This is an idea inspired by the [briandamage] solution for ‘mugdeath’ – the disaster when a strongly desired hot beverage becomes cold and undrinkable through absent-mindedness (see link below).
When you park your car after a trip you can hear the sounds of the metals contracting as they cool. My idea is to make mugs of a metal that will expand sufficiently at 'hot beverage preparation temperature' so that it starts to make those contracting sounds when your beverage is cooling past the 'ideal drinking temperature'. You would not need to divert attention away from the task in hand because the only warning would be the gentle sounds of your mug contracting.
I am a bit weak on my science but I have found out that Zinc has a high thermal expansion coefficient. I am naively hoping that makes it an ideal material for this invention (so long as zinc poisoning was taken into account). By using an alloy it may be possible to make mugs that will give warning at different temperatures.-- Ludwig, Jan 28 2003 The inspiration http://www.halfbake...m/idea/Hot_20stones [Ludwig, Oct 04 2004, last modified Oct 05 2004] I like the idea of this being an inherent property of the mug, but as you note the difficulties may be multiple. I suggest a battery powered heat sensor, that goes beep! when beverage temperature is nearing personally set low enjoyment threshold. Croissant just for the name too though.-- Zircon, Jan 28 2003 Smashing. (+)-- talen, Jan 28 2003 If you drink as much tea as I do - upwards of 10 cups a day - you begin to develop a "tea sense". I instinctively know, without even thinking about it, how much tea is in my cup, and also the approximate temperature. As this operates on a subconscious level I'm not sure how sophisticated it is, but I suspect that it also does some rough calculation about the rate of cooling as related to the volume remaining (obviously it cools more quickly the less liquid there is left), and lets me know that as I approach the bottom of the cup I need to step it up a bit, whereas when it's full I can leave it standing for a while.
I think it's this part of my subconscious that's also responsible for sending me off to the kettle every 20 minutes.-- sild, Jan 28 2003 ...and the toilet every 15 minutes.-- DrBob, Jan 28 2003 Trust me sild isn't the only one who drinks that much tea. And yes I do go to the toilet every 15 minutes (roughly)-- talen, Jan 28 2003 If you used a Seebeck array (thermocouples) around the mug to extract power when the mug was hot, which you then stored in a rechargeable battery or SuperCap, this could then power a CMOS thermometer which monitors the temeprature and beeps when the setpoint is reached. The setpoint is stored in Flash so it's retained between powerdowns. The whole system is heat powered by the beverage itself.
Not very dishwasher proof, but since I never wash my coffee mug anyway I don't percieve this to be an issue.-- 8th of 7, Jan 28 2003 [bliss]: You'd be surprised just how much can be accomplished while sitting on the can. We all know, on the other hand, how little else is done when on the Halfbakery.-- Jinbish, Jan 28 2003 [8th of 7] that is a beautifully hyper-technical alternative to the idea which retains a sense of self-containment. I wish we could donate for notes too.
Part of the reason I came up with this idea was because I like the sound metal makes when it contracts, so I am not keen on all these bleepy warnings at all.-- Ludwig, Jan 28 2003 Use a coiled bi-metallic spring between the walls of a thermos cup. As the drink cools, the tip of the spring can move past little pegs like on a music-box cylinder, "pinging" off each one.-- lurch, Jan 28 2003 Oh yes, now that's good. Bimetallic strips are cheap, and a well understood technology. If you had one "master" strip that released the others, the mug could play a tinkly tune when it reached the optimum drinking temeprature, and as this is sealed inside a double wall it's dishwasher proof. Excellent. [lurch], you should post this as a seperate idea.-- 8th of 7, Jan 29 2003 random, halfbakery