© 2004 plano isd, plano, tx what is a model?. © 2004 plano isd, plano, tx a scientific model is a...

© 2004 Plano ISD, Plano, TX

What is a What is a model?model?

What is a What is a model?model?


A scientific A scientific modelmodelA scientific A scientific modelmodel

is a smaller or larger representation

(pattern, plan, replica, or description) designed to show the structure/function of the real thing

is a smaller or larger representation

(pattern, plan, replica, or description) designed to show the structure/function of the real thing

usually contains the smallest number of parts that are necessary to describe the real thing

usually contains the smallest number of parts that are necessary to describe the real thing can be static or dynamic can be static or dynamic

is a simplification is a simplification

can represent an object, system, or concept can represent an object, system, or concept


A A scale modelscale model can use the same or can use the same or different materials as the original but different materials as the original but the dimensions must be proportionate.the dimensions must be proportionate.

A A scale modelscale model can use the same or can use the same or different materials as the original but different materials as the original but the dimensions must be proportionate.the dimensions must be proportionate.

Examples:mapsblueprintsarchitectural

drawings

Examples:mapsblueprintsarchitectural

drawings

can be a working model (cockpit simulator) can be a working model (cockpit simulator)

scale given in key/legend (ex. 1” = 1 mi) scale given in key/legend (ex. 1” = 1 mi)


A A simulation modelsimulation model simulates the simulates the behavior of something.behavior of something.A A simulation modelsimulation model simulates the simulates the behavior of something.behavior of something.

used in computer games, programs used in computer games, programs involves input from the user (joystick, mouse, throttle, remote control, keyboard), and output

involves input from the user (joystick, mouse, throttle, remote control, keyboard), and output uses mathematical functions uses mathematical functions


Examples of Scientific Examples of Scientific ModelsModels

Examples of Scientific Examples of Scientific ModelsModels


Because atoms and molecules are so Because atoms and molecules are so small, several types of models are used small, several types of models are used to represent molecular structure in to represent molecular structure in chemistry.chemistry.

Because atoms and molecules are so Because atoms and molecules are so small, several types of models are used small, several types of models are used to represent molecular structure in to represent molecular structure in chemistry.chemistry.

perspective drawing - 2D geometric model of atoms and bonds

perspective drawing - 2D geometric model of atoms and bonds

ball and stick - 3D model of atoms and bonds

ball and stick - 3D model of atoms and bonds

HH HH

Ö:Ö:

HHHH

OO :::

space filling - 3D model of atoms and bonds

space filling - 3D model of atoms and bonds

-or-


Models of the Universe

• Scientists have always searched for an explanation of how the universe was formed

• Over the years many theories have developed

• The balloon model represents what we presently know about the universe.

• The Universe (balloon) is getting larger, and the galaxies (dots) are moving apart from each other.


Steady State Theory

• galaxies are not moving away from each other

• new stars are being made from energy in the center of the galaxies

• But if the balloon model it right, does Steady State make sense????


Big Bang Theory

• Proposed by Georges Lemaitre 1926

• Galaxies are expanding in all directions

• Must have started at a central locationwith an explosion

• Does the balloon model work for this theory??


Oscillating-Universe Theory

• universe has gone through periods of expansion and contraction

• the universe is currently in a period of expansion

• What would have to happen to the balloon for this theory to work?


Expansion Theory

• universe is expanding faster than it did a few million years ago

• 1% growth every 200 million years


Limitations of Limitations of ModelsModels

Limitations of Limitations of ModelsModels


Because a model is a simplification, it is Because a model is a simplification, it is necessary to realize that the final result necessary to realize that the final result may not give a completely true may not give a completely true description of the object or system.description of the object or system.

Because a model is a simplification, it is Because a model is a simplification, it is necessary to realize that the final result necessary to realize that the final result may not give a completely true may not give a completely true description of the object or system.description of the object or system.

What are the limitations of these models?

What are the limitations of these models?

© 2004 plano isd, plano, tx what is a model?. © 2004 plano isd, plano, tx a scientific model is a...

Documents