What is Science? Lecture 1

what is science

defined as knowledge obtained through study

1. either accidental observation or result of experimentation

2. refers to body of knowldge gained as a result of these studies

3. dependent on direct observation

what are the 2 primary scientific approaches?

discovery science & hypothesis based science

what is discovery science

result of verifiable observations and measurements

conclusions made from discovery science are a result of inductive reasoning

what is inductive reasoning

conclusions drawn because of large number of observations

ex: conclude all living things are made of cells because of the observation that all biological specimens over 1000s of years all contained cells

hypothesis based science

observations made from discovery science cause us to ask questions about causes and explanations leading to the development of a hypothesis

this form of science makes use of deductive reasoning

what is a hypothesis

a suggested explanation for given set of observations

they are then tested by further observations and by specially designed experiments

deductive reasoning

moves from a general statement down to a specific conclusion

ex: premise 1- all living things are composed of cells. premise 2- human beings are living. this leads to the conclusion that human beings must then be composed of cells

what is a theory

this is very broad and explains many different observations. supported by a large and growing body of evidence + continually give way to new hypotheses

hypothesis based science example

you observe that your flashlight is not working, you then ask yourself why?

two explanations (or hypotheses): hypothesis 1: batteries may be dead. hypothesis 2: bulb may be burnt out.

deductive reasoning & predictions

_____ is then used to come up with ____ based on previous observations (referred to as if-then logic)

hypothesis 1: dead batteries = prediction: replacement of batteries will allow flashlight to work

hypothesis 2: burnt out bulb = prediction: replacing bulb will allow flashlight to work

how can something be a true hypothesis?

it must be both testable and falsifiable.

testable: must be done way of testing whether or not it is correct

falsifiable: experimentation must be able to show it is not true

testing supports….

a particular hypothesis not by showing what it is correct but by not eliminating it by finding evidence that it is false

hypotheses can never….

be proven without a doubt but if it survives various attempts to disprove it than it becomes increasingly likely to be the valid explanation for the observation in study

hypothesis-based science case study

used actual scientific research

begins with an observation

observation example

most poisonous animals are brightly coloured in order to alert predators to the potential danger saving it from predation. there also exists mimics who avoid predation in the same way even if they don’t harbour any poison

hypothesis: mimicry functions to reduce the likelihood that the harmless animal will be eaten

experiment are then designed to test the above hypothesis