Halloween Special: Zombies and Ghosts

Daniel and Kelly talk about Toxoplasma gondii, and the "science" of ghost hunting.

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Episode Transcript

Speaker 1 (00:06):
Happy Halloween everyone. This is my favorite time of year.
The weather's cool, the leaves are changing color here in Virginia,
and creepy stuff is in. So this week Daniel and
I are geeking out about zombies and ghosts. The zombies
I'm going to be talking about aren't like creatures who
have been infected by viruses that bring the creatures back

(00:29):
from the dead in search of delicious brains. But what
are often called zombies in pop science are creatures that
are infected by parasites, and then those parasites manipulate their
living creatures living hosts into acting in weird ways that
benefit the parasite while often hurting the host. But one

(00:50):
of the hard things about studying seemingly zombified creatures is
that behaviors can change when someone is infected for a
lot of reasons. Just because it sounds like a behavior
can benefit a parasite, that doesn't necessarily mean that it does.
In fact, sometimes we've looked into seemingly zombified creatures and

(01:12):
when we look into them more closely, the story that
we had been telling ourselves falls apart. Let's think through
why this can be so tough, all right, So, imagine
you're a kid who's home with a fever. Who does
that fever benefit all right, Well, maybe it benefits the
sick kid. If the high temperature makes it hard for
the bacteria or something to survive and grow, all right,

(01:33):
that's option one. Option two, maybe neither benefits. So if
the fever gets too high, then maybe that's bad for
the kid and it's bad for the bacteria. Anyone who
has allergies knows that sometimes immune systems overact and do
things that are not beneficial. So there are some instances
where something changes about the infected individual that's really not

(01:53):
good for the individual or the bacteria. Third option is
that maybe the change that happens after infection benefits the parasite.
So say a kid comes home with a fever, some
parent is definitely going to bend over and give that
kiddo a kiss on the forehead to see how warm
their forehead is. And if my experience as a parent

(02:14):
is any indication that is exactly when the kid is
going to sneeze directly into your face and often directly
into your mouth. So you could tell a story about
a fever being away that parasites are bacterial infections. Transmit
from kids to their parents. So we've come up with
a fairly plausible story. And I was just spitballing here,

(02:35):
but the point is that it's easy to tell a
story that sounds kind of plausible. So when you see
a story about a creature responding in some way after
it gets sick, it's important to consider all the different
reasons why that could be happening. So today we're going
to start our Halloween show with the chat about toxoplasma
GANDHII and how it changes the behavior of the creatures

(02:57):
it infects, and we're going to evaluate how good the
evidence for these claims actually are. The disconnect between the
strength of the claims about toxoplasma gandhi i'm manipulating the
behavior of the creature and effects and the actual evidence
is kind of spooky. And parents, we talk a bit
about the birds and the bees when describing the life

(03:19):
cycle of this parasite. Nothing too gratuitous or anything. But
now is your chance to pick a different episode for
the car ride with your kids if you think that's necessary.
All right, Welcome to Daniel and Kelly's Extraordinary and spooky universe.

Speaker 2 (03:50):
Hi, I'm Daniel, I'm a particle physicist, and I'm wearing
a Halloween costume chosen by my daughter.

Speaker 1 (03:56):
I'm Kelly Wiener Smith, and I'm excited because this is
the best time a year to not be in California,
because the leaves are changed in color and it's gorgeous
here in California. Just doesn't have anything on Virginia this
time of year. Sorry, Daniel.

Speaker 2 (04:10):
Have you been to California in October? The air is
wonderfully crisp, it still never rains. It's pretty nice.

Speaker 1 (04:17):
I lived there, I've been there in the fall, and
it's not as good as Virginia.

Speaker 2 (04:22):
All Right, I'm gonna have to come gather some data
on Virginia so I can make intelligent comments rather than
just take cheap potshots.

Speaker 1 (04:29):
Sounds good, although you're coming to visit in March, which
is maybe not the best Virginia month.

Speaker 2 (04:33):
But oh, I see right.

Speaker 1 (04:35):
I'm already hedging my bets.

Speaker 2 (04:37):
You're making excuses for it already.

Speaker 1 (04:39):
Yeah, that's right, that's right.

Speaker 2 (04:42):
Well. I love Halloween also because I usually teach my
class in costume, and today I give an exam in
my class, and I told them if they came to
the exam in full costume. They get extra credit.

Speaker 1 (04:54):
What is the best costume your student has ever worn
to class?

Speaker 2 (04:58):
Somebody came in one of those huge, bl low up
dinosaur costumes, took up like three rows of seats and
took their exam. It's hard to fill out a scanshow
with the little t rex arms, but they did it.

Speaker 1 (05:08):
That's commitment. That's actually my daughter's Halloween costume this year.
We got her one of those. I can't wait to
see how she looks at it. She's gonna have a blast.
And I am a giant moth because I like insects,
and so I got a moth onesie so that I
can still wear it for other things, because I don't
want to spend fifty dollars on something I'm gonna wear once.
So yeah, it's gonna be a good Halloween in the
Wienersmith House.

Speaker 2 (05:27):
So you're just gonna hang out in that onesie the
rest of the year.

Speaker 1 (05:30):
Also, yeah, no, probably I might decide that I really
like being a moth and maybe that's all I'm gonna.

Speaker 2 (05:35):
Wear Sunday Moth Day at the Wienersmith Farm.

Speaker 1 (05:38):
Yeah, just one more way I embarrass my children. The
list is getting long.

Speaker 2 (05:43):
Well, I give my daughter free rain to choose my costume.
I said, whatever costume you pick, I'm gonna wear, which
is why I'm now an alien abducting human.

Speaker 1 (05:53):
That's fantastic. How hard was it to make that costume?

Speaker 2 (05:57):
Oh no, she bought it for sure. Oh and I
don't think she listens to the podcast, but she hears
me talk about aliens enough to know that the alien
theme was going to suit me.

Speaker 1 (06:07):
Excellent. It's nice when your kids know you pretty well
a little bit. I can't get my husband to wear
a costume at all.

Speaker 2 (06:13):
What.

Speaker 1 (06:14):
No, He's never worn a costume for Halloween as far
as I know.

Speaker 2 (06:17):
Why is he anti costume?

Speaker 1 (06:18):
He's so creative, he's anti fun. I don't know.

Speaker 2 (06:22):
Come he writes a webcomic. He can't be anti fun.
He makes people laugh. He can't be anti fun.

Speaker 1 (06:29):
I don't know what to tell you, man, he's anti
fun on Halloween. I guess I tried to get a
family costume and he was absolutely no on the family
costume thing.

Speaker 2 (06:37):
Maybe you should all dress up as him one year,
then he's in costume.

Speaker 1 (06:40):
I like that, Eric, Thank you. I'm making a note
in my Google calendar for next year, everybody dresses up
like Zach.

Speaker 2 (06:47):
But we are not here today just to so discord
in Kelly's family. We are here to talk about Halloween.
And because we are science nerds and we'd like to
dig deep into science of everything, we're here to talk
about the science of Halloween, specifically zombies and ghosts, the
biology and physics of Halloween.

Speaker 1 (07:05):
I am so excited about this episode, and I'm also
exciting because it gives me a chance to talk about
probably the most famous parasite that manipulates the behavior of
its host, Toxoplasma gandhi. And as someone who got their
PhD in this field, I am constantly asked about this parasite,
and I am constantly frustrated by the disconnect between what
people think we know and what the evidence actually supports. So,

(07:27):
just like usual, I am going to throw water on
everyone's fun. But there's still some cool things to learn
along the way, so it'll be okay.

Speaker 2 (07:36):
So you're saying it's not just physics that has like nonsense,
popsy clickbait misinformation, it's also biology.

Speaker 1 (07:42):
Oh my gosh, it's also biology. I mean, we're lucky
because we have Ed Yong who writes about parasites that
manipulate host behavior, and he's like, super good about evaluating
the evidence, but not everybody is quite that careful. And
it seems to have emerged in the public consciousness that
Toxoplasma gandhi absolutely makes rodents attract to cats and gets
the meetn by it and changes human behavior and all

(08:03):
sorts of weird pays.

Speaker 2 (08:04):
But let's start with the connection of Halloween. Do you
chose this paraside because it kind of makes things into zombies?
Is that right? What's the zombie connection between Toxoplasma gandhi
and Halloween?

Speaker 1 (08:16):
All right, So every field has their like thing that
everybody fights about and they get upset about, and the
use of the phrase zombie really divides my field. So
there are some people who are like, well, if you
call it a zombie, people are going to think that
the animal that got infected died and then came back
from the dead. And I'm like, I just feel like
you're not giving the general public enough credit, Like, I

(08:37):
don't think anyone thinks that they're being brought back from
the dead. What do you think is that fair to say?

Speaker 2 (08:42):
Yeah, that's a great question. I think my first thought
when I hear, zombie is definitely the walking dead, right,
like these folks have been killed and now they're like
shuffling around. But I've seen enough zombie movies and science
fiction in general to appreciate this like a broadening of
the category. And you know, people being infected by some
sort of disease which makes them want to eat brains
and shuffle around and like are they or not doesn't

(09:03):
seem to be really crucial to being a zombie. It's
more like, you know, drooling a lot, shuffling along and
wanting to eat brains. So it'd be pretty cool if
there was a real life biological effect that made people
act like the zombies in the movies we see. I
think people would accept that as a zombie.

Speaker 1 (09:19):
Okay, well that's not what I'm talking about today. No,
it's not like that. I still feel like if you
use the word zombie, then people think like, okay, some
infectious something that's changing the behavior as high decked the behavior,
And that's really all we mean today. And so it's
a way to try to make the topics sort of
accessible and exciting to a general public. But it has

(09:41):
its drawbacks because I guess, just like any analogy. It's
not perfect and it falls flat in some ways, but
I like it anyway.

Speaker 2 (09:47):
And just to set the context a little bit more like,
I can be infected by some bug or even some parasite,
but doesn't change my behavior. I mean, maybe I get sick,
but it doesn't make me like change what I eat
or decide I'm gonna study biology instead of physics or
some crazy mind bending misdecision in life, or live in
Virginia or something insane. Right, I'm still who I am mentally.

(10:08):
So you're saying that there's a category of bugs or
parasites whatever that also change the way your brain works,
and so the decisions.

Speaker 1 (10:15):
You make, yes, and those decisions that you make are
decisions that benefit the parasite and may or may not
benefit you. So you know the eating brains in the
zombie movies, you know, you take a bite out of
somebody and that transmits the parasite in the saliva to
another individual. And maybe the eating brains is a side effect.
I don't know, but so it's got to benefit the
parasite in some way, and often at the expense of
the host.

Speaker 2 (10:35):
Okay, So now I'm mentally imagining, you know, the rat
and ratitude that sits on the guy's head and pulls
on his hair and controls him. Basically, you're like being
driven by this thing. You're not really making your own
decisions and your own best interest anymore. You're being used
as a vessel for whatever it is that's infected you,
and it's controlling you.

Speaker 1 (10:53):
Yes, And it's usually not all or nothing. It's usually
like a very specific Sometimes it can be a feature
of the way that you look, or a certain set
of behaviors that change. It's often when we're talking about
actual cases where parasites are manipulating the behavior of the
creature they infected, it's actually kind of targeted as opposed
to like a wholesale shambling along change in everything that
you do. But yes, you're essentially to some extent under

(11:15):
the control of another individual.

Speaker 2 (11:17):
On that topic, one of my favorite Halloween costumes ever
is the rat from Ratitui sitting on somebody's head, and
this nerdy engineer actually designed one where the rat is
like moving and controls the person like a puppet or
really hilarious. That's awesome, But let's not talk about Ratituvi
and fictional zombies anymore. Let's talk about the actual science.
So in what way does Toxoplasma gandhii fulfill this category

(11:40):
of zombie ish kind of takeovers?

Speaker 1 (11:42):
All right, Well, first let's just talk about some background
on this organism. It is sometimes called the most successful
parasite on the planet. It can infect just about any
warm blooded animal, so beluga whales have it, hyenas have it,
rodents have it, humans have it, birds have it. It
infects a lot of stuff.

Speaker 2 (12:00):
But what is it? Is it like a little worm?
Is it a bug?

Speaker 1 (12:03):
It's like a little protozoan parasite, so it's eukaryotic, but
it's very small, single cells.

Speaker 2 (12:09):
So it's a single cell, has a nucleus. It's basically
a tiny little critter.

Speaker 1 (12:13):
It is basically a tiny little critter, that's right. And
so a really quick jargon distinction which might be helpful
is that, you know, usually when people talk about pathogens,
they're talking about bacteria and viruses, things that give you
like the cold and the flu. When they're talking about parasites,
we're usually talking about eu carryouts. So organisms with like
a nucleus and a cell wall and stuff, and so

(12:33):
Toxoplasma gandhii is a parasite, not a pathogen. Not a pathogen, okay,
And so.

Speaker 2 (12:39):
It infects a huge number of things worldwide, Like do
you have it? Do I have it?

Speaker 1 (12:43):
So there's probably like a eleven percent chance that either
one of us happens to have it.

Speaker 2 (12:48):
What that's very high.

Speaker 1 (12:49):
Yeah, in the US, about one in ten people have it. Worldwide,
about one in three people have it. And there's a
bunch of different ways that you can get it. And
this is what makes the parasite so successful and so
mind blowing is that those parasites have like one or
two paths to their next host. Toxoplasma gandhi is like
amazing in its diversity. So let's start with cats. So
cats are in any different species of cat is a

(13:11):
very important kind of host for Toxoplasma gandhi. This is
where the parasites get together and have sex. So it's
called the definitive host, and I think of it as
that's definitely where they're going to be having sex. And
that's how I remember that. You're welcome everyone, and so
like we can have a whole episode actually on why
evolutionary biologists think sex is beneficial in general, But it's
something about mixing genetic material up so that you can

(13:33):
have some diversity for dealing with things that might be
happening in the environment or for battling the host immune system.

Speaker 2 (13:38):
And so these guys can only reproduce inside the guts
of cats, or there's something about that environment that's better
and they can do it elsewhere also, or is it
just really only inside cat guts.

Speaker 1 (13:49):
That is only where sexual reproduction happens. So we're going
to talk a little bit later about places where they
can do asexual reproduction where you can essentially just think
they're like copying and pasting the exact same cop be
over and over and over again. So this is where
they get to like swap genetic material to hope to
like stay ahead of the immune system arms race they're
going through with the other animals that they're trying to infect.

Speaker 2 (14:10):
And what is it about cat guts that's so especially romantic?

Speaker 1 (14:13):
Mm? Wow, that's a great question.

Speaker 2 (14:16):
I mean, it's not hard to imagine you find yourself
inside a catgut with somebody else that's a dot. One
thing leads to another.

Speaker 1 (14:24):
So this is a kind of parasite that's called trophically transmitted,
which means a host that's infected gets eaten by a predator,
and that's how the parasite makes it to the next host.
And in different systems, like in trematodes and nematodes and tapeworms,
like lots of different kinds of parasites have this system,
and there's usually one species out of all of them
in there where sexual reproduction happens, and then in the

(14:45):
other hosts they just kind of replicate asexually. And to
be honest, I don't know why they're not able to
flexibly reproduce sexually in all of those hosts. Maybe I'll
look that up and we'll do a different show on it.
I don't know why it's just cats. It seems like
it would be to be able to do it everywhere.
But the other thing about these cats is after they
reproduce sexually, they produce a stage called oocysts, which I'm

(15:07):
just going to call eggs for the rest of the
conversation because it just makes it easier.

Speaker 2 (15:12):
Please do I didn't want to pronounce that word.

Speaker 1 (15:14):
Yeah, maybe I'm saying it wrong. Who cares. But they
get pooped out into the environment when the cat poops,
and that's how the parasite gets back out into the
environment to infect a bunch of other organisms.

Speaker 2 (15:23):
So don't eat cat poop is the lesson here.

Speaker 1 (15:26):
Well, it's not that simple, right, because cat poop looks
like cat poop at first, right, that's pretty obvious. But
over time, cat poop gets like worked into the soil
and you might not know there's cat poop, and these
eggs can stay in the environment for a really long time.

Speaker 2 (15:39):
This episode is going to make me like cats less, Kelly.

Speaker 1 (15:41):
Unfortunately, yes, it will outdoor cats in particular less. So
like if you have a garden and a outdoor cat
comes by and poops in your garden and you don't
realize it, and it gets mixed in with the soil,
then maybe one day you'll pull a vegetable not rinse
it sufficiently, and then you'll get infected. Or you'll be
gardening and you get the eggs on your hands and

(16:02):
you don't realize it. They're like microscopic, and then you
go to eat something else before washing your hands, and
you get infected. And this is also how like birds
and rodents and stuff like that get infected. Once you
get infected, they get ingested and then they move out
into your muscles and into your brain.

Speaker 2 (16:18):
What about the blood brain barrier I hear all about.
Isn't that my vaunted protection for my brain cell.

Speaker 1 (16:24):
Matter doesn't work for this parasite. In fact, the parasite
goes into your neurons, and that's what makes it actually
impossible to get rid of once you're infected. If you're
get infected with this parasite, you're gonna have it.

Speaker 2 (16:34):
Forever, forever. There's no way to get rid of it.

Speaker 1 (16:36):
No, no, because we can't get medication like into your neurons.

Speaker 2 (16:39):
Oh wow, Yeah, this thing is pretty clever and insidious.
I'm terrified now.

Speaker 1 (16:43):
Most successful parasite on the planet.

Speaker 2 (16:45):
This is appropriate for Halloween.

Speaker 1 (16:46):
Yes, it's some spooky stuff. So when it first gets
in there, it starts copying and pasting itself like crazy,
and you feel kind of like you have the flu.
Some people feel worse than others, Like I have a
friend who found out he got infected by toxoplusmos by
bringing in two feral kittens into his house. And when
he was changing the litter box, he must not have
like washed his hands well enough, or maybe they like

(17:07):
you know, scratched around in the litter box and then
walked on the kitchen table or something like that. And
so he got infected. His lymph nodes swelled up, and
he called me and he was like, what's gonna happen
to me? Now?

Speaker 2 (17:18):
You're a zombie. Forget it. That's why life is over.

Speaker 1 (17:23):
So you feel kind of crummy for a while.

Speaker 2 (17:25):
Wait, but how are these things reproducing in your brain?
Does that mean they're eating your neurons? Like where are
they getting raw materials and energy? Like what are they gobbling?

Speaker 1 (17:33):
They are gobbling some nutrients. A lot of parasites at
this stage are pretty energy efficient, So if they were
to straight up kill a host while replicating in their brain,
they probably would not have matured to the stage where
they can survive transmitting to the next host. So often
there's like this stage in between when you first infect

(17:54):
a host and when you can survive if that host
gets eaten to live in the next host, and so
you usually parasites are like pretty careful about energy usage,
so they don't like totally kill the host or like
cause it to I don't know, fall off a bridge
or something. But so, yeah, they're being pretty energy efficient,
but they are replicating. You're feeling kind of grummy.

Speaker 2 (18:14):
And they're active in your brain. Is this how they're
changing your behavior somehow?

Speaker 1 (18:17):
We don't know, So it does seem like behavioral changes
have something to do with either changes in dopaminergic activity.
So dopamine is a neurotransmitter you have in your brain.
The parasite has genes for I think it's called tyrosine hydroxylase,
and that's the limiting factor in the production of dopamine.
So all the other stuff that you need to make

(18:38):
dopamine is present on the inside of a neuron, but
when you dump tirosine hydroxylase in there, the rest of
the reaction just happens and you get dopamine.

Speaker 2 (18:46):
Isn't dopamine good? Don't you want dopamine? Dopamine makes you
feel good, right.

Speaker 1 (18:49):
I mean, dopamine is good. It makes you feel good,
but it also controls a bunch of other sorts of behavior.
Presumably our brains are making something like the right amount,
and then the parasite is notching the us up, so
you're making more of it than you would have wanted.

Speaker 2 (19:03):
Now I'm imagining happy zombies, all these people walking around
mind the grinning. Oh well, they're all infected. Look at them.

Speaker 1 (19:09):
Life is better with tuxo.

Speaker 2 (19:13):
If you meet somebody who's grumpy, you know they're not infected. See,
And that's the what to tell.

Speaker 1 (19:17):
Yeah, And there have been some experiments where they've given
rodents drugs for people who have sort of dopaminergic imbalances
or imbalances of dopamine in their brain, and a lot
of the weird behaviors that the rodents do sort of
either get tamped down or go away. So it does
seem like dopamine has something to do with it. But

(19:38):
one of the things we've discovered in this field is
that nothing is ever straightforward, and I mean the field
of how parasites change the behavior of the creatures that
they infect, It almost always involves lots of different things.
And so there's also some evidence that it's just like
the whole brain has inflammation when the parasites are in there,
and it might be that generalized inflammation causes things. The
parasites might also be localizing in certain parts of the

(20:01):
brain and making behaviors weird. It might also have something
to do with argentine vasa pressin or something to do
with testosterone, So you might notice that in the outline
I hadn't put anything about mechanisms because it's just like
such a mess right now. There's a lot of different
things it could be.

Speaker 2 (20:16):
So it's active in the brain. It probably changes brain chemistry.
We don't understand completely the mechanism for how it's doing that.
Are there behaviors though in people that we can identify
as due to this impact, even if we don't have
all these little pieces that connect the dots. Are there
characteristic ways that it changes people's behavior? Or is it

(20:37):
mostly in cats that we notice the change in behaviors?

Speaker 1 (20:40):
So cats don't usually show behavioral changes, So the parasites
replicating in the gut, we haven't associated any behavioral changes
with that. Humans are interesting. So we're jumping ahead a
little and that's okay. But so usually what happens with
like a rodent that gets infected is you see some
behavioral changes, and then when the cat eats the muscles
of that rodent, the parasite gets back to the cat.

(21:01):
So usually manipulation is supposed to help with some transmission
goal for the parasite. So when you're in a rodent,
the goal is to get it eaten by a cat,
but with humans, we don't usually get eaten by cats.

Speaker 2 (21:14):
Sometimes we do big cats.

Speaker 1 (21:16):
Yeah, yeah, sometimes big cats, but like it's pretty rare
and so we are kind of a dead end from
the perspective of getting back to cats. There are some
other ways that we can pass it. For example, men
can pass it to women during intercourse. We think when
I think about that, I'm like, ah, I'm so glad
I'm not dating anymore anyway, sorry everyone. Moms can pass

(21:38):
it to their children. It's called trans placental, so it
goes from the mom to the baby. So if mom
gets infected for the first time ever when she's pregnant,
it can pass into the fetus. Or if mom gets
infected for the first time when she's breastfeeding, I can
do trans mammory transmission, which means it goes across the
memory lands during breastfeeding into the baby. It still has
some options to get from host to host, but we're

(21:59):
probably not back to cats. But it is associated with
behavioral changes in humans. In humans, right after that stage
where it's replicating like crazy, it kind of slows down.
It slows its replication. But there's still some evidence that
it changes human behaviors. And the interesting thing about like
the study of this is there's this guy named Yaroslav Flager.
He's a Czech scientist, and apparently he was like, you know,

(22:24):
I do a lot of behaviors that really aren't in
my own interest, and I just kind of do a
bunch of weird stuff. I wonder if that, like brain
infecting parasite is to blame. Always makes me wonder like
is he just looking for excuses for like, well, I'm
a jerk, but it's not my fault I'm infected by
this parasite.

Speaker 2 (22:41):
All right, I want to hear a lot more about
Yaroslav and his zombie research and how he wrote zombies
into his proposals to get big money from science foundations.
But first we have to take a quick break. So
go clean up your cat litterbox to keep your family
safe and come right back. All right, we're back, and

(23:14):
we're talking about the science of Halloween, more specifically zombies.
What are they in biology? Are they really like zombie behaviors?
And is toxoplasma GANDHII All it's been cracked up to
be in the popular science literature. And you were telling
us about a guy who's been doing research into the
impact on humans of this little bug. Tell us what

(23:35):
he did and what he learned.

Speaker 1 (23:36):
Well, so what he was doing was he would draw
blood from a group of people. And when you look
at people's blood, if you've been infected by this parasite,
which you'll have forever, your immune system mounts a response
to it, and you always will have that signature of
the immune system response in your blood Forevermore So, if
you draw blood, you can look at the blood and say, Okay,

(23:57):
this person was definitely infected by the parasite at some point.
You don't know when, but you know that at some
point they were infected, and the parasite is probably just
chilling out in the brain.

Speaker 2 (24:05):
Now, okay, Because if you have it, you have it forever, right,
So you're infected at some point, you're still infected, that's right.
This is just a way to tell who's got it
and who doesn't have it.

Speaker 1 (24:13):
Yep, right, So by drawing blood, you don't need to
like invasively dissect someone's brain to know if they've got it.
You can just draw blood, and that way you know
who's got it and who doesn't, and then you can
give people personality tests, and you can look for correlations
between the answers that they give on those personality tests
and their infection status. Does that make sense?

Speaker 2 (24:32):
It does, But these correlational studies are really hard to interpret, right,
Like you might just be selecting for cat people versus
dog people, and there's a whole lot of potential confounding
variables there, right.

Speaker 1 (24:43):
Amen, So we have reached the first of my main
problems with this field. It could be that there's some
third behavior that predisposes people to getting infected, and then
when you give them this personality test which you're really measuring,
is that they have this behavior to begin with, and
that's what got them infected necessarily that the parasite gave
them the behavior.

Speaker 2 (25:02):
So what you really need is some good control where
you take a person, you clone them, then you infect them,
then you create a perfectly identical world for them to experience,
and then you see their changes in behavior. Why don't
people just do that experiment? Kelly? Biology is so easy, that.

Speaker 1 (25:17):
Sounds so ethical, it does, But maybe that's why we
have it yet.

Speaker 2 (25:22):
See, I just don't have those scientific bones. Because particles
don't have consent forms, they don't have rights. We annihilate
them all the time. No big deal. They don't have
a union.

Speaker 1 (25:32):
It's great, no IRB committees. I'm jealous. I mean, there
are some ways to get at this, Like if you
do cohort studies where you follow individuals from the beginning
of their lives and you regularly measure their behavior and
you regularly measure their infection status, then maybe you can
start to disentangle what parasites changed after infection. And these
cohort studies are really expensive, really time consuming. But without

(25:55):
doing controlled infections, that's probably the best we can do.
But there's not a lot of studies that have done all.

Speaker 2 (26:00):
Right, so we've qualified this already by saying we don't
know what we can learn from these studies. But tell
us what do the studies reveal?

Speaker 1 (26:07):
Okay, So here is the stuff that's sort of exciting
to talk about over tea or over beer or something. Okay.
So people who are infected tend to seek novelty less,
so they're less likely to want to go out and
try new things. Don't know why. There's a lot of
sex specific differences. So women who are infected tend to
be less suspicious, and men who are infected tend to
be more suspicious.

Speaker 2 (26:29):
And are men who are infected less likely to wear
Halloween costumes?

Speaker 1 (26:33):
Oh, it depends on how novel those costumes are. You know,
if they're comfortable with it, maybe they're.

Speaker 2 (26:39):
Fine, non novel, non suspicious costumes. That's your pitch to
zact next time.

Speaker 1 (26:44):
Well, I don't know if he's infected or not. It's
hard to say. He does work in the garden a lot.

Speaker 2 (26:47):
There you go. See, I'm starting to ask questions.

Speaker 1 (26:49):
Here you should. And then women who are infected tend
to be more warm and like caring, and men tend
to be either less warm or unchanged by the parasite.

Speaker 2 (27:01):
Interesting.

Speaker 1 (27:02):
I get a lot of questions about like does this
parasite turn people into crazy cat ladies? But actually the
evidence is that women who are infected tend to think
cat urine smells less good. They're like, oh, this is
an unpleasant smell.

Speaker 2 (27:15):
Cat Urine already smells zero good. How can you be
hit less good than zero?

Speaker 1 (27:20):
See, there's various levels of repulsion, okay, and infected women
are more repulsed, but infected men relative to uninfected men,
rate the smell of cat urine as being more pleasant.
What so maybe crazy cat men. I don't know. There
are some quantifiable effects at the country level. Also, a

(27:41):
friend of mine looked at personality aggregate scores by countries
and also the percent of people in a country who
are infected, and we tend to have like pretty good
data on percents because often when women are pregnant, they'll
get a test to see if they have the parasite.
Because if you have the parasite already, your immune system
probably has it in check and it's not going to
transmit to your fetus. But if you get infected, well

(28:03):
you're pregnant, it can transmit. So if you are pregnant
and you're not already infected, then you're often told like,
don't change any litter boxes. Have your partner do that.
But anyway, so we've got these country level scores and
countries with more toxoplasma gandhi I tend to be more neurotic.

Speaker 2 (28:18):
Which countries are more neurotic?

Speaker 1 (28:19):
Come on, oh all right, let's look up Lafferty's paper
real quick.

Speaker 2 (28:25):
I want to slander some nations here. I'm gonna guess
more Pacific, more tropical, more equatorial, is more laid back.
And more northern colder, it's going to be more neurotic.
That's going to be my totally uninformed Basian prior on
this one.

Speaker 1 (28:39):
So this paper was some two thousand and six, so
it looks like Yugoslavia, according to this study, had sixty
seven percent prevalence, and then Hungary had fifty nine percent.
Brazil was it sixty seven percent. So those are some
of the top countries. That doesn't necessarily mean that the
most neurotic. It's like an association, there's some move along

(29:00):
that correlation line, but those are some of the more
neurotic countries, some of the countries with the higher prevalence
of the parasite countries with the lowest prevalence. I'm seeing
Finland is at like sixteen percent, so is Israel. Norway
is at nine percent. South Korea is only at four percent.

Speaker 2 (29:18):
That's basically the opposite of what I predicted. I predicted
like Norway and Finland would be very neurotic and Brazil
would be very chill.

Speaker 1 (29:24):
So why would nor would be very neurotic? They were
pretty laid back when I was there. They take weekends
off in Norway, they were serious about that. They take
August off Man.

Speaker 2 (29:33):
Yeah, they are like the richest nation on earth because
of their oil wealth, so maybe that helps. Maybe their
toxoplasma GANDHII infected them and told them where the oil
was going to be. Oh wait, no, you're saying they're
less infected, they're more infected. I'm confused.

Speaker 1 (29:45):
They're less infected, so probably statistically they would be expected
to be less neurotic.

Speaker 2 (29:51):
All right, So most of the zombies on Earth you're
saying are in Brazil, Hungary and the former Yugoslavia.

Speaker 1 (29:57):
Yes, that's probably the right conclusion.

Speaker 2 (30:00):
And maybe apology to all of our listeners in those countries.

Speaker 1 (30:04):
That's right. So there's also a bunch of other correlations.
We probably don't want to spend too long on this
because I'd also like to get to the rodents real
quick and still leave you some time to talk about ghosts.
But there are some worrying things. There's like association with suicides,
association with schizophrenia, association with being more likely to be
in a traffic accident, which we think is maybe because
of a bit of a delay in reaction times. So

(30:27):
it's not like they're driving from one side of the
road to another like crazy people. Acting like they're drunk.
It's just that if they're in a moment where they
need to make a split decision, they're a little slower
to respond. And we don't know for sure that that's
what it is, but that's one of the working hypotheses
right now.

Speaker 2 (30:40):
All right, So we see these correlations between infection and behavior.
We don't know the calls of mechanism. We don't really
understand how it works from like a micro biochemical point
of view. Do we understand things better in other creatures
where we can actually do experiments like cats and rodents
that life cycle, like, does it change the behavior of
cats and rodents in some way that benefits the parasite?

Speaker 1 (31:02):
Well, for both humans and rodents, there are studies that
don't always say the same thing. So you collect to
the same data in two different studies and sometimes you
find an effect and sometimes you don't. That's complicating.

Speaker 2 (31:12):
Science is hard.

Speaker 1 (31:13):
Science is so hard. But at least with rodents you
can do the controlled infections that you can't do in humans,
so you can look at how behavior changes following infection.
And one of the most exciting things about rodents studies
is this thing that's become called fatal feline attraction.

Speaker 2 (31:29):
I want to see that movie. That sounds great.

Speaker 1 (31:31):
It is, Yeah, it's such an interesting idea. So the
idea is that rodents, when they're not infected, they smell
cat urine, they freak out. They avoid the area because
that's the smell of a predator. They don't want to
get eaten. So if they can smell that a cat
has been around, they don't want to be in that area.
Makes sense, whereas rodents that are infected tend to spend
more time in those areas, almost as though they're attracted

(31:54):
to those areas. And there were some studies done that
show that, like you know, when you have an uninfected rodent,
the part their brain associated with fear kind of lights
up when they smell cat urine, But when you have
infected animals, the part of their brain associated with getting
excited about a potential partner lights up. So it's almost
like the parasite is changing this response to this chemical

(32:16):
cue from absolutely petrifying to like something that's maybe kind
of sexy. But two problems here. One, you don't always
see this effect. Sometimes you do the controlled infections and
you don't see this attraction to the smell of cat urine,
and it looks like maybe it differs depending on like,
are you using an inbred rodent strain that's been living

(32:37):
in the lab for a really long time. Are you
looking at males or females? How long has the rodent
been infected? What strain of Toxoplasma gandhi are you using?
And so if you read the popular literature, they're like, oh, man,
rodents who are infected, they're attracted to cat urine. But
at the end of the day, the answer is much
more complicated. Sometimes we see the effects, sometimes we don't.

(32:58):
At the moment, we don't really understand why.

Speaker 2 (33:00):
And even if the story we're true, the explanation would
be that the parasite wants the rat to get eaten
by a cat because it wants to get back into
the cat's gut for more reproductive.

Speaker 1 (33:11):
Sexy time exactly. And then here's another problem. So I
was talking to one of the people who did the
original fatal feline attraction study, and I asked, when are
we going to see a study where rodents get infected,
we confirm that they're now more attracted to the smell
of cat urine, and then we release them into an
environment with cats and we see if that actually gets

(33:33):
them eaten, because right now we've got this story that
sounds super convincing, but we haven't actually shown it gets
them eaten. And her response was like, look, I would
never feel comfortable doing that to rodents. That's mean to
the rodents. We don't want to be infecting cats. I
don't want to have anything to do with that study.
And I think it would be hard to get past
an institutional Animal Care and Use Committee, which is the

(33:55):
organization that has to approve all of the experiments that
people at universities do. And so we don't actually have
that study. We don't actually have that connection. And you
can imagine that, you know, rodents who spend a lot
of time really examining an area where there's a cue
about a predator get a really good sense for like, Okay,
here's where the predator seems to go. Here are the

(34:15):
hiding places in the area. Maybe they're just like really
understanding the area, and when a cat shows up, they
know how to get out of there better then another
rodent who happens to be passing through. And I don't know,
I'm just making up stories now too, but The point
is we're all just making up stories.

Speaker 2 (34:29):
The point is you're saying it's not so simple as
just rats who are attracted to cat here and get
eaten more. You're saying you could plausibly come up with
a scenario where it actually prevents them from getting eaten more,
and we actually need to go out and measure this
in the world. I think that's a huge lesson, right,
Like we're always attracted to these simple stories and science
and all of our science are stories. But just because

(34:50):
the story makes sense to us, doesn't mean it's the
way the world works. Right. We have to always go
out and do experiments and make measurements because the universe
is filled with surprises. Usually it's the kind of stuff
we're so certain about that turns out to be wrong.

Speaker 1 (35:03):
And there have been some examples where we had this
great story and we thought it made sense, and then
when we did dig in a little bit more, it
fell apart. The behavior was not benefiting the parasite in
any way. So you do have to test these stories.
And I just want to tell you about one more
study that I think is the closest we've gotten so
far to trying to provide support for this, and this
is an indirect study that was done in Switzerland. So essentially,

(35:25):
there was this survey where people were asked like, okay,
when your cat catches something and they bring it home
to you, and they like, put it on your doorstep,
put it in a plastic bag, and bring it to us.
So they got this big collection of rodents that had
been killed by cats, and then they took blood from
all of these rodents and they looked to see what
percent of them were infected by the parasite, Okay, and

(35:47):
what they found was that for European water bowls, eleven
percent of them were infected by the parasite. So let's
walk through a really quick thought experiment to decide if
we're impressed by that or not. If one percent of
the poppylation of European water voles is infected and eleven
percent of the European water boles that are caught by
cats are infected, then that suggests that at least the

(36:08):
infected water bowls are selectively more likely to be killed
by cats. If eleven percent of the water bowls are
infected and eleven percent are being killed by cats, that's
just kind of random. You'd expect that from a random
draw of the population, So possibly the parasite isn't changing
behavior at all.

Speaker 2 (36:23):
You're saying, if bowls are caught by cats more often
than their prevalence in the natural population, that suggests that
there's something making it easier for them to be.

Speaker 1 (36:32):
Caught exactly, And that doesn't necessarily have to mean that
it's because the rodents are attracted to the smell of
cat urine. It could be because when you've got cysts
in your brain, you run into trees or something like that,
so totally different. But they looked at water voles in
another population and they put out traps and they found
that the percent of those water bowls that were infected

(36:53):
by the parasite was zero. So if you assume that
just about throughout all of Switzerland, most of the voles
are not infected by Toxoplasma gandhiy, but eleven percent of
them coming home in the mouth of a cat are,
then that does suggest that they're more likely than you
would expect to be getting caught by a cat after

(37:14):
they're infected.

Speaker 2 (37:15):
So the cats are catching the ones that are infected
more than they're catching the ones that are not infected.

Speaker 1 (37:20):
They're still bringing home more uninfected individuals because there's probably
still not loads of individuals who are infected by the
parasite in the environment. But of the population of les
that are out there, the ones that are infected are
more likely to get caught by cats than the ones
that are uninfected.

Speaker 2 (37:37):
But these are water voles, like swimming around in lakes.

Speaker 1 (37:40):
They don't spend all their time in the water. I
think they tend to be like associated with aquatic habitats.

Speaker 2 (37:45):
I imagine like Brazilian voles, or like on the beach
all the time or something. I want to make a
connection to the human studies. But you know, that's just
me trying to tell a science story.

Speaker 1 (37:54):
Yeah, I'm not sure that's supported by fact, but yeah, so,
I mean that's intriguing at least evidence. But I still
feel like that's not a slam dunk. So that's where
we are right now. We've got this cool story about zombies.
The evidence suggests that there's something happening. We know it's
in the brain that's enticing too, but we haven't really
locked up a bunch of loose ends that we have
to you know, slam dunk. Say this is definitely the

(38:16):
parasite manipulating rodent behavior to its own benefit. So there's
a lot of work left to do, all right.

Speaker 2 (38:21):
So we know that this thing is out there, we
know it's infecting a lot of rats and other rodents.
We understand that it might be changing behavior, and it
might be changing the behavior of rudents in such a
way that gets them caught by cats more often, does
it also change the behavior of the cats or the
cats just the host for reproduction?

Speaker 1 (38:37):
The cats are just the host for reproduction, and in general,
the hosts where the sexual reproduction is happening, we don't
often see a lot of behavior changes in those hosts.
We usually see behavioral changes in the hosts that need
to get eaten by those predators where the sexual reproduction
tends to happen.

Speaker 2 (38:54):
And so tell me how this story then became so
prevalent in the popular media. There's a very simple story
about how this affects you and changes your behavior and
doctor thought you're a zombie. The science is much more
complicated and fuzzy, as it is always was there like
a seminal paper that overstated its claims, or like one
particular news coverage that misunderstood this or how did this

(39:15):
get centered in the popular mind is like the zombie parasite.

Speaker 1 (39:19):
So there was a seminal paper. It was a Burdoi
at all two thousand, I think, and they were the
ones who identified fatal feline attraction. And it was a
good paper. The science was good. Sometimes you do find
this effect, sometimes you don't. They found it, and I
think that kind of blew up. And then Yaroslav Flager's
work suggesting that maybe it impacts human behavior too, came out,

(39:41):
and I think a bunch of people got excited. And
it could just be random chance that the first couple
papers that were looking for an effect hit on something,
and that's the story that made it out into the wild.
And in general, you know, the first study that finds
a cool effect is going to get a lot of press.
The second study that says they didn't find an effect
people don't usually want to talk about that. I did

(40:02):
work in another system that found that the effect of
a brain infecting parasite of fish on the fish's behavior
is like way less than we had previously thought. No
one cites my paper. They cite the first paper where
the effect was huge.

Speaker 2 (40:16):
So even as a scientist. You're throwing cold water on theories,
not just in your popular science communication.

Speaker 1 (40:22):
I didn't think this was going to be my niche.
I didn't want it to be my ditch. But yes,
that is the person that I am. So you know,
call me up and invite me to your parties if
you want to make sure they don't get too rowdy.

Speaker 2 (40:32):
Well, you know, maybe the journalists that covered those papers
they were infected by the parasite, and the parasite influenced
them to write like hyperbolic statements about it because it
just wanted to be famous.

Speaker 1 (40:42):
And that is the fun thing about talking about this system.
You always get new hypotheses and fun conversations. And yeah,
it's just exciting to think about. But you know what
else is exciting to think about?

Speaker 2 (40:52):
What's that?

Speaker 1 (40:53):
Ghosts? Oooooooo, it's as spooky as not having a enough dude.
Let's take a break and come back and talk about
the physics behind ghost busting. And we're back, and now

(41:27):
it's Daniel's turn to tackle ghosts. All right, Daniel, tell
me about the science behind ghost busting, and don't disappoint
me because when you first mentioned this topic, I'm like,
oh man, every once while you have a conversation with
someone and you're like, ah, I thought I understood you,
But you believe in ghosts, and that's fine, but that's

(41:48):
not what I would have predicted.

Speaker 2 (41:49):
I've had that experience, I know, yeah, and I never
quite know how to approach that. I'm like, wow, okay,
how do you hold this in your mind? What is
it you believe or is this in some sort of
portion of your where you don't apply the same sort
of like rational careful thinking that I know you apply
in the rest of your life. I try to always
approach you sort of generally and carefully to keep the
lines of communication open.

Speaker 1 (42:09):
Yes, you know, I usually just transition to my listening
face and I stop asking questions, and I'm like, I
am listening. There are some questions science can't tackle, and
I will just listen to you now. But okay, tell
me about how have people attempted to use scientific techniques
to answer questions about whether or not there's ghosts?

Speaker 2 (42:27):
Mm hmm. Well, first of all, I want to applaud folks,
because while there's a lot of stories about ghosts out there,
there are people out there who are trying to sort
of nail this down from a scientific point of view,
just the same way like you can talk about esp
and you know, pircognition and whatever, and the right thing
to do there is to do experiments like can people
predict what card you're holding in your hand? Can people

(42:49):
predict the future? Like, as we were saying earlier, you
got to keep an open mind because the universe is
crazy and it will surprise you, and you can't hold
on to pre existing narratives. You've got to be open
to it. But the way to learn about the universe
is not to just tell crazy stories that some parasite
in your brain is telling you, but to go out
there and do experiments. So while there's a lot of
like spooky silliness out there about ghosts, there are also

(43:11):
folks out there who try to see is there something
we can detect scientifically? Are there sensors we can use
to discover the physics of ghosts? If they are real,
If they're out there, you know, that means they're part
of the universe, which means they're physical, which means we
should be able to detect them. And predominantly from my
research by watching ghost hunting television shows, which I did
for this podcast, people use basically electromagnetic field meters, Like

(43:36):
they have these EMF meters that measure electromagnetic radiation, So
you can use this if you're curious, like how much
cell signal am I getting my house or whatever. Electromagnetic
Radiation is just like a kind of light. You know,
light is a wiggle in the electromagnetic field. Light is
electromagnetic radiation. It's a very broad spectrum, all the way
from radio waves with very long frequency up to extra

(44:00):
rays and gamma rays. This are not weird and spooky
in any way, Like we know what electromagnetic radiation is,
but there's the thought that maybe ghosts create electromagnetic radiation
or are themselves ripples in the electromagnetic field, because you know,
the electromagnetic field is important to life. You and I
both have a lot of electrochemistry going on, and so

(44:21):
that's one way people try to like use science to
see is there anything actually out there going on?

Speaker 1 (44:27):
Is there an explanation for why we think that the
electromagnetic field, which we know living organisms give off, why
would we expect the dead to also be doing that?
Like why is that the thing that we're looking for?

Speaker 2 (44:40):
M hm, I don't have an answer, But I do
have a hypothesis. Okay, First of all, we don't know
what ghosts are, right, So in order to predict that
they're making some physical impact, you have to have a
physical model. You say, ghosts are this or ghost are
that here? You have to sort of work backwards and
try to say, well, if how could ghosts create this
kind of signal? And I don't have an answer for you.
It's true that the doctromagnetic field is capable of carrying information,

(45:03):
and that information is massless, right, photons have no mass,
And so imagine like I took Kelly, and I broke
her down into her constituent bits and extracted all the
useful Kelly information, the pieces that made Kelly Kelly, and
not like the details of your toenails, but just like
your mind and your thoughts. You can imagine making that
digital the way people imagine you could like upload your

(45:25):
consciousness into a computer and you could encode that in photons.
So you know, I could take Kelly, tear you apart
into your information, convert you into photons, beam you through space.
Would that be ghost Kelly? I don't know. Maybe could
somehow you know people's thoughts and ideas which we don't
fully understand, of course, be transmitted into the electromagnetic field.

(45:48):
I don't know that's sort of the direction people are going.
I think what's really happening here is that people are
trying to be creative about ways we could identify ghosts,
and they're looking for the sensors we have at hand.
And it's easy to get an EMF meter, like they're cheap,
they're reactive. And here's my hypothesis is that old houses

(46:08):
have bad wiring, and when you're in an old spooky house,
you're gonna measure em fields or fluctuations in the electricity
and you're gonna go, oh my god, look we just
saw something. I have no data to support this, but
that's my hunch.

Speaker 1 (46:25):
If someone said, Okay, Daniel, we're giving your lab five
million dollars to do the best study you can think
of to look for the existence of ghosts, what would
you measure or who the heck knows?

Speaker 2 (46:39):
That's a great question which I'm shockingly unprepared for. I
think if you gave me that money, I would try
to find some location where people are reporting sort of
paranormal activity that we couldn't explain and then take as
broad data as we could so yeah, including ef meters
and other kinds of things, to see if we can
make some coral between the data we're collecting and people's experience,

(47:04):
and that way we could start to get a handle
on the physical phenomena. If there are indeed any that
are connected to people's personal experience. I don't know. We
do know that there's some connections between electromagnetic fields and
people's experience. You know, there are these crazy studies where
a psychologist created what he called the God helmet, where

(47:25):
he created his helmet and he put very strong electromagnetic
field emitting coils in the helmet and he put this
on people and he turns it on. So basically he
immersed your brain in a strong electromagnetic field. And he
reported that once the helmet was activated, the wearer's temporal
lobes their brain were pounded with these fields, and eighty
percent of the people who wore this helmet reported feeling

(47:47):
quote a presence of some kind in the room with them,
including on some occasions visions of God. So you know,
we know the brain is made of neurons, and neurons
are electromagnetic. They send little pulses of signals, and so
it's not crazy to imagine that if your brain is
immersed in a strong field, it might change the way
that it behaves. So now we're talking physics zombies, right,

(48:10):
and it changes the way people feel, what they experience
and what they see. So it could be that if
you're in a crazy old house with strong electromagnetic fields,
those things change the way your brain behaves. Plus you're
expecting to see something sort of weird. There's a lot
of psychology and physics going on here, So it could
be that that's a physical phenomena that could connect people's

(48:30):
experience and like readings on an EMF meter.

Speaker 1 (48:33):
And so I assume that this guy set out to
disprove that there are ghosts and just showing that you
can create this with EMFs, not to show that EMFs
are the way that we communicate with the undead.

Speaker 2 (48:45):
Right, Yeah, exactly. I don't think he was saying that
God is electromagnetic. No, he was saying that our perception
of reality is influenced by electromagnetic fields in a way
that it could make you feel like spooky or haunted.
And so you see a lot of EMF meters on
TV with ghost hunters, and I'll say that this is
TV show called the ghost Hunters, and they're always showing

(49:06):
up at these spooky houses looking and they never see anything.
There's never any readings on the meters that are useful
or interesting or conclusive, you know, which is probably why
the show keeps going because if they found ghosts, they
would be done, Oh yeah, we found it, show over,
so it would ruin the drama.

Speaker 1 (49:22):
So I think in those shows they also say something like, oh,
the temperature drops suddenly, what do we know about that?

Speaker 2 (49:29):
Yeah. Another popular technique is just like gathered data about
the temperature. So there are these meters you can buy.
They're called kestrel meters. Again, they're cheap, they're effective, so
a lot of people have them, and they can do
things like detect change in airflow or temperature or barometric pressure.
They're very useful for understanding weather and like it's a
tornado coming. And some ghost hunters believe that like a

(49:49):
sudden drop in temperature is a sign of paranormal activity.
There's no actual data to support that. Nobody's actually found
a correlation between people's reports of paranormal activity and temperature dropping.
But you know, it's another thing we can detect about
our environment, and it's the kind of study I totally support, Like,
let's keep an up in mind, let's go out there,
let's take physical data rather than just say I saw

(50:12):
a ghost in the corner. Yeah, because even if people
believe stuff, eyewitness reports are very very hard to use
scientifically because, as we know, they're influenced by memory and
emotion and all sorts of stuff.

Speaker 1 (50:23):
Okay, So I have been dying for us to get
to the point where we get to talk about Ghostbusters
because when I was a kid, I was obsessed with Ghostbusters.
It's possible that my first crush was on Egon Nice,
the character in the cartoon. So how good is the
science there. They've got those proton packs, they can like

(50:44):
catch them in that box and store them in that container.
What is the science there?

Speaker 2 (50:50):
Yees? So I love Ghostbusters and it's not hard science fiction,
but I do like that they dress it up a
little bit sciencey, you know, and the scientists are kind
of heroes in that story. They're creating technology, they're understanding it.
They're not just running around.

Speaker 1 (51:04):
And being woo woo very handsome too.

Speaker 2 (51:06):
Yeah, exactly, they're good looking, they're charismatic. So what's going
on with the science Ghostbusters? While they have these PKE meters,
you know, which detect psychic activity. pKa stands for psychokinetic energy,
and I think this is just like a fancy version
of an EMF meter. They invent this device, they don't
go into the details, like what exactly is it measuring?

(51:27):
How is it detecting psychic energy? I think it's basically
inspired by real life EMF meters like measure fluctuations in
the electromagnetic field.

Speaker 1 (51:35):
So there is no actual such thing as a pKa meter.

Speaker 2 (51:38):
No, it's just a prop you know, it doesn't actually
do anything. There is no psychic kinetic energy as a
physical concept. That would be awesome. Wow, somebody could invent
that that detected this new field of energy, like huge,
huge discovery about the nature of the universe.

Speaker 1 (51:54):
That would be incredible.

Speaker 2 (51:56):
But my favorite part about Ghostbuster science are the proton packs.

Speaker 1 (52:00):
Well, all right, but clearly those would work, right.

Speaker 2 (52:02):
Those would work in some sense, Like what is a
proton pack? If you look at the picture on their backs,
they have these circles on them, and what they're really
doing there is they're creating a little particle accelerator. Like
what do we do with the Large had Drunk Collider.
We take protons, we speed them up, We bend them
around in a circle so we can keep speeding them
up many many times, and then we smash them into stuff.
That's what a proton pack is. Takes protons, it spins

(52:25):
them around, it shoots them out. It's basically a proton
beam generator. And the science of that is pretty solid.
Like we build those things, we have those things in
real life. I have some comments about like the size
of those things on their backs, but like those are details.

Speaker 1 (52:38):
Do you think one day we could shrink them down
enough that you could actually fit them on your back.

Speaker 2 (52:42):
You could definitely have a proton pack small enough to
put on your back. The question is could it have
enough energy. The reason the Large had Drunk Collider is
so large is that when protons are going really really
fast and they have so much energy, it gets harder
to bend them. So you need super powerful magnets. At
the Large had Drunk Collider, we have like amazing souper
conducting magnets that are really awesome, and they can just

(53:02):
barely bend those protons around in a circle that's like
thirty three kilometers, So to get them within like half
a meter at very very high energy would require incredible magnets,
which would also be pretty dangerous, like you'd be walking
through the streets in New York and like everybody's keys
would be flying out of their pockets and like killing people.
So very small would require very high magnets. So that

(53:24):
part I'm a little skeptical of. The real question is
could you use a proton beam to somehow capture ghosts?

Speaker 1 (53:32):
Okay, so how would that work? What would that have
to say about the ghosts in order for this to
all work out?

Speaker 2 (53:36):
Yeah, exactly, Well, protons are positive, so you're shooting a
beam of positive charges and you're somehow hemming the ghosts
in with that. I mean, in the show, the beam
doesn't move perfectly straight. It's sort of like a whip,
more like Wonder Woman's lasso or something, which is definitely
not scientific, like the protons would move in a straight
line or be bent by a magnet. But I guess
if ghosts were like negatively charged, you know, some know,

(54:00):
then they would get attracted to the beam and you
could like stick the beam to them and even pull
them around with the beam. So yeah, if ghosts are
for some reason negatively charged, then protons are the right
way to hem them in.

Speaker 1 (54:13):
So next year at this time, we'll be reviewing the
science about whether or not ghosts or negatively charged, because
people will probably follow up on your work here.

Speaker 2 (54:21):
Well, if ghosts were positively charged, you could just use
an electron beam to capture them, but then you got
to know the charge of the ghost before you shoot
the beam at them, right, So you could do it
either way positive or negative, and new restriction there.

Speaker 1 (54:32):
Gets very complicated, So let us know if you have
any data on this question. But actually, Barry Rich wrote
a really great book where she interacted with the community
of people who ask questions about this kind of stuff,
and I highly recommend every book ever written by Mary Roach.

Speaker 2 (54:45):
She's excellent.

Speaker 1 (54:46):
Yeah, okay, everybody, Happy Halloween. We hope you have an
amazing spooky day, and if you want to send us
any questions or suggestions for future shows, drop us a
line at Questions at Daniel and Kelly dot org.

Speaker 2 (54:58):
Happy Halloween, everyone, and this episode goes to show you
there's science in everything, in me and you and even
in Halloween.

Speaker 1 (55:06):
W Daniel and Kelly's Extraordinary Universe is produced by iHeartRadio.
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