White matter cells create connections between neurons (grey matter). Yaling Yang's research has found that pathelogical liars have less grey matter in their brains compared to normal people.
Miraculin is a protein that makes us perceive sour foods as sweet!
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Miraculin is a protein that makes us perceive sour foods as sweet!
Thanks for watching. Follow for more videos.
#cosmosspacesciene
#throughthewormhole
#season6
#episode6
#cosmology
#astronomy
#spacetime
#spacescience
#space
#nasa
#morganfreeman
#lie
#spacedocumentary
Category
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LearningTranscript
00:00Did you do this?
00:01I didn't do that.
00:02I realized it's $400 more.
00:03Dude, it wasn't me.
00:04Come on.
00:05Do you ever tell a lie?
00:07Even a little one?
00:15Is technology making it easier for us to lie?
00:19Or maybe nothing ever changes,
00:21and dishonesty is just a timeless part of human nature.
00:25Leon.
00:26Oh, what are you doing?
00:27Could society function in a world without lying or secrets?
00:32No, I do not have another girlfriend.
00:36Well, you're a liar.
00:41Dishonesty might be so widespread
00:44because we're so easily fooled,
00:48and our memories are fallible.
00:52Can we ever see the true nature of reality?
00:57Or is truth just a lie?
01:05Space.
01:06Time.
01:08Life itself.
01:12The secrets of the cosmos lie through the wormhole.
01:16I'm going to let you in on a little secret.
01:35I have never told a lie.
01:37Not once in my long career has an untruth crossed my lips.
01:46Honest.
01:48We all agree that lying is shameful.
01:54Yet we still deliberately deceive each other all the time.
01:58Perhaps we lie because we just can't help it.
02:07When did you tell your first lie?
02:09Perhaps it was soon after you were first lied too.
02:13I told my son if he didn't eat his broccoli,
02:16he would be under four feet the rest of his life.
02:19I told my son his blanket would protect him from monsters in the closet.
02:23I told my daughter if she didn't keep her room clean,
02:26she would never find a man that would want to marry her.
02:29Kang Lee is a developmental psychologist at the University of Toronto.
02:36As a father, he understands why we lie to our kids.
02:41Sometimes you have exhausted all the other bare methods
02:46and the lying sometimes becomes the only way you can deal with the situation on hand.
02:51In fact, Kang is as guilty as the rest of us.
02:55I used to drive my son Nathan to his school every morning.
03:00And sometimes in the back seat and he would be acting up and screaming, yelling.
03:05And I pointed to the hazard light and I said,
03:08that actually is a jack button.
03:11If I push that button, your car seat is going to blow off
03:16and going through the roof and you're going to fly out of the car.
03:20And immediately he became very quiet.
03:23Would children remain honest and pure if we grown-ups didn't corrupt them with our lies?
03:32Kang believes something deeper is going on.
03:35He and his colleagues have run an experiment with thousands of kids of various ages.
03:40What do you think it is?
03:47A dog.
03:48A dog. Come around. Yes, it is a dog.
03:51It starts as a game.
03:54Guess the animal from just the sound it makes.
03:57Kids are promised a prize if they can guess the third animal correctly.
04:08Then the grown-ups leave the room.
04:10I'm not going to play the sound of the gun.
04:12All right, so I'll be right back, okay?
04:13All right, so I'll be right back, okay?
04:14You can guess how well that worked.
04:30Hidden cameras revealed that for many children the temptation was too great.
04:35Sorry. You can turn around now.
04:40When I was gone, did you turn around to people see what it is?
04:43No? Okay.
04:45Now, what do you think it is?
04:47It's a cow?
04:49If they later identified the animal without ever hearing it,
04:52the experimenters knew those children lied.
04:55That's basically the procedure we have been using with kids in the U.S., in Canada, in China, in Africa.
05:06And it works very, very well with kids all over the world.
05:11Researchers used to believe that children start lying around age five,
05:16after more exposure to the adult world.
05:19But Kang has shown that lying starts much earlier.
05:23What do you think it is?
05:25A cow.
05:26Okay, how do you know it's a cow?
05:29Kids actually start to tell lies at two years of age.
05:33So that is very surprising.
05:35At two years of age, about 30% of kids would tell lies.
05:40And at three years of age, about 50% of the kids would tell a lie.
05:45By seven and eight years of age, 100% of the kids would lie.
05:50Did you turn around to peek?
05:52No.
05:53Kang's revelation is enough to send worried parents into a tizzy.
05:57Except, there is a bright side to early lying.
06:01Those kids who lie earlier than the other kids are actually those kids who have better cognitive development abilities.
06:09So they seem to be more advanced than those kids who are telling the truth, which is totally surprising to us.
06:18A good lie requires forethought and self-control.
06:21You have to be able to plan ahead what you are going to say and how you are going to say it.
06:28In other words, the onset of lying is an important stage in brain development.
06:33But why do we start lying as soon as our brains are able to?
06:40Wouldn't we be better off always telling the truth?
06:43Some of them are actually very good, pro-social lies.
06:48The reason we tell white lies is because we do not want to hurt other people's feelings.
06:54Imagine I'm playing cards with my friends.
06:58At the same time, I really want to watch my favorite TV show.
07:02What do I do?
07:03One way I can do it is do it bluntly.
07:06My favorite TV show just came on and so I have to go.
07:10Thank you guys. Bye-bye.
07:13Nobody is going to like you.
07:15Or you can do it differently.
07:18You basically tell a white lie by saying,
07:21Oh, I don't feel very good. I have to lie down.
07:24Sorry guys, I suddenly don't feel very well.
07:26I probably have to go and lie down.
07:28So you really have to be able to know when is the time to tell the truth.
07:33And when it's not good time to tell the truth.
07:39A little white lie doesn't hurt anyone.
07:43But some people can't stop twisting the truth.
07:47No matter how damaging the consequences to others or themselves.
07:53For them, dishonesty is a disease.
07:58What separates these pathological liars from the rest of us?
08:04Charles Ponzi began lying to his investment clients in the early 1900s.
08:10And he couldn't stop even after he'd been to prison three times for fraud.
08:1518th century journalist Daniel Defoe invented as many facts as he reported.
08:23And did time for slander.
08:25What drives some liars to reach pathological levels of deceit?
08:28That's what Yaling Yang, a psychologist at Children's Hospital Los Angeles wants to find out.
08:36We start to spot inconsistency between their statement.
08:41Even when they know that we have other data, including official criminal record, they still lie.
08:50Yaling and her colleagues wondered if there might be physical differences between the brains of pathological liars and the brains of average people.
08:58The brain stores our memories and knowledge in gray matter cells.
09:02But another type of neuron, the white matter cell, creates connections between all that information.
09:12Whenever we tell a story, whether it's true or not, we have to gather details from gray matter cells in different parts of the brain.
09:20It's like gleaning information from a series of books.
09:27The books are the gray matter, filled with the knowledge that you need to fit together into a compelling narrative.
09:34The aisles that lead from book to book are the white matter.
09:39Imagine going to a bookstore to get 10 different books that are scattered across different areas of the bookstore.
09:48Having multiple pathways that lead you to the books will help you get to the books more easily and quickly.
09:57The human brain works in a very similar fashion.
10:01When you have more connections between various parts of the brain, that will make it easier for you to retrieve important information.
10:09For example, let's say a friend asks Yaling what she had for dinner yesterday.
10:14To tell the truth, she only has to gather a few pieces of information.
10:21She ate spaghetti and a salad at home.
10:24But lying is harder.
10:26Yaling would have to ignore the truth and cook up a story about a five-star restaurant and a six-course meal.
10:34A special occasion and expensive champagne.
10:36If she hesitates at any point, her lie will be discovered.
10:42She needs good pathways so she can race from topic to topic grabbing the information she needs.
10:48Since lying requires a lot more information gathering than telling the truth, Yaling and her colleagues conjectured that the brains of pathological liars might have more white matter pathways.
11:07Brain scans proved them right.
11:09Liars had about 25% increase in white matter compared to healthy individuals.
11:22So having more white matter allows all this information to be retrieved and be used in a much faster way.
11:31Yaling also found that pathological liars have 14% less gray matter than average people.
11:40Gray matter stores our memories, but it also has another function.
11:46It controls our reckless impulses.
11:50Gray matter plays a very important role in impulse control.
11:54So this kind of reduction in weight matter is likely to contribute to the lack of impulse control in pathological liar.
12:05Pathological liars can easily ruin their own lives as well as others.
12:11Perhaps, now that we know more about what makes them lie, we can develop therapies to help them stop.
12:16Without that information, it would be very difficult to develop any kind of intervention or treatment for this very damaging behavior.
12:29But isn't technology making it easier for us to deceive one another?
12:34Is there a way to tell what's true and what's not online?
12:38This information scientist has developed a way to find out.
12:48Our modern devices appear to make lying easier than ever.
12:53After all, no one can see us behind a screen.
12:58Today's technology has ushered in a new breed of lie.
13:02It's called digital deception.
13:07Is the information age really the disinformation age?
13:16Information scientist Jeff Hancock at Cornell University is examining the differences between high-tech lies and the old standbys.
13:26If I wanted to call in sick in the old days, I'd need to psych myself up and get my sick voice on.
13:34Yeah, hi. I'm really sorry. I'm too sick to come in today. Yeah.
13:43Nowadays, we can type a message about feeling sick, no voice, no vocal cues, no nonverbal cues.
13:52Hit send, and my lie's done.
13:57Some digital deceptions have become so common that Jeff and his team gave them names.
14:03One of the things we saw in text messages all the time was a lie we call the butler lie.
14:11We used to have people that would act as that buffer, and they would provide that physical buffer between you and the world trying to get in and talk to you.
14:22Now, we all have digital butlers.
14:28People say, well, I'm on my way, when in fact they're not, where my battery was dead.
14:32Because what we realized is they're providing a buffer between that person and the fact that the world can contact them pretty much 24-7.
14:40Even though it makes us easier to reach, the online world also offers unprecedented anonymity.
14:48A new identity is just a few keystrokes away.
14:52This leads to a digital deception known as the sock puppet lie.
14:56Sock puppet is identity deception, where you have an alter ego that can say things on your behalf without appearing like you.
15:07You're not Jeff Hancock, are you?
15:09No. No. No.
15:10Perfect. Because I've got this new book coming out, and I really need a positive review. Could you help me out?
15:14Yeah. Great. Thanks.
15:17It's no wonder we have a hard time deciding what to believe of all that we read online.
15:23Is it possible to sort truth from a lie?
15:26That's what Jeff decided to find out.
15:28He started by looking at something we've all wondered about.
15:33Those consumer reviews we see when we shop online.
15:37Who writes those?
15:39And can we trust them?
15:41The stakes are huge.
15:44Together, we spend trillions of dollars worldwide on online sales every year.
15:52Jeff examined the hotel reviews we used to plan our vacations.
15:56Should we really be relying on the opinions of strangers?
16:01We had people write fake reviews for us, and we paid for them.
16:05We knew they were fake.
16:06We compared them to ones that were real.
16:08So we took them from the verified sites, and we looked at linguistic patterns and how they differed.
16:13If he'd actually been there, Jeff would write about the hotel in a certain way.
16:18He would know about every detail of the room.
16:21A real reviewer will have a sense of what the beds are like, and the bathroom, is it clean? Is the shower small or not? That sort of thing.
16:29Since they've experienced the space, their bodies moved through it.
16:32But if Jeff had never been to the hotel, he wouldn't know if there was mold in the shower or if the internet service was slow.
16:42So he'd have to write about something else. Something made up.
16:46Now me writing a fake review here in my home with my computer is completely different.
16:53When a fake reviewer has to write about something, they're going into storytelling.
16:57We were on business.
16:59So they'll tell stories about who they were with, what they were supposed to be doing.
17:03They're trying to convince people.
17:04Jeff and his team compared the fake reviews they had paid for with the verified truthful ones.
17:11Then they developed a truth or lie algorithm that zeroes in on tell-tale words and phrases.
17:19See here that ones that are true are things like rooms were large and they were more expensive.
17:26Whereas over on the deceptive one, we can see people talking about themselves, I had a reservation, a lot of instances of I.
17:34Jeff has developed keyword algorithms for other products and services and discovered some surprising results.
17:42People tend to think most reviews are fake.
17:45And our estimation is that it's much lower than that. Like maybe five to ten percent are fake.
17:50So online reviews are pretty reliable.
17:52What about digital communications in general?
17:57Do we use our gadgets to lie more or less than in old-fashioned face-to-face talks?
18:03Things like email, there's actually a lot less lying than people expect.
18:08The main reason, I think, is that there's a record.
18:10We evolved to talk and have it disappear.
18:15And now we're in a radically new era.
18:18If I write you an email, not only have I created a record for myself,
18:21I've given you a record.
18:24That record can be copied, it can be searched, it can be shared.
18:27And so telling a lie in a digital format comes with substantial risks that we've never, as a set of communicators, ever had to worry about before.
18:38Jeff found a little more lying in texting, which we use for more informal communication than email.
18:44And as soon as the written words disappear, more lies reappear.
18:51What we find is that it's the phone where people lie a lot.
18:55That's every study, it's always on the phone where you see the most lies.
18:58According to Jeff, we lie the most when we ditch our gadgets altogether and talk to each other face-to-face.
19:07Why?
19:09Perhaps because we are really bad at spotting lies.
19:12But a new device may help us catch a liar every time.
19:20Think you can spot a liar?
19:23Or you may look for certain tells.
19:26Facial expression, unusual tone of voice, awkward body language.
19:32But let's not kid ourselves, folks.
19:34It can be hard to tell if someone is lying.
19:39Could technology restore truth to the expression,
19:43the eyes are the window to the soul?
19:51This University of Utah student is looking to swipe some money from a campus office.
19:57And he just found his chance.
19:59He's not worried about throwing away his future for a measly 20 bucks.
20:05Because it's all part of a mission impossible experiment dreamed up by psychophysiologist John Kircher.
20:14John has spent the last 30 years studying lies.
20:19And this experiment is designed to test a device that may one day make lying impossible.
20:25Today, there are two test subjects.
20:30John doesn't know if one, both, or neither of them will steal any money.
20:36The subjects receive secret agent style instructions.
20:40A mysterious envelope and directions from a computerized voice.
20:45You are an innocent participant in this experiment.
20:49Please wait outside the building for 20 minutes before returning to the lab.
20:53The other student receives a diabolical assignment.
20:59You must steal $20 from the purse.
21:03You must have an alibi prepared.
21:06You will not receive full credit if you are caught.
21:08They get instructions to go to a different building, to go to a secretary's office, and ask her where Dr. Mitchell's office is.
21:20And she'll reply that there is no Dr. Mitchell or that they should check with the dean's office.
21:25The secretary is in on the caper.
21:30She's been instructed to leave her office unattended for a few minutes after the student asks for Dr. Mitchell.
21:37We try to set this up like a mission impossible scenario to get the subject engaged and apprehensive about what they're doing.
21:47Those effects reproduce the kinds of things that we see in field situations with actual criminal suspects.
21:54You can seat right over here.
21:58Now for the moment of truth or lies.
22:02The ocular deception test begins.
22:05The subjects answer identical true or false questions about general topics and about the crime.
22:11Below the screen is John's device, an infrared eye tracker able to spot microscopic dilations and contractions of the pupils.
22:24The changes that we're seeing in the size of the pupil are very tiny.
22:30They're less than a tenth of a millimeter.
22:33But with the computer, we can get a clearer indication that the pupil is dilating when a person is deceptive.
22:39The subject looks like they didn't have a difficult time answering these questions and the pupil data look like we would expect from a truthful individual.
22:55Did the thieves' pupils dilate when answering the same questions?
23:00They're showing the stronger reactions to the questions about the $20.
23:10So I'd say there's a good chance the subjects in a guilty group.
23:19Sure enough, John is right.
23:22The female subject was innocent and the male subject had to give back the 20 bucks.
23:26But how did pupil dilation help John catch the thief?
23:33John knows that when our brains go into overdrive with mental effort, our pupils dilate involuntarily.
23:41And since deception is more complicated than telling the truth, the male student's brain had to work harder.
23:47He couldn't hide his lying eyes.
23:52John's ocular deception device is already 85% accurate.
23:57That's as good as the best polygraph results.
24:01But while people can be trained to beat polygraph tests, pupil dilation is involuntary.
24:07And as technology improves, the accuracy of John's lie detector will too.
24:14With better eye-tracking technology, we'll get better measures of pupil change.
24:22That means the accuracy of John's device could one day reach 100%.
24:27Imagine a future where a person with a cell phone or smart eyewear could use a miniaturized version of John's device on anyone they're talking to.
24:38Husband and wife.
24:40Parent and child.
24:42Worker and boss.
24:44Would the whole truth and nothing but the truth bring us closer together?
24:47Or tear us apart?
24:51According to this cognitive scientist, knowing the real truth about the world around us would simply blow our minds.
24:59What we think of as reality is just a series of illusions.
25:04Why are our brains and senses so easily fooled?
25:08Wow.
25:12We rely on our senses to make sense of our world.
25:15That's why it's so unsettling when they fail us.
25:19We can't trust our ability to see the truth.
25:22And even if we could...
25:25Could we handle it?
25:28Hello?
25:30Hello?
25:33Hello?
25:35I'm Don Hoffman.
25:37As far as I can tell.
25:40UC Irvine cognitive scientist Don Hoffman
25:43thinks that anyone who believes our senses are designed to show us the truth has got it all wrong.
25:50He enjoys proving his point by finding new ways to fool the senses.
25:55I'm about to eat this very tart lemon, which normally doesn't sound like a good idea.
26:01But before I do, I'm going to first eat this miracle berry from West Africa.
26:06It releases something called miraculin, a chemical that binds to the sweet receptors on my tongue.
26:16And what it's supposed to do is when the acid from the lemon binds to the miraculin, it triggers my sweet receptors to give me an illusion of a sweet taste.
26:24Let's see if it really works.
26:27So I'll take the berry out and we'll cut this lemon.
26:34And the moment of truth.
26:39Wow.
26:41That does taste sweet.
26:43I've never tasted a lemon like that before.
26:44That is really good.
26:45Don has identified plenty of ways our senses and brains misconstrue the world around us.
26:55Surely, we think, our sense of touch could never be wrong.
27:01With touch, we feel like we're in direct contact with reality as it really is.
27:07Well, if you tap the shoulder and then tap the elbow and then tap the wrist and you do the timing just right,
27:13what a person will feel is a tap in between.
27:15So you'll feel a tap here, a tap here, a tap there, a tap there.
27:19And it'll feel like there's some animal running down your arm.
27:23The brain is saying, what is the best story about the world that I can come up with?
27:27And the best story that it comes up with is, well, there's probably something crawling down my arm.
27:32With such limited senses, the unfiltered truth of the world never reaches our brains.
27:37So we're forced to use stories or preconceived rules about how reality should be.
27:44But once you're constructing reality based on rules, if something doesn't match your assumptions,
27:51we construct things that aren't really there.
27:54Each of our eyes can only take in a 2D image.
27:58It's our brains that create a 3D view of the world.
28:01There's gradients and shading, so as you go from light to dark and dark to light,
28:07the visual system automatically interprets that in terms of three-dimensional shapes.
28:12As you see things like railroad tracks converging in the distance,
28:15you'll actually give a depth interpretation to that.
28:20Don's radical conclusion is that our senses aren't intended to see the truth of reality.
28:25Our senses do just enough to help us find mates, find food, and avoid becoming someone else's food.
28:34It's the perceptual systems that allow you to stay alive long enough to reproduce.
28:40Those are the ones whose genes get passed on to the next generation.
28:44So in that sense, it's quite clear.
28:46Perception and evolution of perception is about having kids, not about the truth.
28:50Every creature on Earth develops only the senses it needs to survive and reproduce.
28:58This region used to be a much bigger wetland with millions of frogs.
29:03This is how researchers believe the world looks through a frog.
29:07If things aren't moving, the frog pretty much either doesn't see them or is programmed to ignore them.
29:13Luckily for the frog, it's great at detecting small objects flying around close enough to its tongue to become a frog.
29:20a tasty meal.
29:22We can see stationary objects that a frog can't.
29:26But we don't see all the colors that a butterfly does.
29:31And we can't hear every frequency of sound that a bat can.
29:37Which begs the question, what is the world really like?
29:43What are we not seeing?
29:45Imagine a color you've never experienced before.
29:51Nothing happens.
29:52And if we can't even do that, just one new color you've never experienced before,
29:56we're really in the dark about what the full complexity of objective reality might be.
30:01So our senses are this wonderful window on the world, but they're also a prison that we really can't see outside of.
30:12We can't necessarily trust our senses.
30:17But even if we only grasp a simplified version of reality, surely our memories can keep track of where and when things happened.
30:30Or that's what we thought.
30:33New research suggests that our brains trick us into misremembering the truth.
30:45We can't possibly remember every single thing that happens to us.
30:56But we trust the memories we do retain.
30:59We remember every detail about the birth of a child.
31:03We know where we had a special meal and whom we were with.
31:06But what if some of those memories aren't real?
31:12What if we invented them?
31:15Or someone else implanted them?
31:23This is Susumu Tonagawa's favorite spot to enjoy a cup of coffee.
31:28And sitting here also reminds the MIT scientist of the time two cars slammed into each other just a few feet away.
31:41He mentions the accident to his friend.
31:44But his friend remembers it differently.
31:47I had an argument with my friend that he said,
31:51no, no, no, actually the car accident happened in front of our lab.
31:54Susumu thought, no, that can't be right.
32:04But I insisted an accident happen in front of a coffee shop.
32:09And then he realized his mistake.
32:13I was thinking of the conversation I was having with my friend drinking coffee
32:19when an accident actually happened in front of our lab.
32:22He and his friend were in front of the lab when the cars collided.
32:27But his mind was on one of their previous conversations at the coffee shop.
32:32Susumu's brain mistakenly combined the two locations and created a new memory that is actually false.
32:41As a Nobel laureate and a scientist who's devoted three decades to understanding memory,
32:47Susumu wanted to know how this could happen.
32:50He and his team decided to look for physical evidence of false memories being formed.
32:56In the brain, that area called the hippocampus plays a very crucial role in this type of memory.
33:08If you have impairment in the hippocampus, then you cannot form memory of episode very well.
33:16Susumu's research centers on the physical changes in the hippocampus when an episodic memory forms.
33:26When we experience something, like witnessing a car accident, it biochemically changes the small group of neurons in the hippocampus.
33:36Neuroscientists call that changed group an engram.
33:40It is a physical trace of the stored memory.
33:43That stored memory is sometimes triggered when we see something that's new but similar.
33:52A lone majestic pine tree may remind us of our first glimpse of the Eiffel Tower during a vacation years ago.
34:00Susumu found that when old memories are activated by new experiences, both can become confused.
34:07Sometimes the neurons in the old memory engram become physically linked to the recently formed engram.
34:15The result is a false memory that mistakenly combines two events.
34:22That got Susumu and his colleagues wondering, is it possible to intentionally create false memories?
34:29They devise an experiment with a mouse and two chambers.
34:36After the mouse has explored chamber A for several minutes, the mouse forms chamber A memory in the brain.
34:46Then we transfer that mouse to chamber B.
34:50The mouse forms separate memories for each location.
34:53For example, chamber B has a wire floor and chamber A does not.
34:58Susumu then sets about locating each memory in the mouse's brain.
35:06The mouse has a series of tiny wires monitoring activity in its brain.
35:11When he places the mouse in chamber A, Susumu can pinpoint the location of the chamber A memory.
35:17But the wires can also stimulate neurons to respond by emitting small pulses of light.
35:25So whenever Susumu shines a light on those same neurons, he can activate the mouse's memory of being in chamber A.
35:32Once the mouse has formed the memory of chamber A, it's placed in the wire floor at chamber B.
35:39Susumu is ready to create the false memory.
35:42In this second chamber, we give very light electric shock to the footpaths.
35:49And then at the same time, we activate the chamber A memory.
35:55The shock is harmless, but startling.
35:58Since the chamber A memory is activated while the mouse receives the shock in chamber B,
36:05it creates an association between chamber A and the shock.
36:09And sure enough, when Susumu places the mouse back in chamber A, it suddenly freezes in fear.
36:17Even with no wire floor, the mouse acts like it might get a shock.
36:21It now possesses a false memory of being shocked in the chamber where no shock ever happened.
36:28Susumu and his colleagues have successfully inserted false memories into mice.
36:34Does this mean the same thing could be done to people?
36:36What is science fiction today may not be science fiction in 50 years.
36:43Human brain is much bigger than mouse brain.
36:47But theoretically, it's possible.
36:51So if we can't trust our memories, our senses, or each other,
36:55is there any such thing as an ultimate truth?
37:00This physicist is looking for answers in the quantum world.
37:04He's finding that the notion of truth keeps getting curiouser and curiouser.
37:13Truth is hard to find in the human world.
37:16Our brains are wired for lying.
37:20We remember events that never happened.
37:23And our senses don't perceive the reality of the world around us.
37:30But surely, if we use the tools of science to examine the fundamental nature of reality,
37:37we can't see the ultimate truth.
37:43Unless the universe itself lies to us.
37:48I'm Jeff Tollexson, and that's the truth.
37:52Jeff Tollexson, a physicist at Chapman University in Southern California, has taken many trips into the quantum world.
38:03There are a million, million, billion atoms in each individual grain of sand.
38:09But when we're talking about the quantum world, we mean even smaller pieces of matter that make up the atoms.
38:13The protons, the neutrons, and the electrons that make up everything in the entire universe, including us.
38:21Jeff knows that the basic building blocks of existence don't follow basic rules.
38:29Take, for instance, the electron.
38:32The laws of the quantum world suggest that things can be at many different places at the same time.
38:38They also forbid us from knowing everything about the electron.
38:41It's a bit like looking at a hummingbird.
38:46Its wings are moving so fast that they appear as just a blur.
38:50But if I take a photo of the hummingbird, I can learn one of two things.
38:54If I set it to a high shutter speed,
38:59I can clearly see the location of the wings, but I can't tell anything about the velocity.
39:04So now I'll set it to a low shutter speed.
39:06And now it's just a blur. I can't tell anything about the location of the wings, but I can clearly see that they have a velocity.
39:16Similarly, we can never know the true position and velocity of an electron.
39:20So the notion of truth at the quantum level is very different from our usual human understanding of truth.
39:29But as strange as these particles are, we still know they are bits of matter.
39:34And they have certain defining properties such as spin direction and electrical charge.
39:42Matter and its properties go together like rock and hard.
39:48You can't have one without the other.
39:51Or can you?
39:52The more Jeff and his colleagues studied the building blocks of the universe, the curiouser and curiouser it all becomes.
40:02If you've ever read Lewis Carroll's Alice in Wonderland, you know that there's a Cheshire cat.
40:07Now, the Cheshire cat has a grin, and it's a remarkable grin.
40:13So you can't have the Cheshire cat without the grin.
40:16The grin belongs to the cat.
40:18But one day, Alice is having a conversation with the cat, and suddenly the body disappears, leaving just the grin.
40:25To which Alice said, well, I've often seen a cat without a grin, but a grin without a cat, it's the most curious thing I've ever seen.
40:32Now, it seems physically impossible, even in your wildest dreams, that such a thing could happen.
40:39But what's remarkable is we predicted how you could do this, namely separate properties from matter.
40:47In July 2014, Jeff and colleagues at the Vienna Institute of Technology put that prediction to the test.
40:56Could they actually create a quantum Cheshire cat?
41:00They split a stream of neutrons into two beams.
41:05Then they used magnetic fields to give the neutrons in each beam opposite spin direction.
41:11Using other magnetic fields and filters, they manipulated the system until something very curious happened.
41:19The mass of the neutrons went entirely through the upper beam, while the neutrons' spin properties traveled exclusively through the lower beam.
41:27Like a cat and its grin, matter and its properties were separated.
41:34If it's possible to separate an object from the properties that we use to describe it,
41:41is truth itself just another property that can be stripped away?
41:47Are we closer to finding the truth about the universe, or closer to dismissing it as nothing more than a phantom?
41:55Every time we peel back a little bit more of that veil, we discover incredibly beautiful and awe-inspiring new truths.
42:06Whether or not scientists will ever be able to discover absolute truth, deep nature of everything, we don't know.
42:14We don't know.
42:15But it's in the spirit of science to keep trying.
42:20Will we continue to peel back layer after layer of new truths forever?
42:26Could we even comprehend the truth with our limited senses and our faulty selective memories?
42:33There's only one thing we can be sure of.
42:36Anyone who claims to know the ultimate truth is probably just telling you another lie.
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