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Monday, February 27, 2017

Engineering for Engineers Week

Next  week (March 4th to 10th) is Engineers Week.
We know that engineers think about ways in which to make life easier.
We know that engineers design and make things.
Today we were talking about global warming, the melting of the polar ice and flooding.
We acted like engineers and we designed and made flood defenses to protect our Lego men.
Along the way we tried a few other investigations:
We made a bottle containing a (water and oil) wave.
We used a straw to make waves on water.
We tested to see what the pressure of water felt like using a plastic bag under water.
We melted land ice (ice on top of modelling clay) and sea ice (ice directly in water) to see which melting ice would cause flooding and which would not.
And we used a half black, half white box to check and see if the temperature in the black half raised more than the temperature in the white half (this test was inconclusive because the temperature in both halves rose above 26 degrees and our thermometer stops at this temperature.  Maybe we will try this again with different thermometers.) 
We were really interested to hear that when polar ice melts, the colour of the area affected changes from white (ice and snow) to greeen, brown or blue (the colour of land or sea).  Areas that are dark in colour absorb more heat and thus heat up more quickly than white areas.  This causes the remaining ice in this area to melt even more quickly, making the area darker and so heating up more quickly.  Of course, as we saw earlier land ice from the polar caps that melts causes the sea level to rise and causes flooding.
We can really see the connection now between global warming, melting polar caps and flooding.  We are especially sorry for polar bears and penguins who make this ice their home.

Tuesday, February 21, 2017

Still More About Sound

Today we talked more about sound.
We had a demonstration of how sound waves travel through air molecules, but don't travel in space because there is no air/atmosphere.  
We talked about how loud sounds can cause damage to our ears, but how loud sounds can be good warnings for us in times of danger.
We could see how covering our ears can muffle sounds, and how cupping our ears can help us hear sounds more clearly.
We saw how bags of sand could be used to make good (if not strange) ear protectors.
We tested how sound waves can travel down the string of a string telephone and into our ears. We even had conference calls using string telephones.