

The James Webb Space Telescope is seemingly providing scientists with more questions than it is answers.

What is, in your opinion, how can we be seeing massive galaxies just after the Big Bang?

And what changes to cosmology do you see occurring as a part of the data so far?

So, I mean, two questions, but why is it that James Webb sees things in a timeline much closer to the origin of the universe as opposed to other telescopes?

And what do we know now that we didn’t know before because we can see that?

Okay, so a couple of things.

First, I’m actually an adopted son of Richmond, Virginia.

Oh, really?

From Richmond.

Yeah, I have an honorary doctorate from the University of Richmond.

Oh, very cool.

Yes, I do.

So I think about Richmond often.

And so, A, B.

I’ve actually been to Virginia Beach.

Oh, okay, music festival there?

Absolutely, yeah, as a matter of fact.

That’s a great music festival.

So, they said it seems that telescope is posing more questions than answers.

That’s what any good telescope ought to do.

So, in science, we have to learn to love the questions themselves.

Yes.

Lest we become irritated by not having the answers we seek, or maybe the questions we ask are not even what should be asked.

Right.

Because we don’t know what question to ask because we’re not standing in the right place yet to ask it.

Sometimes you ask a question and it leads you to a better question.

For example, what kind of cheese is the moon made out of?

Right.

That question has no meaning, but if you set up devices, you go to the moon and you say, no, in fact, it’s not made of any kind of cheese.

Maybe it’s made of rocks.

There you go.

So a good experiment will be a launch pad for other questions.

So indeed, the telescope discovered five galaxies, was it six or five, that where the sun don’t shine, where it ain’t supposed to be, this telescope is exquisitely tuned to observe the birth of galaxies.

So it is going right where we wanted it to go, and we don’t have a good answer to it yet.

Maybe we don’t understand the birth of galaxies enough to put them there in our distance calculation, right?

It’s our distance, we just spent a whole time talking about the distance ladder.

Maybe there’s some failure of the distance ladder at that point, or we just don’t understand how matter goes from energy and matter into solid objects.

All right.

So yeah.

So we’re not disturbed by this.

We are overjoyed that we are stumped.

And we spend most of our lives stumped at the chalkboard.

The drawing board, the white board.

That’s very cool.

And by the way, it don’t have to be a white board.

There’s also blackboard.

That’s right.

That’s all I’m saying.

Oh.

So yeah, it’s not a problem.

It’s a wonderful challenge that we’re all scratching our heads over.

Awesome.

All right, let’s go to Colin Brum.

And Colin says, Greetings from a small town in Iowa.

I have a question about dark matter.

If it is rarely or completely non-self-interacting, shouldn’t a majority of dark matter particles fall directly to the center of galaxies since there’s effectively nothing stopping them?

Is this a contributing factor to how possibly supermassive black holes got so big?

He says supermassive black holes.

Dark matter is mysterious gravity, is what it is.

It’s literally dark gravity.

It has gravity, we don’t know what’s causing it.

It’s not black holes, it’s not dark clouds, it’s not comets, asteroids.

It’s no ordinary matter is causing what we’re calling dark matter.

It’s the longest unsolved problem in modern astrophysics.

It’s been with us for 90 years, since the 1930s, okay?

So, just let’s put it out there.

So now, here’s what’s interesting about dark matter.

A property not shared with ordinary matter.

Ordinary matter, when it collapses, it sticks together.

Right.

Because other forces, well, gravity will take it, once it comes together, molecular forces kick in, where you get solid objects, okay?

What’s holding a rock together?

It’s not gravity.

No.

It’s electromagnetic forces.

What’s holding you together?

Me together.

Right.

It’s electromagnetic force holding our molecules together.

No such corresponding force holds dark matter together.

So, people say, could we find dark matter galaxies, dark matter planets?

Everything we know about dark matter says it cannot coalesce into quote, solid dark matter objects.

It would just pass because not only does dark matter not interact with us, it doesn’t interact with itself.

Okay, so it’ll feel its gravity, but there’s no place of concentration for it.

It’ll just continually move through space, hanging out in the hood, but not causing discrete dense objects.

And so we have no expectation that dark matter played any role in the formation of black holes, even though the formation of supermassive black holes remains a little bit mysterious to us.

And guess what?

If it’s not interactive, it wouldn’t be interactive with the black hole anyway, or it wouldn’t be feeding the black hole.

No, but what it would do…

Yeah, so it’s where the mass is.

So this mass blob called dark matter does attract regular matter into the blob.

It will do that, okay?

So regular matter is like the froth in the waves of the ocean.

There are these huge waves, which we don’t see.

Regular matter is the froth, okay?

But you look at the froth, the froth are these little things.

The wave is huge.

That’s great, that’s great, that’s great.

Compared to the froth, the waves are huge.

So the dark matter is spread out over the galaxy clusters, over the galaxy, but you can’t point to one spot and say, there’s where the dark matter is hanging out.

That spot, that’s going to pull you at no, it’s a general gathering of regular matter in the vicinities of dark matter.

So, wow, look at that.

So there are causal effects, but it is not interacting with us.

Correct, correct.

And that matters.

If you don’t interact, you can’t make an object.

We don’t think about it that way.

But when you make a snowball, what are you doing?

You’re squeezing it so that the snow sort of melts under pressure and it makes a solid object.

So there’s a lot we take for granted about why things stick together in our world.

But in the world of dark matter, that is not the case.

Wow, okay, man.

Thank you, Colin.

What a great question.

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Bringing the universe down to earth, this is StarTalk with Neil deGrasse Tyson.

Hey, let’s go to our old friend, Kevin Lesamoyer.

Kevin Lesamoyer.

Kevin Lesamoyer, who says, hey.

It’s a prerequisite, we gotta know what wine he’s recommending for this question.

And you know what, he didn’t give, I can’t believe it, he didn’t give us, hey Kevin, man, what’s the problem?

You normally give us something.

So Kevin, if you’re gonna be on our line here.

Exactly, man.

You know, hook us up, okay.

He says, I.

No, no.

Skip his ass, I don’t believe it.

All right, all right.

I know we’re recording this at a time that’s approaching the holiday season.

So a glass of port would be very.

Are you a tawny man or?

I can do tawny and ruby.

All right, okay.

So Kevin.

I am doing your work for you.

There you go, Kevin, look at that.

All right.

Kevin says, I read there were discoveries of galaxies forming in the cosmic dark ages.

Yes, this is what the other question was about.

Right.

That’s what, because it’s before stars formed.

Right.

So we called it the dark ages and we didn’t expect to find anything there and there they were.

And there they were.

Yes, okay.

So does this puts back on the age of the universe to coalesce once facts are earned than we originally thought.

So, but we don’t know.

Yeah, so that’s basically the same question.

Same question.

We don’t know.

We got top people working on it and we’re still scratching our heads.

There it is.

So this is Fadi Hayek and Fadi Hayek says, hello, Dr.

Tyson, Lord Nice.

This is Fadi Hayek from Indianapolis in Indiana.

On the nature of the expansion of the universe, is it that the galaxies are racing away from each other into nothingness or that the fabric of space time is dilating while the relatively distance between the galaxies is really not affected?

Or is the expansion a mere deep field effect created by fundamental misinterpretation as to why redshifting exists?

Look at that.

He’s got three things.

He’s everywhere with this question.

He’s all over.

All over and in it.

So no, it’s a simple answer.

So other than what we call random motions, but they’re not really random.

We call them that.

Random motions of galaxies near each other.

So we’re falling towards Andromeda.

That’s a nearby galaxy.

There’s some other galaxies in clusters.

If you take a step back and you look at the large scale structure of the universe, galaxies are moving away from one another.

If you just take a step back.

When you get up close, the ones near each other will be in orbit, but take a step back, clusters of galaxies, even isolated galaxies, they’re all moving away from one another.

They’re embedded in the fabric of space and time and is that fabric that is itself stretching, carrying the galaxies along with it, as though you drew on the surface of a balloon and then you started leveling up the balloon.

And then the fabric of the balloon is stretching.

The galaxies are not separating from each other within the balloon itself.

They’re embedded in the surface and the surface is stretching.

That is the signature of the expanding universe and we measure that.

Look at that, fantastic.

It’s a great question, man.

Jaden Peters says, Greetings, Dr.

Tyson.

Jaden Peters, aspiring astrophysicist from Ogden, Utah here.

Nice, nice.

I currently help to manufacture the motors for the Artemis programs.

It’s my first time asking a question and I’m extremely excited to do so.

So my man, look at that.

Artemis is the NASA’s return to the moon and Artemis in Greek mythology is the twin sister of Apollo.

Oh, look at that.

And by the way, if anything goes wrong with the mission, we know now who to blame.

Oh, he called himself out.

He called himself out, all right.

That’s right.

So my question is as follows.

He says, what are the necessary technologies for alien life to visit us?

And is it likely that aliens have any interest in Earth at all if they are so technologically superior to us to allow interstellar travel?

What use could they possibly have for Earth?

Thank you so much.

So first, I agree in principle that why would we be interesting to them at all with our backwards-ass technologies if they have interstellar space travel?

However, they might be interested in just life existing anywhere in the universe, as are we.

We’re searching other planets for life of any kind.

If we found microbial life, that would be amazing.

Worms, octopoids, whatever.

We would find that amazing for our biologists.

So I don’t wanna deny them the power of curiosity to see all the ways matter can manifest as life in the galaxy or across the universe.

That’s my first reply.

Second, maybe they live much longer than we do.

He too.

And that would be the real issue.

If they live a billion years, so what if it takes them 100,000 years or half a million years to travel?

Get somewhere.

Yeah, so that’s one factor.

Second factor, if they do have our limited life expectancy, then they would need something like wormholes.

Wormholes.

Without wormholes, which are portals through the fabric of space time where you don’t have to traverse the entire path, but you should just cut a hole through.

Sorry for those who are only listening to this podcast, but I have a wormhole in my hand.

And it is, you see the fabric of space and time as this ribbon, and the ribbon is curved, and the two edges of the ribbon are connected by two sort of dimples.

And you can cross this dimple without having to go the full length of this journey to get to where you’re going.

And so this curvature of space enables this wormhole to exist.

And so then you just jump through the wormhole and you get there instantly.

That’s right.

Yeah.

If we had wormhole, if Star Trek had wormholes, they wouldn’t need transporters.

No, exactly.

And you certainly wouldn’t need warp drives.

You wouldn’t even need warp drives.

You just open up a wormhole.

Just open up the wormhole and get to where you’re going.

And you know who does that every episode?

Is Rick.

Rick and Morty.

On Rick and Morty.

You know who does it on every movie?

No.

Dr.

Strange.

Oh yeah.

He just does it with magic.

Yes.

Whereas Rick does it with science.

I just want to distinguish those two.

Okay.

Yeah, yeah, exactly.

Yeah, that’s very cool, man.

All right.

I’m going to be like, normal matter and normal energy.

Thank you for all that you do.

And I absolutely love StarTalk.

Excellent.

Excellent.

We would have put his question on, even if he didn’t end it with that.

However, to anybody who writes in, feel free to kiss our ass whenever you want.

I’m all about it.

I am all about it.

Love you for it.

Love you for it.

And everybody needs encouragement.

There’s so much negativity in the world.

That’s true.

That’s right.

Anytime you want to put a little lip print on the posterior, I’m like, kudos to you.

Thank you so much.

I forgot the question.

So don’t over read into the fact that we call one dark energy and the other dark matter.

Right.

Because we don’t know what either of them is.

And I’ve said this before, we call Fred and Wilma.

That would be just as accurate as calling it dark energy and dark matter.

So Fred and Wilma, then you’re not biased in what you think it could be.

Because we don’t know what it is.

So could dark matter ever turn into dark energy?

The properties of these two entities are so, maybe, but I don’t see evidence of that.

Because as the universe expands, there’s more dark energy in it, but there’s not more dark matter.

There’s not more gravity.

We haven’t seen this effect of one converting to the other.

Could you see the effects of one diminish and the effects of the other increase?

And we don’t see that happening.

So I’d have to say no.

That’s pretty cool.

I mean, if that makes sense.

Yeah.

Chuck, give me one more and I’m going to sound bite it.

And then we got to call it up.

Hi, this is Charles Macco.

And he says, hey, Dr.

Tyson, and I’m guessing Chuck.

That’s what he said?

Yes, that’s exactly.

Occasionally we have other comedians in it.

Exactly, so he’s like, I’m guessing it’s going to be Chuck.

He says, how has the JWST changed our understanding of the universe itself?

And will it lead to the rewriting of textbooks?

Any textbook that talks about the latest discovery is always being rewritten.

But textbooks that talk about discoveries that are time tested with experiments and observations and repeated experiments, that stays the same.

So textbooks, they always want to be evergreen, but no one is going to buy them if it’s not current.

So textbooks have this issue.

And that’s why an online textbook is better because you can update it in real time as you need it to.

So some things will be rewritten, but it’s because they weren’t ever fully established in the first place.

But they put something in there.

Here’s our latest thinking on cosmology.

Yeah.

So we’ll see.

It’s a new telescope in a new window on the universe.

And for every new window that has ever been opened in the history of my field, it has transformed our understanding of the field in the areas where it specialized in.

So I fully expect that to happen in the days, weeks and years to come.

Also, the James Webb Space Telescope is just the next telescope.

We’re thinking of the stuff even beyond this.

We’re thinking of a 30-meter telescope.

Oh, my gosh.

Which would be far and away the largest telescope ever on Earth or in space to see things dimmer than ever previously imagined.

Because if you don’t have all the contents of the universe and you try to develop hypotheses and theories based on it, and then someone says, wait a minute, guys, there’s a whole other category of object that you didn’t see because your telescopes weren’t powerful enough to see it, that’s embarrassing.

But that’s the way of science.

It’s you do the best you can at any given moment.

But like I said, in the end, we all must learn to love the questions themselves.

There you have it.

There it is.

All right, Chuck, we got to close out.

Well, that was great.

That was a lot of fun.

I got to tell you.

All right, all right, all right.

And so another episode of Cosmic Queries.

And that one was almost all purely about galaxies.

That was all galaxies.

Mostly galaxies.

Well, yeah.

A little dark matter, you know.

I mean, dark matter counts as, you know, galaxies because, well, it does.

Galaxies have dark matter as part of it.

That’s right.

You know what I mean?

And very loosely held part.

Loosely held part of it.

So you got it.

All right, Chuck, always good to have you.

Always a pleasure.

All right, Neil deGrasse Tyson here for Star Talk.

As always, I bid you.

Thank you.

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