Friday, January 20, 2012

Video

Award nominated video.

But please... don't watch only half!! As it goes between Mr. Darcy and Elizabeth

"I could wish, Miss Bennet, that you were not to sketch my character at the present moment, as there is reason to fear that the performance would reflect no credit on either [you or me]."

And watching only half the video will leave you with very confused ideas that will reflect no credit on either you or me.

http://www.youtube.com/watch?v=SSI8docYcfA

Sunday, January 15, 2012

Artistic Streak

We gave Bernie an art set for her birthday.

Alicia read to all the kids for a while that morning.

Bernie glanced across the room and did this with the new art set!!!!



Bernie didn't even know she was glancing across the room at a painting done by her great-grandfather. It was fun to tell her that.

So it seems she's got art in the genes. Which is not to say that it only comes from her paternal great grandfather... her mother has a strong art streak too.

Wednesday, January 11, 2012

Hot Springs in Taiwan

Just a note for travellers. Hot springs are a wonderful gift from mother nature. However, in order to soak in them we (i.e. people) sometimes need to tweak them - - - we want water that is not too deep, too hot, too narrow etc.


When I went to Taiwan's Taroko gorge there was a hot spring next to a river called Wenshan Hot Springs. The Taiwanese brilliantly made 3 pools for the water.





The hot water was captured in the first pool at full temperature. The pool was big enough for at least a dozen people and outfitted with a ledge to sit on so you could be immersed just up to your neck. Then a portion of the water flowed into another, bigger pool. It could hold about 40 people comfortably. The pool was shallow enough that you could sit in any part of it and be comfortably immersed. The brilliant part is that they mixed this water with some of the cold river water so that the temperature was "just right".





The third pool was again mixed for a more tepid temperature which appealed to people who preferred that. All three pools were situated on the river's edge - overlooking the torrent and some of the most amazing canyons and tropical vegitation I have ever seen and the blue skies and sun of Taiwan (OK the picture proves I didn't see blue skies and sun that day). They were sheltered just a bit by the cliff that had been cut by the river but basically open to the world. A delightful experience.







The hot springs on the north side of the island are a different experience. My friend Andrew tipped us off that the public ones tend to have some contamination (bodily fluids) and that the clean ones are almost all indoors. They are private affairs. Virtually all of them are piped into hot-tubs in confined, individual hotel-sized rooms for privacy. Even the one we saw that was open to the outside was a pool on a hotel rooftop. As such they are also done sans-stiches, aka clothing-non-grata, aka (ironically) au natural.


Thanks Andrew for saving us from ourselves!


I am wondering in retrospect whether the Taroko springs were also contaminated. If so I'd like to put in a retroactive "ick".




Update: Apparently the Wenshan hot springs are now closed. Their position under the cliff allowed for a rockslide that left at least one bather dead and others injured.

Why do low-wattage LED lamps need such big heatsinks?

When you think about it doesn't it seem strange that a 10W LED light bulb needs a heavy heatsink with fancy fins when a 100W incandescent doesn't?

Here's what I have found.

A 100W incandescent light is too hot to touch - about 90-130C (200-270F). But that is using the surface of that glass bulb as the heatsink. The filament that actually gives the light is 2000-2500C (3600-4500F)!!! The gasses inside of the bulb actually don't carry heat to the surface of the glass at all. That's an advantage in this bulb since the heat is key for getting the light.

LEDs are semiconductors. Like most semiconductors (like all the ones that drive your cell phone, PC, iPod, etc.) in order to survive at all they need to keep their temperature (Tj) below 150C (300F). In order to have a decent lifetime and keep other parameters within control it needs to be closer to 85C (185F - a good temperature to brew coffee at). That's thousands of degrees cooler than the filament!!

The the actual light producing part, the LED junction, is tiny (less than 10 square mm). Since it is small it doesn't have enough surface area to get rid of the 10W* and still maintain this temperature. So it needs to have more surface area - which is the heatsink. The heatsink is made out of Aluminum since the metal carries the heat to its own surface pretty efficiently. Without the heatsink the LED would get too hot for a semiconductor (not too hot if it was a filament).


*10W is actually not used only by the LED. There are some other electronics inside an LED bulb that convert AC down to the low DC voltage that the LED needs. These parts are not perfectly efficient so they use some of the 10W themselves - which is as much as to say they generate heat too.