Artist Statement for the work “Light Cubed”

The name “Light Cubed”

The name suggests both “light to the third power” and the cubic geometric form.

How it works

The inner LED bulb is powered by a cord plugged into the utility company grid. Solar cells on the inner side of the inner shell convert light from the LED bulb back to electricity. A wire through the inner shell passes the electricity to an electronic unit between the shells. The unit stores the electricity in a capacitor. When the voltage is enough, an electronic switch discharges the capacitor through a green LED, producing a blink.

The LED’s are not coordinated, but blink independently. Rarely, they randomly synchronize and all blink at the same time. (I am also interested in algorithms for synchronizing automata, like some firefly insects synchronize.)

Artistic process

Usually I make solar powered, kinetic mobiles. The exhibition prohibits kinetic works and requires you to use only the provided LED bulb. I was challenged to create a work with more lights, that seemed kinetic.

I chose green LED’s not for any artistic merit but because green and red LED’s were the first LED colors invented. Blue and white came later, courtesy of Cree and others, and now white LED’s are ubiquitous and replacing incandescent and fluorescent.

I sought the “infinite mirror room” effect.

The green LED’s are like spot lights, focused in a narrow beam. The LED in the Cree bulb is similar but has a reflective cone that scatters the light in all directions. A focused LED startles you when you look directly into it. Also, it casts a green stripe onto nearby walls, like a lighthouse.

I chose to blink one second on and one second off, so that the green LED’s might sometimes seem to synchronize.

The inner LED bulb could have been completely enclosed. But I wanted to show the contrast in brightness. The human eye fools you about relative brightness. Sunlight is a thousand times brighter than an overcast day or indoor light. Similarly, the LED bulb uses about 10 watts of power, but the green LED’s use a thousand times less. But the human eye makes sunlight, the LED bulb, and the green LED’s all seem not that much different.

Efficiency

Solar cells and LED’s use the same photovoltaic principle, they just work in opposite directions: electricity to light or vice versa.

The efficiency of both solar cells and LED’s is about 20 percent. Suppose the electric company uses solar panels. They convert 20% of sunlight to electricity. The LED bulb converts 20% of the electricity back to white light. The solar cell in my lamp converts 20% of that white light back to electricity. The green LED’s convert 20% of that electricity back to green light. Thus the overall efficiency is 20% x 20% x 20% x 20%, or 0.03%. That is, the light from the green LED is 3/10,000 of the original sunlight.

So the process is very inefficient. Where does the lost energy go? It is lost as heat. Does this contribute to global warming? No. Roughly speaking, all the heat arrived to the earth in the sunlight anyway. The heat would be here even if we did not use solar cells or LED’s.

More on global warming and the artwork

Burning fossil fuels puts CO2 into the atmosphere which turns the earth into a better greenhouse which keeps more of sunlight’s heat on earth which warms the globe.

If the electric company uses coal to generate electricity, it is releasing energy and CO2 that was captured by green plants from sunlight, millions of years ago. But it is not the energy released that is the problem, it is the CO2. The CO2 lasts a long time in the atmosphere and makes the earth a better green house. Using solar cells to generate electricity releases no CO2 into the atmosphere, at the time of generation.

A complicated question is whether the manufacture of the solar cells releases more CO2 than is saved during generation.