Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

1

UNDERSTANDING NATURE

CONTENTS• DEFINING CONCEPTS• SEARCHING/FINDING UNDERSTANDING• MODELS / REALITY• EMERGENCE

• PRESENT STAGE• WHERE ARE WE NOW• WHAT COULD BE EXPECTED

Tapio Rantalahttp://www.tut.fi/~trantala

Electronic Structure TheoryTheoretical and Computational Materials Physics, TUT

http://www.tut.fi/semiphys

Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

NATURE2

Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

UNDERSTANDING3

FORMATION OF CONCEPTS AND RELATIONS BY OBSERVING WHAT’S GOING ON:

! Observations: recording for concept formation

! Interpretation: classification, sorting, ...

! Understanding: finding/learning relations forming a model

! Prediction of new phenomena from causal relations

! Naming the concepts for communication

Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

MODELING AND REALITY OF NATURE

4

MODEL! Do we have any better than models and theories?! What is REALLY, out there? MODEL vs. REALITY ?

FURTHER QUESTIONS! Ontology, metaphysics, philosophy of nature

! where we come from – where are we going?! what are the limits of our understanding?! origin and purpose of life! who we are: self consciousness, free will

How do we find understanding – models, reality, emergence ?

Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

SEARCHING FOR UNDERSTANDING5

PHILOSOPHY! Ontology, metaphysics, philosophy of nature

RELIGIONS! Belief in authorities

OBSERVATIONS! Do we have any better than returning back to observations?! Can we find any other way to find general agreement?! In history, NATURE has shown that ALL OTHER ALTERNATIVES FAIL

Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

6

SCIENCE

Characteristics of science:• general concepts, no cultural

dependence• experimental observations,

objective truth or probability• consistence, no discrepancies• criticality: self-correcting• cumulative, progressive• publicity, no authorities

Every day observations and empirism

Systematic observations and experiments, interpretation, understanding and prediction

I can explain this to you

F1 D1 = F2 D2

Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

EMERGENCE FROM SIMULATIONS7

USING! Simulator device/machine (mechanical, functional) or ”mathematical” model COMPUTER SIMULATION

WHY! Less expensive than experiment! More detailed understanding of role of parameters/factors! Test of the model and test of the theory! Simulation may be the only way of gaining understanding

Object ofstudy Model

Experimentalstudy

Exact simula-tion of model

Analytical(approx)solution

Test of model

Test of theory(analytical)

Outcome Outcome Outcome

Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

PHILOSOPHY OF NATURE8

SHOULD BE BASED ON MODERN PHYSICS:

RELATIVITY! New concepts – do not fit to everyday experience! ...

QUANTUM THEORY! New concepts – do not fit to everyday experience ! E.g. ”REALITY” needs to be defined! Locality becomes an issue! ...

Department of Physics, TCOMP RCTI – 13 Aug 2013Tapio Rantala: UNDERSTANDING NATURE

PRESENT STAGE9

HISTORY has shown that! progress continues (in a long enough time scale)

and understanding will increase,no end expected

! unexpected discoveries can be expected

PREREQUISITES! science! evolution ?! ...