Scientist are still trying to make heads or tails of this thing called light, and near as they can tell, it sometimes interacts like a particle (like a marble) and other times like a wave (like on the ocean), and you really can’t separate the two because they actually complement each other.
Energy can take one of two forms: matter and light (called electromagnetic radiation). Light is energy in the form of either a particle or a wave that can travel through space and some kinds of matter, like glass.
We’re going to investigate the wild world of the photon that has baffled scientists for over a century. Low electromagnetic radiation (called radio waves) can have wavelengths longer than a football field, while high-energy gamma rays can destroy living tissue.
Here are the scientific concepts:
- Low-frequency electromagnetic waves are called radio waves, which are not the same as sound waves.
- Light you can see (visible light like a rainbow) makes up only a tiny bit of the entire electromagnetic spectrum.
- Light has wavelength (frequency, or color), intensity (brightness), polarization (direction), and phase (time shift).
- Visible light is a small band within a very broad electromagnetic spectrum.
- For an object to be seen, light emitted by or scattered from it must enter the eye.
- Light travels in straight lines except when the medium it travels through changes.
- How simple lenses are used in a magnifying glass, the eye, camera, telescope, and microscope.
- White light is a mixture of many wavelengths (colors), and that retinal cells react differently with different wavelengths.
- Light interacts with matter by transmission (including refraction), absorption, or scattering (including reflection).
- The angle of reflection of a light beam is equal to the angle of incidence.
- A simple wave has a repeating pattern with a specific wavelength, frequency, and amplitude.
- A sound wave needs a medium through which it is transmitted.
- When light shines on an object, it is reflected, absorbed, or transmitted through the object, depending on the object’s material and the frequency (color) of the light.
- The path that light travels can be traced as straight lines, except at surfaces between different transparent materials (e.g., air and water, air and glass) where the light path bends.
- A wave model of light is useful for explaining brightness, color, and the frequency-dependent bending of light at a surface between media.
- However, because light can travel through space, it cannot be a matter wave, like sound or water waves.
By the end of the labs, students will be able to:
- Design and build both a refractor and reflector telescope using lenses.
- Show and describe a mathematical model for waves that shows how amplitude is related to the energy of a wave.
- Develop an experiment that shows how waves are reflected, absorbed, and transmitted.
- Know how to demonstrate how compound microscopes work.
- Understand how to determine how to measure the speed of light.
- Differentiate observation from inference (interpretation) and know scientists’ explanations come partly from what they observe and partly from how they interpret their observations.
- Measure and estimate the weight, length and volume of objects.
- Formulate and justify predictions based on cause-and-effect relationships.
- Conduct multiple trials to test a prediction and draw conclusions about the relationships between predictions and results.
- Construct and interpret graphs from measurements.
- Follow a set of written instructions for a scientific investigation.