Is reality real? These neuroscientists don’t think so | Big Think

Summary

The video script explores the concept of external reality, emphasizing that our senses limit our perception of the world. It discusses how our senses fabricate experiences like color and taste, which aren't objectively real but are real in the sense of personal experience. The script challenges the idea of a single perspective capturing reality, advocating for a transperspectival approach to understanding. It also defends the existence of objective truth and the scientific method's effectiveness, contrasting it with subjective views.

Takeaways

• 🌐 External reality exists, but we perceive it through our senses which may not accurately represent it.
• 👀 Our senses conflate multiple aspects of the world, leading to perceptions that are not direct reflections of reality.
• 🧠 Our perception is a construct of our senses, not properties of objective reality, as colors, odors, and tastes are not objectively real.
• 🔍 We don't see the world as it really is, but rather a version of it that is useful for our survival.
• 💡 The concept of objective reality refers to things that would exist even without perceivers, unlike our sensory experiences.
• 🐍 Our perceptions have evolved to keep us alive, not necessarily to provide an accurate representation of reality.
• 🎨 Colors are a scientific example of how our natural perception is limited and not an accurate reflection of the underlying quantum mechanics of light.
• 🎶 Comparing color perception to sound, we understand that our senses do not always preserve the distinct identities of combined inputs.
• 🌌 Reality is transperspectival, meaning it cannot be fully captured by a single perspective and requires multiple viewpoints.
• 🔬 The scientific method is a systematic approach to understanding reality, starting with observation and hypothesis to test objective truth.
• 📚 Scientific theories can超越 their creators' understanding, as seen with Einstein and the prediction of black holes by his equations.

Q & A

What is meant by 'external reality' in the context of the script?

External reality refers to the world outside of human perception, the physical world that exists independently of whether anyone is observing it. However, the script argues that while it exists, we never perceive it directly or accurately because our senses filter and shape the data.

Why does the speaker suggest that we do not see the world as it is?

The speaker suggests we do not see the world as it is because our senses are limited and conflate various aspects of reality. Our perceptions are not fully accurate representations of the external world, as they are filtered through our biological and sensory systems, which prioritize utility over accuracy.

How do our senses shape our perception of reality according to the script?

Our senses shape our perception by fabricating aspects of reality such as colors, odors, and tastes. These are not properties of the objective world but rather the result of how our sensory systems interpret external stimuli to create experiences that help us navigate the world effectively.

What is the difference between 'real' experiences and 'objective' reality in the script?

Real experiences, like seeing color or feeling pain, exist because we perceive them, but they are not part of objective reality, which would exist even if no one were there to perceive it. Objective reality, as physicists define it, includes things that remain real regardless of observation, such as physical objects and forces.

How does the script describe the limitations of human perception when compared to the actual physical world?

The script describes human perception as limited, using examples like color perception. When we mix red and green light, we see yellow, whereas in sound, we can distinguish separate tones in a chord. This shows that our visual system simplifies and reduces the vast information of the external world.

Why does the speaker argue that it is useful not to see reality as it is?

The speaker argues that it is useful not to see reality as it is because evolution has shaped our senses to prioritize survival, not accuracy. For example, recognizing a snake and avoiding it is more important than understanding its true physical properties. Our perceptions are designed for survival utility, not objective truth.

What is meant by the term 'transperspectival reality' in the script?

Transperspectival reality refers to the idea that reality cannot be fully captured by any single perspective. Each perspective offers only partial information, and to understand reality better, one must integrate multiple perspectives, recognizing that no single view can encompass all the information.

How does the scientific method help in understanding truth according to the script?

The scientific method helps in understanding truth by allowing us to systematically observe, pose questions, create hypotheses, and test them. This approach is a way to investigate reality beyond subjective perception, gradually building knowledge about objective truths.

What is the role of mathematical or physical theories in discovering truths, as mentioned in the script?

Mathematical or physical theories, once formulated, can reveal truths that the originators of the theories may not have anticipated. The example of Einstein's equations predicting black holes, despite his disbelief, shows that the equations themselves can become 'smarter' than the person who wrote them, leading to new discoveries.

Why does the speaker criticize the rejection of objective truth?

The speaker criticizes the rejection of objective truth by highlighting the successes of science. Objective truth, as pursued by science, has led to technological advancements like space exploration, vaccines, and antibiotics. These successes show that objective truth is functional and practical, unlike the claim that everything is subjective or socially constructed.

Outlines

00:00

🔍 Perception and External Reality

The paragraph explores the concept of external reality and our perception of it. It posits that while there is an objective reality, our senses limit our understanding of it. The senses conflate multiple aspects of the world, making it impossible to perceive reality as it truly is. The example of graffiti in a foreign language illustrates how our reactions to stimuli are shaped by our perception. The paragraph further explains that our senses create experiences like taste, odor, and color, which are not properties of objective reality but are real in the sense that they are experienced. It concludes by discussing how our perceptions are not just limited to what is physically present but are also influenced by our subjective experiences and the evolutionary need for survival.

05:00

🌐 The Transperspectival Nature of Reality

This paragraph delves into the idea that reality is transperspectival, meaning it cannot be fully captured by a single perspective. It emphasizes that no single viewpoint can provide all the information about a situation, and thus, multiple perspectives are necessary to understand reality. The paragraph discusses the importance of being able to take multiple perspectives, see the partial truth in them, and then integrate them into a comprehensive understanding. It touches on the scientific method as a way to approach questions about reality and the value of objective truth in science and technology. The paragraph also highlights the importance of theories in science, which can reveal truths that even their creators might not initially recognize, as exemplified by Einstein's initial rejection of black holes predicted by his own equations. Lastly, it suggests that different questions about reality may require different methods of processing and understanding.

Keywords

💡External Reality

External reality refers to the existence of the physical world independent of our perception. In the video, it is discussed that while there is an external reality, we do not perceive it as it truly is, due to our reliance on senses which filter and interpret the world in a way that may not be entirely accurate. This concept is central to understanding the limitations of human perception and the nature of objective existence.

💡Senses

Senses are the faculties by which we perceive the external world, such as sight, hearing, taste, smell, and touch. The video explains that our senses do not provide us with direct access to the physical world but instead confound multiple aspects of it, leading to perceptions that may not be accurate representations of reality. The example of graffiti in the video illustrates how our emotional reaction to what we see is mediated by our senses and understanding of language.

💡Perception

Perception is the process by which the brain organizes and interprets sensory information to create a coherent representation of the world. The video argues that our perceptions are not accurate depictions of the world but are instead constructions made by our senses for survival and practicality. It is highlighted that we do not see the world as it is, but rather through the lens of our perceptions, which can be limited and subjective.

💡Objective Reality

Objective reality is a concept in physics that refers to the existence of things independent of perception or observation. The video discusses that colors, odors, and tastes are not objectively real in the sense that they would exist even without perceivers, but they are real experiences. This distinction is important for understanding the difference between physical existence and sensory experience.

💡Scientific Method

The scientific method is a systematic approach to understanding the natural world through observation, hypothesis, and experimentation. The video emphasizes the importance of the scientific method in seeking objective truth and knowledge. It is presented as a tool for navigating reality and making claims of truth, starting with observation and questioning to develop hypotheses that can be tested.

💡Perspective

Perspective refers to a particular way of regarding something or a particular position from which it is regarded. In the video, the concept of perspective is used to explain that our view of reality is limited and subjective. It is mentioned that reality is transperspectival, meaning it cannot be fully captured from a single viewpoint, and that multiple perspectives are needed to approach a more complete understanding.

💡Transperspective

Transperspective is a term used in the video to describe the capacity to hold and understand the relationships between multiple perspectives. It suggests that no single perspective can capture the entirety of reality, and that a comprehensive understanding requires integrating information from various viewpoints. This concept is crucial for making well-informed decisions and understanding complex systems.

💡Quantum Mechanics

Quantum mechanics is a fundamental theory in physics that describes the behavior of matter and energy at the smallest scales. The video uses quantum mechanics to explain the limitations of human color perception, suggesting that our natural perception does not capture all the information available in the light around us. This example illustrates how scientific understanding can超越 our everyday experiences.

💡Evolution by Natural Selection

Evolution by natural selection is the process by which species evolve over time through the differential survival and reproduction of individuals due to variations in their inherited traits. The video discusses how our perceptions have been shaped by natural selection to ensure survival, rather than to provide an accurate representation of reality. This concept helps explain why our senses prioritize practicality over accuracy.

💡Constructions

In the context of the video, constructions refer to the mental models or interpretations that our minds create based on sensory input. It is argued that physical properties like the shape, mass, and velocity of objects are not directly perceived but are instead constructed by our brain. This concept challenges the idea that our senses provide an unbiased view of the external world.

💡Truth

Truth, in the video, is discussed in the context of objective reality and the pursuit of knowledge through science. It is suggested that while our perceptions may not always align with objective truth, the scientific method allows us to make claims that can be tested and verified. The video defends the existence of objective truth against the notion that all truth is subjective or socially constructed.

Highlights

Existence of external reality is acknowledged, but our perception of it is limited and not entirely accurate.

We do not have direct access to the physical world and rely on our senses which may not be entirely reliable.

Our senses confound multiple aspects of the world, leading to perceptions that may not reflect reality accurately.

The concept that we see more than what is visible is introduced, suggesting a deeper layer to our perception.

The example of graffiti illustrates how our knowledge and language affect our perception and emotional response.

Our senses are not just passive receptors but actively create our experiences of tastes, odors, and colors.

Objective reality is defined in contrast to our sensory experiences, suggesting a distinction between physical existence and perceptual experiences.

The existence of experiences like headaches, which are real but not part of objective reality, is used to illustrate the concept of different types of reality.

The assumption that our senses always tell the truth is challenged, indicating a potential fallibility in our perception.

The idea that space-time and physical properties like shape, mass, and velocity are mental constructions is introduced.

The brain receives meaningless data without context, challenging the notion of inherent meaning in sensory input.

The human perception of color is shown to be limited by quantum mechanics, contrasting with the perception of sound.

The inability to perceive distinct identities in color mixing, unlike in sound, suggests a fundamental difference in sensory processing.

Evolution has shaped our perceptions for survival rather than accuracy, highlighting the practicality of perception over its truthfulness.

The concept of multiple perspectives contributing to a transperspectival understanding of reality is introduced.

The importance of considering multiple perspectives to navigate reality effectively is emphasized.

The scientific method is presented as a way to approach questions and understand the nature of things.

The practical success of science and technology based on objective truth is highlighted, countering the notion of purely subjective truth.

The idea that theories can be smarter than their creators, as illustrated by Einstein's initial disbelief in black holes predicted by his own equations.

The necessity of different ways of processing underlying reality for different questions is discussed, suggesting a complexity in understanding the world.

Transcripts

Is there external reality?

Of course there's an external reality.

The world exists.

It's just that we don't see it as it is.

We can never see it as it is.

In fact it's even useful to not see it as it is.

And the reason is because we have no direct access

to that physical world other than through our senses.

And because our senses conflate multiple aspects

of that world,

we can never know whether our perceptions

are in any way accurate.

It's not so much do we see the world in the way

that it really is,

but do we actually even see it accurately?

And the answer is no, we don't.

However paradoxical it sounds,

if we think of what is visible as just what projects

to the eyes, we see much more than is visible.

Let me give you an example.

I walk into a room and there's graffiti on the wall

and imagine it's graffiti that I find really offensive.

I look at it, I flush, my heart starts to race,

I'm outraged, I'm taken aback.

Of course, if I didn't know the language

in which it was written, I could have had exactly

the same retinal events

and the same events in my early visual system,

without any corresponding reaction.

Much more shows up for us than just what projects

into our nervous system.

Our senses are also making up the tastes,

odors and colors that we experience.

They're not properties of an objective reality.

They're actually properties of our senses

that they're fabricating.

By objective reality I mean,

what most physicists would mean,

and that is that something is objective real

if it would continue to exist,

even if there were no creatures to perceive it.

Colors, odors, tastes and so on are not real

in that sense of objective reality.

They are real in a different sense.

They're real experiences.

Your headache is a real experience,

even though it could not exist without you perceiving it.

So it exists in a different way

than the objective reality that physicists talk about.

We always assume that our senses are telling us the truth.

So it was quite a stunning shock to me when I realized

that it's not just tastes odors and colors,

that are the fabrications of our senses

and are not objectively real.

Space-time itself, and everything within space-time.

Objects, electrons, corks, the sun,

the moon, their shapes, their masses, their velocities,

all of these physical properties are also constructions.

Sometimes it's really difficult for people to understand

that the data that your brain is receiving

is meaningless because when they open their eyes,

they look around, they say, "Well, I see everything.

What do you mean it's meaningless?"

A really simple example is color.

Scientific knowledge of what light is shows us

that our natural perception leaves a lot on the table.

The human perception of color is limited really

by the principles of quantum mechanics.

It's interesting to compare the human perception of color,

to the perception of sound.

When you have two pure tones together,

like a C and a G a simple chord, that's a fifth.

If you hear that, you can hear the separate tones,

even though they're played together and you hear a chord,

you can also sense the separate tones.

Whereas with colors, if you have two different colors,

say spectral green and spectral red and mix them.

What you see is not a chord where you can see the distinct

identities preserved, but rather an intermediate color.

In fact, you'll see something that looks like yellow.

It's as if in music,

when you play to the C and a G together,

instead of hearing a chord,

you just heard the note E the intermediate note.

So at this most basic level,

we don't represent even the information we're getting

in any accurate way.

And the reason is because it was useful to see it this way.

So what are you seeing the utility of the data

not the data.

Evolution by natural selection has shaped us

with perceptions that are designed to keep us alive.

So if I see a snake, don't pick it up.

If I see a cliff, don't jump off.

If I see a train don't step in front of it,

we have to take our perceptions seriously,

but that does not entitle us to take them literally.

Perception itself.

A perspective on something defined by perception

is inherently a reduction of the information of the thing.

My perspective of it is gonna be

a lot less total information than the actual thing is.

I can look at the object from the east side

or the west side or the top or the north side

or the inside, microscopically, telescopically,

they'll all give me different information.

None will give me the entirety of the information

about the situation.

So there is no all encompassing perspective

that gives me all of the information

about almost any situation.

What this means is that reality itself

is transperspectival.

It can't be captured in any perspective.

So multiple perspectives have to be taken.

All of which will have some part of the reality,

some signal.

There may also be distortion.

I may be looking at the thing through a fish eye lens

or through a colored lens that creates some distortion.

Why does this matter?

The ability to take multiple perspectives,

to see the partial truth in them,

and then to be able to seam them together into something

that isn't a perspective it's a transperspective capacity

to hold the relationships between many perspectives

in a way that can inform our choice-making

is fundamental to navigating reality well.

How is it that we make claims of truth?

And how would we begin to know if what we think

is true is actually true.

This is the beginning of the scientific method.

Let us begin with observation, pose a question,

figure out what the hypothesis would be

that would answer a particular question,

and then figure out how we would begin

to address the hypothesis.

That is a scientific approach to questions

that could be addressed any number of ways.

There is a kind of whispering campaign

against the value of objective truth.

Science's belief in objective truth works.

Engineering technology based upon the science

of objective truth, achieves results.

It manages to build planes that get off the ground.

It manages to send people to the moon

and explore Mars with robotic vehicles on comets.

Science works, science produces antibiotics,

vaccines that work.

So anybody who chooses to say, "Oh,

there's no such thing as objective truth.

It's all subjective, it's all socially constructed."

Tell that to a doctor, tell that to a space scientist,

manifestly science works,

and the view that there is no such thing

as objective truth doesn't.

When you write down the theory,

the theory then becomes your teacher.

It becomes smarter than you in a way.

When Einstein wrote down the equations

of general relativity,

he did not know that they entailed

the existence of black holes.

In that sense, the equations were smarter than Einstein.

Einstein didn't believe in black holes for decades.

The equations were very clear that they could exist.

Einstein said no.

Turned out Einstein was wrong and the equations were right.

So it's very interesting.

We do these theories because we can learn from them.

When you try to address the nature of things,

you may find that asking different questions

requires different ways of processing

the underlying reality.

For instance, in understanding the human mind

to understand that physically requires

one kind of processing.

And there's every reason to think

that we already have fundamental physical laws

that are adequate to that kind of treatment.

But to understand how a person works,

how thought processes, moods, and so forth,

add up to a personality and a human actor

will require quite different ways of understanding

and quite different ways of processing

the underlying information structure.