What is Bioluminescence?

Did you know that some fish and sea invertebrates can make their own lights that glow? This is called bioluminescence.


These lights are made when 2 chemicals are mixed together. The chemical reaction makes the glow.

Look at the brainstorm below to find out why sea creatures make lights.


We found out that glowsticks light up in the same way as sea creatures do. The glowstick has 2 tubes, 1 inside the other. Each tube has a different chemical in it. When the glowstick is bent the inside tube cracks open. This makes the 2 chemicals mix together and the chemical reaction causes the glow.

We investigated the glowsticks and put them into ice water and hot water. This is what we observed and found out.

ICE WATER

• The glow was duller.
• It looked like the chemical was freezing.
• The chemical reaction slowed down.

HOT WATER

• The glow was much brighter.
• The part of the glowstick that was in the hot water glowed a lot more than the part that was not in the hot water.
• The chemical reaction sped up.
  

Waste Water Treatment Plant Visit

Last week the science club visited the Hutt Valley Wastewater Treatment Plant to find out what happens to the sewage produced by our homes. We made these slides to explain what we found out.

Water Pressure

Did you know that there is a lot of water pressure in the ocean. This is because water is heavy and when there is lots of water there will be lots of pressure. Deep in the ocean the pressure is so great that if we went down there our bodies would be crushed.

This week the Year 3 and 4 students are investigating water pressure.

For the first experiment we put out hands into a plastic bag and then into a bucket of water.
This is what some of the students said...

"The water is pushing onto my arm."
"The plastic bag is being crushed onto my arm."
"I can feel the water pressing on my arm."
"It is hard to push my hand down into the water because of the water pressure."

Mr Gough joined in with the investigation. He noticed that it was hard to make a fist with your hand with all the water pressing on it.

For the next investigation about water pressure students filled up a milk bottle with water. The milk bottle had holes down the side. Students had to think about why water flowed further out of some holes than others.

"The water comes out of the bottom hole faster than the top holes because the water is pushing down. This makes the water come out further."

"There is more water pressure at the bottom because the water on top is pressing down. "

What happens when you flush the loo?

This is the question that the Year 5 and 6 Science club will find out when they visit the Waste Water Treatment Plant in Seaview.

In preparation for this visit the group discussed the types of waste water we have in our homes. They discovered that waste water comes from many places and has other things in it as well as water.

• Toilet - water, biowaste, toilet paper, tissues, cleaning products
  
• Shower/Bath - water, soap, body oils, dirt, hair
  
• Sink - water, food scraps, detergent
  
• Washing machine - water, dirt, small bits of fabric, washing powder
  
• Dishwasher - detergent, food scraps, dirt, oil

On Friday we will find out how waste water is cleaned before going back into the sea.

Toilet Paper Investigation
Do all toilet papers break down in the same way? Everyone brought in a different type of toilet paper. We put the same amount of toilet paper and water in a jar and then stirred it up. The time it took for the paper to break down into small pieces was recorded.
After 2 minutes of stirring all the toilet papers had broken down into mush.
So our second test was for 1 minute. After 1 minute of stirring some of the toilet papers were still in a big chunk.

We found out that some toilet papers break down faster than others and so may be better to use as they wont clog drains.

We tried using a tissue and this did not break down at all. It stayed as a big lump. So beware when you flush a tissue down the toilet!!!