APES CH 1 - Intro to E.S.

What do scientists do

scientists collect data and develop hypotheses, theories, and laws abt how nature works

Science

a field of study focused on discovering how nature works and using that knowledge to describe what is likely to happen in nature (based on assumption that events in the natural world follow orderly cause and effect patterns

scientific method

research process in which scientists identify a problem for a study, gather data to test the hypothesis, and modify the hypothesis if needed

model

approximate physical or mathematical simulation of a system, scientists use them to study complex systems

scientific theory

well-tested and widely accepted scientific hypothesis or a group of related hypotheses, one of the most important and certain results of science. Why and how things happen in nature

peer review

important part of the scientific process, where scientists publish details of the methods they used, results, etc, for other scientists in the same field to evaluate

Scientific Law/ law of nature

well-tested and widely accepted description of what we find always happening in the same way in nature. They cannot be broken. What happens in nature

Reliable science

consists of data, hypotheses, models, theories, and laws that are accepted by most of the scientists who are considered experts in the field under study

Unreliable science

scientific results and hypotheses that are presented as reliable without having undergone peer review, or are discarded as a result of peer review/additional research

tentative science

preliminary scientific results without adequate testing and peer review. Some results can/will be validated and classified as reliable, others may be discredited and unreliable

Limitations of science

scientists cannot prove anything absolutely because there is always some degree of uncertainty in measurements, observations, models, and the resulting hypotheses and theories.

• instead they will try to establish that a particular scientific theory has a very high probability or certainty of being useful for understanding some aspect of the natural world

Matter

anything that has mass and takes up space

• exists in 3 physical states: solid, liquid, and gas

• 2 chemical states: elements and compounds

element

type of matter with a unique set of properties and cannot be broken down into simpler substances by chemical means

compounds

combos of 2 or more different elements held together in fixed proportions

atoms

smallest unit of matter into which an element can be divided and still have its distinctive chemical properties

atomic theory

all elements are made up of atoms

subatomic particles

neutrons (=) aka no electric charge, protons (+), electrons (-)

nucleus of an atom

contains protons and neutrons (with electrons outside of it in rapid motion)

atomic number

number of protons in the nucleus of the atom

mass number of an atom

total number of neutrons and protons in the nucleus

Isotopes

forms of an element with the same atomic number (number of protons) but different number of neutrons, and therefore a difference in mass numbers

molecule

a combo of 2 or more atoms of the same or different elements held together by chemical bonds

ion

an atom or group of atoms with one or more net positive or negative electrical charges from losing or gaining negatively charged electrons

acidity

measure of the comparative amounts of hydrogen ions and hydroxide ions in a particular volume of a water solution (pH scale)

organic compounds

contain at least 2 carbon atoms combined with atoms of one or more other elements (CH4 aka methane an exception)

hydrocarbons

compounds of carbon and hydrogen atoms (ex: simple carbohydrates)

complex carbohydrates

consist of 2 or more monomers of simple sugars linked together (ex: starch and cellulose)

proteins

large polymer molecules of linked together amino acid chains

nucleic acids

large polymers made by linking nucleotide monomers, DNA and RNA

lipids

chemically diverse, does not dissolve in water

cells

fundamental structural and functional units of life

cell theory

all living things are composed of cells

genes

sequences of nucleotides that make up DNA, they contain instructions of traits that are passed on from parents to offspring

physical change

no change in chemical composition ex: melting ice into water, cutting up aluminum foil

chemical change/chemical reaction

change in chemical composition of substances involved. Chemical equations show how they are rearranged ex: coal being burned in a power plant

law of conservation of matter

whenever matter undergoes a physical or chemical change, no atoms are created or destroyed

first law of thermodynamics

Whenever energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed

also known as the law of conservation of energy

second law of thermodynamics

Whenever energy is converted from one form to another in a physical or chemical change, we end up with lower-quality or less-usable energy than we started with

energy

the ability to do work

kinetic energy

“moving energy”, the energy an object possesses due to its motion. ex: a car speeding down a highway, wind turbines

• electric energy

• electromagnetic radiation

• heat/thermal energy

electric power

the rate at which electric energy is transferred through a wire or other conducting material, commonly expressed in units of watts or megawatts (1 mill watts) per hour

electromagnetic radiation

energy travels from one place to another in the form of waves formed from changes in electrical and magnetic fields. Each form has a diff wavelength (the distance between successive peaks or troughs in the wave) and energy content

• shorter wavelengths=more energy

heat/thermal energy

total kinetic energy of all moving atoms, ions, or molecules in an object, body of water, or a volume of gas. The faster the movement, the more warmer the matter is.

radiation heat transfer

transfer of heat energy through space by electromagnetic radiation in the form of infrared radiation

ex: how hear from the sun reaches the eart, how heat from a fire is transferred to the surrounding air

conduction heat transfer

transfer of heat from one solid substance to another cooler one when they are in physical contact

ex: touching a hot object on the stove

convection

transfer of heat energy within liquids or gases when warmer areas of the liquid or gas rise to cooler areas and cooler liquid or gas takes it place. As a result, heat circulates thru the air or liquid such as water being heated in a pan.

potential energy

stored energy that is potentially available for use. ex: water behind a dam, chemical energy in the molecules of food u eat

nuclear energy

a form of potential energy, stored in the strong forces that hold the particles (protons and neutrons) in the nuclei of atoms together.

renewable energy

energy gained from resources that are replenished by natural processes in a relatively short time (ex: solar energy, wind, geothermal)

nonrenewable energy

energy from resources that can be depleted and are not replenished by natural processes within a human time scale. (ex: oil, coal, natural gas, nuclear energy)

principle of sustainability

the capacity of the earth’s natural systems and human cultural systems to survive.

About 99% of energy that supports life comes from the sun, which is the basis of solar energy p.o.s.

commercial energy

energy that is sold in the marketplace, makes up the remaining 1% of energy used to supplement the earth’s direct input of solar energy. 90% of it used in the world and US is nonrenewable fossil fuels.

energy quality

measure of the capacity of energy to do useful work

high quality energy

concentrated energy that has a high capacity to do useful work (ex: high temp heat, concentrated sunlight, high-speed wind, energy released when we burn wood, gasoline, natural gas, or coal)

low quality energy

so dispersed that it has little capacity to do useful work (ex: enormous number of moving molecules in the atmosphere or in an ocean together)

system

any set of components that function and interact in some regular way

3 components of systems

1. Inputs: of matter, energy, and info from environment

2. flows/throughputs: rate of flow of matter, energy, or information through a system.

3. outputs: of matter, energy, and info to the environment

how can a system become unsustainable

if the throughputs of matter and energy resources exceed the ability of the system’s environment to provide the required resource inputs and to absorb or dilute the system’s outputs of matter and energy (mostly heat)

• If a system uses more resources than the environment can naturally provide and produces more waste/heat than the environment can safely absorb

feedback loop

occurs when an output of matter, energy, or info is fed back into the system as an input and changes it

positive feedback loop

causes a system to change further in the same direction, enhances the initial event

ex: decreasing vegetation in a valley causes increasing erosion and nutrient losses that in turn cause more vegetation to die, resulting in more erosion and nutrient loss

ecological tipping point

a natural system becomes locked into a positive feedback loop. Beyond this point, the system can change so drastically that it suffers from severe degradation or collapse.

negative (corrective) feedback loop

causes a system to change in the opposite direction, counters the initial event.

ex: recycling aluminum. An aluminum can is an output of mining and manufacturing systems, when recycling it, the output becomes a new input.

most systems in nature use negative feedback to enhance long-term stability