Ologies with Alie Ward - Cosmology (THE UNIVERSE) Part 2 Encore with Katie Mack
Episode Date: September 12, 2023Dr. Mack returns with a new introduction and updates on… listener questions! The universe, dimensions, asteroid bags and cosmic vertigo with the amazing Astro Katie, AKA Dr. Katie Mack. Part 1 was a... primer on all things cosmological, from particle physics to black holes, so listen to that first then hop to this episode to get all your questions answered.Visit Dr. Mack’s website and follow her on Instagram, Twitter, YouTube and TikTokBuy Dr. Mack's new book: The End of Everything (Astrophysically Speaking)More episode sources & linksSmologies (short, classroom-safe) episodesSponsors of OlogiesTranscripts and bleeped episodesBecome a patron of Ologies for as little as a buck a monthOlogiesMerch.com has hats, shirts, masks, totes!Follow @Ologies on Twitter and InstagramFollow @AlieWard on Twitter and InstagramEditing by Steven Ray Morris and Mercedes Maitland of Maitland Audio ProductionsTranscripts by Emily White of The WordaryWebsite by Kelly R. DwyerTheme song by Nick Thorburn
Transcript
Discussion (0)
Hey everyone, this is once again your friendly neighborhood cosmologist Katie Mac. I am
giving a little bit of an update to this episode. This episode is mostly answering questions about
astrophysics and cosmology things and
since it was recorded in 2017 there have been a couple of changes, a couple of updates.
One of the things that I answered questions about was asteroid
searches, and I mentioned that there is a big part of the sky we're not really looking at.
That has gotten better in recent years. There are some new observational projects.
We have a much better survey of the sky for finding potentially dangerous space rocks.
finding potentially dangerous space rocks. There's some caveats though.
One of them is that because of things
like these new constellations of satellites
that are going up,
some of that is making those observations
a little bit more difficult.
I think we're still in a much better place than we were,
and we're finding way more potentially hazardous objects.
Nothing is a big threat at the moment, don't worry.
But yeah, it'll
be interesting to see how that develops in the next few years. The other update is just
that my social media stuff is all different now. I'm still on Twitter as at Astro Katie,
though I'm using Twitter less these days. I'm on Instagram at Astro Katie Mac. So check
those out and just check out my webpage astro Katie dot com that hasn't changed.
You can learn about stuff like my book, the end of everything astrophysically speaking,
where I talk about how the universe might end and what that would look like if we could
see that.
And I have a newsletter now that you can also check out.
There's a sign up on my website.
It's called Watch this Space Time.
So thanks for listening and I hope you enjoy the show.
Hey, this is Ali Ward here with allergies. Now a few things up top. If you like allergies, I personally
myself would love it. If you took a second to rate and or review it on iTunes, have you done that yet?
It doesn't cost any money, you just do it.
And I also totally read all of your reviews. I'm thrilled by them. Today someone named
Smile Miss, there are six S's in that, said the actual best. Yep, the actual best. When things get
all jargony, alley fills in the gaps. Great guests, great topics, and a genuinely lovable host,
which by the way I read that while
walking into the post office and I almost started crying or skipping so thank
you everyone for these when you leave reviews and you rate it. Other people say
hey what's this thing? No. Cosmology part two. If you listen to the very very
end of part one last week with the just phenomenal Dr. Katie
Mack, aka Astro Katie.
Then you learned a lot about particle physics and the large heart on collider, um, string
cheese, black holes, the world's most expensive selfie, and your own aching insignificance, all
of ours.
If you haven't listened, give it a go.
I also tell you a somewhat embarrassing secret
at the very end of the podcast.
Maybe I'll do that again.
So part two with Dr. Mack
means getting right into the nitty-gritty,
your questions.
And trust me, I had a million.
But Katie and I were late to meet up with friends
to see Murder on the AuriniXpress.
So I could only ask about half an
hour's worth of questions.
So I may have to nab her in the future to ask the rest because there's so many questions for you.
It's like a rapid fire round.
Sure.
Yeah.
I'm here for it.
I'm going to throw a bunch of questions at you.
If you want to skip any of them, you can just pass.
First question is I'm going to ask her from the Patreon page.
Okay.
So people are patrons.
We appreciate them very much. They are great people.
They are great people. They are fantastic and we want them to continue and ask lots of questions,
which are all very good questions. Yes, exactly. Yes. You can be a patron for 25 cents
in episode. Which is an amazing deal. Is it a good deal? People should totally do that.
I want to make it accessible. If you did feel like tossing a dollar a month, then get yourself over to patreon.com slash allergies. I post calls for questions, some behind-the-scenes
photos, or some patron-only videos, and for $25 a month, I'll be your emergency contact,
which I hope you never need. And also, I may not be reliable. This is a question. I'm just going to
say one of the questions, but three different people asked a variation of it.
Erin Hirdman and Alex Entroini.
Entroini, Alex?
Did I do that right?
I'm sorry.
Both wanted to know.
Is there a name for the disorientation and panic
one feels when considering the vastness of the universe?
Also, do you know of a way to get past it?
There is a name.
So, but there are a couple of names.
One is Cosmic Vertigo.
Okay.
And the other is Cosmophobia.
And I don't know if these are like official names, but these are names that I've heard.
There's so a couple of friends and colleagues in mine have a podcast called Cosmic Vertigo
where they talk about cosmology and stuff and space and things, but it's based on that topic.
And Cosmophobia, I know about because I occasionally get emails from people who say that they
have severe cases and want my help. So it is a thing. Sometimes people get really, really upset about the vastness of space or just
the fact that we have no control over these huge forces. I mean, that is something like,
I have moments where I'm like, whoa, right? Because there are things like, you know,
black holes are colliding with each other. And the universe is expanding and it's accelerating
in its expansion. And it's getting bigger and bigger and faster and faster.
And like sometimes, you know, that stuff is really,
you know, I mean, you think about your little life
and what's going on in your day to day.
And at the same time, like stars are exploding.
And, you know, and we have,
we can look at the Big Bang.
Like we can actually see the primordial fireball at the Big Bang. Like we can actually see the primordial fireball
of the Big Bang.
We can see that.
How?
Ladies and gentlemen, Alley Ward, Zero Chill.
The reason is that the whole universe was hot and dense
and smaller than it is now.
So the Big Bang theory is just the idea
that the universe in the past was smaller and denser
and hotter than it is now.
And so if you kind of dial back the current expansion of the universe, then you get to
the universe being very, very small and dense and hot.
And so every point in the universe now was at some point much hotter and filled with
like radiation, right?
So like this part of the universe now in in the very distant past, was full of radiation
and very hot and very dense, right?
But so, when we look out into other parts of the universe, because light takes time to
travel, every time we look farther away, we're looking farther into the past.
And so, we're looking at that part of the universe as it was, maybe a billion years ago, or
five billion years ago, or whatever.
And there's a part of the universe that's so distant that when we look at it, we're looking at it as it was during the time when it was
still on fire. Right. So we look as we look into the distance in any direction, we're seeing
that part of the universe as it was when it was still in that primordial fireball kind of state, which was how long ago.
Well, that was around, so the fireball started to cool around 380,000 years after the big bang,
whatever, after the moment of the beginning, whatever you call that, because that's still part
of the hot big bang, which is like the hot phase. So we can actually see radiation coming from every direction
in the sky that is the radiation of that heat,
like that radiation from that early time,
just reaching us now from really distant parts
of the universe.
And so we can look at it.
And we're looking at like the fireball universe.
We're looking at that primordial plasma.
I can just go ahead.
And so we see the big shows.
Yeah, and so we know that it happened because we can see it and we can watch it. We can
actually see parts of the universe that are still there as far as we're concerned.
And that can give you cosmic vertigo.
Yeah, just thinking about that was a big, important event.
And like, so this sort of like nice, gentle, stable universe is not that's not how it
always was.
And we don't know, you know, we think that most cosmologists think at the beginning of
the universe before that hot phase, there was a period of very rapid expansion of the
universe called inflation.
We don't know why that started, we don't know why that ended, we don't know that that
couldn't just start happening again right here right now.
There are theories of the theories where you can have the universe like, and right here
right now in this room, oh god, oh god.
So this is an idea called vacuum decay where you can
you can have like the universe like have a quantum event happen where one point in the
universe like transitions to this other state. It's called another vacuum, a true vacuum
state. And that would create this bubble of like, again, bubble of death.
That expands out at the speed of light in every direction, so you would never see it coming.
It sucks.
And it's a probabilistic event.
It's a quantum event, so it could happen at any moment.
It probably won't.
Oh, God.
You know, it probably were just wrong about the theory.
And even if we weren't wrong about the theory
Like the the sort of timescale that we calculate for it would probably take like, you know, trillions of years or something
But like it's a probabilistic event. I could have in an a moment technically. It's just with very low probability
So like that could freak you out and I've gotten emails from people like they read about that and they're like I can't sleep
And I'm like, I'm sorry
Do you have any advice for that? I mean they're like, I can't sleep. And I'm like, I'm sorry.
Do you have any advice for that?
I mean, I tell them like, so about vacuum decay,
I can tell them like a few things.
One is that we don't know, we don't have any,
we don't know for sure that this is even possible.
If it were possible, it probably would have happened
in the very beginning of the universe
because the conditions for it happening then were much more favorable
So it probably would have already happened if it was gonna happen already or if it was possible at all
And then I say well if it's gonna like you it's nothing you can do. Yeah, I mean like it's it's traveling at the speed of light
You won't even see it coming. That's the best way to die. Yeah, you won't I mean you won't notice like it basically like
That's the best way to die. Yeah, you won't, I mean, you won't notice.
Like, basically, like, so it is absolutely the best
because you don't see it coming,
so you can't be scared of it.
You don't even really notice it
because it's happening at speed of light.
And you're not like around afterward.
And everything is around.
Yeah, everyone you love dies at the same time.
Yeah, everything dies.
Everything's gone at the same time.
There's no, there's no FOMO, right?
There's nothing you're not missing out on anything
because the whole universe is done now, right? And so it's kind of, in the same time, there's no FOMO, right? There's nothing you're not missing out on anything because the whole universe is done now, right?
And so it's kind of, in some sense,
it's really inconsequential
because there's no consequences of it.
It's just, so it doesn't matter.
Like you could just blink.
And then you blink and maybe you open your eyes again,
maybe you're consumed by a vacuum bubble of death,
but who cares?
You don't know.
If I could vote on a way for everything to end,
I would be like,
Oh, totally.
Yeah, vacuum decay.
Vacuum decay.
That's gonna be my platform.
It's a run chart.
But 2020 vacuum decay is my platform.
It is the best way to end the universe.
Okay, so that's one way to chill out.
Paula Herrera wants to know,
how scared should we be of a giant asteroid destroying Earth?
Are any of the sci-fi movie methods to save the planet plausible?
Are we basically doomed?
Should an asteroid come our way?
Yeah, that's a little bit of a sadder point.
Because like, okay, so we're basically not really monitoring about half the sky right
now. What?
Okay, no big deal.
No big deal.
Because we used to have some monitoring stations that have a Southern hemisphere and they
lost funding.
Oh, so we don't have as good a handle on the number of objects out there that could cause really big problems.
There's some kind of goals about how many, what fraction of objects above a certain size
we should be aware of, right?
It's like you're supposed to see 90% of objects above some size or whatever, and we're not
really there.
Oh, no.
So I think there are programs being put together now
and there's efforts to have a better catalog.
It's not like we're due for a giant impact or anything.
These are still things that are probably not gonna happen
anytime soon, but I can't honestly tell you
that we're on top of it.
Wow.
We have, we're monitoring a lot, but we're not monitoring enough to say that we definitely
don't have anything coming.
Okay, so whether or not we could stop it.
There are a couple of methods. If we find out about it early enough,
like five years ahead, 10 years ahead,
then there's a possibility of sending a spacecraft
to it and changing the course of it in some way.
You don't want to just blow it up partially
because some of these things are like kind of loose rubble piles.
And so it wouldn't really
work to try to blow it up but also because like if you have a huge asteroid and then you blow it up
then you have like a bunch of smaller asteroids and that's not always better. Yeah, but
but there are a bunch of really cool ideas for just nudging a little bit and if you find out about
long enough in the you know before it comes then you don't have to nudge it very far at all
to get it totally off course, it will miss the earth. So like one of them is to take a really,
really massive spacecraft and just like park it next to the asteroid in the orbit for a while.
And so then it gets like, pulled a little bit by the gravity of the spacecraft. And that can,
if you get it early enough,
that's called a gravitational tractor.
Yeah, if you get it early enough, that can work.
There are other ideas about like creating a giant sack and like,
capturing it in a sack because you can't necessarily,
let's not necessarily like a solid thing.
How are you going to make a bag big enough to put it on an asteroid?
I mean, it depends on the size of the asteroid, right?
But I mean, I don't know.
Like, is there...
What is that made out of like mylar?
Uh, cap don't tape?
I don't know.
I'm sorry.
I'm a little activated by this.
I looked up asteroid bags.
I was distracted for a few minutes on some galaxy printed
totes and duffles and I was like, oh, that's nice.
And then, okay, I realized that space people called these capture bags like this is just no big deal like just used to collect
fallen leaves or a dog doodle but NASA introduced a plan a few years ago and I asked a search engine
gods what the bag might be made of and I found out it could be inflatable could be metal mesh
or could just be high strength
material.
Sounds like they're figuring that out too.
My guess is it's just a very large blue IKEA bag.
Toe that fucker in.
Those things are strong.
It's another idea, which is also really cool, where you spray paint half of the object so
that it changes the reflectivity.
And then that means that the solar wind will push a little bit more on one house
than the other in some way.
And that can change the trajectory.
So there are a couple of possibilities.
Those are some good options.
Yeah.
Yeah, but you need a lot of lead time.
And a lot of paint and a really big bag.
Yeah.
Yeah.
Oh my God.
I just can't believe that we're kind of sleeping
on the job there.
I mean, it's like we're not, I mean, there are people,
there's a lot of, a lot of these things are being monitored
and there's nothing that we know about
that's anytime soon coming as a threat,
but there's also like we're not fully on top of this
in the way that I feel like we should be.
Oh, man, good to know.
Yeah.
Russell Kelly wants to know,
will the universe expand forever
or will it eventually collapse in on itself?
That is a great question.
Based on our current understanding and the data that we have now, it looks like it will
expand forever, which will lead to something called the heat death, which is the most depressing
way for the universe to end, which is that we have dark energy, dark energy is whatever
is making the universe expand faster and faster. If it's a cosmological constant, which is just a kind of dark energy that first
invented by Einstein, but it seems to be the case, then what'll happen is that over time
the other galaxies will get farther and farther away, not in dramatic. The endromania
galaxy is coming for us now. It's on its way. It's gonna collide with the Milky Way in about four billion years.
That'll be fine, whatever.
But then the more distant galaxies,
they'll just get farther and farther away.
And eventually we won't be able to see
any other galaxies outside of our little local group.
This is like when all your friends grow up
and move out to the suburbs,
or get rich and go to Santa Monica.
And then we won't be able to see
the cosmic microwave background anymore,
that after glow of the big bang,
so the universe will just get really, really dark and really empty.
And then our little group of galaxies will kind of be combined into one big blob,
but eventually all the stars will burn out,
because they'll run out of fuel, and there's no more gas coming in to make new stars from other galaxies.
So the stars will burn out, and then a bunch of things will collapse into black holes and
the black holes will evaporate and the protons will decay and everything will just kind of
decay into nothingness.
And there will be this really empty, cold, dark universe with nothing in it and just like this tiny amount
of radiation and no ability for any new structures to form, except maybe through some kind of
quantum process, which is kind of a cool thing, but that's another topic.
That's so goddamn lonely.
Yeah, that's called a heat death.
So what happens when the indromino galaxy collides with Milky Way, though, you glanced
right over that.
What the hell is that about?
That's really cool, actually.
So the indrom in a galaxy is a spiral galaxy like around.
It's got about a trillion stars.
It's more massive than the Milky Way.
And it's got a super massive black hole.
And they're all coming toward us at something
like, I think it was like a hundred kilometers a second. Anyway, they're all coming toward
us right now. And is it going to smishy smash? Yeah, it's going to come. And in about
four billion years, it'll get here. And it'll, it'll collide with the Milky Way galaxy.
The way that galaxies collide is kind of cool.
They like sort of merge and they make these long trails
of stars coming out.
And it'll be this sort of like really spectacular light show
of like gaspled collide and make new stars.
And there'll be this burst of star formation.
And the black holes might like turn on
and start like pulling in matter and like getting really bright.
And stars will be flung out into space
and on these long tails.
This sounds like a warehouse space rave.
I'm not gonna lie.
I'd be down for this.
But because galaxies,
because there is so much space between stars in galaxies,
probably our solar system will not be affected.
Okay.
Like probably we'll just like this, this guy would get really interesting.
But you know, it'll also be four billion years from now.
So the sun will be burning out and, you know,
the earth will already have its oceans boiled away
and life on earth will be possible.
But if you know, we left something here to take pictures,
they would be really pretty.
Yeah. Mike, uh, Mel, Mel Choir, Mel Choir wants to know
are Uranus jokes still funny?
It's really Uranus, isn't it?
So actually, I don't know which is a better pronunciation.
I usually say Uranus just because I don't want to deal with it,
but then it's got the name Uran in it too.
I know, it doesn't really help.
No, they're not, they're not particularly funny.
Okay, just checking out.
So I use an AI for transcription for this podcast, and it transcribed to your NAS. And I'm sorry, but yes, that, no. So I use an AI for transcription for this podcast and it transcribed to your and ask.
And I'm sorry, but yes, that is funny.
Megan Gerard wants to know slightly more on a local, practical level.
She loves Stargazing, but even in a small city, it's hard to do because of light pollution.
So can you recommend any tactics, resources, organizations for helping reduce light pollution. Also she thinks maybe light pollution
is bad for us and animals. And so good way to stargaze and good way to reduce light pollution.
So there are there are national organizations for like dark skies. I don't remember the names,
but if you if you look them up, there's they have their charities charities that their whole purpose is to try to get better lighting
in cities so that more of the light goes down and not up and changing what the lamps are
made of and stuff like that.
So you can get involved in these campaigns and they're really helpful.
Yeah, I can't remember the name of the organizations right now, but there are a few of them out there. DarkSky.org has a bunch of information on
getting involved in DarkSky Advocacy and membership in this kind of a Dark
Sky club. So hit that up. I will try to do my part and stop falling asleep with
lights on. I fell asleep with them on again last night, but tonight, tonight,
International Dark Sky Association.
I'm going to do my part.
If you want to go stargazing and your city's too bright, you just have to go somewhere else,
basically.
So, when I was living here, when I was growing up in LA, in Long Beach, I was part of the
LA Astronomical Society, and they would have Dark Sky Star Parties where we would drive
like four hours into the mountains, and it would be dark skies out of star parties where we would drive like four hours into the mountains and It would be really dark. Yeah, so you don't have to get that far out of that out of city to do good stargazing
So getting the fuck out of Dodge. Yes, got it. Yeah, that's pretty much it
There's there's a really great film called the city dark, which is about
It's about light pollution and what it does to us and what it does just astronomy And I'd recommend checking that out. I felt so little light on last night
It's not good for you. Yeah, and now this set of questions comes from the Facebook group. There's okay
Allegis podcast Facebook group
But before we take questions from you we're gonna take a quick break for sponsors of the show
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and thanks sponsors. Okay. Isabelle Lourian wants to know, what do you think the shape of the
universe is? Hyperbolic, Toroid? What do you think? Did I say Toroid, okay? You said Toroid, okay. Okay.
Toroidle is the adjective.
Okay. But yeah, it's, so Toroid, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, the, also, a Taurus, apparently, technically, would
be like an inner tube. Hollow. And a solid Taurus is a donut. But I want to say, I was on
a desert show called Unique Suites. For like, a lot of seasons, I have to say, a cake
donut seems like a solid Taurus. But if it's a fluffier yeast donut, there's all kinds
of air pockets in there,
and the volume and density seems somewhere between a torus and a solid torus. And I need a
physicist to get on this for me. Thank you. Okay. Oh, yeah. Back to the ship of the universe.
The universe, the way she's asking the question, the answer is the universe is probably flat.
Okay. Which just means, it just means that there's no large-scale curvature to the universe.
So I said that matter curves space.
So you get these like dense in space.
On the very large scales, the space is flat in the sense that it's not large-scale curved.
It's still probably three-dimensional.
I mean, the space part is three-dimensional, and then there's time.
That's a force to mention.
But it's flat in the sense that if you had two beams of light that were parallel,
they would stay parallel forever.
OK.
That seems to be the case.
At least as far as we can measure, there could be some larger scale curvature that we don't measure,
because it's just so big.
Like, if you have a ball that's big enough, enough it looks flat like the surface of the earth looks flat
but
But the universe on the whole as far as we know
Here's to be flat. There's no evidence for curvature, but it could be curved around on some really large scale
Okay, we'll find out in before the stars all collapse on themselves. Hopefully
maybe We'll find out before the stars all collapse on themselves, hopefully.
Maybe.
No, no, no, no.
I don't know.
T.J. King and Laurie March both had kind of the same question.
Is there a reason why some stars appear to twinkle more than others?
Oh, yeah.
Well, so stars appear to twinkle when you're looking through the atmosphere,
because the atmosphere is bending the light a little bit just by being like a little bit hotter a little bit wetter or something in different parts.
And so when you look through that sort of, you know, messy air, it makes the position of the star move around a little bit from your perspective. And that means that
sometimes it'll look a little bit brighter and sometimes a little bit dimmer and that makes
the twinkling. So the brighter a star is, sometimes that makes it look less twinkly or more,
it depends on kind of what the air is doing. But planets don't twinkle. Why not? So the reason
planets don't twinkle is because so the the the reason planets don't twinkle is because the twinkling of a star
comes from the fact that it's just a point of light.
From our perspective, it's just a single point of light.
And so it can be moved around, and that little point of light
can be magnified a little bit, and that makes it look brighter
or less.
But a planet is a disc of light from our perspective.
It's really, really small disc, but it's a disc of light
that's big enough that the little sort of turbulence
cells or whatever in the atmosphere only just
move the light around within the disc mostly.
And so it doesn't get significantly brighter or dimmer
because the motion of the air is not
enough to really change the sort of size and shape of that disc.
So if you twinkles, you got to star.
If it doesn't twinkle, you got to plant it more or less.
Yeah.
Yeah, more or less.
So if you see something pretty bright in the sky and it's not twinkling and other things
are, then you've probably seen a planet and they're probably seeing Jupiter, Saturn, Mars, or Venus. That's so great. Yeah. If you end if that
does happen and it's the first time you've heard this, then you should high five Katie on Twitter.
Lauren Oaks wants to know, what is the deal with other dimensions? This might not be the right person
to ask, but I still want to know. Okay. So we have three dimensions of space.
So that's forward, backward, left, right, up and down.
We also considered time to be about dimension.
So when you think about things like relativity,
you have to include time as part of your coordinate grid, basically.
And so that coordinate grid has to have four dimensions.
So the time is the fourth dimension.
And the reason for that is that space and time
can kind of affect each other.
Like moving through space at a higher speed
changes the way you move through time.
And when you're close to a gravitating object
that changes the way you move through time. And so it has to be part of the same sort of malleable fabric in some mathematical sense.
There could be other dimensions of space.
And that we just can't interact with, we can't see, we can't perceive.
And in some cases, those other dimensions of space might be kind of wrapped
around themselves. Okay. Which is a weird concept. But it's kind of like if you imagine, like,
like if you imagine a string, right? A string is a three-dimensional object. Two of those
dimensions are kind of wrapped around, really tight. So it only has a little bit, a little
direction you can go in two of the dimensions. you can go a really long way in the other one. And so it might be that in space, in our universe,
we can go as far as we want in our three dimensions, but the other dimensions are so small that we
don't notice them because they're all wrapped up. And one of the reasons that those extra dimensions
are hypothesized is that it might be that all
of our sort of particle interactions of stuff can only happen in this three-dimensional
space, but gravity can leak out into the other ones a little bit.
And so if that were happening, that would explain why gravity is so weak compared to all
the other forces.
So that's a hypothesis, you know.
So there could be other dimensions that might solve that problem.
But what about multiverses, and is there another me with a better life living in a different
dimension?
So, that, so when people say dimension in that sense, they just mean another universe.
The dimensionality, like the dimension doesn't mean space anymore, it means something else.
So there could be other
universes depending on how you define a universe because you could just define a
universe to be everything and then everything is part of the universe by
definition. There can't be a second everything. Yeah, okay. But you can define a
universe as just the observable universe. So what's within our sort of the
distance out to which we can observe anything, which is a set distance.
And then there could be stuff beyond that. We know there's stuff beyond that. So that's kind of outside of our universe. You can think of that as another universe. And then you can have other
universes that are separated by higher dimensions from us. So you can have like, like,
you can imagine our universe is a flat sheet and there's another flat sheet.
So we've just taken one dimension down
and they could collide maybe.
And this is like, there's a theory
for the big bang that comes from these two sheets collide
and that makes a big bang and then they come apart
and then they collide again later on.
It's called the ecopirotic model.
My thesis advisor was one of the people who came up with that.
a psychopirotic model. My thesis advisor was one of the people who came up with that. And then there are other ways to have other universes, like with the many worlds idea of
quantum mechanics, which says that every time a quantum event happens, basically, another
universe branches out from ours in a way that somehow makes sense mathematically, but
sounds ridiculous
when you think about it.
Is that kind of like an alternate reality?
Kind of, yeah.
Is there another me in another universe, in another reality who brushes her hair more regularly?
Well, in the many worlds hypothesis, I guess technically, that would be the case.
But, so if that's a good rabbit hole that you want to go into just like we start googling
Because in many worlds like there's another universe where like a photon just went through that
Window-ordent and that's the only difference. Oh my god. Oh my god. So like every possible thing
Ricka land wants to know is there actual scientific proof that there might be life beyond our planet? Aliens, yes, no.
Probably. Okay. So what is Katie hate about her job? What does she hate?
So one is the uncertainty of the kind of academic career letter. Okay.
So I spent the last eight years as a postdoc, which means I had my PhD and I was doing research,
but I didn't have a permanent job and I didn't know where I was gonna go next
or how long I would be there
or whether or not I would be able to continue in science
because it was just, you know, applying for jobs.
And it's a difficult thing to be doing.
And I, you know, all jobs have some uncertainty
at some stage, but I feel like in academia,
that uncertainty and that sort of tenuousness lasts a really long time.
Yeah.
And if you get to the stage where you're definitely not going to get an academic job and you
wanted one, then you have spent many years making not very much money when you could have done something more lucrative
and it would have been better off in like every way.
So, I mean, I enjoyed doing the research.
And so for me, it was like, well,
I'll just keep doing science as long as I can.
I enjoy it.
I'm willing to make that sacrifice.
But for a lot of people, it's just so disruptive
and it's so difficult that it's like,
it's a really high anxiety time and it's really hard and a lot of people it's just so disruptive and it's so difficult that it's
a really high anxiety time and it's really hard and a lot of people leave because that
is just really hard to deal with.
That's the main thing.
And then the other thing is that it's just, it's really easy to have a lot of self-doubt
and you have to be very kind of self-driven and it's hard to know if you're doing a good job.
And like it's,
academia can be very competitive
and you don't get a lot of like positive feedback.
And so it can be just hard to kind of like,
keep doing what you're doing
and know that you're doing it well
or know how to do it well
or you know, all of that stuff can be difficult. Which is great that you're doing and know that you're doing it well or know how to do it well or you know all of that stuff can be
difficult. Which is great that you're a science communicator as well because you get to get a lot of feedback from the public.
I can't imagine right? Yeah, I mean that does help a lot. Like if I'm you know sitting in my office banging my head again
and something that I feel like I really should know this thing or I really should understand it, this should come more easily.
And then you know I feel like I'm a total failure,
and I don't know anything.
And then I go talk to room full of school kids,
and suddenly, I'm an expert.
And then I feel like I know a lot of things,
and then it helps a lot.
So yeah, for me, it's made a big difference,
and just keeping me from getting too depressed
about not understanding the universe, as well as I wanted to.
What about your favorite thing about the job
or cosmology or physics or?
My favorite thing is that I get to ponder
the deep questions of reality as my job, you know?
Yeah, like I was at a conference a couple of weeks ago
and it was most of the topics in this conference
were not stuff I work on.
So it was like really deep questions about the nature of reality and like whether or not
space time is really a thing and how particles really work and all of that.
And I was just like, like, I didn't, it's not the area I work in.
So there was a lot I didn't
understand about it, but I could grasp some of it.
And I felt like, I just felt so privileged to be able to be in that room and to think
about these things and to have some grasp of these huge concepts.
And like, I get that was part of my work, you know.
And that was just an amazing, that's just, every time that happens, it's an amazing feeling
that I get to do these mental exercises and learn about the fundamental properties of
the universe.
And that's my job.
That's your job.
I mean, writing the papers and teaching and all of that stuff is also my job.
So there's a lot of other aspects to it, but just learning about the universe is a big part of my job, and I love that.
It's so baller.
Yeah.
Alright.
Thank you for letting me talk to you for so long.
I'm so sorry.
It's the longest interview I've ever done, because there's so many questions.
Okay, let's go to a movie.
Okay, bye.
So we barely made it to the movie, which was a very forgettable mystery romp about a
train stuck in the snow, but stellar moustaches and I will remain forever shooketh by this
conversation.
I'm glad we took it as long as we did.
Now, to follow Dr. Mack, you can find her on Twitter as Astro Katie or on Instagram at
Astro Katie Mac.
And this podcast is at Allligis on Twitter and Instagram,
and I'm at Allie Ward on both, and for T-shirts and Toads
and Mugs and to support the podcast,
while also covering your new body,
go to Oligismerch.com.
And of course, if you like the podcast
and want to support, just tell a friend,
or make a post about it, or rate it on iTunes.
That's huge. And yeah, I'll give you a secret.
This week's secret is that I record all the narration in my closet because the sound is pretty good.
There's all these clothes to dampen it. But the real nugget here is that I have a real laundry situation.
And about half my body, currently sitting on a pile of towels, which I will get to this weekend
about half my body, currently sitting on a pile of towels, which I will get to this weekend after I obtain some soap. So yeah, I'm podcasting from a laundry nest. I'm like a cozy little woodland
rodent. Talking at you through a machine! Big huge thanks to Stephen Ray Morris, patron saint
of podcasts for editing this episode and to Shannon Feldes and Bonnie Dutch for all of their
help with merch and Aaron for running theology's podcast Facebook group and the theme song was composed
never formed by Nick Thorburn aka Nick Diamonds of the band Islands he's great check out his music
until then ask smart people all the dumb questions you want. The universe is big,
and regret is maybe the scariest thing there is.
Okay, bye bye! Technology, technology, technology, and seriology.
It's a technology.