The U.S. Navy will be hosting a free virtual field trip geared towards middle schoolers and will be providing exclusive access to one of their premiere science labs (Space and Naval Warfare Systems Center) on Oct. 16th at 1 p.m. eastern. The Navy is encouraging classrooms interested in STEM to join them by viewing a live stream of their scientists performing 7 experiments that will inform about “Ocean Light and Communication/Invisible Light.” Scientists will explore light in the atmosphere and ocean as well as infrared light and laser systems during this time and will provide your class with a short post event worksheet/quiz.
U.S. Navy Virtual Field Trip to one of their Premiere Science Labs
WHO: Presented by multiple Navy Scientists (bios available upon request)
WHEN: Oct. 16th at 1:00 p.m. Eastern (10:00 a.m Pacific)
WHERE: From your classroom you will see the Space and Naval Warfare Systems
Center, San Diego, CA
HOW: Via this webcast link https://urldefense.proofpoint.com/v2/url?u=https-3A__www.dvidshub.net_webcast_17026&d=DwIF-g&c=SIStQSL0VMIUJoLS-Q8giiFlA-AKdP7tpJHyQh8DeXk&r=Q4iBSYrcppMdjRhY0KaeaPwe918y6dQkEvGinTvjW1o&m=6SHHxUIQjNr8iMJ7tL5ZP8IwntgiEHlE_j3D1lHyvaE&s=ZCj6sbqvqkag8A8ytf3qla6NuCG10rtHPIrBuiT0Zfk&e=
NAVY STEM FAQ’s
Q: What will I need to watch?
A: A good internet connection and computer/projector with sound
Q: What grades is this appropriate for?
A: This presentation is geared toward 6-8th grade, but all classes are welcome.
Q: What experiments will my class see?
A: 1) Experiment (#1) on dilute milk in glass: "recreate the sky and sunset”, Experiment (#2) on pure milk in glass: "make a cloud, Experiment (#3) on milk vs. ink: "scattering vs. absorption”, Experiment (#4) with blue LED transmitter (see Experiments attachment for more details).
Q: Can my class conduct similar experiments to emphasize the labs during or after the virtual field trip?
A: Yes, See “Experiments” below.
Q: Is there a worksheet or short quiz I can use to test my students on what they learned?
A: Yes, please see “Navy Lab Worksheet Q &A’s” below.
Experiments that Will be Conducted by the Navy
Lab 1 – Ocean Light and Communication
Experiment (#1) on dilute milk in glass: "recreate the sky and sunset." Several drops of milk are added to a glass of clean water, and a white lamp is placed beside the glass. The milk particles are generally smaller than the wavelength of light. The light appears blue like the sky because the small particles are scattering light out of the beam, and this occurs more strongly for the shorter wavelength (blue) colors. ["Wavelength will be presented in segment #2."] When the lamp is placed behind the glass, the light appears red like a sunset because most of the blue and green has already been scattered, and what remains are the yellow and red parts of the white light.
Experiment (#2) on pure milk in glass: "make a cloud." The water droplets in clouds are larger than the wavelengths of visible light, so they scatter this light, rather than absorb it. Briefly note that up to half of the ultraviolet light from the sun can still reach the ground on an overcast day, so don't forget your sunscreen, even if it's cloudy. Now, milk and clouds aren't the same, but a glass of pure milk and a large cloud are similar in that they are both dense enough to scatter all light from the source (sun or lamp), so they look white to us.
Experiment (#3) on milk vs. ink: "scattering vs. absorption." Attenuation is the combination of scattering and absorption, and it describes how much light makes it to the observer. A dish of milk and a dish of ink (or dye) may attenuate the same, as seen by two white lights passing through them. But they are different: milk mostly scatters, and ink mostly absorbs. The ocean is similar: blue water has minimal scattering, and mostly absorbs non-blue light. But particles and organic matter in green water scatter significantly, and also absorb blue light. The result is greener water with reduced visual range.
Experiment (#4) with blue LED transmitter: show a pair of blue-LED optical transmitters that can transfer information at 1Mbps (a modest speed by current standards). Explain data speeds using Harry Potter book series as examples. Can include slower acoustics (reviewing whales and their long-range communication ability) and faster lasers.
Items Teachers can use to follow along or reinforce experiments
Experiments #1-#3 could be done in the classroom with milk, water, glasses, and flashlights/lamps.
Lab 2 – Invisible Light
Experiment (#1) 2 minute video using military infrared cameras to track scientists on the way to the lab. You will see footprints on the floor where someone walked. See link for a teacher’s guide on infrared:
Experiment (#2) The moderator will talk about the camera that was used in the transition video and how it is different from regular cameras. We’ll do an exercise about wavelengths and energy and discuss how that relates to the camera. We will also look at a regular camera and one that has had some adjustments to the sensor to show the wavelengths of the lasers in the lab.
Experiment (#3) This will be about the laser systems in the lab and what we (the Navy scientists) do with them. There will be basic discussion about what different optical components do in the lab and why we use them. We’ll have a discussion about laser safety goggles and how we safely work in laboratories (this will be a theme interwoven throughout part 2). The laser goggles also provide a visual representation of different wavelengths being absorbed by different colors.
Items Teachers can use to follow along or reinforce experiments
Spectrometer - Here is an affordable spectrometer that can be used in the classroom to see the different colors in light that are produced by different light sources. This will emphasize the visible spectrum:
Demo Link – This demo link has an optional follow-on in the classroom using rope and rulers.
Navy Lab Worksheet Questions
- The daytime sky has a _________ color because the atmosphere tends to (scatter or absorb) this color.
- Clouds have a white color because they strongly scatter all wavelengths. (True/False)
- Clear ocean water looks blue because it strongly absorbs blue wavelengths. (True/False)
- Two properties that describe lasers are their (narrow or wide) wavelength bands and their (narrow or wide).
- Light transmits information [faster or slower] than acoustics, but the range is [shorter or longer].
- _________ and ________ are used to describe light .
- Shorter wavelengths have _________ energy than longer wavelengths.
- The infrared light that the camera was able to see has a ______ wavelength than visible light.
- Human eyes can see infrared light. (Tre/False)
- Special _________ are worn to protect scientists’ eyes from laser damage.