I wonder if the cashier reacted to my somewhat strange shopping list last Saturday morning: 1 kg of salt, three kilos of ice and a bottle of food coloring. Had he asked, I’d gladly have told him that I was on my way to “Passion for ocean”, a festival showing off everything that Bergen has to offer that’s related to the ocean; food, music, fishes, starfish, aquariums, organizations, activities, kayaks, boats – and off course research and science!
Nadine and I joined up with Ingunn Skelvan and students from GFI in the Bjerknes Centre tent to set up our demonstrations – it was quite a challenge in the strong wind!
Ingunn showed to anyone interested how blowing (CO2) into seawater lowers the pH (which causes the pH-indicator in the water to change color). When the pH in the ocean decreases it is more difficult for organisms in the water to build their shells.
What balloon will explode first when hold over an open flame? The one filled with water or the one filled with air?
Since the heat capacity of water is much higher than that of air, the water balloon will not get nearly as warm as the air balloon (and hence not explode). That’s also why the water in the lake doesn’t heat up as quickly as the air when the sun is out – and why the majority of the heat that the earth is accumulating due to our emissions of CO2 is stored in the ocean.
Nadine had a more difficult question for the visitors: If you put an ice cube in a glass of sea water and one in a glass of sea water – which one will melt first? Do you know? You can try at home – or visit Mirjam’s blog to find out!