In the last unit, students explored the relationship between vibrations and sound. In this unit, students continue to explore the phenomena of human senses, focusing on how objects can be seen when they are illuminated by a source of light, and how light passes through opaque, transparent, and translucent materials differently. Students then investigate how a beam of light changes when it hits a mirror.

This page showcases excerpts from the first lesson in this unit which has students exploring the cause- and-effect relationship between sight and light with an investigation into how objects can only be seen when they are illuminated. Students compare objects that produce their own light with objects that need an outside source of light to be illuminated.

Science Background for Teachers:

The science background gives teachers more complex information about the phenomena students study in this unit. 

One of the caves that Dave Bunnell has visited and photographed is the Lechuguilla Cave, which is part of the Carlsbad Caverns National Park in New Mexico. This cave is the fifth longest cave in the world, with at least 219 kilometers (136 miles) of passages that reach almost 500 meters (1,640 feet) below ground.

Lechuguilla Cave has been called one of the most beautiful caves in the world. It is home to various geological features, including 20-foot gypsum chandeliers, stalagmites, stalactites, and draperies. 

In 2012 a team climbed more than 120 meters (410 feet) into a dome and discovered several previously unexplored parts of the cave. They called the newly discovered section “Oz” and named many of its features after parts in the Wizard of Oz, including a large room named “Munchkin-land” and a pit named “Kansas Twister.”

When people descend into a deep cave such as Lechuguilla Cave, they have to bring outside sources of light because the sun cannot penetrate the layers of rock that separate the cave from the open air. This is because the layers of rock are opaque, which means they block all light from passing through.

The closer cave explorers are to the entrance, the more light there is because it is illuminated by light from the sun. This is possible since air is transparent, which means light completely passes through it. Clear plastic and glass are also transparent materials. Some materials, such as wax paper, are translucent, which means they let some light pass through.

Supports Grade 1

Science Lesson: Exploring Light

In this lesson, students explore the cause-and-effect relationship between light and our ability to see. Students begin by investigating how objects need to be illuminated in order to be seen and then explore the effects of placing objects with different properties within a beam of light.

Science Big Ideas

  • Hearing is one sense that humans and many animals have, and sight is another sense.
  • Objects can only be seen when they are illuminated, and this illumination can come from another source, such as the sun, a flashlight, or a lightbulb shining on other objects, or from self-illumination, when objects make their own light.

Sample Unit CTA-2
Discover Complete Hands-on Screens-off Core Science Curriculum for K-8 Classrooms

Prepared hands-on materials, full year grade-specific curriculum, and personalized live professional development designed to support mastery of current state science standards.

Science Essential Questions

  • How does your sense of sight change if you’re in a room that is completely dark?
  • What has to happen to see the objects in the room?
  • Have you ever been in a place that is completely dark, where there is no light?
  • Using one of the places referenced in the last answer, what would have to happen to be able to see in that space?

Common Science Misconceptions

Misconception: As long as we have eyes, we can see.

Fact: For an object to be seen, it must reflect light. We see different colors and textures because of how light bounces off of different materials and into our eyes.

Misconception: The ability to see is separate from the presence of light. We can sometimes see objects when there is no source of light.

Fact: All sight occurs because of how light reflects off of different objects. Without a source of light, we cannot see.

Science Vocabulary

Opaque : a material that blocks all light

Reflect : to bounce off of

Sight : the sense that uses the eyes to take in light information about an object’s position, shape, and color

Transparent : a material that light passes through completely

Translucent : a material that some, but not all, light passes through

Lexile(R) Certified Non-Fiction Science Reading (Excerpt)

Exploring Caves

Dave loves to explore caves. Caves are large open spaces under the ground. One cave is deep beneath the desert in New Mexico. Dave used a rope to lower himself into the cave. It got darker the farther down he went.

Lighting Up Objects

Before long, Dave was surrounded by darkness. He could see only the rope in front of him. He could see headlamps on. the rope because he had a headlamp.

His headlamp lit up whatever was in its beam of light. This light let Dave see the things in front of him. Sight is a sense. It uses the eyes to take in light information about an object’s position, shape, and color.

Seeing in a Cave

We can only see objects when there is light. Caves are dark places. This is because they are underground. Light from the sun doesn’t reach them. When Dave first enters a cave, there is some light. This light is from the sun. The farther he moves into the cave, the darker it gets.


Hands-on Science Activity

In this lesson’s hands-on activity, students conduct an investigation to help them answer the focus question: “Why can’t you see well in the dark?” Students investigate to see how well they can see the figurine inside the cardboard tube when all light is blocked, some light is blocked, and a little light is blocked. They use their observations from the investigation to construct an explanation about the relationship between illumination and sight. After the investigation is complete, students present their analysis to the class and discuss the cause-and-effect relationship between sight and light.

Science Assessments

KnowAtom incorporates formative and summative assessments designed to make students thinking visible for deeper student-centered learning.

  • Vocabulary Check
  • Lab Checkpoints
  • Concept Check Assessment 
  • Concept Map Assessment 
  • And More...

Screenshot (3)

Science Standards

See How KnowAtom Aligns to NGSS Science Standards

Discover hands-on screens-off core science curriculum for student centered K-8 classrooms. KnowAtom supports classrooms with all hands-on materials, curriculum, and professional development to support mastery of the standards.

Download the Alignment to NGSS

Standards citation: NGSS Lead States. 2013. Next Generation Science Standards: For States, By States. Washington, DC: The National Academies Press. Neither WestEd nor the lead states and partners that developed the Next Generation Science Standards were involved in the production of this product, and do not endorse it.