Oct. 18, 2023

Do you know about ghosts? 👻

In this episode, we discover why you might have thought you saw a ghost. We found out that many cultures, even if they are far apart, have tales about ghosts or spirits. We looked at ghosts from a science perspective and learned that sometimes our eyes and brains play tricks on us, like seeing things that aren't really there. We also talked about how you could design an experiment to find out if the ghost your friend saw was real. Plus, we dived into the magical world of rainbows, the buzz of mosquitoes, and the mysteries of our noses. Did you know mosquitoes really like Type O blood and are drawn to carbon dioxide and sweat? 

Sleep Tight!, Sheryl & Clark

❤️👂🔬

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📢 Have an interesting science topic you would like investigated? Send us an email at hello@sleeptightscience.com and we may feature it in an upcoming show.

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About Sleep Tight Science

Sleep Tight Science is an engaging (but not too engaging) bedtime show for the whole family that answers the questions kids have about science. Each episode explores a fascinating topic in science and technology, from the mysteries of outer space to the wonders of the human body. Sleep Tight Science is the perfect bedtime companion for curious minds of all ages. Have an interesting science topic you would like featured? Send us an email at hello@sleeptightscience.com and we may feature it in an upcoming show.

See omnystudio.com/listener for privacy information.

Transcript
00:00:44
Speaker 1: Hi, science fans. Guess what. We are launching season four of sleep Tight Science this September, and we need your help to make it extra special. Did you know that your voice can be part of our show? We want to hear your amazing voices in our show opening. It's super easy and fun to join in. Just record yourself saying you are listening to sleep Tight Science. Then send your recording to the email address in our show notes.

00:01:19
Speaker 2: How cool is that.

00:01:21
Speaker 1: We can't wait to hear all your fantastic voices. Thank you for listening. You're listening to sleep Tight Science. Did you know that the White House in Washington, DC is reputed to have its own resident ghost? What Numerous reports suggest that the ghost of Abraham Lincoln has been seen wandering the halls of this famous building. Could it be true? Hello, friends, and welcome back to sleep Tight Science, a bedtime show that answers your questions about science. In this episode, we will start talking about the science of ghosts.

00:02:34
Speaker 2: But don't worry.

00:02:35
Speaker 1: We promised not to be too spooky because we wouldn't want you to be spooked before bed. Have you ever wondered about the science behind.

00:02:51
Speaker 2: Ghosts or if ghosts were real?

00:02:56
Speaker 1: Or as long as humans have told stories, ghosts have haunted us, from folklore to modern accounts of unexplained phenomena. The concept of a presence beyond our tangible world has fascinated and frightened us. But what if we tried to understand ghosts using science In the realm of the unknown. Science seeks to shine a light deciphering mysts from measurable phenomena. As we start learning about the science of ghosts, we'll look at the mind, brain, and surroundings to explain why people might feel or see these spooky press presences. Throughout history, ghosts are often thought of as the spirits of souls or individuals.

00:03:58
Speaker 2: Who once lived among us.

00:04:01
Speaker 1: They are often depicted as shadowy or airy figures, sometimes appearing transparent or even as just amist. Some stories say they can move objects, while others claim they just want to communicate or finish some unfinished business here on earth. The stories around these entities vary widely. Some are benign, perhaps returning with messages or attempting to fulfill an unresolved purpose from their time among the living, while others are seen as more mischievous. These ghostly figures are often believed to retain their emotions, consciousness, or memories, making their appearances deeply personal and frequently tied to specific locations, objects, or individuals from their past lives, whether perceived as benign visitors or haunting presences, Ghosts have been a cornerstone of cultural stories for centuries, representing our attempt to grapple with the mysteries of existence. Scientifically speaking, there is no solid evidence that ghosts exists. Most phenomena people think our ghosts can often be explained through other means, like optical illusions, very low frequency sounds, or even just the power of suggestion. But the idea of ghosts has been around for thousand of years and it's a fun thing to explore, especially during Halloween. Across the globe, cultures have had their own interpretations of ghosts. For example, ancient Egyptians believed in ka, a spiritual double. If it wasn't properly cared for after death, it could cause mischief. Chinese folklore gives us the hungry ghosts, spirits who don't receive proper rituals after death and wander around causing trouble. In European history, ghosts were often restless souls who had unfinished business or wanted to deliver a message. Indigenous peoples had their own spirits and entities, and not all fit the ghost mold we might think of. They believed in nature spirits, ancestral spirits, and other entities. Many African cultures have deep rooted beliefs in ancestor's spirits, some of whom can guide or influence the living.

00:07:00
Speaker 2: The fact that so.

00:07:01
Speaker 1: Many cultures, even those isolated from one another, have stories about spirits or ghosts, hints at something fascinating. Some scientists and psychologists believe that ghost stories may arise from common human experiences or fears, like the fear of the unknown or the mystery surrounding death. Shared environmental factors like the eerie sounds the wind makes or the shadows cast by candlelight might have contributed to stories too. It's also a way for humans to explain things they don't understand. After all, before we had science to explain why the wind blew a door shut, it might have seemed plausible that a ghost did it. Remember, science is all about asking questions and finding answers, even when it comes to the supernatural. So next time you hear a ghost story, think like a scientist, what other explanations might there be. This approach can also be applied to other things like alien spaceships in the sky, the myth of Bigfoot, and the locked nest monster.

00:08:36
Speaker 2: Did you know that?

00:08:37
Speaker 1: The idea of white sheet ghosts, where ghosts are depicted as draped in white sheets, became popular in the nineteenth and twentieth centuries, particularly in stage productions and early films. Before this, ghosts were often depicted in regular clothing. Have you ever been in a dimly lit room and thought you saw something eerie out of the corner of your eye, or wandered in the fog and thought you glimpsed a ghostly figure. Well, before you say the word ghost or even call the ghostbusters, let's see if there might be another explanation. Sometimes it's not phantoms, but our eyes and brain playing tricks on us. Let's learn how our eyes can be tricked. First, is the limitation of our peripheral vision. Most of our visual encounters with ghosts are often glimpsed in our peripheral vision. Peripheral vision is what you see on the sides when you're looking straight ahead, like when you notice something moving beside you without turning your head to look at it. The edges of our visual field are not as adept at picking up details or colors.

00:10:07
Speaker 2: Still, they are.

00:10:08
Speaker 1: More sensitive to light and movement. A fleeting shape or shadow seen from the corner of our eye might be misinterpreted as a ghostly figure, especially if we're already in a spooky context or location. Second, our eyes adapt to low light by making the rods light sensitive cells in our eyes more active. However, rods aren't great at providing sharp images or discerning colors, where you might misinterpret objects, shadows, or even people in dim conditions as something other worldly. Third, staring at a bright light and then looking away can produce a lingering image known as an after image. If you suddenly turn your gaze from a light source to a dimmer space, the after image might look like a ghostly presence. Now, let's look at how optical illusions and brains often craft their own spectral tails. First, there is paradolia, which is the brain's tendency to see familiar shapes like faces where none exist. Think of the man on the moon or seeing faces in clouds. This is a fun game too, seeing if you can see a face in a cloud or other object. In a dimly lit room or a complex environment like a forest, our brain might piece together random shapes and interpret them as figures or faces. This can easily be the root of many ghost sightings. Next, we are subject to our own expectations and suggestions. If you are in a place that's said to be haunted, your mind is already primed to see something supernatural. Combine that with dim lighting or unfamiliar surroundings, almost anything can seem ghostly. Third, atmospheric conditions like mist, fog, or dust can distort our perception and create ghostly apparitions when filtered through these mediums. The light of a car, a flashlight, or even the moon can create seemingly ghost like shapes. Lastly, glass mirrors and even water surfaces can reflect light, objects or people, producing ghostly apparitions. If the angle is just right, a window might reflect something from inside or outside the room, giving the appearance of a phantom figure. So while the ambiance of a creaky old house or a foggy graveyard can set the stage for a ghostly encounter, our eyes and brains often provide the main performance. Knowing how these illusions work, doesn't necessarily take away the fun of a ghost story. Still, it does offer a scientific perspective on our spooky experiences. Can you think of a time and optical illusion made you see something unexpected? So what do you do if a friend tells you they've seen a ghost? Before jumping to conclusions, we need to think like scientists and design an experiment to see what's really going on. To do this, we are going to use some key steps from the scientific method. Step one gathering information. First, you will ask your friend to describe exactly what they saw, where they saw it, and when you need lots and lots of detail.

00:14:52
Speaker 2: The more you know, the better.

00:14:57
Speaker 1: Step two, you need to replicate the conditions. Go to the place where the ghost was supposedly seen. Was it dark, was there a window? Was there anything that might have cast a shadow or reflection. We want to set up everything just like it was when the ghost was spotted. Step three observation time. Now it's time to look around. Bring a notebook and maybe even a camera. Spend time in the spot, preferably at the same time of day or night. Record anything you see here or even feel. Step four. There are a number of variables you need to consider lighting. Are there any light sources like street lights, car headlights, or moonlight that could create shadows or reflections? Windows and mirrors. Reflective surfaces can make it seem like there's something there when it's just a reflection.

00:16:14
Speaker 2: Sounds.

00:16:15
Speaker 1: Sometimes what we think we see is influenced by what we hear, So listen closely. Step five, Analyze and conclude. After gathering all the data, it's time to see what's up to draw a conclusion based on the evidence gathered. Did you notice any patterns anything that might explain the ghostly sighting? Remember science is all about asking questions, making observations, and coming up with the best explanations based on science. And always keep in mind it's okay to say I don't know. Some of the best scientific discoveries started with a mystery and a curious mind, just like yours. Now for some listeners questions. Boston, age five, Violet, Madeleine Menzies age seven from Ketchum, Idaho, Greta five years old from Ohio, and Ivy all asked.

00:17:44
Speaker 2: Questions about rainbows.

00:17:47
Speaker 1: With so much interest in these beautiful stripes in the sky, we might need to produce an episode all about rainbows. Still, First, we are going to try to answer some of their questions.

00:18:03
Speaker 2: What are rainbows made of?

00:18:06
Speaker 1: Rainbows aren't made of matter, like chairs, apples, or unicorns. They are made of light. Sunlight, to be exact, gets bent, split into colors, and reflect it inside tiny raindrops. This process is called refraction, and it's like each raindrop becomes its own mini prism, spreading out sunlight into its many colors red, orange, yellow, green, blue, indigo, and violet. Why are rainbows around when it's sunny and rainy? You need sunlight the sunny part and something to refract or bend that light, the rainy part or the rain drops. The sunlight shines through the rain drops, bending as it goes, splitting into a spectrum of colors, and you've got a rainbow. The light source, angle, and water droplets all need to be just right for this to happen. Why can't they just appear whenever we want? While it would be amazing to summon a rainbow on command, nature has its own rules or rainbows to appear. We need specific conditions sunlight, and water droplets in the atmosphere. But if you're really keen on making your own rain bow, try this on your own on a sunny day, grab a garden hose, make a fine mist of water, and with your back to the sun, spray the water.

00:19:57
Speaker 2: Into the air.

00:19:59
Speaker 1: You might just create a mini rainbow right in your backyard. Thank you for the questions, Boston, Madeleine, Violet, Greta, and Ivy. Our next question comes from Reese, who is eight and from Scotland. He asks, when mosquitoes bite you, does our blood taste differently by what blood type we are? Whenever I am outside, mosquitoes always seem to like me more than anyone else. But do mosquitoes have a preference for different blood types? It turns out they kind of do. Studies have shown mosquit are especially attracted to people with type O blood. In fact, if you have type O blood, you might be twice as likely to get bitten compared to someone with type A blood. But it's not so much about the taste of the blood. It's more about the chemicals our bodies release, which makes us more detectable to those buzzing bugs. Besides blood type, mosquitoes use other cues to find their next meal, like the carbon dioxide we exhale, body heat, and even certain compounds in our sweat. So while blood type is a factor, it's just one of many things that makes us a mosquito's favorite snack.

00:21:36
Speaker 2: Thank you for the question, Reese.

00:21:39
Speaker 1: Our last question comes from Helia, who is nine years old.

00:21:44
Speaker 2: Hellia asks why do we have a nose?

00:21:50
Speaker 1: Our noses serve a few super important purposes. Smelling first and foremost, noses help us detect odors. Deep inside, there's an area called the olfactory epithelium packed with special cells that recognize different smells. Imagine a world without the smell of fresh baked cookies.

00:22:14
Speaker 2: Thanks nose breathing.

00:22:19
Speaker 1: Our nostrils lead to the respiratory system, letting air flow in and out. As air comes in, our noses warm and moisten it, preparing it for our lungs. Plus, the nose has little hairs called cilia that trap big particles like dust and pollen, keeping our lungs cleaner taste Ever, notice how food tastes different when you have a cold. That's because your nose plays a big part in flavor detection. Our sense of smell and taste are closely linked voice resonance. Your nose, along with your mouth and throat, acts as a resonating chamber, affecting the quality of your voice.

00:23:14
Speaker 2: That's right.

00:23:15
Speaker 1: Your nose helps give your voice its unique sound, So our noses are pretty important. They help us smell the world, breathe, taste our food, and even shape our voices. Thanks for the question, Helliah.

00:23:43
Speaker 2: Fun facts.

00:23:45
Speaker 1: Did you know that the biggest pumpkin ever recorded weighed over two thousand, five hundred pounds. That would make a lot of pumpkin pies or a gigantic Jack O'Lantern. Did you know that ghosts like to play sports too. Their favorite is booling. Did you know that the belief in ghosts dates back thousands of years. Ancient Egyptians believed in life after death and often depicted ghost like figures in their art and hieroglyphics. Did you know that Halloween has its origins in the ancient Celtic festival of Soloen, where people would light bonfires and wear costumes to ward off ghosts. Ever, wonder what a way which's favorite gadget is? It's her spellchecker. Did you know that in the past, it was believed that if you wore your clothes inside out and walked backward on Halloween, you would see a witch at midnight. In this episode, we learned a little bit about why you might think you saw a ghost. We noticed that a lot of different cultures have stories about ghosts or spirits even though they are not located close by. We looked at ghosts from a scientific approach and found out sometimes it is a trick played on us by our eyes and our brains, like an optical illusion. We also talked about how you could design an experiment to find out what is going on if a friend or someone tells you they have seen a ghost. We also talked about rainbows, mosquitoes, and noses. We learned that mosquitoes are attracted more to type old blood, as well as carbon dioxide and sweat. This episode was made with questions from Boston, Violet, Madeline Menzies, Greta, Ivy Reese and Hellia. Thank you to Samantha age seven from San Francisco, Sirscha Fou aged six, Wesley Rogers Henry age six from Middleton, Wisconsin, Carter age four and a half, Benjamin Pinner and Newton Pinner from Norwich, United Kingdom, Theo age six, Raife from Islington, England. Millie aged nine from Pennsylvania, Frank Snooker, Eli age five from Winnipeg, Alessandro age five, Henry age seven from North Carolina, and Elizabeth, age eight in Cape Town, South Africa. We love getting your feedback on our show. If you have any feedback, please send it our way, and if you want to make sure to get all the episodes, please ask your parents to subscribe. You can find us on Apple Podcasts or wherever your parents listen to podcasts. And please, if you love learning about science with us, leave us a review. It may help others find our show. If you'd like to send us your questions, please send them to Hello at sleeptightscience dot com.

00:27:38
Speaker 2: Thank you, sleep Tight