remember, remember the tale of inquisitive Mpemba?

Ever heard that Hot water freezes faster than Cold water?

Sounds counter intuitive doesn’t it? Well it’s true. This phenomena is one of the long standing puzzles that still defy explanation. The question has been asked over the millenia and to this day there has yet to be a simple solution to the bizzarre behavoir exhibited by water.

He’s my musings that have been bugging me for quite some time with regards to this question.

After hearing out the Merlin 2012 competition created by the Royal Chemistry Society regarding this subject I have looked at this an issue of chance. Probability and form.

Simply put, water freezes faster when heated beause it reduces the contrainsts upon the water molecules imposed by the formation of Hydrogen Bonds. It is these bonds that are at the heart of the conumdrum. As stated by Wikipedia, the average number of bonds reduces in water as it is heated and increase as it cools.

With less bonds, the probability of the jostling H2O molecules are statistically more likely to bond more easily as they do not have the constraints of existing bonds, rotation etc upon them.

It’s akin to making a puzzle, you start with the outer edges and work inward. With water freezing, we see the outer surface freeze first then freeze toward the centre.

With hot water the reduced h-bonds allow the water molecules to re-orient more easily and with a greater rate due to the inherent energy in the fluid.

This is counter to cold water where the number of h-bonds is higher and with less energy the rate of interaction is slower.

So, as i said, it’s all to do with chance and form. the beauty of ICe formation is that it has rules. The molecules only form ice on the basis of angle & distance.

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10 years to save the touchscreen, here’s a 10 year old solution.

There’s been some exposure of the last year to the fact that our love of gadgets has a flaw, that flaw is the use of rare earth metals that are required to make our favourite technological devices.

One issue that has been discussed is the scarcity of metals used in the construction of touchscreens. It’s rarity is pushing up costs and manufacturers are looking for a solution.

Graphene has been proposed amongst others as an alternative for Indium tin oxide (ITO, or tin-doped indium oxide) but it has it’s drawbacks as the manufacturing process hasn’t been developed to allow for economical manufacture.

So, what can be done?, well here’s a solution I devised over a decade ago now. I tried to sell this at the time to the company I worked for, but they weren’t interested. What was the idea? Ah well, let me explain…

In a nutshell it is simple; combine (FITR) Frustrated total internal reflection with a modified design of LCD or flat panel display.

Take a standard LCD display and modify the design to include infra-red photosensors that are evenly dispersed between the cells of the screen. Then above the LCD screen add a sheet of glass. Shine infra-red light of a specific frequency though the side of the glass and use the photosenors to detect the reflected infra-light that would occur upon a user touching the glass.

Hey presto! You get a true multi-touch touchscreen and reduce the depth of the display while saving on the amount of rare earth metal used in the construction.

You’d think this would be obvious but it seems the sometimes the wood cannot be seen for the trees.

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