The Nature of Time in Philosophy, Physics and Psychology
1. TIME IN PHILOSOPHY,
PHYSICS AND PSYCHOLOGY
Hamed Abdi
PhD Student in Computational Cognitive Modeling
Institute for Cognitive & Brain Science (ICBS)
2. WHAT IS TIME?
What is time? If nobody asks me, I know; but if I were desirous
to explain it to one that should ask me, plainly I know not.
– Saint Augustine
3. TIME IN GREEK MYTHOLOGY
The ancient Greeks had two words for time:
• Chronos
• Kairos
While the Chronos refers to chronological or sequential
time, the Kairos signifies a proper or opportune time
for action.
• Chronos is Quantitative and Objective
• Kairos is Qualitative and Subjective
4. THE NATURE OF TIME
Time is …
• Continuous or Discrete
• Linear or Cyclical
• Endless or Finite
• Objective or Subjective
• Real or Unreal
• Tensed or Tenseless
• Conventional or Phenomenological
• Quantitative or Qualitative
and so on
5. ANCIENT PHILOSOPHY
The early Greek philosophers generally
believed that the universe and time were
infinite with no beginning and no end.
• Antiphon
• Heraclitus
• Parmenides
• Plato
• Aristotle
• St. Augustine
• Nicole Oresme
6. AGE OF ENLIGHTENMENT
Sir Isaac Newton and Gottfried Leibniz:
• Realism vs. Antirealism
• Absolute vs. Relational
• Dimension vs. Appearances
Immanuel Kant:
• Space and Time as a priori
• Phenomenally real but Noumenally unreal
• Time (linear) is one element of the systematic
framework we use to structure our experience
7. PHENOMENOLOGY
William James:
• the present as the most recent part of the past. whatever we experience always has
an element of an earlier part and a later part. (Specious Present)
Edmund Husserl:
• we cannot have any perception of the immediate present without some memory of
the past and some expectation of the future to give it context.
Martin Heidegger:
• we do not exist WITHIN time, but in a very real way we ARE time, and the whole
concept of time is inseparable from the human experience.
8. MODERN PHILOSOPHY
The philosophical debate on the nature of time
continued without any reduction.
• Tenseless theory of time
• Tensed theory of time
• Presentism
• Eternalism
• Endurantism
• Perdurantism
• Platonia (Multiverse Theory)
9. PHYSICS OF TIME
In the sciences time is usually defined by its
measurement: it is simply what a clock reads.
Periodization is the division of time into suitable and
useful periods or blocks.
• Human Time Scale
• Geological Time Scale
• Cosmological Time Scale:
• Planck Epoch: 10-43 seconds after the Big Bang,
theoretically the smallest time period it would ever be
possible to measure.
• Grand Unification, Inflationary, Electroweak, Quark,
Hadron, Lepton, Photon, Reionization Epoch.
10. RELATIVISTIC TIME
According to relativity, time is not considered as
“passing” or “flowing”, nor is time just a sequence of
events which happen: both the past and the future are
simply “there”, laid out as part of four-dimensional
space-time.
• Absolute speed of light vs. Absolute Time & Space
• Time Dilation and Twins Paradox
• Relativity of simultaneity and Causality
• Time Travel and Faster than Light Particles (FTLP)
• Tachyon
• Neutrinos
Tachyon
After a tachyon has passed nearby, we would be able to
see two images of it, appearing and departing in opposite
directions. The black line is the shock wave of Cherenkov
radiation, shown only in one moment of time.
11. QUANTUM TIME
Is time divided up into discrete quanta?
NO! or Chronon
• Problem of time is a conceptual conflict
between general relativity and quantum
mechanics. Quantum mechanics regards the
flow of time as universal and absolute,
whereas general relativity regards the flow of
time as flexible and relative.
• Wheeler-DeWitt equation:
Time does not exist at all and that, at its most
fundamental level, the universe is timeless.
12. THE ARROW OF TIME
Most of the events we experience are irreversible and
usually we see things progressing in a particular direction.
This one-way direction or asymmetry of time is often
referred to as the arrow of time.
Although events and processes at the macroscopic level
are quite clearly time-asymmetric, physical processes and
laws at the microscopic level, whether classical, relativistic
or quantum, are either entirely or mostly time-symmetric.
In theory, most of the laws of physics do not necessarily
specify an arrow of time. There is, an important exception:
The Second Law of Thermodynamics (Entropy). "Entropy" by Polish sculptor Lukasz Cendrowski
13. PSYCHOLOGY OF TIME
Time Perception refers to a person’s subjective experience
of the passage of time, or the perceived duration of
events.
Time perception differs from our other senses, since time
cannot be directly perceived, and so must be
“reconstructed” in some way by the brain.
Time Expectations suggested that the brain operates on
some kind of an expected order and speed of events, and
alterations to these expectations may lead to illusions like
the kappa effect.
Cortical and subcortical areas involved in the time
perception cerebral mechanisms
Walsh V. A theory of magnitude: common cortical metrics of time, space and
quantity. Trends Cogn Sci 2003;7:483-8.
14. TEMPORAL CONSCIOUSNESS
The most commonly favored options fall into three main categories:
• Cinematic Model
• Cinematic Realism
• Cinematic Antirealism
• Retentional Model
• Broad’s Later View
• Brentano, Husserl
• Extensional Model
• The Discrete Block Model
• The Overlap Model
