How was careful observation of the sky used in early cultures?

How was careful observation of the sky used in early cultures? • To determine the seasons • To decide when to plant crops • To navigate on long voyages • All of the above • 1 and 2 only

When was the Earth known to be circular and its circumference measured? • From the earliest times • By the Greeks • At the start of the Renaissance • By Galileo, in the early 17th century • Around 1800

In what ways do most people employ scientific thinking in everyday life? • Observe the world and notice patterns • Use trial and error–experiments – to test ideas • Predict things before they happen • All of the above • 1 and 2

In what ways do most people employ scientific thinking in everyday life? • Observe the world and noticing patterns • Use trial and error–experiments–to test ideas • Predict things before they happen • All of the above • 1 and 2

What characterizes a scientific explanation? • It is based on the ideas of the smartest people • The more ancient the wisdom, the better the explanation • It is based on observations • It is tested through prediction and experiments • 3 and4

Why is a scientific theory supposed to predict, and not just explain after the fact? • The scientific method is supposed to be followed in order • People can usually think up explanations after something happens, but they may not be right • Predicting things before they happen requires more understanding–you are more likely to have the correct explanation • 2 and 3

What is the difference between the word theory as used in everyday speech, and the word theory as used in science? • Theory, in common speech, is something uncertain (“It’s just a theory”) • A scientific theory is different. It has been thoroughly tested • A scientific theory must be discarded if it fails to explain what is observed in any experiment • All of the above

What method or processesdo scientists use when they are doing science? • Observing the world; looking for patterns that can be clues to underlying laws • Sorting, classifying, or measuring • Suggesting a hypothesis,which explains what has been seen already and predicts something not yet seen • Doing an experiment or collecting data to test the hypothesis • All of the above

Do you think scientists follow the steps of the scientific method given in the previous slide in order (step 1, then 2,then 3…) ? • Yes–that’s the scientific method • No • Often, but not always

If scientists skip a step in the scientific method–for instance, intuitively guessing the answer even before doing the experiment–what happens? • They flunk out of science • Real scientists never skip steps • They go back later and do the steps they didn’t do • Other scientists repeat the experiment • 3 and 4 often happen

Is science more about answers, or about the process of how to find and test answers? • Answers • The process of finding and testing answers

Do you think that the scientific method involves much creativity? • Yes • No

Do you think that science is a system of beliefs? • Yes • No

Do you think that science is a system of beliefs? • Yes • No [Science is based on evidence, experiment, predicting, and testing. A belief system is based on belief or faith.]

Are there ways of knowing other than scientific ones? • Yes • No • Not really

What is special about scientific knowledge, compared to other ways of knowing? • It is based on data • It has gone through a process of prediction and testing • Scientists not involved with the original discovery test it after a new scientific discovery has been published • Explanations are based on natural causes • All of the above

What is pseudoscience? • Something that looks like science but isn’t • Something that often uses scientific words but not the method of science • Something that may want the respectability of science but does not actually use the methods of science • Something that usually doesn’t really work, or doesn’t work the way claimed • All of the above

What are some of the common characteristics of pseudoscience? • It explains things people care about that may not have other explanations • It is based on postdiction not prediction. It explains after the fact • If it fails, there is always an excuse–the theory is not discarded (e.g., astrology is only a tendency; it isn’t supposed to always work….) • Uses scientific-sounding jargon incorrectly (e.g., Energy flows….) • All of the above

What are some of the common characteristics of pseudoscience? • It explains things people care about that may not have other explanations • It is based on postdiction not prediction. It explains after the fact • If it fails, there is always an excuse–the theory is not discarded (e.g., astrology is only a tendency; it isn’t supposed to always work….) • Uses scientific-sounding jargon incorrectly (e.g., Energy flows….) • All of the above (common No. 6: It wants your money!)

The great scientist and teacher, Richard Feynman, said science is, “A way of trying not to fool yourself.” What do you think he meant? • Scientists are very smart. Become a scientist and you will know more • It is natural to believe our own ideas, but not to want them critically tested. Science forces us to test our ideas • Subconsciously we tend to see evidence that agrees with our ideas and ignore that which doesn’t. In science, different groups of scientists repeat experiments, removing some of this bias • All of the above • 2 and 3

Whose suggestion that the Sun is the center of the solar system was first taken seriously by many people? • Copernicus • Tycho • Kepler • Galileo

What did Tycho do that advanced astronomy significantly? • Realized that orbits didn’t have to be circles, they could be ellipses • Made more accurate observations than anyone before (improved the data) • Thought of the idea of circles moving on circles (epicycles) to explain planet’s motion

Johannes Kepler, • Came up with a theory–elliptical orbits–that explained Tycho’s very accurate data • Found that planets don’t orbit at constant velocity–they speed up when nearer the Sun • Discovered the relationship between orbital period and a planets distance from the Sun • Thought he heard the “music of the spheres” • All of the above

Why do many scientists consider Galileo the originator of modern science? • He invented the telescope • He proved that Copernicus was right • He emphasized how important it is to test ideas through experiment

Could you distinguish between earth and sun-centered solar system models by observing Venus with a telescope? • Yes, it would show phases • No, either model shows phases • Yes, in one model apparent size is correlated with phases • No, both make similar predictions • I’m not sure

Suppose a comet had a very eccentric orbit that brought it quite close to the Sun at closest approach (perihelion) and beyond Mars when furthest from the Sun (aphelion), but with an average distance of 1 AU. How long would it take to complete an orbit and where would it spend most of its time? • One year, mostly beyond Earth’s orbit. • One year, mostly within Earth’s orbit. • Over one year, mostly beyond Earth’s orbit. • Less than one year, mostly within Earth’s orbit • It depends on the exact value of the eccentricity.

In science, saying that something is a theory means that it is really just a guess. • Yes, but a guess by a highly educated person. • Yes, but it has strong support by other scientists. • No, a hypothesis only becomes a scientific theory after it has been well tested. • No, it must have detailed mathematical equations to back it up. • No, a theory is published in books, a guess isn’t.

Upon its publication in 1543, the Copernican model was immediately accepted by most scientists because its predictions of planetary positions were essentially correct. • Yes, and it was therefore subsequently referred to as the “Copernican revolution.” • Yes, and it was subsequently used by navigators to explore the New World. • Yes, because there was a growing recognition that the Ptolemaic model was inaccurate. • No, it was not substantially more accurate than the Ptolemaic model. • No, it was only after spacecraft explored the solar system that scientists were convinced of its validity.

How was careful observation of the sky used in early cultures?