Are space and time real?
According to cognitive neuroscience, our perceptual experience of reality
is only a distant and convenient mapping of the physical processes
causing the sensory inputs. Sound is a mapping of auditory inputs, and
space is a representation of visual inputs. Space and time are "unreal"
from this point of view.
Though we may not like to accept it, the foundations to our knowledge are
philosophical. These foundations are assumptions in most cases. Some of
the assumptions, especially the ones in physics, are not difficult to
spot. Others that pertain to the nature of reality itself are far
trickier to appreciate. The elusive assumptions include the existence of
time and space, for instance. The realness of reality is not merely a
philosophical issue; it is a subject matter of cognitive neuroscience as
well. Once the issue of reality gets back to the realm of science, it
becomes something that physics has to describe. Physics, in turn, is
erected on the philosophical assumptions on the existence of time and
space.
We can logically accept the virtual nature of time because we have no
direct sensory mechanism to sense or perceive time. Despite this glaring
absence, we do have a strong sense of time that plays a crucial role in
every conscious decision we make in our lives. We can argue that the
reason for the existence of time is our knowledge of our finite
life-span. We can illustrate this argument by mapping the history of the
universe to 45 years. This mapping also shows how our physics of the
universe is an ambitious extrapolation from a very short span of
knowledge to incredibly long time scales. Also, physics has multiple
notions of time - Newton's constant time and Einstein's malleable time.
The difference between these notions of time is indicative of its unreal
nature. Time is unreal the same way as mathematics is unreal; they are
both products of our intellect. And philosophically, they can be thought
of as formal languages.
Space
Unlike time, our perception of space is the end-result of our most
precious sense, namely sight. For this reason, the unreal nature of space
is not as obvious as that of time. If we understand the workings of our
sense of sight from the perspective of neuroscience, we quickly start
doubting space as well. This suspicion turns into a conviction once we
look at the cases where tiny physiological defects manifest themselves as
drastic disorders in visual perception. How sight creates space is
analogous to how hearing creates sound. Sound is not the intrinsic
property of a vibrating body, but our brain's cognitive representation of
the air pressure waves our ears sense. In fact, our whole reality is
nothing but a cognitive representation. Space is our visual reality, or
the cognitive representation of the light inputs to our eyes. It is no
more real than sound or smell. Or time.
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