WHAT IS THIS SCIENCE STUFF?!

Science

• “The goal of science is to investigate and understand the natural world, to explain events in the natural world, and to use those explanations to make a useful prediction”

• So…what does that mean!?

Science

• Science is how we understand and learn about the world around us

• It is an organized way of using evidence to learn about the natural world

What is Biology?

• Biology is the study of living things

Scientific Inquiry

• Scientific Inquiry – a way to investigate things and purpose an explanation as to why it happens

What are some questions a biologist may ask about this critter?

Think like a Scientist

• Observation – information that is gathered using your senses, mainly sight and sound

• Data – the information collected from your observations

Quantitative vs. Qualitative

• There are 2 main types of data we can collect…

• Quantitative – data expressed as numbers; we get this data from counting or measuring

• Qualitative – data that is describing but can’t be counted

Quantitative vs. Qualitative

• There are 12 blue M&Ms in a bag…• Quantitative

• The candy tasted sweet…• Qualitative

• Susie is 5 feet 6 inches tall…• Quantitative

• The water feels cold…• Qualitative

Inferences

• Scientists can use data they collect to make inferences

• Inference – a logical interpretation based on prior knowledge

Inferences

• A scientist is testing water in a reservoir, she tests water in 3 different parts. Each part tested safe to drink. She makes the inference that all the water is safe to drink.

Hypothesis

• Hypothesis – a proposed scientific explanation for a set of observations

• Should be written as an “IF…THEN…” statement

Forming a Hypothesis

• Back in the day…people believed that somehow life could arise from non-living things!

• Spontaneous Generation – the idea that life can arise from non-living matter

Francesco Redi - 1668

• Redi, an Italian physician who proved “spontaneous generation” was false

• Redi observed that maggots appeared on meat a few days after flies had landed on it.

• Redi then hypothesized that flies lay eggs too small to see

Redi’s Spontaneous Generation Experiment

Louis Pasteur• Some scientists argued that air contained a “life force”

and Redi’s experiment did not take this into account• Louis Pasteur – a French chemist who designed an

experiment using broth to finally disprove the idea of spontaneous generation

• Proved that living things only come from other living things

Pasteur’s Broth Experiment

Farmer Bob

• The Farmer Bob experiment…• IF Farmer Bob uses Miracle Grow in his garden THEN his plants will grow bigger!

Scientific Method

• Step 1: State the Problem• Step 2: Gather Info/Make Observations• Step 3: Form a Hypothesis• Step 4: Test the Hypothesis• Step 5: Analyze Data• Step 6: Draw Conclusions• Step 7:

• Hypothesis not supported – Modify• Hypothesis supported – Repeat several times

Monty Python Scientific Inquiry?!

http://www.youtube.com/watch?v=C7q_b31JmBs

Designing an Experiment

• If possible, your hypothesis should test only ONE variable at a time!

• Controlled Experiment – an experiment involving one experimental variable and one controlled variable

Variables

• Independent Variable – what you change in an experiment

• Dependent Variable – what you measure in an experiment

• Controlled Variable (the control) – what you keep the same during an experiment

Controlled Variables

• Some controlled variables:• Soil• Amount of sunlight• Type of plants• Temperature• Amount of time tested

Scientific Theory

• You may think of a theory as something not yet proven BUT in science…

• Theory – a well tested explanation for a group of observations

Back to Farmer Bob…

• Hypothesis: If Farmer Bob uses Miracle Grow on his garden then the garden will grow bigger.

• Control Group: • A garden with only water, NO Miracle Grow!

• Experimental Group:• A garden with Miracle Grow!

Farmer Bob’s Variables

• Independent Variable: • Whether Bob uses Miracle Grow or not

• Dependent Variable:• The size of the plants!