Chapter 2: The Scientific Process

Energy

________ is neither created nor destroyed, we end up with less usable energy than we started with.

-scientific method

questioning how things are done

Questions

why is mom showing favoritism

Hypothesis

brighter colored ones able to beg for food

Prediction

baby birds of the species will become more brightly colored over time

How to test

tagging and weighing

Dependent

size, lifespan, survival rate

Independent

brightly colored

10 different nests

want larger numbers

- energy of movement

heat and electromagnetic radiation

- stored energy

can be changed into kinetic energy

Albedo

objects ability to reflect light

Describe a feedback loop

a process in which the result either continues or does the opposite of what it originally did

How do scientists solve problems?

Scientific method

What is the process of peer review?

other scientists in the field need to redo your experiment and decide if your results make sense

Why is peer review important?

prevents improper science and bias

What is empirical evidence?

evidence from observation and experimentation

What are scientists always looking for?

evidence

What are the four important features of the scientific process?

curiosity, skepticism, reproducibility, peer review

What is a scientific theory?

rarely overturned unless new evidence discredits it

What is scientific law and the law of nature?

based on repeated experiments or observations, that describe or predict a range of natural phenomena

What are the  limitations of science?

cannot prove or disprove anything absolutely, not free of bias about hypotheses and results, systems in the natural world involve a huge number of variables and complex interactions

What is an organic compound?

compound containing at least two carbon atoms

What are the types of organic compounds?

hydrocarbons and carbohydrates

What is a macromolecule?

complex organic molecules

What are some examples of a macromolecule?

complex carbohydrates, proteins, nucleic acids, lipids

What kinds of changes does matter go through?

physical, chemical, nuclear

What is a physical change?

no change in chemical composition, often a change in state

What is a chemical change?

change in chemical composition

What is a nuclear change?

radioactive decay where neutrons are lost over time, nuclear fusion when particles fuse, nuclear fission where particles break apart and release energy

What forms does energy come in?

kinetic, potential

What is kinetic energy?

energy of movement: heat and electromagnetic radiation

What is an example of kinetic energy?

wind’s kinetic energy moves turbines

What is potential energy?

stored energy: can be changed into kinetic energy

What is an example of potential energy?

water stored behind a hydroelectric dam

Would it be smart to cut down trees near a reservoir in order to preserve drinking water?

no, cutting down trees would do more harm than good because they will use rain water more often than water in the reservoirs

What is a watershed?

precipitation falls and goes to a central location

What is a stream gaging station?

also called a weir, v shaped notch that measures streamflow

What is evapotranspiration?

rate at which plants take water up through the ecosystem and evaporate it into the atmosphere

What happened in 1965 that caused a split in the streamflow?

clear cut of the forest

Why would precipitation not increase when evapotranspiration does?

scale is too small

What do we call calcium, potassium, and nitrate?

nutrients

Where do nutrients end up when a forest is clear cut?

bodies of water

What happened to the clear cut site?

streamflow increased, but more nutrients went to bodies of water which is bad for aquatic life

Why would there be more soil erosion in the clear cut forest?

roots stabilize soil, more water means more erosion

What are systems and how do they respond to change?

systems have inputs, flows, and outputs of matter and energy, and feedback can affect their behavior

How do systems respond to change?

feedback loops

What is a system?

set of components that interact in a regular way

What are some examples of a system?

human body, earth, economy

What is a feedback loop?

any process that increases or decreases a change in a system

What are the types of feedback loops?

positive and negative

What is a positive feedback loop?

causes system to change further in the same direction

What is a negative feedback loop?

also known as corrective feedback, causes system to change in opposite direction

What type of feedback loop is the Hubbard Brook experiment?

positive

Albedo

object’s ability to reflect light

Describe a feedback loop

a process in which the result either continues or does the opposite of what it originally did

How does time play a role in feedback loop responses?

systems change over time

What is energy and how does it undergo change?

energy is the ability to do work, it can change when it is used and changes from high to low quality

What is a time delay in a feedback loop?

amount of time between the input of feedback stimulus and its response

What is a tipping point/threshold level?

fundamental shift in system behavior

What are the first two laws of thermodynamics?

energy is neither created nor destroyed, we end up with less usable energy than we started with

What is renewable energy?

gained from resources that are replenished by natural processes in a relatively short time

What is nonrenewable energy?

resources can be depleted and are not replenished by natural processes within human timescales