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Tok natural sciences presentation by karan suresh on prezi
What is Science?• ‘Science’ can be defined simply as a methodology oftesting knowledge claims through empiricalobservation (experimentation)– Hypothesis– Experimentation– Analysis of results– Develop scientific laws– Develop scientific theories– Repeat the cycle• This is integrated with publication, peer review,replication and falsification‘science’ is therefore not really just a body of knowledge, as is commonly thought 3.
The Scientific MethodLawHypothesis (must be falsifiable)Experiment (with independent,dependent and control variables)ConclusionTheoryPeer review,replication ofexperiments,scrutiny by thescientificcommunityand attemptsat falsificationA paradigmshift may (butnot always)lead tochanges inscientific laws 4. The Scientific Method• The scientific method is a fairly simple idea• But it took us over 2000 years to perfect it• In fact, the last piece was only added in the 1960swhen Karl Popper (1902-1994) proposed theprinciple of falsification 5.
The Scientific Method• The principle of falsification dictates that a scientist should abandon atheory when it is falsified• Sometime this doesn’t happen - it may be difficult for a scientist to admittheir (lifetime’s?) work is incorrect• However the falsification itself may be incorrect (or limited by availableinformation):– When Newton was asked why gravity did not cause the Universe to collapse hestated that God was counteracting it (we now know the Universe is actuallyexpanding, overcoming gravitational attraction between galaxies)– When Mendeleev saw that some atomic masses did not fit into his periodictable, he concluded that experimental error was to blame (it was actually due tothe occurrence of isotopes)– Lord Kelvin had measured the rate of cooling of the Earth and concluded(incorrectly) that the Earth was approximately 100 million years old. WhenDarwin realised this would mean the Earth was too young to support his theoryof evolution by natural selection, he merely stated that Kelvin was wrongTherefore, is there a level of subjectivity to the Popper’s principle of falsification? 6.
What is Pseudoscience• When a knowledge claim purports to be scientific but does notmeet the requirements of the scientific method, we label itpseudoscience• Such claims are often falsifiable or make such vague claims thatthey cannot be falsified (often supporters simply reject anyfalsification)• They are often based on belief systems which are not supported byempirical observation• While a good scientist (hopefully) should reject a hypothesis if it isfalsified, a pseudoscientist will often introduce ad hoc exceptions toavoid doing so /2013/12/ 7. However, just because something is not scientific does not mean it isautomatically pseudoscientific.
A pseudoscience claims to be scientific whenit is not 8.
Tok presentation on natural sciences by ege sarışenoğlu
Two Different Ideas• The Story ofCreation inGenesis• Darwin’s Theory ofEvolution byNatural SelectionWhich is scientific and why? 10 9 Mar 2015 - TOK PRESENTATION ON NATURAL SCIENCES Studies physical and natural world, events happening around us in the context of matter and energy. NATURAL SCIENCES Counterclaims Implications Real Life Example Earth was forever increasing in size (Darwin and Tesla based on underwater .
Pseudoscience or science?• Acupuncture• Astrology• Intelligent design• Crystology• Feng shui• Graphology• Homeopathy• PhrenologyIf it works for people, whybother about whether it isscientific or not?But if it works then surely weshould find out WHY.
Won’tthis then involve a scientifichypothesis and testing andtherefore make it scientific?Can something be unscientificbut NOT pseudoscienceCan something that has beenregarded as pseudosciencebecome accepted as science? 11. Science• Name as many sciences as possible• What do they have in common?• Science is thought of as being based on inductive logic(observing the general and moving towards the specific) –in other words, it is knowledge through verification• However, in his essay ‘Science as Falsification’ Karl Poppershowed that scientific conclusions are reached viafalsification rather than verification• Therefore the scientific method is not entirely inductive 12.
The Problems of Science• Since science is based on empirical observation, it is affected by theproblems that beset observation:– Sometimes your expectations can lead you to see things that are not reallythere. Planet Vulcan– Acceptance of expert opinion or a fixed idea can lead you to not see (oroverlook) things that are really there.
in May 1952 (a year before Watsonand Crick made their model) Rosalind Franklin had all the evidence sheneeded to conclude that DNA was a double helix, but she didn’t interpret theinformation correctly– The act of observation itself has an effect on results (the observer effect) 30 Jul 2013 - Transcript of TOK natural sciences presentation. TOK Presentation Natural Sciences Real life situation. Knowledge issue. The Fukushima Nuclear Radiation Crisis Why does science prevail in generating faith despite the uncertainties associated with it? Real Life Situation The Japanese nuclear reactor .
placing a thermometer in a liquid affects the temperature of the liquid– There are some things that the human brain doesn’t seem to be able tounderstand (or things that lie outside our experience).
Empiricism• Rationalists look to reason to support knowledge claims while empiricists embraceexperience (observation)• You might think this is the same thing, but while a rationalist would support abeautiful theory over observational evidence, an empiricist would support theobservation over the theory (falsification)• The correct stance in terms of the scientific method is really to be empirical.
Reason is limited by unconscious prejudices (although you could argue that oursense perception has similar problems)• In practice, science progresses through an uneasy mixture of rationalism andempiricism• This introduces problems into our idea of falsification 18 Apr 2010 - If you wanted to make use of one of these clips as a real life situation you could generate your own knowledge question for a presentation. Here are some examples: Comparing natural science and history, how do we decide what is a convincing interpretation of the evidence and why? To what extent do we .
While a scientific theory cannever be proved (certainly not in the same way as a mathematical theorem),perhaps it may not be possible to properly falsify either. However, be careful not toequate this to relativismPerhaps Newton, Mendeleev, Darwin and Einstein were rationalists rather than empiricists.
WhenEinstein was asked what he would have felt if Eddington’s observations had failed to support hisTheory of General Relativity, he said “Then I would feel sorry for the Good Lord. ” (Einstein was, after all, an ‘armchair theorist’) 14. The Nature of Scientific Discovery• Paradigm ‘A framework of belief, usually applied to rulingtheories of science’• Paradigm shift ‘A complete change from one paradigm toanother, due to a major change in scientific thinking’• The term was first used by philosopher Thomas Kuhn in hisbook ‘The Structure of Scientific Revolutions’ (1962)• Kuhn used the duck/rabbit illusion toshow how a paradigm shift could leadto you seeing the same information ina completely different way 15.
Examples of Paradigm Shifts in Science• The Copernican Revolution• The replacement of phlogiston theory with Lavoisier’s ideasof chemical reactions (‘The Chemical Revolution’)• The publication of On The Origin of Species by CharlesDarwin• The acceptance of Mendelian inheritance rather thanDarwin’s idea of ‘pangenesis’ (the idea that all of thecharacteristics of a parent are heritable)• From Newton’s idea of gravity to Einstein’s view of relativity• Publication of Heisenberg’s Uncertainty Principle• The elucidation of the structure and function of DNANote that paradigms exist in all areas of knowledge, not just natural scienceWe associate paradigm shifts with the idea of ‘genius’Note that the IB does not like you to use clich d examples of paradigms in your essay 16. Recognising a Paradigm Shift• Sometimes a paradigm shift occurs very suddenly – e.
Real life situations for the natural sciences - theoryofknowledge.net
Thomas Kuhn likened this to religiousconversion• Sometimes claims are made for a paradigm shift which thescientific community rejects. homeopathists claim thattheir remedies work because water molecules have a‘memory’ of a cure and pass this on to their patients.
Thiswould require a new paradigm in chemistry and biology tobe correct 17. Reaction to Paradigm shifts• Reaction to a paradigm shift can be very negative, sometimes violent andsometimes very long-lasting (often in opposition to the scientific evidence)• e.
The Catholic Church condemned Copernicus and imprisoned Galileo• e.
Tok presentation natural sciences - youtube
Progress in Science• Kuhn claimed that progress in science is punctuated -i. there are periods of crisis which result in scientificrevolutions• He stated there are periods where paradigms exist togetherand scientists must choose between them. At other timesscientists simply work within the existing paradigm withouteven questioning it• Popper felt that scientific progress was much smootherwith new paradigms being accepted much more easily intothe body of scientific knowledgeInterestingly, a similar argument exists in evolutionary biology - Stephen Jay Gould developed atheory of punctuated equilibrium in which evolution occurs in marked jumps.
Richard Dawkinsbelieves gaps in the fossil record which support this are due to migration events 19. Reductionism• Reductionism is an approach to building descriptions ofsystems out of the descriptions of the sub-systems that theyare composed of• Biology: atoms form molecules form organelles form cellsform tissues form organs form organ systems form bodiesform species form communities ….
and so on• Physics: atoms form molecules form minerals form rocks formplanets form solar systems form galaxies… and so on• The idea is that if we fully understand atoms we canunderstand basic systems, and then we can understand thesystems that are formed from them 20. Chaos Theory• In mathematics and science, chaos theory describes the behavior ofcertain systems which evolve with time – these may be highlysensitive to initial conditions (popularly referred to as the butterflyeffect)• This occurs due to the exponential growth of perturbations in theinitial conditions and the behavior of chaotic systems appears to berandom• This happens even though chaotic systems are deterministic (theirfuture dynamics are fully defined by their initial conditions with norandom elements involved)• Chaotic behavior is also observed in natural systems, such as theweather, and mathematical patterns such as fractals /2012/11/ 21.
Emergence• The observation that from chaotic behaviour,order can spontaneously arise.
Examplesinclude hive behaviour of insects, schooling offish, flocking of birds and even the predictablemovements of a crowd of people /2014/08/ /2009/05/ 22 TOK AND NATURAL SCIENCES. 14.1. Examples of themes for group presentations and discussions. Work in groups of 2-3 people and present briefly the main arguments of both sides in these controversial science-related issues. Then present your own stance and/or lead a short discussion about it. astrology - are .
The Game of Life• The Game of Life is a computer simulation devised in the1960's by the mathematician John Horton Conway. It's a verygood example of how a few simple rules can quickly createorder out of chaos, resulting in emergent behaviour.
Thesimulation takes place on a 2-dimensional grid divided intocells. Each cell has eight neighbouring cells and can be either"alive" or "dead".
The rules which determine it's fate are verysimple:• 1. If a cell has one or no living neighbours, it will die ofloneliness.
If it has too many neighbours - four or more - it will die fromovercrowding.
Where can i find a real life situation from natural science for my ib tok
Science and Truth• Science is a tool for getting closer to the truth• There are problems involved in falsification and a scientific theory bydefinition can never be claimed as fact (some people think the use of theword ‘theory’ in science equates to a lack of certainty)• However, perhaps paradoxically it is the best method we have forapproaching truth about our observations of the Universe around us• If a scientific theory has supporting evidence, corresponds to previousknowledge, coheres to the current paradigm and is pragmatic then we canaccept it as true (at least until a better version of the theory comes alongor there is a paradigm shift)“Science does not aim at establishing immutable truths and eternal dogmas;its aim is to approach the truth by successive approximations, withoutclaiming that at any stage final and complete accuracy has been achieved 11 Aug 2014 - Natural Science; 2. What is Science? • 'Science' can be defined simply as a methodology of testing knowledge claims through empirical observation Examples of Paradigm Shifts in Science • The Copernican Revolution • The replacement of phlogiston theory with Lavoisier's ideas of chemical reactions .