I have some bad news to share with the Blogging community; yes today my balls dropped.
It hit 40 degrees and the brightly coloured balls of the Galilean Thermometer are at an all time low. The principles of the Galilean Thermometer took a while to work out. I assumed that it would work on density expansion and contraction of the liquid leading the rise and fall of the balls. It took me a whole three days to get my head around it. Stace will attest to my outburst the other day.
The following story is true only the characters, locations and words have been changed because I can't remember exactly what happened...
Act One Scene one
Enter: Aidan the hero of the play and his beautiful and buxom wife Stacy.
Stacy: 22 across Tatting is back in olde Calcutta
Aidan: (Yelling) the density of the surrounding fluid.
Aidan: The Thermometer, I know how it works. Change the density of the fluid it is all suspended in.. not the balls. I am an idiot.
Stace 22 across is lace
Aidan: I am glad we had this conversation.
The principals of buoyancy.
Buoyancy is an upwards force generated by the displacement of a fluid. (ever wondered why ships weights are given in displacement?) Buoyancy will be driven by two factors the volume of the object (balls) and the density of the fluid (what they are floating in).
Analogy: a hot air balloon, as we all know hot air rises, ( if you believe this you will believe anything, hot air does not, contrary to popular opinion have the ability to levitate, it is merely displaced by the cooler denser air.) it is "rising" due to the surrounding medium being significantly cooler (denser) than the air contained within the balloon. Less dense goes up… Now lets keep the density in the balloon the same and change the background (the air around)…. If we reduce the density to such a level that the surrounding air is less dense than that of the balloon the balloon will descend. Are you with me so far? In this analogy you can see the back ground responsible for the fall of the balloon.
Galilean Thermometer: Each ball in the solution has the exact same shape and displaces the same amount of fluid… however contained in each ball is a different weight of coloured liquid. The weight force (downward) remains constant for each of the coloured balls. Each of these are kept afloat by buoyancy… As the temperature increases the density of the surrounding fluid decreases, and therefore the amount of fluid displaced decreases. As a result of the reduction of fluid displacement the net upward force is reduced (less buoyant), the force becomes a net downward force (weight (down force) > buoyancy (upforce)) and the ball sinks. Simple.