What’s the meaning of all this?

NASA’s conception of a space-based “sun tower.”

Nanotechnology: An emerging arena involving extremely small materials, devices and components. A nanometer equals one-billionth of a meter.

Carbon nanotubes: Graphite structures 50,000 times thinner than a human hair. Among other promising characteristics, they are extremely strong and can behave like metals or semiconductors.

Semiconductor: A material with electrical conductivity between that of metals and insulators. Semiconductors are the basic material of many electronic devices used in computer technology, telecommunications, control systems and other applications.

Photovoltaic devices: Devices such as solar cells that convert light into electricity.

High efficiency thermionics: A developing technology for the conversion of heat into electricity using semiconductor structures.

Quantum dots: Granules of a semiconductor material made up of only a few hundred atoms. These tiny “boxes” can selectively hold or release electrons.

Lithium-ion batteries: Rechargeable batteries that are smaller, lighter and have a higher voltage and hold a charge longer than other types of batteries.

Ultra or supercapacitors: High efficiency electrical energy storage devices.