Nature of Science

Bellwork: Wed. August 23, 2017 See if you can fill in the blanks from memory, then go back and look in your notes or the book The Characteristics of Living Things They are made of basic units called _____________ Based on universal genetic code (________) Obtain & use materials and energy (m_____________) Grow & _________________ Reproduce ether ______________________ or _____________________ Respond to environment (s______________) (move, grow towards sun) Maintain a stable internal environment (h____________________) Change over time. (___________________)

They are made of basic units called cells The Characteristics of Living Things They are made of basic units called cells Based on universal genetic code (DNA) Obtain & use materials and energy (metabolism) Grow & develop Reproduce ether sexually or asexually Respond to environment (stimulus) (move, grow towards sun) Maintain a stable internal environment (homeostasis) Change over time. (evolve)

Nature of Science: Science must be: Consistent: results of repeated observations/ experiments about naturally occurring events must be the same when tested by scientists again and again. The weight of the evidence agrees with well established observations and limits.

Like… when things are dropped…. they fall…. where?

Which is the scientific statement: 1 Which is the scientific statement: 1. Green plants will grow towards a light source. 2. Walking under a ladder will cause bad luck. (Which one happens consistently?)

Science must be observable Observable: with the basic human senses (sometimes with the aid of microscopes, telescopes, Geiger counters, etc.) Our 5 senses are? sight, “hearing”, taste, touch, smell…

If you can’t see it is it there? ……..our blind spot Take a blank sheet of paper, and place an open hand in the middle of the sheet. Using a pen or pencil, make a small dark cross on the paper next to the right side of your hand. Then draw a dime-sized dot on the paper next to the left side of your hand. Remove hand, and the dot should now be about 12 cm (5 inches) from the cross.

Hold your hand over your left eye, hold the paper at arm's length (about 60 cm, or 2 feet) with the other hand, and stare at the dot on the left with the right eye only. Both the dot and the cross should be visible. Now bring the paper closer, while continuing to stare at the dot. Do you notice something strange happening?

Are you surprised that the cross seems to disappear when the paper is a little more than a foot away? If you continue to bring the paper closer to the face, the cross will reappear. Repeat to see that there is a small distance range where you can't see the cross. Now, do this with the right eye covered, the left eye open, and staring at the cross. In this case, the dot will not be seen at about the same distance range as with the other eye.

This nicely demonstrates that we all have a blind spot in each eye This nicely demonstrates that we all have a blind spot in each eye. These are the spots where the retinal nerves all come together and exit the eyeball through the retina to form the optic nerve. Our eyes are not perfect, and the sense that we normally see a complete field of view with no blind spots is an illusion

Science must be Natural Natural: natural cause (mechanism) must be used to explain why or how the naturally occurring event happens. Scientists can’t use supernatural explanations to explain how naturally occurring events happen -

Which is a natural scientific statement, and which one isn’t. 1 Which is a natural scientific statement, and which one isn’t? 1. Some plants eat meat. 2. Extraterrestrial beings have visited Earth.

REALITY CHECK 2: Which of the following is the natural scientific statement? 1. Green plants convert sunlight into energy. 2. If you like purple you are groovy person who is a throwback to the “hippie” era

Science must be Predictable: Predictable: cause of the event can be used to make predictions. Each prediction can be tested to determine if the prediction is true or false.

Which is predictable? Which is the scientific statement? Write the scientific example 1. Without sunlight (or comparable artificial light), green plants will die. 2. If you are a "Scorpio", your horoscope for today is "You'll be in a terrible accident.”

Science must be Tentative – or subject to change Tentative(ness): Scientific theories are subject to change, even to the point of the theory being proven wrong.

3. We know that the world is flat, and nothing will change that. Which is the scientific statement? 1. The number of human chromosomes was once "known" to be 48, but is now considered to be 46. 3. We know that the world is flat, and nothing will change that.

Really… there was a flat Earth Society International Flat Earth Society

Science must be Testable Testable: the cause (mechanism) must be testable with the Scientific Method using controlled experimentation. ADD: Can only test 1 VARIABLE AT A TIME Reference to supernatural events or causes are not relevant tests. No!

AND Not…

Can you test these? Which of the following is a scientific statement, and which one is not a scientific statement? 1. The Bermuda Triangle causes ships and planes to sink and disappear. 2. Cells come from other cells. Using the idea of "Testability", how can we determine which statement above is a scientific one?

Most of all the scientists who study science must not be biased

Bias: when a person shows favor to one side, or one way of thinking – to be prejudiced (prejudge) example:

It is a hot August afternoon It is a hot August afternoon. The location is the living room in an old Victorian mansion. The 7 foot window is open and the curtains are blowing in the breeze generated by the thunderstorm that just passed through the area. On the floor are the bodies of Bill and Mary. They are surrounded by puddles of water and broken glass. Close your eyes and picture the scene in you head. Neither Bill nor Mary has clothing on. How did they die?

Bill and Mary are fish…

A man leaves home and makes three left turns. He returns home again A man leaves home and makes three left turns. He returns home again. On the way he passes two men with masks. Who are the two men The umpire and the catcher