1. Luminescence
Life at the bottom:
Deep Dark Ocean

2. What is light? Light Basics
Light is a form of energy that can be released by an atom. It is made up of many small particle-like packets that have energy and momentum but no mass. These particles, called light photons, are the most basic units of light.
Atoms release light photons when their electrons become excited. An atom's electrons have different levels of energy, depending on several factors, including their speed and distance from the nucleus.

3. Let there be light.
Atom
The ground state of an electron, the energy level it normally occupies, is the state of lowest energy for that electron.
When an electron temporarily occupies an energy state greater than its ground state, it is in an excited state. An electron can become excited if it is given extra energy, such as if it absorbs a photon, or packet of light or collides with a nearby atom or particle.
Electrons do not stay in excited states for very long - they soon return to their ground states, emitting a photon with the same energy as the one that was absorbed.

5. Engagement Different types of luminescence
Florescence (Fluorescent rocks)
Phosphorescence (glow-in-the dark)
Chemoluminescence (glow stick)
Bioluminescence (light from an organism)
Discuss briefly the different types of luminescence.
1. Florescence is where atoms in a crystal are excited by ultraviolet light. They then release that energy as visible light. (Fluorescent rocks glow when exposed to ultraviolet light, when you take the light away, then the glow disappears immediately.)
2. Phosphorescence is similar to florescence except the material continues to glow after the light source has been removed . This is because the excited atoms do not drop down to ground state right away, but slowly over time. (Hold an glow-in-the dark objects--up to the light for some time, remove from light and then darken room. These phosphorescent materials will produce light for awhile.)
3. Chemoluminescence occurs when two chemicals mix, react, and one of the by-products of the reaction is light. (This can be demonstrated by cracking the middle of the glow stick and shaking the two chemicals together to create light.)
4. Luminescent ostracods produce light, but since it comes from an organism, it is called bioluminescence

6. Inquiry minds want to know … How Does the “Glow stick” Work?.
Procedure
1. Introduction to “the glow.”
Begin with a discussion of what your students already know about the “glow.” Ask students if any of them have seen a firefly or any other similar creatures. Have one or two students share their experience.
2. How to make the light in the light stick
a. Ask students how they think fireflies and other “glowing” animals make their light.
b. Show students a light stick. Ask students how they think they can activate the light in the light stick. Tell students to write down their initial hypothesis, observations, and results. (The answer is the light stick will light when broken and then shaken) To help students, ask them to shake their light stick. (The answer is nothing will happen) What happens when they bend the light stick? (initial light) How can they make the initial light spread throughout the rest of the stick? (shake it
A light stick consists of a glass vial, containing one chemical solution, housed inside a larger plastic vial, containing another solution. When you bend the plastic vial, the glass vial breaks, the two solutions flow together, and the resulting chemical reaction causes a fluorescent dye to emit light
The reaction between the different chemicals in a light stick causes a substantial release of energy. When the chemicals are mixed, the atoms are excited, causing electrons to rise to a higher energy level and then return to their normal levels. When the electrons return to their normal levels, they release energy as light. A typical commercial light stick holds a hydrogen peroxide solution and a solution containing a phenyl oxalate ester and a fluorescent dye. The chemical compounds are kept separated in the light stick in two chambers. The phenyl oxalate ester and dye solution fill most of the plastic stick. The hydrogen peroxide solution is contained in a small, fragile glass vial in the middle of the stick. The “snapping” or bending action breaks the glass vial and allows the chemicals to mix. The chemicals immediately react to one another, and the atoms begin emitting light. The particular dye used in the chemical solution gives the light a distinctive color. The chemical reaction may last for a few minutes to a few hours to even a few days depending on the formulation. Most light sticks found in the stores will last for a few hours.
A typical light stick holds a hydrogen peroxide solution and a solution containing a phenyl oxalate ester and a fluorescent dye

7. How to control the rate of reaction
How can you speed up or slow down the rate of the reaction.
Cylume light sticks
As you discovered in this activity, temperature can speed up or slow down the rate of the reaction. If you heat the solutions, the extra energy will accelerate the reaction, and the light stick will glow brighter. However, the light stick will glow for a shorter amount of time. If you place the light stick in cold water, the reaction will slow down, and the light will dim. So, if you want to preserve your light stick for the next day, put it in the freezer. The cold temperature will not stop the reaction, but it will slow down the reaction until you warm up the light stick.

8. Visible light in the ocean
Extra Background
Light and the Color of Water
What is visible light?
The entire range of different kinds of light including the ones the human eye can see is called the electromagnetic spectrum.  What we can see is called visible light. A rainbow shows the colors of visible light. Visible light has wavelengths that range between 400 and 700 nanometers (one billionth of a meter).
Visible light penetrates into the ocean, but once past the sea surface, light is rapidly weakened by scattering and absorption.  The more particles that are in the water, the more the light is scattered. This means that light travels farther in clear water.  Absorption can be caused by phytoplankton which use the light for photosynthesis, particulate matter in the water, dissolved material in the water, or the water molecule itself.

9. Purpose
Simulate what happens to light intensity and wavelength at increasing depths in the ocean.
Identify variables that may affect light production in ostracods.
This lesson introduces students to bioluminescence and light production in deep sea environments. Our design integrates biology, chemistry, and physics to show the students various behaviors exhibited by deep sea organisms.
In the first activity, special deep sea glasses are used to simulate low light levels in the deep sea, helping students to visualize the adaptations needed to survive in this extreme environment.
Students will also use dried ostracods, a light producing organism, to explore bioluminescence and how light production in deep sea environments can be both costly and beneficial.

10. Materials Deep-Sea Glasses Pattern Half of a file folder
8 pieces of transparent blue plastic, each 5cm x 6cm
Scissors
Stapler
large sheet of black construction paper
Bag of M&Ms
Sandwich size Ziploc bags
Plastic cups
Binder clips

11. Deep sea glasses template

12. Record what happens to your ability to see the colored M&Ms with varying layers of blue film in the chart. Each layer of blue film represents a deeper depth in the ocean.
Have student groups use the two data sheets to record changes in their ability to see the colors of M&Ms through the Deep Sea Glasses as they add layers of blue film (representing increasing ocean depth). Students should observe that the red, orange and yellow M&M’s become harder to see. (Students may also notice that the black background becomes difficult to see.

13. Ocean water strongly absorbs which colors?
red, orange and yellow light
The upper m of the ocean  is called the photic zone (photo = light).   Beyond this depth, light does not penetrate, and it is pitch dark. All the production of food by photosynthetic marine plants occurs in this thin surface layer.
Only green and blue wavelengths pass through water a great distance.
 White light, as many people know, is composed of different light wavelengths, which range from long (red) to short (violet).  Ocean water strongly absorbs red, orange and yellow light.  Mostly only blue and a little green and violet light reaches depths of 50 , and at 100m, most of even the blue light is absorbed.  Below 200m, the only light comes from bioluminescent organisms.  Since photosynthesizers produce food with energy from light, they are restricted to the upper layers of the ocean.

14. Spectrum of Light in the Ocean
This diagram offers a basic illustration of the depth at which different colors of light penetrate ocean waters. Water absorbs warm colors like reds and oranges (known as long wavelength light) and scatters the cooler colors (known as short wavelength light).
If you take a red object under water with you, the deeper you go the less red it will appear. This happens because there is a decreasing amount of red light available to reflect back to your eye. Remember that a red apple appears red because it absorbs all other colors and reflects red light. If there is no red light available, the apple will look gray or black

15. “You Light Up My Life”
Bioluminescence in fireflies is nanoscale. The glow is caused by the exciting of electrons by a firefly’s enzyme.
When the electrons quiet down and go back to their stable state, they give off light.
They glow to attract mates and communicate.
What’s an enzyme?
Bioluminescence is simply light produced by a chemical reaction which originates in an organism
An enzyme is a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction. Most enzymes are proteins
Angler fish use bioluminescent lures to attract fish.

16. Bioluminescence is simply light produced by a chemical reaction which originates in an organism.

17. A “Blue Light Special”
Tiny crustaceans, Ostracods, also known as "seed shrimp" or "sea fireflies," also use this enzyme to produce bioluminescence in courtship. The males produce blue dots in the water, which are used to attract mates.
A close-up using a scanning electron microscope

18. Bioluminescence in Ostracods
Investigating bioluminescence in ostracods
Brainstorm variables that affect the duration of light produced by the ostracod
Materials
dried ostracods
plastic cup
metal spoon
stopwatch.
Demonstrate the crushing and glowing of the ostracods
Per group: dried ostracods, watch glass, metal spatula, stopwatch.
Brainstorm variables that effect the duration of light produced by the ostracod (salinity, temperature, amount of water), then test it.

19. glowing of the sea fireflies
Place some sea fireflies in a clear cup.
Turn off the lights and demonstrate the bioluminescent light in the sea fireflies.
Use your popsicle stick to crush the sea fireflies. (mixing the chemicals)
Add water and then stir the mixture.
Start timing. The timer is stopped when no more luminescence is observed
Turn off the lights and demonstrate the bioluminescent light in the sea fireflies. The room will have to be very dark to be most effective. Place some sea fireflies in a clear cup. Use your popsicle stick to crush them. Explain to your students you are mixing the chemicals together. Notice they will not activate until you mix the chemicals. Add water and then stir the mixture. (additional element of ATP- stirring motion)
ATP stands for adenosine triphosphate. It is a nucleotide that is used as an energy source for cellular reactions.
Crush the dried ostracods in the watch glass using the metal spatula prior to added the water. Turned off lights and the appropriate water is added, and begin stirring the mixture while timing. The timer is stopped when no more luminescence is observed (which can take up to 10 minutes) The process also requires the elements of oxygen and ATP.
Male and female fireflies use their lights to communicate with one another. A sea firefly (ostracod) is a tiny organism which lives in the ocean. The male ostracod produces a bright blue light to attract the attention of the female.

20. Disphotic “Twilight” Zone 200-1000 m
Ocean zones
Euphotic Zone < 200m
Disphotic “Twilight” Zone m
Aphotic the “midnight” Zone
> 1000m
sunlight
darker, colder, and under higher pressure
The ocean makes up 95 percent of the part of the world in which life exists. Because so many of the ocean's creatures use the "living light" of bioluminescence, it may be the most common form of communication on Earth.
The ocean is divided into three light zones: the photic zone (less than 220 yards or 200 meters from the surface of the ocean), the "twilight" zone (between 220 to 1,100 yards or 200 to 1,000 meters from the surface), and the aphotic zone (more than 1,100 yards or 1,000 meters from the surface). In the "twilight" zone, it becomes increasingly difficult to see, and colors become obscured. The aphotic zone receives no light at all, and this region's inhabitants live in complete darknesswith the exception of the lights they emit from their own bodies. This phenomenon is known as "bioluminescence." While bioluminescent organisms can be found at all levels of the sea, their light-emitting capabilities come in particularly handy at the deeper levels.
extreme cold, high pressure, low oxygen levels, and no sunlight

21. Adaptations
Deep-sea creatures have several adaptations that help them survive in the harsh conditions of the disphotic and aphotic zones.
Design a creature that would live in these conditions. Include the characteristics the organisms need to have to survive in these zones:
The euphotic
The disphotic
The aphotic
A common and eye-catching adaptation is the use of bioluminescence (bi oh loo mih NEH sunts). Bioluminescence is light produced by a chemical reaction in a living organism