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.
The Müller-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.