Science Vs - Ghosts

Episode Date: March 30, 2017

One third of Americans believe in ghosts, and one fifth have had a personal encounter. We go to a haunted house with some paranormal investigators and things get spooky. But, scientists aren’t scared - they have a range of explanations for why so many people encounter ghosts. We speak to Dr. Katie Mack, Baland Jalal, Dr. Shane Rogers, and Prof. Chris French and find out what ghosts are all about. Credits: This episode has been produced by Ben Kuebrich, Wendy Zukerman, Diane Wu, Heather Rogers and Shruti Ravindran. Senior Producer Kaitlyn Sawrey. Our editor is Annie-Rose Strasser. Production assistance: Audrey Quinn. Fact Checking by Michelle Harris. Sound engineering, music production and original scoring by Bobby Lord. Thanks to Dr. Ciaran O’Keeffe, Dr Neil Dagnall, Dr. Giulio Rognini, Raymond Swyers, Dr. Joseph Baker, Prof. Kwai Man Luk, Prof. Kin Seng Chiang, Prof. Tapan Sarkar, Prof. Maxim Gitlits, The Zukerman family, Joseph Lavelle Wilson as well as Jorge Just, Devon Taylor ...and thanks to Haley Shaw for the spooooky violins in the Science Vs theme. Our Sponsors: Meet real Subaru owners and hear their stories on MeetAnOwner.com. Selected References:Baland Jalal’s Sleep Paralysis Hallucination HypothesisReview of Folklore Surrounding Sleep ParalysisWorld Health Organization’s Guidelines for Indoor Air Quality: Dampness and MouldChris French’s Haunted Room Experiment Learn more about your ad choices. Visit podcastchoices.com/adchoices

Oh, why am I getting this weird interference? Is it my phone? Could it be the occult? Is the interference gone now that you've moved your phone? Yeah, I've moved my phone. Okay, so not the occult this time. Not this time. Hi, I'm Wendy Zuckerman and you're listening to Gimlet Media's Science Versus.

On today's show, ghosts. Ghosts, you say? Well, many of us have had those moments where things get a little spooky and we start to believe. To tell you the truth, I was like being sarcastic, but I was a little bit freaked out when you said you had interference on your microphone. Science Versus senior producer Caitlin Sori and I are about to enter a haunted house. We've been told that it's a hotspot for paranormal activity. Oh, here we go. This one's... There's a blue door. It's very beautiful. It's pretty dark inside.

Hello! Hello! Come in, girls. This is Lynne. She's tall, has big glasses and a Howling Wolf T-shirt. And she grew up in this house, which is a totally unassuming two-storey clapboard on a busy street. And Lynn moved here with her parents when she was just five years old. She's now in her mid-fifties. The house is in Queens, New York, and it's surrounded by nine cemeteries.

I always say, I always make the joke, if the zombie apocalypse happens, I'm at ground zero, so I'm gone in the first wave. And from the first moments when Lynn walked into this house when she was just a little girl, she knew something wasn't right about it. I don't remember it, but my grandmother always used to say, you came in and the first thing you said to me was, Grandma, I don't want to move to the haunted house.

Her parents didn't believe her. But my grandmother knew right away that there was something in the house. And soon after the family moved into the house, Lynn had her first paranormal experience. She woke up to a very scary presence in her bedroom. This used to be my bedroom. I would wake up in the middle of the night and there would be a black figure standing here. And I used to call him the priest when I was little. He had a long black gown.

And as a kid, it was pretty scary. I always found him very unsettling. In fact, I used to go to sleep and I used to line up all my stuffed animals in between me and the corner. To protect you from the priest? My raccoon, my teddy bear, you know, all my little animals to protect me from him. But as I got older, he gradually, you know, went away.

So that was the first thing? That was the first thing. That was the first thing. But over the years, other things have happened. Lynne took us to the living room and told us a more recent story about her late mother's old music box. That music box right there. How old is that?

That is probably from the 70s, I'd say, maybe. It's a small wooden box with little wooden dolls from around the world. And one time, when Lynn was nowhere nearby, the music box just turned on. I was sitting there and all of a sudden I heard this melody. It took me a few seconds to actually realize that it was coming from the front of the house. And when I walked to the front of the house, I'm like, okay, it wasn't moving, but I could hear the thing very slowly going... And it was my mother's birthday. I walked up to it, and as I walked up to it, all of a sudden it stopped.

Like, when I got within a minute, it stopped playing. And other stuff has happened around Lynn's house too. A statuette disappeared. A stuffed rabbit that she had appeared at the foot of the stairs and then up on the landing. And it's not just her. People who come to her house feel weird stuff all the time, she says, especially when they go into her basement. Some people feel tired and woozy. Others have even fainted. And sometimes, Lynn says, people can hear the calls of a man yelling, get out.

She calls him the get out man. And then there was that time when the plumber had to go down into that basement. The table started to rock back and forth. And I actually grabbed it when it started to roll. I was like, oh, nothing. And Joe, the plumber, was like, we're almost ready to leave. I said, yeah, I think you should. Lynn believes that ghosts are moving things around in her house and scaring her guests.

And she has an idea as to why so much haunted stuff happens in her house. She's come to believe that there is what she calls a portal between our world and the next. And that portal is on the first floor of her house and it runs all the way down to the basement. The portal kind of cuts through the floor, goes all the way through, so sometimes you get people getting busy at the base of the steps too. And Lynn doesn't like talking about all of this haunted stuff

to people who think that ghosts aren't real because she knows how it sounds. Crazy. And the whole time she was growing up, while her grandmother believed in ghosts and encouraged what she saw and felt, Lynn's mum was not a believer. My mother had spent her whole life telling me,

my grandmother, she was crazy, and telling me that stop imagining things. Well, if Lynn and her grandmother were imagining things, they're certainly not alone. According to a Pew survey taken a few years ago, almost one in five Americans report having seen or been in the presence of a ghost. That's twice what it was in 1996. And many people who haven't had encounters still believe.

Surveys from the US and the UK show that around a third of us say we believe in ghosts. And this all means that chances are you either believe or you have a friend who believes. You know, that friend with the really creepy story that they like to tell you around the campfire. So, what's going on here? Is it possible?

Could ghosts exist? When it comes to the paranormal, there are lots of apparitions. But then, there's science. Science vs Ghosts is coming up just after the break. After decades of shaky hands caused by debilitating tremors, Sunnybrook was the only hospital in Canada who could provide Andy with something special. Three neurosurgeons, two scientists, one movement disorders coordinator, 58 answered questions, two focused ultrasound procedures,

one specially developed helmet, thousands of high-intensity focused ultrasound waves, zero incisions. And that very same day, two steady hands. From innovation to action, Sunnybrook is special. Learn more at sunnybrook.ca slash special. So I first came to Edward Jones with a great deal of trepidation. When I first met with my advisor,

and I really was feeling vulnerable about what I would have to share, I was, of course, pleasantly surprised to find that there was absolutely no judgment and a lot of support. And when it was time to get serious, he really took my hand and helped me to do that. Edward Jones. We do money differently. Visit edwardjones.ca slash different. What does the AI revolution mean for jobs, for getting things done? Who are the people creating this technology and what do they think? I'm Rana El-Khelyoubi,

an AI scientist, entrepreneur, investor, and now host of the new podcast, Pioneers of AI. Think of it as your guide for all things AI, with the most human issues at the center. Join me every Wednesday for Pioneers of AI. And don't forget to subscribe wherever you tune in. Welcome back to Science Versus, the show that pits facts against phantoms. After meeting Lynne and seeing her haunted house, we at Science Versus went searching high and low

for what could explain Lynne's experiences. Now, ghost believers sometimes lean on theoretical physics to explain how ghosts might exist. Some paranormal groups, for example, argue that ghosts may exist in another dimension that closely parallels ours. So we spoke to a theoretical physicist to find out if this was possible. Dr Katie Mack is at the University of Melbourne.

I'm a theoretical astrophysicist. I do cosmology, which is the study of the whole universe from beginning to end, all that kind of stuff. So, everything in the universe, that would include ghosts, right? So, we wanted to know if there was any room for ghosts in theoretical physics. If you really wanted ghosts to exist, what would you pick? Like, where's your best bet? Right. So, yeah, I mean, I guess, you know, let's say that you want to believe in ghosts

and you just really, really want to show that it's possible. Like you can go to the edges of what we understand and what we have really solid theory about. You can posit another universe, composite a parallel universe, you can posit like a parallel reality that's disconnected from our own. Yes, a parallel universe. You can put anything you want there. Like absolutely anything. All the fairies live in the multiverse. Fine.

And the reason that Katie is fine with putting ghosts in another universe is because most theories about parallel universes say that whatever is in that other universe can't interact with ours. So ghosts in another universe can't mess with our atoms, our electricity, or anything that we can measure in labs around the world. And if they're not messing with this stuff, then they're not messing up our fundamental understanding of the world.

But... That also means they can't talk to you and they can't move stuff around in your house and, you know, you'll never know if they're real or not. So that doesn't help us because Lynn's ghosts do interact with our world. They're moving stuff around and scaring her plumber. But Katie says there is one theory about parallel universes that could mean that ghosts living in that parallel universe might be able to interact with our universe. But here's what you need to know.

Her idea of what a ghost is is very different to Lynn's and probably yours. Katie is a theoretical physicist after all. If you had a ghost that was pure mass, like a black hole, if your ghost is a black hole. Yes. Say the ghost itself is a black hole. And your ghost is living on this other plane. A black hole, by the way, is a place in space where gravity is incredibly strong. But say that black hole in the other universe bumped right up against our universe. And again, that black hole is the ghost. Then, in principle, your ghost could have,

could create some gravitational pull in our universe. So if your ghost was a black hole, it could not scare you? Yeah, I mean, like, I don't know. I guess, like, it could create a little bit of gravity here somewhere in the universe. that there could maybe, just maybe, be a parallel universe that is next to ours and a black hole in that parallel universe that might be leaking just a little bit of gravity into Lynn's house. Could it knock over glasses or move things around by changing the gravity? Um, sure. Yeah. Sure.

Yeah. If that happens, if you... Really? Really, Katie? Couldn't it? Like, yeah, I mean, if you have a black hole, stationary black hole that you put on this other dimension and you got it to stand still

and it happened to be nearby to one of your glasses. However, it would also be pulling on your table, and you probably would notice other effects from the gravity. And if you do, you should definitely make some measurements and write a paper and send it to the Astrophysical Journal, because that would be very interesting. Do not send it to me. That's an important caveat. Please do not send it to me. Absolutely do not send it to me or any other physicist. However, if somebody can make a measurement of the gravity of a black hole from another dimension affecting their silverware, that would be a very interesting experiment that we should do in a laboratory.

It would be very weird if it were just, you know, your own kitchen where this was happening. But, I mean, yeah, I can't rule that out. Can't rule it out. OK, so that's exciting. But the thing is, even if this ghost black hole theory is true, it can only explain why things are moving around in Lynn's house. But what about the phantom priest? What about the music box turning itself on?

Alright, we're going back to Lynn's haunted house to get more answers. And this time we're hearing not from scientists, but from paranormal investigators. Ghost hunters. And it's time to see what evidence they have Lynn invited her paranormal investigating friends Anthony Simonelli and Trey Howard over Anthony!

Man, I see all your posts I'd be wondering, are you going to hit New York anytime soon or what? We all head down to Lynn's basement where she said most of that ghost activity happened The basement was hot, musty and dark and every now and then the heater turned on with a big clank. I was just interviewed back in October for an Italian newspaper for Haunted New York.

Anthony is a committed investigator. He leads a group called Seekers Club of the Paranormal and he's been doing paranormal investigations for a long time. I'm saying 30 years, but I've actually been doing this since I was 13 years old. The first time he saw a ghost, he and his friends were taking a shortcut through a cemetery on the way home. I'm standing and my friend's in front of me, and I see over his shoulder there's a woman over a grave praying

with her hair blowing. She had this long red hair, a white gown, and she's praying, like, you know, with her hands crossed, with her head down. So, you know, 13-year-old, I was like, hey, you guys, check this out, and she was gone. Anthony's made it his life's work to try to find out what he saw. But I want to prove it,

because everybody tries to make you look silly doing this and make you crazy. And everybody that's into the paranormal now had experiences when they were kids or something and they're trying to find an answer for themselves. To find those answers, Anthony has bought a whole bunch of equipment, all sorts of gadgets to capture and communicate with ghosts. He's got a digital audio recorder, cameras, and a meter to measure electromagnetic activity. I haven't caught nothing yet,

but the first time we catch something, it's going to be wild. First, he whips out that digital recorder. He's trying to pick up noises from the spirits that are otherwise inaudible to us humans. You see, in the ghost community, these sounds are called electronic voice phenomena, or EVP. And these types of audio recordings are a popular method for ghost detection among hunters. With his recorder on, Anthony and the team start putting questions to the spirits. The room may sound eerily quiet while they record, but when they listen back, they sometimes hear weird sounds. Evidence, they say, of a ghost.

Today, they thought they felt the presence of a monk in the room and they wanted to know more about him. Trey started asking questions. To the monk, I want to ask, what is it that you're wearing? What colour is your robe? Can you tell us what date you were from? Are you from the 1500s? Earlier? Later?

After they'd finished questioning the monk, we listened back to the tape. Can you tell us what date you were from? Are you from the 1500s? Earlier? Later? Listen to this. Earlier? Later? Yep. You hear it? Yes.

Anthony was sure he heard a ghost. It was that little sound, that little... Huh. was sure he heard a ghost. It was that little sound, that little... We'll get back to the science of this EVP session just a little later. But for now, Anthony tells us that there is another way that ghosts can communicate with us, by changing electromagnetic fields. And that's why his next device records changes in these fields. This device that he's got looks a bit like a handheld transistor radio with a very long antenna. What is that? What is that noise? That's just the noise it goes. It's a detector. It's an alarm that if something comes close to it, like a spirit. Or a hand. You're doing it with a hand.

Yes. You know, you have electrical charges that pump your heart and everything. So when a spirit manifests, it has electrical charge. So that's what causes this to go on because electrical charge is part of the spirit that's manifesting. And quick side note, electromagnetic fields are invisible energy fields that happen when there's an electric charge.

It's what makes your hair stand up when you get static electricity. You can feel the electromagnetic field when you move metal around a magnet, but most of the time there are electromagnetic fields all around you that you just don't notice, like radio signals or even the magnetic fields of the earth. And there are lots of things that may affect these fields, like electrical power lines, transmitting TV antennas and cell phones, as well as thunderstorms. And, according to Anthony, ghosts.

Anthony kept the electromagnetic field detector out the whole time that we were there, but it didn't pick up much. He did have another device to show us, though. It was what's called a ghost box, which is about the size of an iPhone. Anthony had bought it on the internet, and according to the manufacturer, when the electromagnetic fields around the box change, it will spurt out one of its 2,000 pre-programmed words. So, like, you know, you ask a question, something comes out, it's right on the money.

Buried. Buried. See? Ah. See? Yeah. Apple. Apple. Mommy. Do you want your mommy? We listened for a while. It said, shot, 15, fit. And then the box said something a little spooky to senior producer Caitlin Sori. Paranormal.

Oh. OK, if you want to talk to us, come talk to us now. You know I do paranormal. Come speak to me. What did he say? Possible. What's possible? The paranormal is possible.

Paranormal is possible. Caitlin asked the ghost. Is that your message for Science Versus, that the paranormal is possible? Anthony was stoked. Thank you very much. For him, this was evidence of a ghost. And for a moment, Caitlin was a little bit bewitched. That was cool, actually.

That was very cool. But now it's time to jump into our portal, back to theoretical physicist Katie Mack at the University of Melbourne. I asked Katie, is it possible that ghosts could be interfering with electromagnetic fields? No, I mean, the thing is that if ghosts created magnetic fields, then you would measure that in laboratories. We have very high precision measurements of things like electric and magnetic fields.

So if ghosts were messing with electromagnetic fields, then what happens to all of those precise measurements that scientists have recorded? Then all of our measurements would be off everywhere. And while other ghost hunters have their own evidence for ghosts existing, perhaps photographs with flashes of light or faint images, nothing's that convincing. We looked and looked and it's all very anecdotal. Which leaves the very, very big question of how could it be that one in five

Americans reckon they've encountered a ghost? That's a lot of people. And that answer is coming up just after the break. Music Welcome back. So, we've gone through some of the evidence that ghost hunters have that ghosts exist, and we've even posited a theory for how things could get moved around your house, a ghost black hole theory, or as we like to call it, GBHT. But really, with such little evidence for ghosts around, why are so many people having these experiences? If it's not the paranormal, what else is there?

Well, scientists have been wondering this very thing and they've been searching for other explanations. Remember Lynn's first run-in with a ghost? She was sleeping and she saw a figure. A lot of times I would wake up in the middle of the night and there would be a black figure standing here. Bilal Jalal, a neuroscientist at Cambridge University, has been researching this very type of encounter.

And he got started because about a decade ago, it happened to him too. So basically I slightly woke up and I realised, OK, I'm paralysed paralyzed here I can't move I can't speak and I had this feeling of of some evil presence it was a ghost or some entity and then I felt like suddenly this creature was pulling my legs and it was pulling my legs up and down and up and down I and I and I knew I wasn't I knew I wasn't dreaming. And then it started to choke me and it started to press on my chest so I couldn't breathe.

This was very real. I had a very real supernatural experience. Baland was totally confused. It was just one of those things, right? You know you're not crazy because you're not crazy in all other respects. It's only in this particular thing. Baland has devoted a large part of his career

to researching what happened to him. And he tells us that similar experiences to his own have been documented for thousands of years in cultures all around the world. In ancient Rome, this apparition was called incubus or succubus. And today in Italy, nonnas warn their grandkids of ghost-like creatures who come in the night.

These ghostly creatures are spoken of in Scandinavia, the Middle East and Japan. But Berland and others now believe that these ghostly encounters are actually something called sleep paralysis. Sleep paralysis is actually a pretty common medical phenomenon. One review of 35 studies found that around 8% of the population have had it. But people can experience it in very different ways. It often happens when you're dreaming during REM sleep and you wake up and you can't move your limbs. I've had it and it's really scary. Even though I knew what sleep paralysis was, I woke up and I thought, oh my

God, I'm going to be paralyzed for life. But I wasn't. No, I wasn't. I can move. I'm happy about that because it's just sleep paralysis. It's just a phenomenon. And to know why it happens, you have to know that sometimes when we sleep and have vivid dreams, our brains prevent our bodies from moving. In order to prevent us from acting out these very vivid and real dreams. When you're in REM sleep, parts of the brainstem can send their own messages stopping those move signals from getting through. And that's why

sometimes you can't move. But during sleep paralysis, you wake up, but your brainstem is still blocking those move messages. So you can't move your body. So it's simply a glitch in the machine, right? A little technical glitch, and we are mentally awake even though our bodies are physically paralyzed. And that all makes sense. But just because you're paralyzed, why would you start seeing ghosts or thinking that your legs are moving up and down? Bland has an idea, but he hasn't tested it yet. So this is where the science gets a little shaky. Here's his hypothesis. It all has to do with our perception of our body. So I occupy this body. You occupy your body, okay? I don't occupy Brad Pitt's body,

unfortunately, all right? So we all have a sense of a body image, right? Okay, this is created in the brain. But during sleep paralysis, when the brain tells the body to move, it doesn't. And that creates mixed messages in the brain and it gets confused. You send command neurons, move, OK? Move. But there's no feedback from your body. So your body image gets distorted. And according to Balan's hypothesis, your brain is so confused about where your body is in space

that it's kind of projecting your body out in front of you and this can cause you to feel a presence in the room or even have a full-blown hallucination of a figure. Add to this, potentially, you start being afraid because you can't move, which is terrifying and maybe you've even woken up from a frightening, vivid dream. You put it all together and it might make you see a shadowy figure that perhaps looks like a scary priest or something else,

just like Lynn saw as a little girl. So you wake up and see something weird and it don't look good. And you create a very vivid, very real hallucination of creatures in your bedroom that can have all kinds of shapes. So it's like a little bit like when you misspell something in Google and it just says, I think this is what you meant. Exactly. That's a very good way to put it.

But in this case, your mind's autocorrect has gotten it wrong. Very, very wrong. Conclusion. One scientific answer for ghosts is that sleep paralysis is causing you to sense something that isn't there. But this research is really new. And the thing is, even if this hypothesis does pan out, while it's a very ghoul idea,

it would only explain the ghosts that people encounter when they're just waking up. We need more ideas. What else might there be? We kept trying to scare up explanations and found our way to Shane Rogers, a professor of environmental engineering from Clarkson University in upstate New York. Now, Shane has been interested in paranormal activities since he was a boy. When he was 11, he also lived in a creepy house like Lynn's. It was close to a cemetery and he had a spooky experience one night. I came downstairs to get a glass of water and it

was dark in the living room and I saw a light kind of shining around the living room. And then the light itself, I realized wasn't on the wall and it was in the room. And so, of course, I ran back upstairs into my room and had to process that information. And so by you had to go upstairs and process that information, does that mean you were, like, scared out of your mind? I spent some time under my blanket there. About ten years ago, Shane started thinking about that experience that he had,

but he was thinking about it from a new perspective. He was a scientist now, and he started seeing things a little differently. He thought about that house. It was old and musty, which made him think that perhaps mould was growing there. Yes, mould. And maybe that's what made him see that paranormal light. So, why would mould cause something strange in the neighbourhood? Well, Shane tells us that when moulds reproduce,

they can release spores in the air that you breathe in. And sometimes, if you're sensitive, these spores can make you cough or wheeze and potentially trigger an inflammatory reaction. And Shane suspects that maybe this inflammatory reaction might affect your brain as well, potentially making you more anxious and more likely that you think you see a ghost.

And he thinks that this might happen if you're already in a scary place, somewhere that already seems haunted. Perhaps as you process information in those types of places and you're having unease, anxiety and those sorts of things, you process it in those types of places and you're having unease, anxiety, and those sorts of things. You process it in a different way. Oh, so you're already primed to be thinking, this is going to be a haunted house,

and then the mold tips you over the edge. Yes, yes. The experiences that you have because of your exposure to the mold tips you over that edge, yeah. To make his case, Shane leans on small studies and case reports that document neurological symptoms like fatigue and difficulties concentrating in people living or working in damp or mouldy places. He also points to a study showing brain inflammation in mice exposed to a particular toxin found in black mould. But the idea that mould in buildings can cause neurological problems

is all very controversial. A large report by the World Health Organisation said there is no conclusive evidence that living in mould-infested buildings could lead to neurological problems. Either way, fatigue and difficulty concentrating are a far cry from an apparition. And Shane readily acknowledges that at the moment, there's no evidence that mould has made people see ghosts. Right now, it's just an idea. And so to test it, Shane started an experiment which involves heading to haunted houses and unhaunted houses

and testing for mould. There's no official name for it. Students like to call it mould busters. The mould busters head to places that people say are haunted. Houses, museums, restaurants, abandoned buildings. And then to compare, they look at a bunch of similar-ish places where hauntings have not been reported. At each site, they take air samples.

OK, so basically what you're hearing is just a vacuum pump. And so we'll put on kind of just a filter. So we're trapping whatever might be in the air. And this thing, his vacuum pump, looks straight out of Ghostbusters. If I could strap it on my back, I would. While Shane says his results are preliminary and unpublished, he says that so far... I can't say that we've seen some interesting trends,

at least up to this point, where places that are reportedly haunted, we've been seeing higher mole counts in those to places that are not reportedly haunted. And some of those locations have had very, very high mold counts. Shane tells us that he still has to test more haunted places and non-haunted places. Then he has to do statistics to show whether certain types of mold are more likely to be found in so-called haunted houses. And then we'd still need to investigate whether these molds really are affecting people's brains

and increasing the likelihood that they experience a ghostly hallucination. Other groups of scientists around the world have tried to explain why people are encountering ghosts by looking at other things in the environment, like infrasound, that's sound waves that humans can't hear, or even magnetic fields. But a paper looking into this found the evidence is so inconsistent that, quote, further research is urgently needed, end quote. Conclusion, while things in your environment, like moulds,

might increase the risk you'll encounter a ghost, we need a lot more evidence. So, until we get more data, we have to move on to a science that is a little more concrete. Psychology. But seriously, the vast majority of research into ghosts and specifically why so many people see or feel them is looking at the psychological forces at play. So let's take a deep dive into the mind. Last up, who are we going to call?

Chris French, a professor and head of the Anomalistic Psychology Research Unit at the University of London. And that means he studies why people believe in ghosts and other paranormal phenomena. Well, ghosts are a tricky one because typically with ghosts... Sorry, we've got a dog in the room with us. She just flapped her ears.

Let's listen again. Definite dog flap. Stop it, Chasey. Right. So, for a long time, Chris was a real believer. When I was a kid, I was terrified of ghosts. I had to sleep with a nightlight for many, many years. Did you see a ghost? No, I don't think I ever actually saw one, but I'd always lived in fear that I might. All through university, and even as he started his PhD, Chris thought that ghosts might

exist. But now, as a professor, he thinks there are other reasons. He even devised a psychological study to test why people keep encountering ghosts. So we thought, wouldn't it be fun to create an artificial haunted room? Can we actually induce these kinds of experiences in people? So he builds this room. If you went inside, it was just white, it was circular, and there was nothing in it. He got about 80 people to wander around alone in the room, and he told them they might experience mildly unusual sensations. Go in there, stay in there for 50 minutes, you can wander around and tell us whether

you have any strange experiences. Were you tempted to go on the speakers? That would be totally unethical and we wouldn't dream of it. Yeah, it would have been funny, but no, we didn't do it. And people did have experiences in the room. No full-blown ghosts, but... Some people came out saying, whoa, that was really weird. Some people felt dizzy or odd, and a few people even experienced terror. And those are the kinds of experiences that people typically report when they go to reputedly haunted locations.

I mean, although typically when you talk about ghosts, it summons up an image of some kind of full-blown apparition. That is actually kind of remarkably rare. It's much more common for people to just report these kinds of milder anomalous experiences that I'm talking about. And what he found, and this is critical to the study, is that people who were found to be more suggestible were more likely to have these odd experiences. So the most parsimonious explanation is basically that if you say to some suggestible people, go in here and you might have some weird experiences, some of them do. It's just the power of suggestion.

And Chris says that we can all be affected by this. I'm sure you've had this experience yourself. If you go into an old building and somebody says, oh, it's supposed to be haunted, it suddenly feels very different. You start noticing every little anomaly, every little creak, every little noise that you might otherwise have not paid much attention to. Could it be the occult? No, no idea what he's talking about. Anyway, while there isn't a lot of work on this and the studies tend to be quite small, other work has found that the power

of suggestion can play a role in making people encounter ghosts. In one study, researchers created fake seances with an actor and brought 110 people to the events. The actors suggested that a table had moved during the seance, when it hadn't. After the fact, almost a third of the participants thought the table had moved. A third. It's pretty compelling. A table moving when it was still. But when it was suggested that another item, a handbell, was moving,

only 10% believed that it was. And this is why Chris says that this isn't just about suggestibility. There's another factor at play. A second important factor is belief. If you believe in ghosts, you are more likely to report these kinds of experiences. Chris told us about another study where a group of researchers tracked the experiences of over 450 people as they walked around Hampton Court Palace, which is reputed to be one of the most haunted places in England. And yes, you can guess the results. It was the believers who reported the most of these kinds of experiences, and they were more likely to say they thought it was

due to some kind of ghostly encounter. Believers had significantly more paranormal experiences, like sensing a presence or hearing unusual sounds, than did the non-believers. And in some people, Chris says that these psychological forces can be so potent that when people say they see or hear or feel ghosts, they actually see or hear or feel them. Chris says it's like a hallucination. Typically, if you say to someone who reports that they've seen a ghost, well, maybe you were just seeing things. In other words, you were hallucinating.

They'll get very defensive because they interpret that to mean you're saying I'm crazy. But it doesn't mean that at all. We can all, under the kind of appropriate circumstances, hallucinate. On top of that, once you believe something to be true, you can start seeing signs of it all around you. This psychological phenomenon is called confirmation bias and we can all fall prey to it. So when your friends say they saw a ghost, believers are more likely to take that as even more evidence that ghosts exist. Remember that EVP session?

Anthony, who believes in ghosts, heard a little chink. Earlier, later. And was convinced that it was a ghost speaking to him. And then once he said that it was. Yep. You hear it? All of his friends agreed. This is cool. Conclusion.

When you've got a group of people who believe in ghosts and go on hunts together expecting to find them, psychological forces can kick in, which ultimately means that the friends create a world in which, find them, psychological forces can kick in, which ultimately means that the friends create a world in which, for them, ghosts can exist. We spoke to Lynn about all of our scientific ideas, the black hole, sleep paralysis, a mould infestation

and even the notion that it's all psychological forces. But ultimately, Lynn said that these ideas just didn't satisfy her. For people who believe no proof is necessary, for people who don't believe no proof is ever enough, you know? I mean, that's just the way I look at it too. So we haven't convinced you, or these scientific theories don't help you out? No, I mean, I'm not saying these aren't theories that might actually explain other situations and other things, but it's not my reality. We're not here to convert anybody. We believe what we believe. We have our

reality and our experiences. And truth is, the science isn't that robust. One paper published in 2015 wrote that the scientific explanations for hauntings thus far, quote, have yet to provide comprehensive theories that account for the breadth of encounters reported, end quote. Now, that's mostly because most scientists aren't working on paranormal activities. But it's also probably because there are some things that science just can't prove, or in this case, disprove.

And that leaves room for believers to keep believing. And Dr. Katie Mack has a rather spirited response to all of this. If you tell me that, you know, one of these days when I flip a coin, the coin is going to, you know, come out of my hand and shoot off into space, you know, I can flip the coin thousands and thousands of times and not have that happen and you can always be like, it's going to happen next time. And, you know, there's not a lot I can say to that. But I feel like really the burden of proof

is on you at that point. If you want to hypothesize something as extraordinary as ghosts, you need mountains and piles and decades of evidence that prove it beyond a shadow of the doubt. And that is not something I've seen. That's science versus... So the bit about the black hole in another universe knocking the glass off the table, I feel like I need to check my numbers on that. Hello? Hi, Katie?

All right, so I think we're ready, yeah. So Katie, could the black hole ghost knock over your glasses? No. No. No, so if... No. I'm just going to say no. That's Science vs Ghosts.

This episode has been produced by Ben Kebrick, Diane Wu, Heather Rogers, Shruti Ravindran and me. Our senior producer is Caitlin Sori. Our editor is Annie-Rose Strasser. Production assistance from Audrey Quinn. Fact-checking by Michelle Harris. Sound engineering, music production and original scoring by Bobby Lord. Thanks to Dr Kieran O'Keefe, Dr Neil Dagnall,

Dr Giulio Rognini, Raymond Swires, Dr Joseph Baker, Professor Kwai-Man Luke, Professor Kin-Seng Chiang, Professor Tappan Sarkar, Professor Maxim Gutlitz, the Zuckerman family, Joseph Lavelle Wilson, as well as Jorge Just, Devin Taylor, and thanks to Hayley Shaw for those spooky violins during the Science vs Theme song. Next week, we're throwing down on the biggest controversy yet. I'm Wendy Zuckerman. Back to you next time.

Who would you call if you were really scared? Ghostbusters. What? Ghostbusters. I can't hear you. Ghostbusters. Ghostbusters? Ghostbusters, mommy? Ghostbusters.