Deductive reasoning
Deductive reasoning
Reasoning is the action of constructing thoughts into a valid argument.
Deductive valid: if premises are assumumed true, it is impossible for conslusion to be false
Deductive sound: if it is valid and all premises are actually true
* Deductive Reasoning:
General Principle → Specific Case–> conclusion
All birds have feathers–> a parrot is a bird–> parrot has feather ( become valid argument)
All adult birds have feathers–> a parrot is a bird–> therfore adult bird has feathers
Inductive reason
Specific case followed by general principle
All bears I have see are black–> inductive general principle becoomes all bears have black fur then
- not a logically valid statement, rather used to form hypothesis in science and test it while deductive in math
What is the scientific method
organized process that scientists use to investigate
scenarios/problems and to find solutions
Steps of the scientific method: observation of topic–> hypothesis guess-> experiment made–> examine data –> does data support guess–> can this be replicated
Begin with a topic , followed by a educated guess to answer the issue–> design experiment to test hypothesis
Experimental designs
- Well defined study: detailed to be repeated
- Controlled all varaibles that we do not want in the study , minimize effects of varaibles
- Independent ( manipulated varaible that is changed in a
scientific experiment or a variable that does not depend on another and is not affected by the state of any other variable in the experiment
e.g. color of light bulb (red light) - Dependent: responding varaible, varaible being tested in experiment, occurs as a response to changed indep. variable.
Other varaibles
Control variable: A control variable is any variable that’s held constant in a research study. It’s not a variable of interest in the study, but it’s controlled
because it could influence the outcomes.
Experimental control:- e.g. grass growing under regular white light bulb (where you do not
include the independent variable that is tested)
a control allows you to compare your results
Confounding: interactions with varaibles of interest and cause researcher to analyze results poorly
+ control ( not exposed to experimental treatment but rather to other treatment known to produce desired effect of experiment)
- control ( NOT exposed to the experiment or others that is expected to have simialr effect of experiment- no treatment)
Placebo
Lacks the active ingredient of a treatment being tested in the- study but is identical in appearance to the treatment.
- Thus, the participants cannot distinguish the placebo from the real treatment
- Refers to situations where pt recieving placebo improve since they believe thet are getting better treatment
Blinding
is the practice of keeping participants and/or researchers in the dark as to who is in the control group and who is in the treatment group.
- Single blind: participants don’t know whether they are in treatment or placebo group
- Double blind: neither researcher nor particpants know who is in treatment or control groups to eleminate placebo effects
Examine data in study
review the data collected and observations that were
made and drawing a conclusion from the results
–> check to see if results support hypothesis
–> Lastly see peer reviewed
Hypothesis
–> a tentative explanation for an observation,
phenomenon, or a scientific problem that can
be tested
–> trying to predict the answer to the problem
Theory: An integrated, comprehensive
explanation of many “facts,” become widely accepted to explain
A theory can often generate additional
hypotheses and testable predictions.
Contintenital drift theory
Illustrates the development of a scientific
- Theory from the starting point of a scientific Hypothesis
- Theory that the contienents were once all joined but have become sepereated.
- 1912 Wegeneer conducted hypothesis that the contineinets joined to form Panega ( one mass contienet) but has sepereated since
Wegener evidence
- Matching margins that all fit together
- Fossil matching throughout
- Match rock types and moutain range crusts same age, location of younger moutains towards edge of land, ice sheets near equator
Why was theory dismissed
- Wegener could not prove how the contienents would move, what made them split.
- Poor explanation for the forces that push and pull massive contients. - what is the cause of the contienital drift?
What new evidence suggested support and created theory of plate tectonics?
- Development of echo sounds to map ocean floors
- Harry Hess used to map ocean floors
- Found underwater ranges, mid ocean ridges,, deep valleys and volcanoes present
Harry Hess Mid Ocean ridges
–> Magma was welling up and new
earth crust was being formed in these locations and then moving laterally outwards
Magnetometer data
revealed an alternating
“striped” pattern of
seafloor rocks:
- new ocean crust was
created at the ridge crest
and then spread outward
in both directions
- The pattern of magnetic
strips shows that the
seafloor is spreading at
mid-ocean ridges.
- Earth crust formed via magma–> crust formed at the ridge , spread old crust lateral ( wider)
Seafloor spreading
- New data Harry Hess–> seafloor spreading
- Seafloor crust was continually formed at these mid ocean ridges–> new crust form and force older crust lateraly
- Seafloor spreading used to support Wedgener originial contintenal drift theory
What is the theory of plate
Lithosphere and asthenscophere ( changes to earth)
Litho= tectonic plates
Asthensophere= lubricant for plates to slide
–> Researchers combined continetial drift and seafloor spreading hypothesis to propose theory of plate tectonics
–> Earth outer lithosphere is divide divided to tectonic plates
–> Plates floating on top of underlying rock later called asthensophere (rocks under heat and pressure behave like liquid)
–> Contienents embedded on plates ( whole plates shift)
“ tectonic plates ( divided lithosphere) and these plates constant motion due to viscous layer underneath= asthenosphere
Plate boundaires
More than just contients shifting, rather the plate boundaries ( location 2 tect. plates are meeting)
Divergent / convergent/ transfrom
Divergent boundaries
Regions where neighboring
tectonic plates move away from each other ( crust is made)
magma (molten rock) rises from the earth’s mantle to the surface, solidifying to create new sea floor crust.
Mechanism of sea floor spreading
–> Iceland with the mid-atlantic ridge ( largest above sealevel)
- Rift valley formation ( rift filled by water) Arabian - africain plate –> low levels of crust
- Mid ocean ridges ( younger areas of new crust forming, magma pushes through, older crust spreads lateral)
Convergent boundaries
- Regions where neighboring plates come
together - usually results in a subduction
(one plate descends below the other)–> subducting plate underneath while overidning crust goes overtop. - Zone of collsions ( volcano, earthquake colloiding boundaries–> destructive process the recycle of earths crust.
- earthquakes/volcano destruction
–> Convergent boundaries more dense
–> Oceanic always subducted plate , less dense than contential ( lighter always above heavier) heavy dense oceanic crust subducts while overiding lighter contineital crust goes over.
Oceanic ( rocks- more dense) contenital ( granite less dense)
Convergent boundaries
- Oceanic-Oceanic convergence: if subducting oceanic plate subducts beneath adjacent oceanic plate - Japan foming island arc
- Oceanic continetial convergence: if the subducting oceanic plate subducts beneath a contineital crust- then a simialar belt of volcanoes- volocano arcs- south american andes
Formation mountains ( himalyasia due to indian and eurasian plates)
Transform boundaries
- Regions of neighbouring plate slide past one another.
- Horizontal movement ( no new creation or destruction of crust)
- Movement is rather constant , plates stick due to friction cause earthquakes - san andres
Earthquakes
- Near plate boundary - know where not when
- Ring of fire ( high rate of disasters)
- Intenisty ( measures amount of ground shaking- earthquake damage)
- Mercalli scale measure quantiiative damage to building , different levels of destruction ( strudy infrastructure)
Terms
Seismology: study of earthquakes , seismic waves
Seisomograph: instrument to record
3 waves ( Primary , secondary, surfave waves)
Epicenter ( location on surface direclty above focus, greatest intesnity ground shake)
Focus ( undergound , place energy released) Shallower earthquake, focus close to surface or epicenter where people are = more damage)
Seimic wave
- Body waves go through inside of earth, 3 waves:
- P ( primary waves) first, longitudinal wave fast and first recorded: move across inside- particles remain same spot
- S (seco) waves transverse move only through solids, slower than P but quciker than surface wave- move up/down particles stay
- Paritcles will move in postion but not carried with wave
