Archive for February, 2009

The Paradoxes of Color Temperature

Posted in Physics, Science, Seattle, Sustainability on February 22nd, 2009 by leodirac – Be the first to comment

Compact Fluorescent Death RayLast week I went to the Indoor Sun Shoppe in Fremont and got a couple new CF bulbs for the house.  I love their selection — they have everything from tiny 7W candelabra bulbs to these massive 150W bulbs that look like death-rays.  A giant 105W bulb (pictured) is now trying to make my monstera deliciosa's home in the living room a little more like tropical mexico and less like winter-in-seattle.

In addition to a huge range of powers, they also clearly show you the color temperature of each bulb.  Some of my friends have avoided CF bulbs because of their harsh color.  But not all CF bulbs cast a vampirish hue on everything.  In fact if you know what to look for, you can tell how cool or warm the color will be by reading the box.  But not always.  Depends on the brand.

The key is to look for a color temperature number like 5000 K or 2700 K.  The higher the number, the more cool or blue the light will be.  The lower numbers will be warmer or more yellow.  Bulbs that are described as "full spectrum" typically do so because their color temperature matches that of regular sunlight — 5000 K or 6000K, but indoors these lights look pretty blue.  A typical incandescent bulb will be more like 3000 K.  Here is a good page showing what color temperature numbers typically mean.
Indoor Sun has CF bulbs at 2700 and 4000.  They're not quite as efficient, but they're still a lot cleaner than incandescent, and if it pushes you away from "I won't use them because they're ugly" then that little efficiency drop is well worth it.

A little science

The irony of color temperatures is in our vocabulary for describing them.  What we call a "cooler" light with more blue in it actually corresponds to a hotter temperature.  When we describe a light as 5000 K we mean this is the spectrum of light that would be emitted by something heated to 5000 degrees Kelvin, or about 8500 Farenheit.  (Technically, it's a black box radiation spectrum, but most hot objects radiate pretty darned close to a theoretical black body.)  Just as bluer flames represent hotter combustion, so with color temperature.  But we still call lights "warm" when they've got plenty of yellow and red in them and not so much blue.

Putting these numbers in context gives us a little physical grounding for lighting.  With a basic incandescent bulb, we really are heating a tiny filament up to about 3000 Kelvin, just to see it glow.  Incandescent bulbs are ancient, incredibly simple, and really inefficient.  The color temperature of sunlight is about 6000 K, because that's just how hot the surface of the sun is.  Thinking about how the sun is this amazingly hot nuclear fire that powers practically everything on the planet, it might be surprising that we can achieve about the same temperature in a piece of wire protected by nothing more than a couple inches of glass globe.  The discrepency there is because the atom smashing fun doesn't happen at 6000 K on the surface — the real power is in the middle of the sun where things are well over 10,000,000 Kelvin.  And even heating your bit of wire that hot would start a nuclear fire without the incredible pressure caused by gravity pushing things together.  So in case you were worried, there really is no danger of making a hydrogen bomb out of a lightbulb, just because you can get it as hot as the surface of the sun.
[Oh and props to Six Apart for updating the typepad editor and supporting Chrome.  Thanks!]

Creative Commons Licenses

Posted in Intellectual Property on February 15th, 2009 by leodirac – Be the first to comment

Creative_commons_2
Creative Commons is a type of license, which is somewhere between a traditional all-rights-reserved copyright and public domain.  There are many variations of CC licenses, and they’re onto the 3.0 version of the licenses, so expect more soon.  Generally CC licenses require Attribution, which is to say, you can do stuff with this content, so long as you say where you got it from.  Often this is in the form of a hyperlink back to the original author’s website.  Flickr popularized this by making CC licenses an option on all their photos.  You’ll see that almost all of my photos are CC licensed.

Creative Commons licenses can either allow somebody to make commercial use of your material, or not, at your discretion, assuming you’re the one who created the license.  Independently, you can allow anybody to modify, adapt, or remix the content.  Or not.  Or you can allow modification so long as the modified content shares the same license, a so-called “Share Alike” license.  Here’s a nice page that shows you the options and allows you to pick a license appropriate for your material.

A CC attribution license is in many senses more realistic in the modern world than an all-rights-reserved license.  It is practically impossible to stop people from using or distributing your work.  The all-rights-reserved license is a threat to take legal action to prevent somebody from using your work.  But suing somebody is such a hassle that it almost never happens for personal content.  Asking somebody to put a link to your website is a pretty reasonable thing and easy to accomplish.   An all rights reserved copyright is for most individuals a bluff.

CC content is also easier to use.  Negotiating terms of licensing under a traditional copyright is daunting.  It necessarily requires a back and forth with the author and probably a whole lot.  The underlying mindset is that content costs money, so if you’re going to use my content, then you’re going to sell it and I deserve some of that money.  As the music industry is slowly, painfully learning, in modern times this model doesn’t work so well.  Access to information is generally free, and those who are making money here are doing so by providing value-added services on top of merely distributing the information.  (Think ads by Google, or concerts for music.)  With a CC license the terms of use of the license are right there.  No need to negotiate.  Just follow the attribution instructions and do what you will.  Instead of requiring negotiation and payment in the traditional economy, this is payment in the nascent reputation economy.

The Strangest Man in my family

Posted in Ego, Physics on February 8th, 2009 by leodirac – Be the first to comment

A new biography of my grandfather has just been published called "The Strangest Man: The Hidden Life of Paul Dirac, Quantum Genius."  I’m quite excited about it for a number of reasons I’ll describe below.  The summary of the book on the publisher’s site is great:

The first full biography of Paul Dirac, the greatest British physicist
since Newton – and one of the strangest geniuses of the twentieth
century, who may have suffered from autism.

Paul Dirac was a
pioneer of quantum mechanics and was regarded as an equal by Albert
Einstein. He predicted, purely from what he saw in his equations, the
existence of antimatter. The youngest person ever to win the Nobel
Prize for Physics, he was also pathologically reticent, strangely
literal-minded and almost completely unable to communicate or
empathise. His silences were legendary and when he spoke, he betrayed
no emotion. Through his greatest period of productivity, his postcards
home contained only remarks about the weather. He is said to have cried
only once, when his friend Einstein died.

I’m very much looking forward to reading it, mostly because somebody
wrote a whole book about somebody in my family. I recently met Francis Crick’s granddaughter and she said how fun it
was to read her grandpa’s biography and wished somebody would write
them about all of her relatives!  I’m waiting for Amazon to ship me my copy, but they say it’ll still be a couple of weeks, although apparently I can get it faster from Amazon.co.uk so I might just do that.  I’ve had a few chats with Graham Farmelo, the author, over the last few years as he’s been working on it, but I hadn’t been in touch with him recently and was tipped off to its publication by the Economist’s book review.

I’m also very happy to see that Graham is being upfront about the possibility that Autism or Asperger’s was at the root of his strangeness.  Many of us in the family suspected this, but it hasn’t been talked about publicly much if at all.  I’m happy to see this out in the open especially with the dramatic rise of Autism in the world today.  When people hide or just don’t talk about medical conditions, it creates a stigma that makes them that much harder for the afflicted to deal with.  Moreso, my grandfather can be a role model of what is possible to accomplish even with a potentially debilitating condition like that.

I’m also happy that it will provide authority to improve his wikipedia page.  I’ve tried making corrections and additions myself in the past, but I quickly learned that wikipedia’s editorial policy does not allow me to include anything I know about my grandfather in the article, until it has been "published" by somebody else, otherwise it’s "original research."  I include the quotations because the definition of publication is rapidly becoming less clear these days — is this blog published?  How about an IM conversation in a chat room that is persisted at a public URL?  But I digress — this policy is big part of why wikipedia is the important modern reference that it is, so I can’t really begrudge it.  And now that Faber & Faber has blessed Graham’s work into dead trees, wikipedia’s policy will allow his extensive research to be included on their summary.

How to stop getting phone books

Posted in Community, Transhuman Morality on February 1st, 2009 by leodirac – 2 Comments

A while ago I posted about how to stop getting Dex phone books delivered in Seattle.  Unfortunately doing that wasn’t enough to stop all the dead trees from showing up on my doorstep.  Now there’s a new grass-roots service called Yellow Pages Goes Green which handles this nation-wide across all providers of phone books.  They liken themselves to a national do-not-call registry for dead trees.  If you use the internet or your phone to look up people and businesses, I encourage you to visit

http://www.yellowpagesgoesgreen.org/stop-yellow-pages/

and stop the unsolicited deliver of unwanted phone books.  Even if recycled, these books waste resources through paper processing, transportation and the recycling process which produces a lower quality paper, supported by inefficient advertising.

While I’m on the subject, if you haven’t tried Google SMS, it’s a great way to look things up.  Just send a text to 466453 ("GOOGLE") with the name of the business you want, and a location specified in writing or zip-code and it’ll respond with what you’re looking for.  It does all sorts of other good things too.  Works on all phones.  I’m a big fan.