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  • Hey, Vsauce. Michael here. This is a completely still

  • image but as your eye reads well I'm saying and jumps from word to word,

  • the paragraph will appear to slightly, just

  • subtly, wave and boil. The allusion is called anomalous

  • motion. It's neat. But to say it's fun

  • is tautology because the word

  • illusion literally means to have fun,

  • to mock, to play with. But illusions aren't

  • just fun and games. They also teach us

  • about our brains. Anomalous motion,

  • for instance, demonstrates that our brains process

  • things at different rates and piece by piece.

  • After a saccade, a quick eye movement, higher contrast

  • elements are perceived sooner than lower contrast

  • ones. When arranged in just the right way, this delay is exploited

  • and your visual system only has one explanation.

  • Low contrast parts of the image didn't get processed later

  • because this myelinated machine is wrong but rather because the image

  • itself

  • must be moving. Akiyoshi Kitaoka's brilliant

  • "Out of focus" causes nearby neurones to disagree about the little slices they

  • each detect. Some see big changes

  • after a saccade and some see hardly any. This makes it difficult for our brains

  • to calculate and factor in the effect

  • of our own eye movements, so the image itself

  • appears to be moving. But illusions aren't just about

  • moving. They can also be

  • moving, poignant, significant,

  • practical. They can mean the difference between life and death,

  • like in nature or during World War I

  • as dazzle paint on ships. This form of camouflage doesn't conceal the object

  • but rather

  • makes it difficult for an enemy to ascertain its prey's

  • true shape and thus where it's heading

  • or how fast it's going. In 1955

  • the Soviet Union displayed their new Bison and Bear long-range bombers

  • at an air show. It looked like they had

  • a lot. Afraid of falling behind, the US ramped up production on their own

  • B-52 bomber. But the whole thing

  • was an illusion. In the Soviet's film of the air show

  • the same few planes had been flown past the camera multiple times

  • in formations that gave the illusion of them having more bombers

  • than they really did. By the end of the 1950s the Soviet Union

  • only had about 150 long-range bombers,

  • whereas the Americans, fooled

  • by the illusion, had built nearly 2,000

  • at a cost of 900 million dollars.

  • Architecture is full of examples of real-world practical

  • optical illusions. My favorite are Disney castles.

  • They appear huge but it's

  • forced perspective - a lie. The tops

  • appear further away from us because they are actually

  • quite tiny.

  • Illusions also tell us about ourselves culturally.

  • Theller-Lyer illusion is classic.

  • The horizontal lines are all the same length but the bottom ones

  • appear longer to people from Western cultures,

  • familiar with our rules of perspective and man-made straight lines.

  • However, bushmen from Southern Africa and tribespeople

  • from northern Angola or the Ivory Coast aren't

  • fooled at all. Akiyoshi Kitaoka

  • is using optical illusions to discover glaucoma

  • earlier than current techniques can. And

  • anamorphic illusions are used to save lives.

  • They look weird from any perspective but one, from which they seem to pop out

  • defying the environment's actual shape.

  • Hoping to remind drivers to always pay attention

  • traffic safety organizations in West Vancouver, Canada placed a skewed

  • decal on the road. From the right perspective,

  • the perspective of the driver in this case, it becomes a 3D illusion of a child

  • you are about to hit.

  • Slow down. Brusspub has made some incredible examples of the 3D effect

  • such illusions can happen.

  • This object? Just an anamorphic projection.

  • Anamorphic illusions have also been used to safely practice

  • political dissent.

  • In 1746

  • supporters of the Stuart claim to the British throne

  • had to be quiet about it. It was treasonous.

  • So, sympathizers served things on

  • trays that looked like this.

  • Innocuous enough until only supporters

  • were around. And it was safe for someone to place a reflective

  • goblet or cylinder on the tray, revealing the tray's anamorphic secret a

  • hidden portrait

  • of their elicit love, Charles Edward Stuart himself.

  • The Encyclopedia Titanica lists descriptions

  • of everybody recovered from the Titanic.

  • It's quite macabre. Why was the iceberg

  • not seen until it was too late?

  • And why did the nearest ship - the Californian -

  • not come to the Titanic's rescue sooner?

  • Tragic questions whose answers might be

  • optical

  • illusions. The Titanic was sailing through conditions

  • perfect for mirages.

  • This theory points out that the Titanic sank

  • at the border of the warmer Gulf Stream and the frigid Labrador Current,

  • where the normal case of cooler air at higher altitudes

  • was inverted - a thermal inversion.

  • Now, because the temperature of air effects its index of refraction,

  • a thermal inversion means light bending

  • in a typical ways. If light reaches the eye

  • from higher up than usual, objects can appear to float.

  • Seriously. Like this ship off the coast of Australia.

  • A thermal inversion can also render objects completely unrecognizable,

  • hidden within a haze, like this ship(?)

  • Or like an iceberg.

  • Or a sinking ship in need of help.

  • The Delboeuf illusion may be causing

  • teeth to split and crack more often than they should

  • when dentists drill holes in them.

  • Doctor Robert O'Shea observed

  • 8 practicing dentists and found that they were all drilling holes

  • that were too big, even though they knew the correct size

  • to be drilling.

  • Why? Well, it may be the same reason people

  • eat more food when they're given a bigger plate.

  • Objects appear smaller when enclosed by larger areas.

  • Holes of the same size may appear different sizes on bigger

  • teeth. Dentists may be deciding that correctly sized

  • holes drilled in the teeth need to be made larger,

  • not because they do, but because perception

  • is a tricky thing.

  • Illusions affect not only big ships and

  • teeth but also your future.

  • The End of History Illusion is our tendency to think of ourselves today

  • as somehow done.

  • Sure.

  • I went through a lot of personal growth and changes in taste

  • in the past, but today, who I am now,

  • this is pretty much the final me.

  • But that's not true.

  • Studies have consistently shown that people underestimate just how

  • different they will be, say, 10 years in the future,

  • even though they can easily point out how much they've changed

  • since 10 years ago. I like how Daniel Tomasulo puts it:

  • "We believe we are going to live, love,

  • and long for where, who, and what we are thinking about

  • right now. But the research says it just ain't so.

  • This too is a transient state."

  • Yogi Berra put it even more succinctly: "The future

  • ain't what it used to be."

  • Their advice

  • is don't imagine your future.

  • Look at other people and their experiences instead, take their advice.

  • Your imagination is just that, their experiences

  • are actual data. Well, of course,

  • it's not that simple. Which brings us to our final

  • illusion: The illusion of control.

  • Named by psychologist Ellen Langer, it's our tendency to believe we control the

  • outcomes of things.

  • We demonstrably don't.

  • It can help motivate us to not give up

  • and, in healthy people at a healthy level, it is

  • optimistic self-appraisal.

  • But it's a lie.

  • In one study, traders in the City of London's investment banks were shown a

  • graph

  • of a real time stock price and given three

  • buttons that secretly didn't do anything

  • to affect the price. But they were told the buttons might have an effect -

  • try them out, see what you can do.

  • Afterwards, the traders were asked to rate how much they felt they had been

  • able to control the stock price

  • with the useless buttons. And it turns out

  • the traders who reported the greatest sense of control over the stock price

  • were the ones who scored lowest on risk management tests

  • and, in the real world, contributed the least

  • to their company's profits and in terms of salary

  • made the least money.

  • It's kind of a bummer. The illusion of control is a nice feeling

  • but sometimes it's fine, sometimes it even pays handsomely to admit

  • you don't have control.

  • And as always,

  • thanks for watching.

Hey, Vsauce. Michael here. This is a completely still

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ムービングイリュージョン (Moving Illusions)

  • 62 4
    Jason lee に公開 2021 年 01 月 14 日
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