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.