Sundials and Shadows

What TWO parts make up all sundials?

• wedge or stick

• turn wheel

• blank base

• marked base

The marks on a sun dial show __________ intervals

• shadow

• time

• season

• marks

Tags

NGSS.MS-ESS1-1

Read the sentence from the passage.
"People in ancient Egypt, Greece, and China made shadow clocks, or sundials, in all shapes and sizes." 
"At night, or on cloudy days, they didn't work. So how did people tell time when there was no  sunlight?"
Which point is the author making with the evidence in these sentences?

• Sundials did not endure through the years.

• Ancient sundials worked better than modern sundials.

• Sundials were not ideal devices for telling time. 

• Large sundials would tell time on cloudy days.

Ty created and measured the length of his shadow every hour. The measurements are shown in the table and graph below. Analyze them and answer the questions below. At what time of day is the shadow the shortest? Longest?

• It is shortest at 2 p.m. and longest at noon.

• It is shortest at noon and longest at 5 p.m..

• It is shortest at 1 p.m. and longest at 4 p.m..

• It is shortest at noon and longest at 8 a.m..

Tags

NGSS.MS-ESS1-1

NGSS.MS-PS3-1

Carter created and measured the length of his shadow every hour. The measurements are shown in the table and graph below. Analyze them and answer the questions below. What is the pattern of the shadow throughout the day?

• It starts short, gets long then ends up short at the end of the day.

• It starts out short, is short at noon, then gets long at the end of the day

• It starts out long, gets short at noon, then gets longer at the end of the day.

• It starts out long, is long at noon, then gets shorter at the end of the day.

Tags

NGSS.MS-ESS1-1

The Sundial Bridge is in Redding, California. It is one of the largest sundial structures on Earth. The wedge is about 66 meters (217 feet) tall. The base of the sundial is very large, and is used as a place for the community to gather. Twelve large boulders below the bridge divide the day into twelve parts. Due to constraints on the design, the sundial is only completely accurate during the longest day of the year, June 21. However, the sundial is so large that viewers can see the shadow moving. You can actually watch as Earth rotates!

During what time of day will visitors to the Sundial Bridge most likely see the shortest shadow cast by the bridge?

• sunrise

• sunset

• noon

• mid-afternoon

Why is it likely that the sundial on Sundial Bridge is only accurate during one day out of the year?

• All sundials are only accurate on June 21

• The wedge is pointing north to south when it should be pointing east to west.

• The size of the sun dial is too large to accurately tell the amount of daylight during any season.

• The wedge is not pointed in exactly the same direction as Earth’s axis.

When the sun rises in the morning your shadow is ____and points ____.

• short, west

• long, west

• short, east

• long, east

Tags

NGSS.5-ESS1-2

You measure a flag pole's shadow at noon during summer. How will that shadow compare to a shadow at noon during winter?

• The winter shadow is longer.

• The winter shadow points south.

• The shadows are the same length.

• The summer shadow is longer.

Tags

NGSS.MS-ESS1-1

What is the primary function of a sundial?

• To measure temperature

• To tell time using the position of the sun

• To predict weather patterns

• To navigate directions