Dimension

I'll insert from time to time a post about mathematics and its relevance to design. It doesn't happen as often as in engineering that some affinity might appear, but sometimes maths can be not only a strong tool, but rather inspiring.

So, this is a set of 9 videos of explanations about dimension, 2d, 3d and 4d and other mathematical abstractions that, if you cannot understand a thing, you can still feel very attracted and inspired by the images.

Let there be light! [1]

After the short enlightenment [sight] posted about what light is, and about it's wavy nature, remains, among others, the neat question of how to produce light. This can sound like a little obvious, but after listing a few ways, I hope it will be clear that every different way opens very interesting possibilities and/or holds complicated downturns. The really only way to hack those characteristics is to understand where they come from, and why are they like this.

The first and obvious source of light to be understood is the sun. The sun is a huge sphere of gas (mostly hydrogen) that reaches high temperatures.

That's it.

We are not going into the details of how and why is it hot (thermonuclear reactions in the core - and that's enough about it for this post). Very hot gas will emit light. As a matter of fact, any other body will radiate light at high temperatures. If you take, for instance, a piece of metal, say, iron, and heat it to 1000° C, it will glow at a reddish/orange color.

A Light Bulb works pretty much this way. It has a tungsten (temperature resistant metal) coil that resist to the electricity that flows through it. By resisting the electricity, it heats up. And, as said, whatever body heats up, will radiate light.

So, here comes the first disadvantage of using such method to create light: reaching high temperatures. High temperatures requires heat insulators and protection from fire, among other problems.


[Picture above: on every temperature (the curves) different distributions of colors. At 4500 Kelvin, most of the energy is concentrated on the infrared side. At 7500 K, most of the light comes from the blue. Interestingly, at 6000 K (temperature on the surface of the sun), the peak is at the yellow. Even if the light from the sun is mostly white, the sun looks yellow to us.]


The second disadvantage comes together with a great advantage. Remember spectrum of light briefly explained before? Well, light emitted from a hot body will come in a wide spectral range. That means: not one single frequency, but a full range of colors. In this situation, the light will look fairly whiter and nicer to the eyes, mostly because our eyes had gone through an evolutionary process over ages that made it very sensible to this kind of illumination. More then this, because since all visible colors are available in more or less the same strength, the illumination will reveal colors much closer to the real color of objects (if you take an apple under blue light, for example, it will look black. If a color is not available in the ambiance, it obviously cannot be reflected by objects, and they will not reveal their true colors).

Well, the disadvantage lies in the fact that most of the energy resides in a region of the spectrum that cannot be seen by the eyes: infra-red. This is not only a huge waste of energy, but also a dangerous one, for infra-red means basically heat. That's why not only light bulbs are hot, but they heat everything around them.



[Picture Above: for comparison from the previous graph, this is how is distributed the light emitted from a "white" led: here the distribution of the light is much less equal over different colors. And this is the reason that under this kind of illumination objects take a very weird color value]

NY goes to LED public illumination

From the New York Times:

"The city’s Department of Transportation has contracted with the Office for Visual Interaction, a lighting design group, to install and test L.E.D. street lighting. If the tests are successful, the city’s entire stock of 300,000 street lamps could one day be replaced with L.E.D. versions."

LEDs could save trillions of Dollars

Small article from Science Daily:

"A new generation of lighting devices based on light-emitting diodes (LEDs) will supplant the common light bulb in coming years (...). In addition to the environmental and cost benefits of LEDs, the technology is expected to enable a wide range of advances in areas as diverse as healthcare, transportation systems, digital displays, and computer networking."

Not fresh news, in my opinion, only plain logic and little math. But shows the relevance on trying on design with LEDs.

About the Nature Of Light

I'll let Richard Feynman (which is slightly more qualified then me) to explain about the wavy nature of light. Feynman in my opinion was one of the coolest Nobel Prizes winners ever. His research in theoretic physics is cool, he plays bongo (which is cool) and wrote one of the nicest physics textbook I've ever read. And his autobiography is great reading. The video is short enough, concise enough and full of typical Feynman good humor;



I'll complete the post with the video of another great character. The subject is more general and in it's details, the lecture barely touches the subject of the post. But Murray Gell-Mann is another character, and what he says is very inspiring;

Farewell to Maxwell!

The whole concept of what light is took an interesting turn, quite long ago, with a Scottish fellow called James Clerk Maxwell. What he basically did was very much unintended and until the end of his live, very much unexplained. Putting in very simple terms, what he did was to take the experiments of a very talented physicist called Michael Faraday and transform them into a set of 4 equations (know, until today, as Maxwell Equations, for very obvious reasons).

(note: For the historical formality, the final form of his equations were not written by him, but are an evolution of what he wrote in his works).

The equations are kind of encrypted for anyone who is not familiar to vector mathematics. Even their meaning are kind of obscure to who doesn't know physics. But what they describe is the nature of magnetism, electric field and light. And more than this: it says that one is the result of the changing on the other.

So, take your little magnet you have in your refrigerator. Around it, we have a magnetic field in a certain form, shape and strength. Now, start shaking it! Yeah! Just like this: hold it in your hand and shake it as fast and hard as you can. What you are doing is changing the magnetic field in space, from left to right, right to left. What the equations of Maxwell says is that this change creates electromagnetic waves in the space, and those waves are... light.

But I cannot see a thing, you would say. And I would be very worried if you said you could see something. The reason you cannot see anything happening is that the strength and frequency of the changes you are provoking in the electromagnetic field are way to small for your eyes (or even an electronic device) to notice. Electromagnetic waves, as any other kind of wave, may come in low frequency (as your shaken magnetic) or very high frequency, or anything in between. Here goes a table that shows more or less the names we call every kind of electromagnetic wave:

The names and the division between the different frequencies are pretty much arbitrary and are defined more or less by the way those radiations (which are all from the same electromagnetic nature) interact with mater.

So, here we have: low frequencies (left in the graph) are called radio and TV waves. If you could shake your little magnet more then 1.000.000 (10e6) times a second, you would interfere with your radio reception. If you could shake it more then 10e14 (a 1 with 14 zeros after it) times a second, you would probably loose your hand, but you could then see visible light. Higher frequencies are ultra-violet, x-rays and gama-rays.

So, the "stuff" your radio catches from the air through the antenna, is, in nature, the very same "stuff" your lamp radiates. The difference is in the frequency of those waves. Our eyes can only perceive a little part of this whole spectrum (which we call visible light).

The most interesting part of Maxwell studies is the fact that he tried to make an understanding of the magnetic phenomena, and he ended up finding out the astonishing conclusion that magnetics and light are intricately connected.

This is profound. When two totally unexpected different fields of physics (or any knowledge field) are found to be connected, it brings a huge feeling of order in nature. Sometimes, it brings people to do stuff like this:


Here is a great link for a detailed explanation and meaning of the 4 equations. No need for previous knowledge, but it will sure helps a lot.