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Dr. Craig Cary AudioIs there a pressing question — a societal need — or even just a cool idea, the answer to which can be found on the ocean floor? This is your turn to be the scientist. Yes, you be the scientist! We challenge you to design an experiment for the Extreme 2002 team at sea!

One experiment per classroom may be submitted. Your teacher should submit the experiment using the on-line form in the Teachers Corner. The scientists will review all the experiments and select a number of them to perform aboard R/V Atlantis and the submersible Alvin.

Keep in mind that the scientists will be over 1,000 miles offshore and nowhere near a hardware store. So you should use common, everyday materials that you might expect to be housed aboard a ship that serves as both a laboratory and a home on the ocean for the scientists and crew.

For example, during Extreme 2001 last year, teachers Rob Adams and Kathy Griffin and their students at Polytech High School in Woodside, Delaware, wondered if an egg would crack under the extreme pressure of the deep sea. The scientists tethered the egg to Alvin and down the egg went on one of the sub's dives, over a mile to the seafloor. What do you think happened to the egg, and why?


Selected Experiments

Compression of a Fluid vs. a Gas

School: Newark High School, Newark, Delaware

Teacher: Robert C. McDowell

Experiment Question: Will seawater compress because of the extreme pressure at the
bottom of the ocean?

Experiment Hypothesis: If we subject seawater to high pressure, it will compress.

Step 1: Fill 2 two-liter soda bottles completely — one with air, the other with seawater.

Step 2: Make sure that no air bubbles are in the bottle filled with water.

Step 3: Cap both bottles tightly, so no fluids can escape.

Step 4: Lower both soda bottles to the bottom, on the submarine.

Step 5: View both bottles from the submarine, and photograph them for viewing at the surface.

Step 6: Determine from the photos if the bottles were compressed at all, and to what degree.

Scientific Results

Two Gatorade bottles were used for this experiment.  One bottle was labeled "empty" and one was labeled "full.The top of the full bottle was colored black with a marker in order to be able to easily distinguish the bottles while in the submersible. The full bottle was filled to the top with seawater, while the empty bottle contained air only.  Both bottles were sealed around the lid with electrical tape. The bottles were wire tied on the basket on the submersible and photographed. They were launched on dive 3830 on October 29, 2002.  Videotaping using the pan-and-tilt camera started when the dive commenced.  The empty bottle began to crush at 5 meters and continued to crush until it was completely flat at 72 meters. Videotaping stopped at 100 meters. Neither of the tops popped off of the bottles.  When the sub was brought back up on deck, the empty bottle had returned to its original form.  It had a small amount of water in it, but there were no cracks.
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This is the "before" shot of the bottles.

Explanations:

What do you think happened to the air in the empty bottle? Why was the bottle not flat when it was brought up onto the deck? How did the water get into the bottle and why? It's really pretty cool! If you have any questions, e-mail Jen Click Here.

 

Rising Under Pressure

School: The Charter School of Wilmington, Wilmington, Delaware

Teacher: Conrad Rice

Experiment Question: Does Pressure Affect the Rising of Bread?

Experiment Hypothesis: Because of the high pressure, the yeast (mold) won't be strong enough to cause the bread to rise.

Step 1: Attach a packet of yeast (or bread mix with yeast in it) in a zip-lock bag to the outside of Alvin.

Step 2: Take the yeast down to the ocean floor and then bring it back to the surface.

Step 3: Use the yeast to bake a standard loaf of bread.

Step 4: See if the bread rises, even though the yeast was under extreme pressure.

Step 5: Compare the results to another loaf of bread made from yeast that was not under such pressure.

Additional Steps: Perform a taste test and look for additional differences.

Scientific Results

Objective - to see if pressure has an effect on the enzymatic action of yeast.

Materials - yeast (8 tablespoons)
heat sealed plastic sheets

depth

Procedure: Hepsi's note: We added a control feature to this experiment. We wanted to isolate the effects of pressure and minimize the effect that the cold temperature of the deep sea might have on the yeast. We were fairly certain that dry yeast would not be changed, but thought that activated yeast (wet) might be affected by the pressure at 2,500 meters.

1. Four samples of yeast were prepared for this experiment. Two dry and two wet (activated).

2. The dry samples were prepared the night before the dive (Oct. 28) and sealed using a Seal-a-Meal heat-sealing device.

3. The other two samples were prepared at 6:15 the morning of the dive. Two tablespoons of yeast were moistened with water and sealed in the same way as the dry samples.

4. One each of the dry and wet samples was placed in the mesh bag of Alvin at 6:30. The sub dove at 8:00 and was on the bottom in 2,502 meters of water by 9:45. The ambient water temperature for the majority of the dive was 2° Celsius. Surface-water temperature was 85,° and I estimate that the sub was in the surface water for 15 – 20 minutes.

5. The two control samples were placed in the refrigerator at 9:00 a.m. to simulate the same temperature conditions that were in the sub.

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The results of the yeast from the deep. In spite of our best efforts to evacuate all the air, some water leaked into both of the yeast packets. The yeast that had been activated showed signs of rising; however, it was contaminated with seawater and was not valid. We're going to try again this weekend.

 

Results:

When the packets of yeast were retrieved from the sub, the following things were noted:

a. The wet packet has some kind of enzyme action going on as it was bulging. However, one could see that seawater had forced its way into the seals and contaminated the sample.

b. The dry packet also showed evidence of contamination. It was moist - not soaking wet - but definitely moist from seawater.

The Plan - We're going to rerun this experiment on Saturday or Sunday, but we're going to vacuum pump the air, roll the edges, and double seal the edges. The lesson so far is that water is insidious - and more so at pressure. If water can find a way into a crack or flaw in a material, it will.

 

My Cup Shrinks

School: Mainland High School, Daytona Beach, Florida

Teacher: Robert Hillenbrand

Experiment Question: Examination of Pressure Effects on Foam Cup

Experiment Hypothesis: Because pressure acts in all directions, the cup will shrink.

Step 1: Attach several styrofoam cups (4 – 6) to the outside of Alvin.

Step 2: Descend to dive depth to expose cups to pressure.

Step 3: Return to surface and send cups to Mainland High School for examination.

Step 4: One control cup (unexposed example) , one cup to be retained as "example," and one cup to be "dissected" for microscopic examination.

Step 5: One cup to be tested for compressional effects, and one last cup as a space.

Step 6: Class to determine the effects of pressure, and perhaps develop an experiment to duplicate some of the effects.

Scientific Results

Departing Video/Requires Quictime 5.0 or higher
This 350k video was taken as the Sytrofoam cup was subjected to the ocean's pressure. Click on the picture above to view.
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Liz McCliment displays the cups after they came up from the bottom of the ocean.

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The cups are standing at attention.

 

Soda Squeeze

School: Aliso Niguel High School, Aliso Viejo, California

Teacher: Erik Silberman

Experiment Question: How will the extreme pressure of the ocean bottom
affect the shape of a soda can?

Experiment Hypothesis: The soda can will crush slightly due to the gas content in the can.

Step 1: Attach soda can to Alvin.

Step 2: Bring can to the bottom, recording observations along the way.

Additional Steps : An alternative to this experiment would be to place the can in a large jar (pickle jar?) of water. We have learned that liquids cannot be compressed and the small amount of gas in the can that could be compressed should not be enough to break the glass. HYP: The can will not be affected. Would be neat to see both run side by side.

Scientific Results

 

Plant Pressure

School: Aliso Niguel High School, Aliso Viejo, California

Teacher: Erik Silberman

Experiment Question: Will a plant maintain its structural integrity or stiffness while subjected to the extreme pressures of the ocean bottom, and after returned to the surface?

Experiment Hypothesis: Because the outside pressure will be greater than the necessary turgor pressure, the plant will become "limp," then will retain it's wilted state when returned to the surface.

Step 1: Attach plant to Alvin (a piece of fresh iceburg lettuce may be substituted if there are no plants aboard) so that it is secure but can still show movement.

Step 2: Videotape plant as Alvin decends.

Step 3: Videotape plant as Alvin returns to the surface.

Step 4: Check for changes to texture/stiffness when plant is returned to surface.

Step 5: Compare plant cells under microscope to plant cells that were not brought to the bottom.

Step 6: Take pictures of both types of cells so we may compare at our school site.

Scientific Results

 


University of Delaware
Copyright University of Delaware, Oct. 2002.