00:00SPEAKER- Brad, I realized something amazing.
00:02SPEAKER- Go on.
00:03SPEAKER- Next weekend on Friday,
00:06SPEAKERTears of the Kingdom comes out, the new Zelda game.
00:09SPEAKER- True, yes, I've heard of it.
00:10SPEAKER- Also on Friday, my wife and daughter
00:13SPEAKERare leaving for a weekend camping trip.
00:15SPEAKER- Huh.
00:16SPEAKER- So I'm gonna go ahead and tell you, full goblin mode.
00:19SPEAKER- Okay. - 100%.
00:20SPEAKER- Okay.
00:21SPEAKER- I gotta figure out what kind of food I'm ordering,
00:24SPEAKERand I'm just going to put on some comfortable pants,
00:29SPEAKERmaybe.
00:30SPEAKER- Do you ever feel, okay, I mean,
00:31SPEAKERpeople will definitely get this sense in the episode to come
00:35SPEAKERthat, you know, the universe is typically cold and unfeeling
00:39SPEAKERand without compassion or logic,
00:42SPEAKERbut every so often, reality just aligns in a way that is.
00:47SPEAKER- Look, if serendipity is the only thing
00:48SPEAKERthat brings a small amount of joy
00:50SPEAKERin an otherwise cold and uncaring universe,
00:53SPEAKERI say embrace the chaos.
00:55SPEAKER- Yeah, yeah, just enjoy it when it comes.
00:57SPEAKERAnyway, sounds like you have a weekend ahead of you.
00:59SPEAKER- Okay, I gotta figure out my food strategy, though.
01:01SPEAKERIn the old days, I would have just ordered
01:03SPEAKERa couple of big pizzas and then, you know,
01:05SPEAKERgobbled out on those for three days.
01:08SPEAKER- Is it goblin, okay, are there tiers?
01:10SPEAKER- I think there's a tier structure, yeah.
01:12SPEAKER- Okay, there's goblin mode, where does gremlin fall?
01:14SPEAKERI tend to think of gremlin as even more intense than goblin.
01:19SPEAKER- Oh, I assumed goblin mode was the bottom of the pile,
01:22SPEAKERbut maybe you're right, maybe gremlin's worse.
01:24SPEAKER- I've heard the term gremlin energy recently,
01:26SPEAKERand I feel like it's even more dire or sinister.
01:30SPEAKER- Sometimes I worry, especially since I've been spending
01:32SPEAKERtime on Blue Sky lately, that I'm completely out
01:35SPEAKERof the vernacular that the children are using
01:37SPEAKERon the internet these days.
01:38SPEAKER- Well, the children are no longer on Twitter,
01:40SPEAKERif they ever were, so I think I'm with you
01:42SPEAKERon that at this point.
01:44SPEAKER- Yeah, but, so yeah, like, like, feral,
01:46SPEAKERferal was the original one for me.
01:48SPEAKERLike, I'm unsupervised, it's not even that I'm unsupervised,
01:52SPEAKERbut like, I don't have any other commitments
01:53SPEAKERfor a period of time, I would go feral in the old days,
01:56SPEAKERbut I feel like goblin mode is one step beyond that,
01:58SPEAKERwhere it's just like, you know, all other bets are off.
02:01SPEAKERAnd then, you know, like, I have computer maintenance stuff
02:03SPEAKERthat I've been putting off for ages,
02:05SPEAKER'cause I never have time to do it
02:06SPEAKERwhen I'm not using the computers on the day to day,
02:08SPEAKERand I was like, I could just do that.
02:10SPEAKERThen I realized that the stars have aligned,
02:12SPEAKERand I can go korok hunting, korok seed hunting instead, so.
02:16SPEAKER- You can't waste this opportunity.
02:18SPEAKERFixing computers decidedly not goblin mode.
02:21SPEAKER- No, that's a useful activity that good contributors
02:26SPEAKERto society will do.
02:27SPEAKER- Are we now going to start trying to one up each other,
02:29SPEAKERthough, on the scale of degeneracy of food and video games,
02:34SPEAKERand not cleaning the house?
02:36SPEAKERThere's goblin mode, there's gremlin energy,
02:39SPEAKERI'm going owlbear status, man.
02:41SPEAKER(laughing)
02:43SPEAKER- Look, I'm just alphing it up over here,
02:44SPEAKERit's just me and a bunch of cats doing weird elf business.
02:48SPEAKER(upbeat music)
02:56SPEAKER(upbeat music continues)
03:16SPEAKER- Welcome to Brad and Will Made a Tech Bot, I'm Will.
03:19SPEAKER- I'm Brad, you have now coined the term alph style.
03:23SPEAKER- Alph style? - Yeah.
03:24SPEAKER- Look, I don't think I invented anything to do with alph
03:27SPEAKERafter the last week on the alternate Twitter social,
03:31SPEAKERpost Twitter social network, blue sky.
03:34SPEAKER- You know, is alph invented or discovered, who can say?
03:38SPEAKER- I mean, it's alph is really all of us,
03:40SPEAKERis what I've learned.
03:41SPEAKERSpeaking of alien life forms and things from space,
03:44SPEAKERI'm so excited about our guests this week.
03:46SPEAKERDr. Katie Mack is a theoretical astrophysicist
03:48SPEAKERwho studies a range of questions in cosmology.
03:51SPEAKERShe currently holds a position of Hawking chair
03:53SPEAKERin cosmology and science communication
03:54SPEAKERat the Perimeter Institute for Theoretical Physics,
03:57SPEAKERwhere she carries out research on dark matter
03:59SPEAKERand the early universe and works to make physics
04:01SPEAKERmore accessible to the general public.
04:03SPEAKERYou most likely know her from her presence on social media,
04:06SPEAKERwhere she provides context and clarity
04:07SPEAKERon a broad variety of science topics,
04:09SPEAKERor from her 2020 book,
04:11SPEAKER"The End of Everything Astrophysically Speaking."
04:14SPEAKER(upbeat music)
04:17SPEAKER- How have you found people respond
04:18SPEAKERto the subject matter of the book?
04:19SPEAKERI mean, people thinking about the end of all existence,
04:22SPEAKERis that something that inspires mortal terror in people?
04:25SPEAKER- Sometimes, yeah.
04:28SPEAKERSo there is a healthy dose of mortal terror that comes in.
04:33SPEAKERYeah, it's interesting.
04:34SPEAKERLike a lot of people are just kind of fascinated
04:36SPEAKERby the ideas, I guess.
04:38SPEAKERAnd a lot of people are kind of,
04:41SPEAKERthey're a little bit nervous about the whole concept.
04:44SPEAKERAnd yeah, and so it just really varies.
04:48SPEAKERBut I definitely get a lot of messages
04:51SPEAKERfrom religious people with various objections
04:54SPEAKERto the idea of the end of the universe,
04:56SPEAKERor claiming that their own religious texts
05:00SPEAKERcompletely supports what's in the book.
05:03SPEAKERWhich is interesting because
05:05SPEAKERthey're all different religious texts.
05:06SPEAKERSo every religious text apparently has,
05:09SPEAKERis supported in one way or another by what's in the book.
05:12SPEAKERSo that's been kind of amusing
05:15SPEAKERto see them all kind of coming in and being like,
05:16SPEAKER"Well, this proves that mine is right."
05:18SPEAKERAnd then it's like, "Well, let me tell you what I got last week."
05:21SPEAKERSo that's been really interesting.
05:24SPEAKERAnd some people are just really very, very certain
05:27SPEAKERabout their own ideas about the end of the universe,
05:32SPEAKERor lack of end of the universe.
05:34SPEAKERAnd they share those with me as well.
05:36SPEAKER- I find the whole idea that entropy comes for us
05:40SPEAKERall in the end kind of comforting.
05:42SPEAKER'Cause it means that no matter how I screw up,
05:44SPEAKERhow much I screw up on the day to day,
05:46SPEAKERultimately it's not gonna matter, right?
05:48SPEAKER- Yeah, yeah, nothing's gonna matter.
05:50SPEAKER- Is that kind of a healthy nihilism maybe?
05:52SPEAKER- I mean, I guess for me, I do feel like it's,
05:56SPEAKERI do feel like it kind of reminds me that
05:59SPEAKERyou can't really hold on to stuff
06:01SPEAKERand you have to sort of live in the moment to some degree
06:03SPEAKERand appreciate life as it's happening
06:06SPEAKERbecause there's no alternative that makes any sense.
06:10SPEAKER- I find, I don't know if this is like a psychological quirk
06:12SPEAKERthat's unique to me, but thinking about
06:15SPEAKERfive billion years from now, the planet will most likely
06:16SPEAKERbe swallowed by the sun.
06:17SPEAKERI think actually something I was gonna ask it,
06:20SPEAKERdo I understand that even like three, four billion years
06:22SPEAKERbefore that, the planet will no longer be able
06:24SPEAKERto support life too, to just the sun heating up?
06:26SPEAKERIs that correct?
06:27SPEAKERSo we actually only have like a billion years?
06:28SPEAKER- Yeah, we have about a billion years
06:29SPEAKERbefore the oceans boil away.
06:31SPEAKERSo, you know, however you wanna try and survive that,
06:37SPEAKERthat's gonna be a big challenge in terms of global warming.
06:40SPEAKERBut there's, yeah, so it's about five billion years,
06:44SPEAKERabout a billion years, the estimates vary a bit
06:48SPEAKERfor the oceans boiling, and then the sun goes red giant
06:52SPEAKERwithin about five billion years.
06:54SPEAKERAnd probably, well, it's a little unclear exactly
06:58SPEAKERwhat happens to the Earth's orbit at that point,
07:00SPEAKERbut most likely it'll kind of spiral in eventually.
07:05SPEAKERThere's a chance that it could wander off instead,
07:08SPEAKERbut the most likely thing is spiraling in.
07:10SPEAKERAnd in any case, it's certainly cooked
07:12SPEAKERbefore any of that happens.
07:13SPEAKER- This weird quirk of mine is that I hear things like that,
07:15SPEAKERand like I instantly seize up, you know,
07:17SPEAKERit's like, oh no, the end is coming for us.
07:19SPEAKERAnd then I think like, oh, it's a billion years from now,
07:22SPEAKERwe have plenty of time.
07:23SPEAKERAnd then it's like, if this was 150 years from now,
07:26SPEAKERit wouldn't matter to me.
07:27SPEAKERBut somehow I like get terrified by it
07:29SPEAKERuntil there's some weird like lizard brain
07:32SPEAKERversus rational mind thing going on.
07:34SPEAKER- Oh yeah, no, it's super like disturbing
07:38SPEAKERin ways that really don't make rational sense
07:40SPEAKERbecause, you know, I mean, I think the thing is
07:44SPEAKERthat people have developed strategies
07:47SPEAKERfor dealing with the idea of mortality,
07:49SPEAKERand all of them involve some kind of legacy, right?
07:53SPEAKERLike some kind of idea that like something of us
07:56SPEAKERlives on into the future and makes a difference.
08:00SPEAKERAnd if you take that away,
08:01SPEAKERit's a lot harder to deal with non-existence
08:05SPEAKERof yourself personally,
08:07SPEAKERbecause then you're also taking away whatever purpose
08:11SPEAKERyou thought you had in the universe,
08:16SPEAKERbecause that goes away.
08:19SPEAKERLike whatever consequence you might've had goes away.
08:22SPEAKERSo I think that's a lot harder to deal with.
08:25SPEAKER- It's, I mean, it's interesting,
08:27SPEAKER'cause like when I asked you to come on the podcast, Kay,
08:29SPEAKERwhen you said, hey, do you want me to come on your podcast?
08:32SPEAKERI didn't think we'd be talking about metaphysical stuff
08:39SPEAKERand existentialist dread.
08:42SPEAKERBut I'm curious, what drew you to the,
08:46SPEAKERhey, I want to study the very,
08:49SPEAKERyou know, I want to know what happens
08:50SPEAKERwhen the electron soup breaks down
08:52SPEAKERat the end of the universe and what was the appeal for you?
08:57SPEAKER- You know, so I've been studying cosmology for many years.
09:00SPEAKERSo when I started in graduate school,
09:02SPEAKERI knew I wanted to study cosmology.
09:04SPEAKERAnd so that includes all of those big questions.
09:07SPEAKERAnd I mostly thought I was going to work on
09:09SPEAKERlike the early universe and stuff like that,
09:12SPEAKERand dark matter, dark energy, all these big mysteries.
09:16SPEAKERBut I found that I kept running into these
09:19SPEAKERreally interesting research problems
09:22SPEAKERaround the end of the universe
09:24SPEAKERand not things that I worked on specifically,
09:26SPEAKERbut things like papers I read or talks I attended
09:29SPEAKERwhere people talked about
09:31SPEAKERsome of these sort of universe ending ideas.
09:35SPEAKERAnd I just found that I was really, really fascinated
09:38SPEAKERby all of that and really sort of excited
09:42SPEAKERby the idea of understanding the destruction of the cosmos
09:47SPEAKERas much as the production of it.
09:49SPEAKERAnd so when I was thinking about
09:52SPEAKERwhat I might like to write a book about,
09:55SPEAKERI thought about all the talks that I give
09:57SPEAKERthat touch on the end of the universe
09:59SPEAKERand how much fun it is to talk about
10:02SPEAKERthe end of the universe.
10:03SPEAKERAnd I thought, well, if it's fun to talk about it
10:04SPEAKERto an audience and if audiences enjoy it,
10:06SPEAKERthen clearly this is a good topic for a book.
10:09SPEAKERAnd there had not been a sort of comprehensive
10:13SPEAKERend of universe book in a while
10:16SPEAKERof the kind that I was thinking of writing.
10:17SPEAKERSo it just all kind of made sense.
10:19SPEAKER- I know the book's not that old,
10:22SPEAKERbut has any more certainty developed in the,
10:25SPEAKERsay, what is it, two, three years since it came out?
10:28SPEAKERIn terms of which one is the one,
10:30SPEAKERI assume that probably takes longer.
10:32SPEAKER- No, there hasn't been any more certainty.
10:34SPEAKERThere have been more sort of questions that have arisen.
10:39SPEAKERSo one of the things that I talk about in the book
10:42SPEAKERis places where we have some confusion about cosmology,
10:48SPEAKERabout stuff that we don't understand
10:51SPEAKERthat might or might not be pointing us toward
10:53SPEAKERa better theory of the universe.
10:55SPEAKERAnd that includes things like the Hubble tension,
11:00SPEAKERwhich is this question of how quickly is the universe
11:03SPEAKERaccelerating in its expansion or, well, specifically,
11:05SPEAKERhow quickly is it expanding now, right?
11:07SPEAKERLike what is the rate of expansion of the universe?
11:10SPEAKERAnd that's still controversial.
11:14SPEAKERThere are different measurements
11:17SPEAKERthat give you different answers about the rate of expansion.
11:21SPEAKERAnd I thought maybe by the time the book came out,
11:24SPEAKERthat would be answered and it has not been answered.
11:27SPEAKERSo that remains a big question.
11:31SPEAKERAnd then, you know, with JWSC out there
11:34SPEAKERlooking at these very, very, very early galaxies
11:37SPEAKERin the universe, it's also finding some things
11:39SPEAKERthat are confusing about, you know,
11:42SPEAKERpossibly seeing galaxies that are too bright too soon.
11:47SPEAKERSo maybe galaxies are forming faster
11:50SPEAKERand bigger than we thought they should be,
11:52SPEAKERwhich doesn't really necessarily challenge
11:54SPEAKERa cosmological model, but is a question
11:56SPEAKERabout galaxy formation that we don't understand.
11:59SPEAKERSo stuff like that is still, you know,
12:03SPEAKERit just, everything just gets more confusing.
12:05SPEAKERWe haven't solved any problems.
12:08SPEAKERWe've just made new ones, basically.
12:10SPEAKER- As far as the rate of expansion goes,
12:12SPEAKERI hope I'm not getting too into the weeds here,
12:14SPEAKERbut is it at least agreed on at this point
12:16SPEAKERthat it is increasing and is it just a disagreement
12:18SPEAKERover how fast it's increasing or is there still,
12:20SPEAKERokay, is that at least a settled component?
12:22SPEAKER- Yeah, it's very clear from many different measurements
12:25SPEAKERthat the expansion of the universe is speeding up.
12:28SPEAKERIt is not clear why, and we have very little understanding
12:32SPEAKERof what it is that's making the universe speed up
12:35SPEAKERin its expansion, but the fact that it is expanding
12:38SPEAKERand accelerating is pretty much a, you know,
12:44SPEAKERsettled point at this stage.
12:46SPEAKER- So the increasing expansion, does that also,
12:48SPEAKERthat also kind of implies another type of end, right,
12:51SPEAKEReven before the sort of like physical or cosmological end
12:54SPEAKERin the sense that things will become less observable
12:57SPEAKERover time from any given point.
12:58SPEAKERIs that accurate? - Yeah.
13:00SPEAKER- Billions, I don't know, trillions,
13:02SPEAKERhowever many years from now that, you know,
13:03SPEAKERany one given galaxy is just gonna be able to observe
13:06SPEAKERless than we could right now.
13:07SPEAKERIs that accurate? - Yeah, absolutely.
13:08SPEAKERSo our, a good estimate is that in about 100 billion years,
13:15SPEAKERwe will not be able to see other galaxies in the universe.
13:17SPEAKERSo there's a caveat there, which is that there are,
13:21SPEAKERthere's a local group of galaxies that we're part of,
13:23SPEAKERand that's a group that sort of formed together,
13:26SPEAKERand so that group is merging over time,
13:28SPEAKERand so we're gonna merge with the other galaxies
13:31SPEAKERin that group within only like four or five billion years.
13:34SPEAKERBut then after that, there's all the galaxies
13:39SPEAKERoutside of our sort of immediate gravitational influence
13:43SPEAKERwill become, I mean, essentially what's gonna happen
13:47SPEAKERis they'll be far, really far away,
13:50SPEAKERbut also they'll be moving away from us really quickly,
13:53SPEAKERand it's really the latter that makes it
13:56SPEAKERso that they'll be impossible to see.
13:58SPEAKERSo as the universe is expanding,
14:01SPEAKERit's red shifting the light of distant galaxies.
14:05SPEAKERSo when, you know, when things that emit light
14:10SPEAKERmove through space, as they're moving away,
14:13SPEAKERit stretches out the light basically,
14:15SPEAKERand puts it to the redder part of the spectrum.
14:17SPEAKERIf they're moving toward you, it gets bluer.
14:19SPEAKERAnd so that's, and that's cosmological redshift.
14:22SPEAKERThat's the term we use for that.
14:25SPEAKERSo the cosmological redshift of all of the distant galaxies
14:28SPEAKERin the universe is gonna get higher and higher and higher,
14:31SPEAKERso the light is gonna be stretched out to radio
14:33SPEAKERand then to, you know, unobservable long wavelengths
14:37SPEAKERof light, basically, lost in the cosmic background radiation.
14:40SPEAKERAnd so there will not be, it will not be possible
14:43SPEAKERto observe other galaxies in about 100 billion years.
14:48SPEAKERAnd so in that time, like if you took a space telescope,
14:53SPEAKERlike JWSC, and you put it out there in 100 billion years,
14:56SPEAKERand you tried to, you know, take pictures
14:58SPEAKERof the early universe, you would just see nothing.
15:00SPEAKERIt would just be black.
15:02SPEAKERAnd it's fascinating because at that point,
15:05SPEAKERthere will be essentially no evidence for the Big Bang
15:08SPEAKEReither because we won't be able to see
15:10SPEAKERthe cosmic microwave background radiation anymore.
15:13SPEAKERWe won't be able to see the light from other galaxies.
15:17SPEAKERWe'll just be sort of alone in this empty space.
15:20SPEAKER- This may be way too much "Star Trek" talking on my part,
15:22SPEAKERbut I always feel like, oh, we drew the short straw
15:25SPEAKERbeing relatively early in the evolution of the universe,
15:28SPEAKERright, 'cause like, oh, we can have so much more technology.
15:29SPEAKERMaybe there would be other intelligent species
15:31SPEAKERto encounter, blah, blah, blah.
15:32SPEAKERBut it almost actually seems like maybe civilizations
15:35SPEAKERthat come way later actually have it way worse, right,
15:38SPEAKERbecause you run into that problem you're describing
15:41SPEAKERor even people that are around at the end of the universe.
15:43SPEAKERLike, presumably there's not going to be much
15:46SPEAKERthey can do technologically about that.
15:48SPEAKER- Yeah, I mean, you know, the energy density
15:51SPEAKERof the universe is just decreasing over time, right?
15:54SPEAKERSo like, you're gonna run out of energy to do stuff with
15:57SPEAKERif you wait too long.
15:59SPEAKERI don't know what I would say is like the best time.
16:01SPEAKERI mean, if we wanted to be in the heyday of star formation,
16:05SPEAKERright, then we would have been, we would have existed
16:08SPEAKERmaybe like six or seven billion years after the beginning.
16:12SPEAKERSo we're already,
16:16SPEAKERthe universe is already well past its prime in that sense.
16:20SPEAKERAnd it's kind of, it's a little bit disturbing
16:25SPEAKERwhen you go through the numbers on that because,
16:27SPEAKERso there was this peak of star formation.
16:29SPEAKERAnd then since then, the amount of star formation
16:33SPEAKERhas been going down and that's for a couple of reasons.
16:35SPEAKEROne is that galaxies are kind of using up the gas
16:38SPEAKERthat's within them to form stars,
16:39SPEAKERbut also galaxy collisions and interactions are reducing
16:43SPEAKERand they're not happening as often because, you know,
16:47SPEAKERclusters and groups are getting moved farther apart
16:49SPEAKERfrom each other.
16:50SPEAKERAnd so we can look at that cosmic star formation history
16:55SPEAKERand we can calculate how many stars have formed
16:58SPEAKERin the universe so far and how many will form in the future
17:01SPEAKERbased on, you know, the amount of gas that's left
17:05SPEAKERand the amount of interaction that's gonna happen
17:06SPEAKERin the future.
17:07SPEAKERAnd what we find is that of all the stars
17:10SPEAKERthat have ever formed or ever will form,
17:13SPEAKERabout 90 or 95% have already happened.
17:16SPEAKER- Oh, wow.
17:17SPEAKER- And so from now until the end of time,
17:20SPEAKERwe're working on that last like five or 10%
17:22SPEAKERof star formation.
17:24SPEAKERSo we're almost done.
17:26SPEAKER- So then that implies to me that there's a sweet spot
17:29SPEAKERwhere enough stars have formed and blown up
17:32SPEAKERthat there's heavy elements in the universe,
17:35SPEAKERbut then there's still enough energy left
17:37SPEAKERfor new stars to form.
17:39SPEAKERSo maybe we are in the sweet spot right now.
17:40SPEAKERMaybe this is the good time.
17:41SPEAKER- Yeah, I mean, that's a little bit dependent
17:43SPEAKERon the kind of environment you're into
17:44SPEAKERbecause if you're in like the center
17:46SPEAKERof a rich galaxy cluster, for example,
17:48SPEAKERthen you get a lot more star formation,
17:51SPEAKERa lot more generations of stars.
17:52SPEAKERIf you're out in the weeds like in a galaxy
17:56SPEAKERthat's not surrounded by other galaxies,
17:58SPEAKERand then it sort of takes longer to enrich that space.
18:05SPEAKERSo the best thing to do if you want a lot of heavy elements
18:10SPEAKERand also continuing star formation is to be in a cluster
18:15SPEAKERwhere there's just a lot of matter going on.
18:17SPEAKERAnd you can start out earlier in that cluster
18:20SPEAKERand still have heavy elements to work with.
18:23SPEAKERAnd also as the universe is winding down,
18:26SPEAKERif you find those galaxy clusters,
18:28SPEAKERthere's still gonna be some stars in them.
18:30SPEAKERIt's what you don't want is to be kind of out in the void
18:35SPEAKERin one of these sort of more empty spaces in the universe.
18:39SPEAKER- One of my favorite things to do with people
18:42SPEAKERwhen we're sitting looking at stars late at night
18:43SPEAKERand if they're not sciency people is to talk about
18:48SPEAKERstars exploding and forming everything
18:49SPEAKERthat's heavier than the hydrogen and the helium
18:52SPEAKERand the gases.
18:57SPEAKERThe two ideas seem very counter, right?
18:59SPEAKERLike that, A, the space between stars is large enough
19:04SPEAKERthat it's infinite to human brains,
19:05SPEAKERalthough small on the galactic scale.
19:08SPEAKERAnd B, that all the stuff that we're made of
19:10SPEAKERcame from some exploding star
19:14SPEAKERlight years and light years away.
19:16SPEAKERAnd I wonder, it's because of the time, right?
19:19SPEAKERIt's because we can't grasp the time,
19:20SPEAKERthe scale of time involved.
19:22SPEAKER- Yeah, so part of it is the time.
19:24SPEAKERIt's just that you have enough time for all that matter
19:27SPEAKERto diffuse around the galaxy.
19:30SPEAKERBut part of it also is that
19:34SPEAKERthe galaxy kind of mixes around,
19:36SPEAKERlike the stars that are around us now
19:38SPEAKERare not the same stars that were around us
19:40SPEAKERearlier in the history of the galaxy.
19:42SPEAKERSo like our sun has been traversing the galaxy over time
19:48SPEAKERand the sort of the mix of stars and gas and dust
19:52SPEAKERand stuff around us has been changing.
19:54SPEAKERSo there's mixing that goes on
19:56SPEAKERthat's not just like everybody's sitting still
19:59SPEAKERand waiting for matter to diffuse around.
20:01SPEAKERThere's also a lot of sort of churning within a galaxy.
20:06SPEAKERSo it's both of those things, really.
20:08SPEAKER- We're scooping up as we move through the galaxy.
20:10SPEAKER- Yeah, like we're moving through different regions
20:13SPEAKERof the galaxy and the stuff that our sun was made of
20:17SPEAKERwas in sort of different environments in the past.
20:20SPEAKERSo there's, it's kind of a combination of things,
20:24SPEAKERbut, and, you know, yeah.
20:27SPEAKERI mean, when galaxies come together,
20:31SPEAKERa lot of gas comes in from other regions, right?
20:35SPEAKERAnd so like everything kind of comes in,
20:38SPEAKERturns around, flattens out into a disc
20:41SPEAKERand then you get stars forming.
20:43SPEAKERSo it's, there's a lot of mixing that happens
20:45SPEAKERthat's not just like, you have to wait, you know,
20:47SPEAKERfor the stuff from billions of light years away
20:50SPEAKERto come to you or something, that's not what's happening.
20:54SPEAKER- Will's just kind of given me the idea of like,
20:56SPEAKERand this probably, I'm sure this is relevant to you
20:58SPEAKERas kind of a science communicator
21:00SPEAKERoutside of your research and your day job,
21:02SPEAKERjust speaking to the public of sort of assembling
21:05SPEAKERlike a short list of the exotic,
21:06SPEAKERbut fairly easy to understand ideas
21:09SPEAKERthat could really peak people's interest
21:10SPEAKERin this kind of thing.
21:11SPEAKERLike what Will said about, hey, you know,
21:12SPEAKERall the atoms in your body are billions of years old
21:14SPEAKERand came out of stars except like the hydrogen
21:16SPEAKERis basically as old as the universe, right?
21:18SPEAKER- Yeah, yeah.
21:19SPEAKER- Now I'm sitting here thinking of like,
21:21SPEAKERlike time dilation and relativity is one that I found
21:24SPEAKERthat if you tell, if you're talking to somebody
21:26SPEAKERwho has no idea about astrophysics and you're just like,
21:28SPEAKERhey, did you know that the faster you go,
21:30SPEAKERthe slower time goes compared to somebody who's at rest
21:32SPEAKERand it just like, you just see brains exploding
21:35SPEAKERand I feel like you could probably come up with
21:37SPEAKERlike a good short list, right, of things that are just like,
21:39SPEAKERif you just throw out these nuggets,
21:41SPEAKERpeople could really just like start thinking about
21:43SPEAKERlike all of reality in a different way, right?
21:46SPEAKER- Yeah, I put all of those in my book,
21:48SPEAKERwhich means that now I can't write another book
21:50SPEAKERabout cosmology 'cause I used up all the good stuff.
21:53SPEAKERSo my new book is gonna be about particle physics
21:55SPEAKERbecause I haven't used all those yet.
21:57SPEAKERBut the thing about relativity,
22:00SPEAKERI had one of the most surreal moments of my life
22:03SPEAKERwas I was at a conference and I met an astronaut.
22:06SPEAKERWe were talking about, it was a conference
22:09SPEAKERwas sort of about science communication stuff.
22:12SPEAKERAnd we were talking about relativity
22:15SPEAKERbecause I told him I was an astrophysicist
22:17SPEAKERand we were talking about time dilation.
22:20SPEAKERAnd so I was kind of explaining that concept
22:24SPEAKERof when you're moving quickly,
22:28SPEAKERyour time is going more slowly,
22:30SPEAKERbut also when you're farther away from the center of a,
22:33SPEAKERlike from a gravitational well,
22:34SPEAKERyour time is moving more quickly.
22:36SPEAKERSo there's these two things.
22:37SPEAKERAnd I was explaining this,
22:39SPEAKERbut like using the example of his lived experience.
22:44SPEAKER- He's gone 18,000 miles an hour
22:47SPEAKERfor a significant period of time,
22:48SPEAKERfar from the center of the earth.
22:49SPEAKERAnd wow, that's fabulous.
22:53SPEAKER- That doesn't usually happen to me.
22:54SPEAKERUsually this is totally a thought experiment,
22:56SPEAKERbut in this case, it was like, no, no,
22:58SPEAKERthis is what happened to your body.
23:00SPEAKER- Well, right, 'cause I mean,
23:02SPEAKERthe Kelly twins were on the space station
23:05SPEAKERfor one was up for a year and one wasn't, right?
23:08SPEAKERSo he's younger than his brother at this point.
23:13SPEAKER- Yeah, I mean, the departure from the womb is,
23:18SPEAKERthe difference there is much more significant
23:20SPEAKERthan however many microseconds or whatever you get from,
23:23SPEAKERor milliseconds, I think it is.
23:25SPEAKERBut yeah, those processes are always happening
23:30SPEAKERand you can calculate how much it is
23:32SPEAKERif you're doing something like orbiting the earth
23:35SPEAKERevery 90 minutes.
23:37SPEAKER- That's funny.
23:39SPEAKER- So pretty broad question here,
23:40SPEAKERbut what is exciting to you in cosmology at the moment?
23:43SPEAKERI mean, obviously JWST is big in the news,
23:45SPEAKERbut is there anything else maybe
23:47SPEAKERthat's less in the spotlight in terms of research
23:50SPEAKERor theory or anything that is just the thing
23:52SPEAKERyou're excited about right now?
23:54SPEAKER- Oh, there's so much going on.
23:57SPEAKERSo one of the things that's really exciting is,
24:00SPEAKERso as you say, we're getting these amazing images
24:03SPEAKERof the early universe or the early galaxy formation stages
24:06SPEAKERof the universe and that's really exciting
24:08SPEAKER'cause we're learning about how the first galaxies
24:11SPEAKERmight've formed and the processes around that.
24:14SPEAKERAnd we're just getting a better idea
24:17SPEAKERof the evolution of the universe.
24:18SPEAKERBut one of the things that's really exciting
24:23SPEAKERthat I think isn't talked about quite so much right now
24:26SPEAKERis gravitational waves.
24:28SPEAKERSo the first gravitational wave detection happened
24:33SPEAKERin I think 2017 or something where they detected
24:38SPEAKERtwo massive black holes in a galaxy
24:42SPEAKERof a billion layers away or something
24:44SPEAKERcolliding with each other.
24:48SPEAKERI mean, that was an amazing achievement
24:50SPEAKERbecause the level of precision you need to do
24:54SPEAKERthat experiment at to get that data is just astonishing.
24:57SPEAKERLike it's amazing what they were able to measure
25:00SPEAKERand they were able to sort of measure the movement
25:03SPEAKERof space itself as these black holes are colliding
25:07SPEAKERin another galaxy, like just amazing stuff, right?
25:10SPEAKERSo that experiment, the LIGO experiment
25:14SPEAKERand a couple of others, Virgo is one of them as well.
25:18SPEAKERThose experiments have been just taking data
25:20SPEAKERfor the last several years.
25:22SPEAKERAnd now they've seen many, many collisions of black holes.
25:26SPEAKERThey've seen collisions of neutron stars
25:29SPEAKERthat then form black holes, presumably as they collide
25:32SPEAKERand in the process create these,
25:35SPEAKERwhat's called a kilonova, which is a burst of radiation
25:39SPEAKERin various parts of the spectrum.
25:41SPEAKERAnd we've seen that radiation.
25:44SPEAKERWe saw an event where the neutron stars collided,
25:48SPEAKERLIGO saw the collision through gravitational waves
25:51SPEAKERand then a bunch of telescopes saw like the afterglow
25:54SPEAKERor the explosion in a bunch of different wavelengths.
25:57SPEAKERSo that was really cool.
25:58SPEAKERBut anyways, it's kept going and there've been some events
26:01SPEAKERthat might be like a neutron star and a black hole,
26:04SPEAKERwhich is pretty cool.
26:05SPEAKERAnd there are events that suggests black holes at masses
26:09SPEAKERthat we didn't think black holes should be forming at,
26:11SPEAKERwhich is also really interesting.
26:13SPEAKERAnd so we're getting a ton of information
26:17SPEAKERabout black holes and neutron stars
26:21SPEAKERand just like the evolution of objects in the universe.
26:26SPEAKERBut there's a new experiment.
26:28SPEAKERIt's not really a new experiment.
26:29SPEAKERSo the experiment's been going on for a long time
26:32SPEAKERthat's looking for gravitational waves in a different way.
26:35SPEAKERAnd there's rumors that there might be new data
26:39SPEAKERfrom that coming soon.
26:40SPEAKERSo this is called a pulsar timing array.
26:43SPEAKERAnd what it does is it looks at a whole bunch of pulsars
26:46SPEAKERin various parts of the sky
26:48SPEAKERand just watches the click of these pulsars.
26:51SPEAKERSo pulsars are neutron stars
26:52SPEAKERthat are rotating very, very rapidly.
26:54SPEAKERThey have radiation coming out of one of the poles
26:57SPEAKERand the radiation pole and the rotation pole
26:59SPEAKERare not lined up.
27:00SPEAKERAnd so they sweep past,
27:02SPEAKERthe radiation sweeps past the earth at regular intervals.
27:05SPEAKERAnd some of these are like in micros or sorry, milliseconds.
27:09SPEAKERSo they're rotating really, really quickly
27:10SPEAKERand you get these millisecond pulses.
27:12SPEAKERSome of them are longer, seconds, whatever between pulses,
27:16SPEAKERbut there's a whole range.
27:18SPEAKERAnd these pulsar timing arrays use radio telescopes
27:22SPEAKERto monitor all these pulsars.
27:25SPEAKERAnd they look for changes in the timing
27:27SPEAKERas gravitational waves pass between us and the pulsar
27:32SPEAKERor pass through that space.
27:33SPEAKERAnd so the idea is that you'd get this like time dilation
27:38SPEAKEReffect as the pulses are coming
27:42SPEAKERand it would change the timing in a predictable way.
27:45SPEAKERAnd you can look for a background of gravitational waves
27:49SPEAKERfrom populations throughout the universe
27:53SPEAKERor from early universe processes or various other things.
27:57SPEAKEROr you can look for gravitational waves
28:00SPEAKERthat are coming from the collisions
28:01SPEAKERof much more massive black holes.
28:04SPEAKERAnd so those experiments have been going on for years
28:09SPEAKERand there've been like a couple of little hints
28:11SPEAKERof like maybe something cool is coming out of that,
28:14SPEAKERbut they didn't really know how to interpret it.
28:16SPEAKERAnd so there's new data coming apparently soon
28:20SPEAKERthat might also be really, really interesting
28:23SPEAKERand show us something cool there.
28:24SPEAKERSo, I mean, it gets a little esoteric, I guess,
28:27SPEAKERbut I'm really excited about what we're learning
28:29SPEAKERfrom like not observing the light
28:34SPEAKERfrom processes in the universe,
28:36SPEAKERbut observing the effect of those processes
28:38SPEAKERon like the motion of space itself.
28:41SPEAKERLike just the fact that we can do that at all
28:42SPEAKERis really, really cool.
28:44SPEAKER- Yeah, the fact that we can do a astronomical tool
28:48SPEAKERthat we have now is that we can measure
28:50SPEAKERthe shape of space is an absolute trip.
28:55SPEAKER- Something that really impresses me
28:57SPEAKERis the ingenuity that goes into,
29:01SPEAKERbecause observational ability is so limited
29:03SPEAKERto look at things directly,
29:05SPEAKERthe ingenuity of kind of using other
29:08SPEAKERnot really related features or bodies as reference points,
29:11SPEAKERlike is it the type one A supernova
29:14SPEAKERthat was used to measure like redshift and-
29:16SPEAKER- Dark energy, the accelerated expansion of the universe.
29:20SPEAKER- And like the thing you're talking about with pulsars here,
29:22SPEAKERit's like you have such a limited toolbox
29:25SPEAKERbeing on this tiny planet
29:26SPEAKERwith all this interference and stuff
29:28SPEAKERthat you kind of have to use everything you have
29:30SPEAKERat your disposal as a reference against everything else.
29:33SPEAKERLike it's kind of amazing to see that little ingenuity
29:35SPEAKERin coming up with this kind of experimentation.
29:38SPEAKER- Yeah, yeah, I mean, it's super cool.
29:40SPEAKERLike I love how creative you get to be in cosmology
29:44SPEAKERwhere you can say, well,
29:47SPEAKERI'm interested in this weird thing
29:49SPEAKERthat theory says might happen.
29:51SPEAKERWhat are the tools available to me?
29:53SPEAKERWhat can I look at?
29:53SPEAKERAnd what would the consequences of that theory be
29:56SPEAKERin terms of all these things that I can look at?
29:59SPEAKERAnd then you try and match that up.
30:00SPEAKERThat's an area of research called phenomenology.
30:03SPEAKERAnd that's sort of where I work.
30:05SPEAKERLike I don't make up the new theories
30:06SPEAKERof weird stuff happening in the universe.
30:08SPEAKERAnd I don't do any of the observations.
30:10SPEAKERLike I never touched data at all, basically.
30:13SPEAKERBut I sit in the middle and I ask the question,
30:16SPEAKERlike if this thing is happening
30:18SPEAKERthat the theory says might happen,
30:19SPEAKERwhat would we see with new telescopes
30:23SPEAKERor with new experiments?
30:25SPEAKERAnd how can we best optimize the experiments
30:31SPEAKERand the observations to see those cool, weird things, right?
30:35SPEAKERSo for example, when I was in grad school,
30:39SPEAKERI was working on a project about cosmic strings,
30:41SPEAKERwhich are these hypothetical like strings of energy
30:44SPEAKERthat might stretch through the universe
30:45SPEAKERin this weird sort of network.
30:47SPEAKERAnd sometimes they would sort of
30:49SPEAKERbutt off these little loops of string
30:50SPEAKERand these little loops would kind of vibrate
30:53SPEAKERand radiate away energy in either particles
30:55SPEAKERor gravitational waves.
30:56SPEAKERThere's this whole complicated thing
30:58SPEAKERthat may or may not be happening.
31:00SPEAKERAnd cosmic strings are predicted by certain theories,
31:02SPEAKERnot others.
31:03SPEAKERThey're considered exotic and sort of speculative.
31:07SPEAKERAnd I was interested in how you would search for these,
31:11SPEAKERhow you would put constraints
31:12SPEAKERon the existence of these things.
31:14SPEAKERAnd I had been talking a lot with radio astronomers
31:19SPEAKERabout other things.
31:20SPEAKERAnd so I worked out like, well, okay,
31:22SPEAKERwhat if you look for the way
31:24SPEAKERthat these little loops of strings
31:26SPEAKERwould distort the space around them
31:28SPEAKERand then change what you see with these distant radio sources
31:31SPEAKERthat are useful for completely different purposes, right?
31:34SPEAKERAnd so we were able to write up a paper
31:37SPEAKERlooking at like constraints on these cosmic strings
31:39SPEAKERthrough what new radio telescopes might or may not see.
31:45SPEAKERAnd so, and these are completely unrelated things
31:47SPEAKERlike the sources of these radio signals
31:52SPEAKERare like galaxies that have supermassive black holes in them
31:56SPEAKERand have an accretion disk
31:58SPEAKERand are creating radio waves from that.
32:01SPEAKERCosmic strings have no relation to that at all,
32:04SPEAKERbut you might be able to use the two together
32:06SPEAKERto learn something about the early universe.
32:08SPEAKERSo that kind of thing is really, really fun for me.
32:11SPEAKER- So I haven't, I have not even looked at anything
32:14SPEAKERabout string theory in like a decade.
32:15SPEAKERSo I have, this is woefully out of date, I'm sure.
32:18SPEAKERBut I feel like I remember reading one of the big,
32:21SPEAKERthe big objections was that it was kind of untestable
32:23SPEAKERat the time that there was kind of no way to verify it.
32:25SPEAKERIs that, has that changed?
32:26SPEAKERIs that what you're describing here?
32:28SPEAKERSounds like, is there more of an observational capacity
32:30SPEAKERthere now or?
32:32SPEAKER- Well, so there's a difference between string theory
32:34SPEAKERand cosmic strings.
32:36SPEAKERSo some, so cosmic strings are a more generic
32:39SPEAKERkind of phenomenon that where it's technically called
32:42SPEAKERa cosmic defect or sorry, a topological defect
32:46SPEAKERwhere there's, it's something that affects
32:51SPEAKERsort of the configuration of space time in its vicinity.
32:56SPEAKERAnd there are several things that can create cosmic strings
32:59SPEAKERand some of them are, some of them have to do with
33:02SPEAKERvery early universe processes like cosmic inflation.
33:06SPEAKERSome of them have to do with things like string theory.
33:10SPEAKERAnd, but the observational consequences, you can,
33:16SPEAKERthey're affected a little bit by the origin of these strings,
33:19SPEAKERbut they're not necessarily, not necessarily determined.
33:23SPEAKERSo, so yeah, so if we found cosmic strings,
33:27SPEAKERdepending on what we saw, then they might be something
33:31SPEAKERthat points us toward a kind of string theory,
33:34SPEAKERbut they might not.
33:35SPEAKERIt depends on their properties.
33:37SPEAKERString theory itself as a sort of model is,
33:42SPEAKERit's a really interesting thing.
33:43SPEAKERSo it was designed as a way to connect quantum mechanics
33:46SPEAKERand general relativity, Einstein's theory of gravity.
33:49SPEAKERAnd it's a cosmic, as a quantum gravity theory.
33:55SPEAKERAnd it was sort of written as to be sort of a theory
33:58SPEAKERof everything and the early versions of string theory
34:01SPEAKERwere all based on like supersymmetry, which is another kind,
34:05SPEAKERit's like an extension of the standard model
34:07SPEAKERof particle physics that hypothesizes a whole new set
34:09SPEAKERof models of particles that are related to the particles
34:13SPEAKERthat we have.
34:14SPEAKERI mean, so I'm not a string theorist.
34:16SPEAKERI don't know too much about the history here,
34:18SPEAKERbut my understanding is that there, you know,
34:20SPEAKERthere's a connection between supersymmetry
34:22SPEAKERand certain models of string theory.
34:24SPEAKERAnd we haven't seen any evidence of supersymmetry.
34:26SPEAKERAnd so where that leaves string theory is a little unclear
34:31SPEAKERin terms of like, like there's,
34:36SPEAKERI don't, yeah,
34:37SPEAKERI don't really know what we can say about string theory
34:40SPEAKERat the moment because there's still people are completely,
34:42SPEAKERyou know, constantly working on various aspects
34:45SPEAKERof string theory, but in kind of different contexts
34:49SPEAKERand with different goals and at the moment,
34:55SPEAKERyou know, finding like testing,
34:58SPEAKERtesting these theories in a comprehensive way, yeah,
35:02SPEAKERit would require, would require doing experiments
35:06SPEAKERthat reach into that quantum gravity regime,
35:08SPEAKERwhich is not something that we can do.
35:10SPEAKERSo you need to find, you need to do an experiment
35:12SPEAKERwhere you're going to such high energies
35:14SPEAKERthat gravity is important and we can't,
35:17SPEAKERwe can't do that with current technology
35:19SPEAKERor we need to find observations that connect
35:22SPEAKERwith regions of space or, you know,
35:26SPEAKERtimes in the cosmic history where both quantum mechanics
35:29SPEAKERand gravity are important.
35:30SPEAKERAnd again, we don't have access to that easily.
35:34SPEAKERThat doesn't mean that we'll never find ways
35:37SPEAKERto test these things or to, you know,
35:39SPEAKERrule out certain models.
35:40SPEAKERAnd there are, there are lots of hypotheses about,
35:46SPEAKERabout how you can sort of put constraints
35:48SPEAKERor rule, you know, rule out different kinds of models,
35:52SPEAKERbut also there are lots and lots of models
35:54SPEAKERin string theory that have lots and lots
35:56SPEAKERof different predictions.
35:57SPEAKERAnd so it's, it's a little bit difficult to,
35:59SPEAKERto really like say yes or no on that.
36:02SPEAKER- I was going to ask like,
36:03SPEAKERone of the things that's always fascinating to me
36:05SPEAKERis the idea that like, like there's consensus, right?
36:10SPEAKERLike the, like the consensus changes over time
36:13SPEAKERabout what, what, you know, what,
36:15SPEAKERwhat is the best understanding we have.
36:17SPEAKERAnd it's like the,
36:19SPEAKERwhen you read about that stuff in history
36:21SPEAKERof science books, it's always like, well,
36:23SPEAKERand then all of a sudden Galileo did this
36:25SPEAKERand we're like, oh, well, here we go.
36:26SPEAKERI mean, everybody agrees.
36:28SPEAKERBut in reality, it's, it's that,
36:30SPEAKERthat transition is always a lot messier
36:32SPEAKERand we're kind of always living through them, right?
36:35SPEAKERAt least in the, in, in our modern age,
36:37SPEAKERthings have changed.
36:38SPEAKERLike I was born in 1975 and our understanding
36:40SPEAKERof how the universe works is dramatically different now
36:43SPEAKERthan it was when I was, when I was born 45 years ago,
36:46SPEAKER46 years ago, 28 years ago, wow.
36:49SPEAKERIt's, it's a complicated thing like to,
36:52SPEAKERto explain like how, how our understanding changes,
36:57SPEAKERhow the, how the consensus changes,
36:59SPEAKERbecause I think it can happen in a few different ways.
37:02SPEAKEROne of them can be just sort of a slow evolution
37:05SPEAKERtoward a new understanding,
37:08SPEAKERbut also we can have situations where a new observation
37:12SPEAKERor, or a new explanation comes up
37:14SPEAKERthat kind of takes the field by storm.
37:16SPEAKERAnd it doesn't mean that everybody
37:17SPEAKERimmediately changes their mind,
37:19SPEAKERbut you know, you, you can have a lot of excitement
37:22SPEAKERabout a particular idea that, that, that can, you know,
37:27SPEAKERhave, have a lot of influence.
37:28SPEAKERSo for example,
37:29SPEAKERwhen the accelerated expansion of the universe
37:32SPEAKERwas discovered, you know, fairly, fairly quickly,
37:36SPEAKERI would say astronomers and physicists had to grapple
37:41SPEAKERwith the idea that the universe is accelerating
37:43SPEAKERand we might have this cosmological constant
37:45SPEAKERas a, as a, an element of, of cosmology.
37:49SPEAKERAnd it took, you know, I mean,
37:51SPEAKERthis was sort of before my time
37:53SPEAKERas a professional astronomer, but it took, you know,
37:57SPEAKERmany years before it was really, really accepted
37:59SPEAKERthat this is, this is how things likely are.
38:02SPEAKERAnd, and so, you know, now when,
38:05SPEAKERwhen you look at recent textbooks,
38:07SPEAKERthey, they kind of just assume that,
38:09SPEAKERthat dark energy is real,
38:10SPEAKERthat it's cosmological constant
38:12SPEAKERand look at other possibilities.
38:13SPEAKERBut, but with that as the default,
38:15SPEAKERwhereas in older textbooks, you know,
38:17SPEAKERthose that were written in the sort of 1980s, 1990s,
38:21SPEAKERit was considered as maybe a possibility,
38:24SPEAKERbut not, not the likely one.
38:26SPEAKERSo it takes some time.
38:28SPEAKERAnd that was, but that was like a,
38:30SPEAKERthat was a pretty definitive observation.
38:33SPEAKERThat was a pretty clear thing.
38:35SPEAKERLike, yeah, the, you know, this,
38:37SPEAKERthis is a really, is really strong support
38:39SPEAKERthat the universe is accelerating its expansion,
38:42SPEAKERwon a Nobel prize several years later,
38:45SPEAKERlike it was clear that this was a big deal.
38:47SPEAKERSo sometimes stuff like that happens where, you know,
38:50SPEAKERyou have, you have evidence that's so powerful
38:52SPEAKERthat you have to kind of accept it.
38:55SPEAKERBut, but then, you know, with other things,
38:59SPEAKERit might be that there's just kind of a slow evolution
39:02SPEAKERtoward a different understanding of, of how things work.
39:06SPEAKERAnd, and if it's not like,
39:08SPEAKERif it's not sort of ground shaking, like the,
39:11SPEAKERlike the dark energy thing,
39:13SPEAKERthen it's, it's not always clear that it's changed.
39:16SPEAKERSo an example of that is like, when,
39:20SPEAKERwhen I talk to people about the very early universe
39:23SPEAKERand the big bang,
39:24SPEAKERa lot of people imagine the big bang to have been
39:27SPEAKERlike a singularity that then exploded outward
39:30SPEAKERand, you know, created whole space.
39:33SPEAKERAnd then, you know, maybe at some point,
39:35SPEAKERit's gonna collapse again and,
39:37SPEAKERand re-collapse into a singularity
39:39SPEAKERand then start a new universe.
39:40SPEAKERAnd none of that is likely based on our current understanding
39:43SPEAKERright? Like, so maybe there was a singularity.
39:46SPEAKERWe don't actually have any evidence of that,
39:49SPEAKERthat there are certain arguments in general relativity
39:51SPEAKERthat would suggest there should have been one at some point,
39:53SPEAKERbut, but our, our current models of the early universe
39:57SPEAKERreally don't work unless something happened
40:01SPEAKERin the very early universe
40:02SPEAKERthat looks nothing like a singularity.
40:04SPEAKERSo there that like, we have this idea of cosmic inflation,
40:07SPEAKERwhich is where at very early times,
40:10SPEAKERthe universe accelerated,
40:11SPEAKERaccelerated in its expansion very, very rapidly
40:14SPEAKERand kind of emptied out the universe
40:16SPEAKERand then a process filled it with radiation.
40:19SPEAKERAnd then we see the hot radiative phase of the universe
40:22SPEAKERas the cosmic microwave background radiation.
40:25SPEAKER- That's what we can literally look at with the JWST.
40:27SPEAKER- That's what we can actually,
40:28SPEAKERit's not with, it's not with JWST,
40:29SPEAKERit's with, with micro telescopes,
40:32SPEAKERlike the Planck telescope, WMAP,
40:35SPEAKERCOBE back in the day,
40:36SPEAKERthere are telescopes that see microwave radiation
40:39SPEAKERand there's a background light.
40:41SPEAKERThere's, there's light that everywhere you look
40:43SPEAKERin the universe, there's this background of microwaves.
40:47SPEAKERAnd that background light is, is what's,
40:50SPEAKERwhat that is, is that you're looking so far away
40:53SPEAKERthat you're seeing part of the universe
40:55SPEAKERthat is still on fire.
40:56SPEAKERLike from your perspective,
40:57SPEAKERyou're looking so far back in time
40:59SPEAKERthat you're looking at a part of the universe
41:01SPEAKERthat's so far away from you, it's so far back in time,
41:03SPEAKERthat it's within the first, you know,
41:05SPEAKERa few hundred thousand years of the universe
41:07SPEAKERand the universe is still on fire.
41:08SPEAKERFrom that hot radiative phase.
41:11SPEAKERBut, but, but so yeah, so that's astonishing.
41:14SPEAKERWe can talk about that for days,
41:16SPEAKERbut the thing is that the,
41:19SPEAKERthe properties of that light that we see
41:22SPEAKERmake it really clear that it can't be just that there was,
41:24SPEAKERthere was a singularity
41:26SPEAKERand then the universe was hot and dense immediately.
41:30SPEAKERAnd that's the hot dense universe that we see.
41:32SPEAKERThere had to have been something between the singularity
41:35SPEAKERand that background light and that hot phase.
41:39SPEAKEROr maybe the singularity didn't happen at all,
41:41SPEAKERbut you can't just go straight from singularity
41:43SPEAKERto the hot phase in a way that makes sense
41:45SPEAKERwith our understanding of physics.
41:46SPEAKERSo this cosmic inflation thing probably happened.
41:50SPEAKERWe don't know for sure.
41:51SPEAKERThere are other explanations, but, but, you know,
41:54SPEAKERthe popular like understanding of the early universe is like,
41:59SPEAKERoh, there was a singularity.
42:00SPEAKERThen there was the fireball and then, you know,
42:02SPEAKERbut like that, that's not how it is at all.
42:04SPEAKERAnd then also, you know,
42:05SPEAKERwe're not gonna collapse into another singularity
42:08SPEAKERin the future, most likely.
42:10SPEAKERIn the 1960s, that was kind of the best understanding
42:13SPEAKERthat we have that we're headed toward a big crunch.
42:16SPEAKERBut, but as far as we know,
42:17SPEAKERthat's extremely unlikely at this point
42:19SPEAKER'cause the universe is, you know,
42:21SPEAKERaccelerating in its expansion.
42:23SPEAKERIt's not gonna fall back down, right, as far as we know.
42:27SPEAKERSo that, that understanding is very clear within cosmology,
42:31SPEAKERbut it absolutely is not filtered out into the,
42:34SPEAKERinto the public.
42:35SPEAKERLike a lot of people,
42:36SPEAKERas I've been talking to people about my book and stuff,
42:38SPEAKERa lot of people thought that the universe would collapse
42:41SPEAKERand that was it, right?
42:42SPEAKERAnd then the idea that the universe would collapse
42:45SPEAKERand then bounce and become, you know, a new big bang,
42:49SPEAKERthat's really difficult to do actually in physics,
42:51SPEAKERlike theory-wise, like it's, it's,
42:53SPEAKERit's reasonable to get the equations to create a big crunch
42:57SPEAKERif you have the right conditions,
42:58SPEAKERbut then a big crunch to a big bang is not a transition
43:01SPEAKERthat is, that like it makes sense within that,
43:04SPEAKERwithout theory.
43:05SPEAKERSo you have to work in all sorts of other things
43:07SPEAKERto try to get a bounce to happen.
43:09SPEAKERAnd there are theories that'll do that,
43:10SPEAKERbut it's, it's not straightforward
43:12SPEAKERand not sort of what we call generic.
43:14SPEAKERSo, so that, that whole story that,
43:17SPEAKERthat people have about like the singularity
43:19SPEAKERand then this, and like, none of that is,
43:22SPEAKERis actually how we talk about the early universe now.
43:25SPEAKERSo it's, it's kind of fascinating
43:26SPEAKERhow somebody told a really good story about that,
43:29SPEAKERyou know, in the, in the sort of 1980s,
43:33SPEAKERmostly Stephen Hawking and, and, and people,
43:37SPEAKERpeople latched onto that story, but when the,
43:40SPEAKERwhen the story changed, as far as our understanding goes,
43:44SPEAKERit did not, it did not filter out.
43:46SPEAKERSo it's, it's really, I mean,
43:48SPEAKERthat doesn't quite answer your question about like
43:51SPEAKERthe change of understanding within the field,
43:53SPEAKERbut it's kind of like there,
43:56SPEAKERsometimes these stories can persist even if the science
44:00SPEAKERcarries on and changes how we, how we think about stuff.
44:03SPEAKER- Yeah, I think it's complicated as a fair answer.
44:06SPEAKERRight? - Yeah, yeah.
44:07SPEAKER- It turns out, who knew, right?
44:09SPEAKER- Yeah.
44:11SPEAKER- Katie, I'm curious, like,
44:12SPEAKERwhat's the day-to-day like for an astrophysicist?
44:15SPEAKERIf, if you're like, do you just sit around or are you,
44:18SPEAKERare you, are you, is it just a lot of time thinking
44:21SPEAKERand reading and hanging, and like, what's,
44:26SPEAKERyeah, you, 'cause you said you're not looking at,
44:27SPEAKERyou're not looking at data, you're not doing math,
44:29SPEAKERand I'm like, where, where?
44:30SPEAKER- I didn't say, I didn't say I'm not doing math.
44:31SPEAKERI said I'm not coming up with new theories.
44:33SPEAKER- Okay, okay.
44:34SPEAKER- Some of my colleagues are, just coming up
44:36SPEAKERwith new theories, but we're kind of all doing math
44:39SPEAKERone way or another. - Okay, well, that makes me,
44:41SPEAKERI was worried, I was worried for not doing math.
44:43SPEAKERI made a mistake when I was deciding
44:45SPEAKERwhat I was gonna do with my life.
44:47SPEAKER- No, so, yeah, you know, when I first started,
44:51SPEAKERor when I first decided I wanted to get into cosmology,
44:54SPEAKERmy, my picture of what a physicist does,
44:57SPEAKERor was that like, you know, I would,
45:00SPEAKERI would go to, to a little room with a blackboard,
45:03SPEAKERand I would just fill that blackboard
45:04SPEAKERwith equations all day, and then I would have
45:06SPEAKEReureka moments and like, and like, you know,
45:09SPEAKERdiscover the meaning, like the, you know,
45:12SPEAKERI'd discover everything there is to know
45:13SPEAKERabout the universe through a process of like,
45:15SPEAKERmathematics and will, right?
45:16SPEAKERLike that was my, that was my picture of how physics went.
45:20SPEAKER- That's how it's depicted in film generally, I think.
45:22SPEAKER- Yeah, no, it is, and that's the, that's a big problem.
45:26SPEAKERAnd I mean, there's, there's that,
45:27SPEAKERand then the other thing that people think of is like,
45:30SPEAKEReverybody's just kind of like sitting around being like,
45:32SPEAKERwhat if the universe was shaped like a football?
45:35SPEAKERLike, ooh, dude, you know, it's kind of like,
45:37SPEAKERwe're just sort of making stuff up and being like,
45:40SPEAKERoh, that would be neat.
45:41SPEAKERAnd yeah, none of it's, none of it's like that.
45:44SPEAKERIn terms of the day to day,
45:46SPEAKERit's certainly a lot more collaborative
45:48SPEAKERthan I ever thought it was when I first started.
45:50SPEAKERLike I spend a lot of my time in, you know,
45:54SPEAKERgroup meetings or seminars or, you know,
45:58SPEAKERtalking over lunch with other,
46:00SPEAKERother cosmologists about new ideas and, you know,
46:04SPEAKERbouncing ideas off each other to come up with projects or,
46:10SPEAKERyou know, answer questions about phenomena that were like,
46:13SPEAKERsay, oh, I saw this paper about this thing.
46:15SPEAKERWhat do you think of that?
46:17SPEAKERLike, so there's, there's a lot of,
46:19SPEAKERa lot of sharing ideas, a lot of discussion,
46:22SPEAKERa lot of going to seminars,
46:23SPEAKERa lot of giving talks about research and progress
46:27SPEAKERor research that's been completed.
46:29SPEAKERAnd then there's a lot of reading papers.
46:31SPEAKERSo reading papers that other people have written.
46:34SPEAKERThere's the, the archive, which is,
46:37SPEAKERit's an online preprint server, but it's not just preprints.
46:40SPEAKERIt's like, if you, if you write a paper, like if I,
46:43SPEAKERif I complete a calculation and I finished a project and,
46:46SPEAKERand I want to share my results,
46:48SPEAKERwhat I do is I write up a paper
46:50SPEAKERand I submit it to a journal, right?
46:51SPEAKERBut either at the same time or shortly before
46:54SPEAKERor shortly after submitting to the journal,
46:55SPEAKERI put it on the archive, which is a, an online repository
47:00SPEAKERfor like all knowledge in physics.
47:03SPEAKERAnd, and so there, and it goes there.
47:06SPEAKERAnd then if you're, if you're a researcher in,
47:09SPEAKERin the field, then you can,
47:11SPEAKERyou can browse through the archive every morning
47:13SPEAKERand see the new papers that have been posted.
47:16SPEAKERThere are a lot though.
47:17SPEAKERThere's like in, in astrophysics alone,
47:20SPEAKERyou get like 90 papers a day or something.
47:22SPEAKERSo it's impossible to keep up with everything,
47:25SPEAKERbut that's one of the ways that, you know,
47:28SPEAKERwe can see what people have been doing.
47:30SPEAKERThen we go to conferences and hear about projects that way.
47:33SPEAKERAnd there's a whole, a whole sort of process
47:36SPEAKERof just keeping up with what everybody else
47:38SPEAKERis doing in the field.
47:40SPEAKERAnd then in terms of the, the actual like work part,
47:45SPEAKERfor me, that's mostly,
47:48SPEAKERmost of the stuff I do is, is like I'll,
47:51SPEAKERI'll go through, I'll go through the literature.
47:53SPEAKERI'll figure out like what it is I'm trying to understand.
47:57SPEAKERI'll do a lot of kind of jotting down equations
48:01SPEAKERand things on paper and do some sort of rough calculations.
48:08SPEAKERAnd then I'll use other, then I'll use like,
48:12SPEAKERI'll use a computer to solve,
48:14SPEAKERto actually solve these equations and do calculations.
48:18SPEAKERSo I'll write up a code that calculates.
48:20SPEAKERSo for example, in my research group right now,
48:23SPEAKERwe were working with a code that calculates what happens
48:26SPEAKERif dark matter particles come together
48:28SPEAKERand annihilate with one another,
48:30SPEAKERand then produce a sort of shower of high energy particles.
48:34SPEAKERAnd then that, then what happens if that,
48:37SPEAKERif that occurs inside the gas in which the first stars
48:41SPEAKERand galaxies are forming and where does that energy go
48:43SPEAKERand how does it heat the gas?
48:44SPEAKERAnd then, you know,
48:45SPEAKERhow does that affect the process of star formation
48:47SPEAKERand so on?
48:48SPEAKERAnd then, so you can work all,
48:50SPEAKERyou can put together a whole code package to figure that out
48:54SPEAKERand then you can put that together with other code packages
48:57SPEAKERthat figure out like what telescopes would see.
49:00SPEAKERAnd then we can make predictions for the signals
49:02SPEAKERthat we'd see in radio telescopes that are looking for
49:06SPEAKERevidence of the sort of process of star formation
49:08SPEAKERthrough the universe.
49:09SPEAKERSo there's those kinds of, those kinds of things.
49:12SPEAKERSo it's a whole lot of code.
49:14SPEAKERAnd when I first started, it was all Fortran.
49:18SPEAKERAnd I didn't start that long ago, I mean, this is like the,
49:20SPEAKERyou know, the, the nineties, two thousands,
49:23SPEAKERwe were using Fortran 77.
49:25SPEAKERAnd then, and then eventually like, you know,
49:29SPEAKEReventually you stop having to use, you know,
49:31SPEAKERyour, your older advisor's code
49:33SPEAKERand you can write your own code.
49:34SPEAKERAnd so you do that in C or C++.
49:37SPEAKERAnd then, and then lately there's,
49:41SPEAKERmy students are mostly using Python or Julia,
49:46SPEAKERbut there's kind of this, yeah, this process of,
49:51SPEAKERyou still like some of the stuff we do still has,
49:53SPEAKERstill has Fortran in it because we're using like libraries
49:56SPEAKERthat other people put together.
49:57SPEAKERSo this is kind of long, long string of,
50:00SPEAKERof horrible code that goes back for generations.
50:03SPEAKER- Dependency nightmares, that's fantastic.
50:05SPEAKER- Yeah, yeah.
50:06SPEAKERSo, yeah, so then anyway, so we write code,
50:08SPEAKERwe produce plots, we write papers.
50:11SPEAKERSo it's, I sit in front of a computer most of the day.
50:14SPEAKERAnd when I'm not in front of the computer,
50:16SPEAKERI'm meeting with colleagues or reading papers
50:19SPEAKERor occasionally, you know, writing down equations.
50:22SPEAKERAnd my colleagues who work on other areas,
50:25SPEAKERespecially the more sort of hardcore theory people,
50:28SPEAKERspend a lot of their day, like paired up
50:30SPEAKERin front of a blackboard writing down equations
50:32SPEAKERand sort of having a discussion via the, you know,
50:37SPEAKERthe mathematics of the theory that they're working on.
50:40SPEAKERI don't do that as much,
50:42SPEAKERbut when I do meet with my colleagues,
50:43SPEAKERthere's usually a blackboard involved
50:45SPEAKERbecause we need to write down our equations
50:46SPEAKERand our plots and everything.
50:48SPEAKERSo there are a lot of blackboards in my institute.
50:51SPEAKERIt's kind of like kind of famous
50:53SPEAKERfor the number of blackboards we have
50:54SPEAKER'cause we're a theoretical physics institute.
50:56SPEAKERSo there's, there's a lot of that.
50:58SPEAKERAnd even like when you go to lunch,
51:00SPEAKERwe have a little bistro in our, in our institute.
51:02SPEAKERAnd, and there are, there are little paper holders
51:08SPEAKERand pencil holders on the tables,
51:10SPEAKERon each of the tables and little slips of paper
51:12SPEAKERthat you can use to write down your equations
51:14SPEAKERwhen you're talking to your colleagues over lunch.
51:16SPEAKERSo like, we're always prepared.
51:18SPEAKER- That's fantastic, so you don't have to use the napkin.
51:21SPEAKER- And are they still chalkboards, not dry erase?
51:23SPEAKER- Oh yeah, no, they're chalkboards, yeah.
51:25SPEAKERYeah, we, we, so theoretical physicists in general
51:28SPEAKERvastly prefer chalkboards, but it's really-
51:31SPEAKER- Why is this? I'm curious.
51:33SPEAKER- I mean, I think it's, I think it's a few things,
51:35SPEAKERyou know, it's annoying to deal with pens
51:37SPEAKERthat are running out of ink and like,
51:38SPEAKERit's annoying to get the ink on your fingers
51:41SPEAKERwhen you're using these things a lot.
51:43SPEAKERAnd we have really good chalk
51:44SPEAKERand we have really high quality chalkboards
51:46SPEAKERand it's just more satisfying.
51:48SPEAKERSome of the chalkboards have colored chalk,
51:50SPEAKERso we can still do different colors and things.
51:52SPEAKERBut it's really funny because there's a,
51:55SPEAKERan institute for quantum computation down the road
51:58SPEAKERthat we're, that our institute has a lot of interaction with
52:01SPEAKERbecause we have a lot of quantum computing people
52:03SPEAKERat the Primer Institute and the quantum computation people,
52:08SPEAKERthat's all whiteboards.
52:11SPEAKERYou go over there and it's the whiteboards,
52:12SPEAKERbut at the Theoretical Physics Institute
52:14SPEAKERare the blackboards.
52:15SPEAKER- That's, it's fascinating 'cause I, I, yeah, okay.
52:18SPEAKERI had no idea that this was a split
52:20SPEAKERthat existed in the world and I'm just, my mind's blown, so.
52:24SPEAKEROkay, so you use Python, you use C and C++,
52:27SPEAKERlike any other, we always ask people
52:28SPEAKERwhat kind of tools they use on the day to day.
52:31SPEAKERLike, are you, do you do, does the computation you do
52:33SPEAKERcan like comfortably live inside a laptop
52:36SPEAKERor a desktop computer or whatever?
52:38SPEAKERYou do have like heavy metal someplace offsite
52:39SPEAKERthat you can connect to if you need to.
52:41SPEAKER- Yeah, so for the stuff I do, it's usually,
52:44SPEAKERit's usually on the laptop.
52:45SPEAKERI occasionally use Mathematica as well,
52:47SPEAKERjust for different kinds of computations.
52:50SPEAKERBut yeah, but we do have access
52:52SPEAKERto high performance computing clusters.
52:56SPEAKERSo there are some at Primer Institute,
52:57SPEAKERthere are some that I have access to
52:59SPEAKERthrough my affiliation with North Carolina State
53:02SPEAKERand my students use the NC State cluster a lot.
53:06SPEAKERAnd so yeah, a lot of the computations are just,
53:10SPEAKERare just complicated and take a while.
53:11SPEAKERAnd so if we can do them on the HPC, then that's better.
53:16SPEAKERBut I don't personally do any of the,
53:20SPEAKERany of the sort of big simulations,
53:22SPEAKERlike numerical simulations that are,
53:25SPEAKERthat require banks and banks of course.
53:27SPEAKERLike I, some of my colleagues do those
53:30SPEAKERwhere you get these simulations of galaxy formation
53:32SPEAKERwhere you can see the gas swirling in
53:34SPEAKERand those are massive and those are, take a long time.
53:38SPEAKEROr even, or things in like numerical relativity
53:41SPEAKERwhere they're solving general relativity equations
53:43SPEAKERfor like black hole collisions.
53:45SPEAKERThose take a lot more computing power,
53:47SPEAKERbut the stuff that I do is usually not quite so,
53:51SPEAKERnot quite so intense.
53:52SPEAKER- Since you mentioned the chalkboards versus dry erase,
53:55SPEAKERI have to ask the computer version of that.
53:57SPEAKERIs there a preference for operating systems
53:59SPEAKERamong you and your colleagues
54:00SPEAKERor across different institutes in terms of,
54:03SPEAKERI'm just curious.
54:05SPEAKER- Most of us have Macs, but I think
54:09SPEAKERbecause it's so easy to do command line stuff
54:13SPEAKERand things like that with the Mac,
54:16SPEAKERvery few people would use Windows, for example.
54:19SPEAKERBut yeah, most of us have Macs.
54:21SPEAKER- I wanted to ask a question
54:22SPEAKERabout something you touched on earlier,
54:24SPEAKERwhich is the ongoing attempt
54:26SPEAKERto kind of unify gravitation and quantum mechanics.
54:30SPEAKERI guess what I really want to ask is,
54:31SPEAKERam I looking at this the right way?
54:33SPEAKERLike as sort of, you know, you had like Newton's mechanics
54:37SPEAKERand then you had relativity.
54:38SPEAKERLike is it accurate or fair to look at that
54:41SPEAKERas the sort of next big step in understanding
54:44SPEAKERor is that too grandiose a way to look at that
54:47SPEAKERas a milestone?
54:48SPEAKER- No, I think that's reasonable.
54:49SPEAKERSo yeah, one of the things that I talk about a lot
54:53SPEAKERwhen I talk to people about like, you know,
54:55SPEAKERwhen we go from one theory to another
54:59SPEAKERas our understanding changes is, you know,
55:02SPEAKERwe're not disproving the previous model per se.
55:09SPEAKERSo for example, going from Newton's mechanics
55:11SPEAKERto general relativity is not saying
55:15SPEAKERthat if you roll a ball down a hill,
55:17SPEAKERNewton's laws are not gonna give you the answer
55:20SPEAKERto what that looks like, right?
55:22SPEAKERIt would be ridiculous to use the equations
55:25SPEAKERof general relativity to calculate
55:27SPEAKERhow a ball rolls down a hill.
55:28SPEAKERYou could probably do it.
55:29SPEAKERYou'd probably make mistakes somewhere.
55:32SPEAKERAnd if you didn't, you wouldn't, you know,
55:35SPEAKERthe accuracy you get from that is not gonna be better
55:37SPEAKERfrom that from Newton's equations
55:39SPEAKER'cause there are other things that are, you know,
55:40SPEAKERlike the sources of error are much bigger
55:42SPEAKERthan the differences between those two calculations.
55:45SPEAKERSo Newton's mechanics is entirely correct
55:48SPEAKERin the regimes that we use it for
55:49SPEAKERin the appropriate regimes.
55:51SPEAKERAnd that continues to be true
55:54SPEAKEReven though we have general relativity for regimes
55:58SPEAKERlike when you're really close to the sun
56:00SPEAKERand the orbit of mercury is perturbed
56:02SPEAKERby, you know, general relativistic effects.
56:05SPEAKERSo you can't use Newton's mechanics
56:08SPEAKERto calculate the orbit of mercury
56:09SPEAKERbecause that's in a regime where the general relativity
56:15SPEAKERaspects become really important.
56:17SPEAKERSo in the same way, you know, quantum mechanics
56:21SPEAKERand general relativity work great in the regimes
56:23SPEAKERthat we generally use them for,
56:24SPEAKERthe only places where there's gonna be problems
56:27SPEAKERwith those two things is in places
56:29SPEAKERlike the center of a black hole
56:32SPEAKERor the very, very early universe
56:33SPEAKERor places where we think that both of those
56:38SPEAKERmight be important to what's happening
56:41SPEAKERand then we would need to find a way to connect them.
56:44SPEAKERBut if you just talk about, you know,
56:48SPEAKERall the regimes we use quantum mechanics to talk about,
56:52SPEAKERgeneral relativity is completely unimportant
56:54SPEAKERand all the regimes in which we use general relativity
56:56SPEAKERto talk about what's happening,
56:58SPEAKERquantum mechanics is clearly unimportant.
57:00SPEAKERAnd so what we're trying to do
57:01SPEAKERis find something that works in those regimes
57:04SPEAKERwhere the two come together potentially
57:08SPEAKER'cause that's where they disagree.
57:10SPEAKERBut it doesn't mean that either of those models
57:13SPEAKERis gonna be wrong, right?
57:15SPEAKERAnd even if we came up with some new theory
57:18SPEAKERthat was a totally different formulation
57:20SPEAKERthan general relativity,
57:21SPEAKERa totally different formulation than quantum mechanics,
57:23SPEAKERwe could still use GR and quantum mechanics
57:26SPEAKERas effective theories in the regimes
57:29SPEAKERthat we use them for now
57:30SPEAKERbecause they currently work great.
57:34SPEAKERThey pass all of the observational tests
57:36SPEAKERin all the experiments that we do right now.
57:40SPEAKERSo, yeah, so it's one of these things
57:42SPEAKERwhere if we did find a quantum gravity theory
57:45SPEAKERand we're able to sort of confirm it,
57:47SPEAKERthen that would give us the possibility
57:50SPEAKERto reach out into those new regimes
57:52SPEAKERand learn something new about, you know,
57:54SPEAKERmaybe the structure of physics at a different level
57:58SPEAKERand a different energy scale.
58:00SPEAKERBut you're always gonna have these effective theories
58:02SPEAKERin the regimes that we currently use them.
58:05SPEAKERAnd Newton's laws are always gonna work
58:07SPEAKERfor a ball rolling down a hill.
58:09SPEAKERWe're never gonna throw that and say like,
58:11SPEAKER"No, that's the wrong equation," right?
58:13SPEAKERSo it's, yeah, so I think that,
58:16SPEAKERyeah, I don't think it's grandiose
58:17SPEAKERto say that this is the next big thing.
58:19SPEAKERI mean, quantum gravity is very much
58:21SPEAKERa sort of holy grail for theoretical physics
58:24SPEAKERand there are a lot of people working on that,
58:26SPEAKERa lot of people working on that
58:28SPEAKERwhere I'm at at the Perimeter Institute.
58:30SPEAKERThere's, you know, it's a really, really important question
58:34SPEAKERfor our understanding of the universe,
58:36SPEAKERour understanding of the beginning of the universe,
58:38SPEAKERour understanding of these extreme environments
58:41SPEAKERin the universe, but it's not gonna prove wrong
58:46SPEAKEReverything that we've already done.
58:48SPEAKER- Katie, thank you so, so much.
58:49SPEAKERIt's so good to spend time with you
58:51SPEAKERand to talk about like, you know,
58:54SPEAKERthe end of the universe and the insides of black holes
58:57SPEAKERand all the things that impact us so much on the day to day.
59:02SPEAKERWhere can people find out more about you and your work?
59:04SPEAKER- Yeah, so my website is astrocady.com.
59:09SPEAKERThat's Katie spelled K-A-T-I-E.
59:12SPEAKERSo I, yeah, I've got a lot of stuff there.
59:16SPEAKERI'm on Twitter as @astrocady, although Twitter is dying,
59:19SPEAKERso I don't know.
59:21SPEAKERI'm posting there a little less than I used to.
59:25SPEAKER- Whole other topic these days, it turns out, yeah.
59:27SPEAKER- I'm also on Instagram as @astrocadyMac
59:30SPEAKERbecause somebody else had the Astrocady handle.
59:33SPEAKERSo anyway, and I'm on Blue Sky now.
59:38SPEAKERAnd on Blue Sky, I'm connected to my URL, astrocady.com,
59:41SPEAKERso you can find me there that way.
59:45SPEAKERYeah, I even do some stuff on TikTok a little bit.
59:48SPEAKERAstrocady, it's @astrocadymac on TikTok.
59:52SPEAKERI have a few little videos about the first slide
59:54SPEAKERof the universe, and I have one about using
59:58SPEAKERstatic electricity to bend the water in my faucet,
1:00:01SPEAKERjust because I had a lot of fun with that one day.
1:00:05SPEAKERSo yeah, there's stuff kind of everywhere.
1:00:11SPEAKER- Thank you so much, Katie, for coming by.
1:00:14SPEAKERThis was absolutely fantastic.
1:00:17SPEAKERWe could have spent another two or three hours
1:00:18SPEAKERtalking about this, I think,
1:00:20SPEAKERbefore we got out of time there, but.
1:00:22SPEAKER- Honestly, when we started this podcast,
1:00:24SPEAKERtalk to a working astrophysicist was right at the top
1:00:27SPEAKERof the list of things I would like to do with it.
1:00:29SPEAKERSo it's really been an honor to get to talk to her
1:00:31SPEAKERand draw on her extremely extensive knowledge.
1:00:35SPEAKER- As always, if you're new to the show,
1:00:37SPEAKERthis is a listener-supported podcast.
1:00:38SPEAKERWe have a Patreon at patreon.com/techpod,
1:00:41SPEAKERwhere if you would like to support the show
1:00:43SPEAKERfor five bucks a month, you can.
1:00:45SPEAKERAnd you also get access to our Patreon-exclusive episode
1:00:47SPEAKERevery month, where we talk about
1:00:50SPEAKERusually more technological stuff.
1:00:51SPEAKERSo usually it's stuff like what's going on in computers
1:00:54SPEAKERor what we're working on, projects that we have
1:00:57SPEAKERin development, maybe episodes, future episodes
1:00:59SPEAKERthat we're doing research on, stuff like that.
1:01:01SPEAKERAnd you can find out about that, again,
1:01:03SPEAKERat patreon.com/techpod.
1:01:05SPEAKERAs always, at the end of the show,
1:01:07SPEAKERwe thank our executive producer tier patrons,
1:01:09SPEAKERincluding Nick Johnston, Paddle Creek Games,
1:01:12SPEAKERmakers of Fractured Vale, Andrew Slosky,
1:01:14SPEAKERBrad's mid-size hoodoo voodoo switcheroo.
1:01:18SPEAKEROctothorpe Bunny Crimes, Just Wedge, Joel Krauska,
1:01:21SPEAKERTwinkle Twinkie, David Allen, and James Kamik.
1:01:23SPEAKERThank you all so, so much.
1:01:24SPEAKERI forgot the best part about the Patreon
1:01:26SPEAKERis you get access to the fabulous TechPod Discord as well.
1:01:28SPEAKER- That's right, a fount of knowledge,
1:01:31SPEAKERboth technical and non.
1:01:33SPEAKER- Information constantly on all topics.
1:01:36SPEAKERI've quite enjoyed The Gardening Channel,
1:01:38SPEAKERwhich we opened up a couple of weeks ago.
1:01:40SPEAKERAnd people are coming in and sharing their good stuff.
1:01:46SPEAKERAnd to steal a good bit from our friends
1:01:49SPEAKERover at The Daily Tech News Show,
1:01:52SPEAKERwelcome to our newest patron, Woodhop.
1:01:54SPEAKERThanks for supporting the show, Woodhop.
1:01:55SPEAKERWe appreciate you.
1:01:56SPEAKER- Woodhop.
1:01:58SPEAKER- So, thanks to Katie.
1:01:58SPEAKERMake sure you check her out on socials,
1:02:01SPEAKERor go to astrokatie.com,
1:02:03SPEAKERand we will see you all next week.
1:02:05SPEAKER- Thanks for listening, everybody.
1:02:07SPEAKER(upbeat music)