The process of ScienceHomework

Design an experiment!Think about what it would

take!

Due

• Monday – 8/29 – Period 1-3-5-7• Tuesday – 8/30 – Period 4-6-8

• Warning – Mid-Quarters Go home 9/2 and this will be a grade on it.

Basics• Write up the design for figuring out the

answer(s) to the following questions.• Use the Process we looked at –

• Question• Hypothesis• Experimental Design ***** this is the important

one!!!• What will you do? Step by step. What Materials? What

data will you collect? Prepare a data table. What Problems will there be in doing this experiment? How many repetitions / days will it take?

The Curiosity

• How long is a Day? (first decide what a “day” is)

• How long is Daylight during a Day?

• Which direction is North – the Spin Axis of the Earth?

OK

• How to write it up – Look at your notes on the scientific process and follow them!

• Hints:

Process of Science homework – Part 2/try 2

• The Problem: to come up with a DESIGN for an experiment.

• The experiment is to figure out how long a “day” is. (we’ll try the first one first)

• First – we have to decide what a day is in a way that we can test!

What’s a Day?

• From the Dictionary:• The period of light between sunrise

and sunset• The 24 hour period during which to

earth makes one complete rotation on its axis

• The part of the day devoted to work or study

What’s a “day”• From the “net”:

• The duration of one rotation of the Earth, or occassionally another celestial body, on its axis. Its is measured by successive transits of a reference point on the celestial sphere over the meridian, and each type takes its name from the reference used… www.reson.com/Gloss-d.htm

• 1. A basic time increment defined by the earth's motion; specifically, a complete revolution of the earth about its own axis. The sidereal day is defined as the time required for the earth to make one complete revolution in an absolute coordinate system, that is, with respect to the stars. The day in common use is the mean solar day, derived, by means of the equation of time, from the apparent solar day, which is determined directly from the apparent relative motion of the sun and earth. amsglossary.allenpress.com/glossary/browse

Which definition is best?

• First, which of the definitions is easily do-able? A couple of them let you know exactly how to do it!

• “The duration of one rotation of (a)… body on its axis. Its is measured by successive transits of a reference point on the celestial sphere over the meridian…”

Lets translate:

• “The duration of one rotation of (a)… body on its axis. Its is measured by successive transits of a reference point on the celestial sphere over the meridian…”

In basic English :

• The time it takes for a particular point The time it takes for a particular point (sun or star) to pass “overhead” twice.(sun or star) to pass “overhead” twice.

How can we do that?

• Seems simple enough – just measure the time for a star or the sun to cross the meridian twice.

• We need an accurate watch, and a way to figure out when the sun/star crosses the meridian.

Meridian?

• The meridian is the “imaginary” line going from the North to South pole and going directly overhead.

• For the Sun, that would be “real” noon. (12:00 is rarely Solar Noon!) (on Monday 5-Sept-05 the sun’s transit for Keaau was 12:18)

Transit?

• The crossing of a meridian is called a “Transit”

• How can we determine the time of the transit?

DisclaimerAloha

I put together these power points for use in my science classes.You may use them in your classes.

Some images are public domain, some are used under the fair-use provisions of the copyright law, some are mine. Copyright is retained by the owners!

Ted Brattstrom