The Sound of Light

Lillian YanagawaWade Nakamura

Bryan Silver

Photoacoustic Effect

• A G Bell discovered phenomenon in 1880s.

• Light affects surface tension producing sound.

• Technological advancements in the biomedical imaging field.

Hawaii Standards 3

• SC.PS.6.5• Compare transverse and

longitudinal waves and their properties

• SC.PS.6.6

• Explain and provide examples of electromagnetic tradition and sound using a wave model.

Preliminary Observations:• Sound and light are forms of energy• Sound and light both produce waves• Sound waves are compressional

(longitudinal) waves that require a medium to travel

• Light waves are transverse waves that do not require a medium to travel

• Visible Light exists in a larger spectrum from radio waves to gamma waves

Research Question:

• Which wavelength(s) of the visible spectrum produce(s) sound?

Hypothesis:

• If a photovoltaic cell is connected to a speaker/amplifier and exposed to the different spectra of visible light from infrared to ultraviolet, then the entire spectrum will produce sound, but the greatest decibel level will occur at the ultraviolet end of the spectrum, because the ultraviolet end of the spectrum is the most energetic.

Materials:

• Amplifier/speaker• Vernier LabQuest

Microprocessor• Microphone• Photovoltaic cell• Wire

lead/connectors• Y-adapter• Motor• Pie plate

ScissorsD-batteryAlligator clipsPrismShadecork

Procedure:

• In three easy steps• Assemble apparatus

Procedure: • Obtain readings under

•Red, white, and Black light•Repeat with prism outside −IR, red, green, blue, UV

Infra Red Light Sound

Red Light Sound

Green light sound

Blue Light Sound

Ultra Violet Light Sound

White light Sound

Conclusion:

• Sound produced at all spectra of visible light

• Intensity of sound varied by light wave

• Loudest wave produced by UV• Hypothesis correct, higher

energy light produces greater decibels.

Extension:

• Using a 100w bulb and colored filters.

• Use of a prism to separate sunlight.

• Intensity of light in generating sound.