Pink Noise - Leonid Korogodski [65]
See also magnetic sail.
This is an equivalent rephrasing of the common mnemonic for determining the direction of the Lorentz force.
S
San
The Khoi and the San are the olive-skinned aborigenes of South Africa that have been living there since before the arrival of the Bantu tribes. While the Khoi were herders, the San were hunters and gatherers. Khoisan languages are rich in click consonants. They are the source of clicks in the Bantu languages in South Africa (for example, Xhosa and Zulu).
Also known as the Hottentots and the Bushmen, respectively, the Khoi and the San were categorized as the Colored racial category during the apartheid in South Africa.
single-threaded
When multiple tasks cannot be run in parallel.
singularity
A sudden, dramatic change in the state of a system, led there by incremental small changes.
sleepwalking
The phenomenon when a person walks, uses tools, and sometimes performs very complex actions—while asleep. Sleepwalking is not a conscious state like dreaming. It occurs during the deep stage of sleep.
solenoid
A kind of electromagnet, a solenoid is a spiral coil of wire that creates a magnetic field when conducting electric current.
solar storm
Powerful plasma eruptions from the Sun, much stronger than the normal solar wind. The speed of protons is known to reach at least the quarter of the speed of light on some occasions.
solar wind
A nearly continuous current of charged particles (net positive) that permeates the solar system, accelerated by the electric field of the Sun. One could say that we live within a tenuous extension of a star.
stack
In computer science, stack is a data structure that contains the information about the current state of an executing thread.
stem cell
An “unspecialized” cell that can potentially turn into any kind of cell in the body, from skin cells to neurons. Indeed, some research has already been done on turning skin cells into stem cells into neurons.
subcutaneous
Under the skin, like in “subcutaneous injection.”
sublimation
The process of changing the state of matter from solid straight into gaseous, bypassing a liquid state.
See also triple point.
sulcus,pl.sulci
The distinctive furrows on the surface of the brain.
superconductivity
The phenomenon of zero electrical resistance in some materials at very low temperatures. A current in a superconductor can theoretically be maintained forever, since it loses no energy to resistance.
Besides a rise in temperature beyond the critical value, superconductivity can be broken by the rise in electric current beyond a certain threshold, called the critical current, and similarly by the rise in magnetic field beyond the critical value.
superlens
A magnification device made of left-handed metamaterial. Since it doesn’t have to be curved, a superlens can beat the diffraction limit on magnification, providing a view of objects smaller than the light’s wavelength.
See also metamaterial.
swiss-cheese terrain
A unique terrain found at the Martian south polar cap, this is an often beautiful mosaic of shallow pits in the ice.
See also Cryptic Region.
synapse
A junction between neurons.
synchrotron radiation
Electromagnetic radiation with a characteristic signature, emitted by relativistic electrons accelerating across the field lines of a magnetic field. This is the most common kind of nonthermal radiation in space.
T
thalamus
Strategically placed at the center of the brain, the thalamus coordinates the process known as the self.
theta oscillations
Brain oscillations in the 4–8 hertz range produced in the hippocampus, theta oscillations are key players in memory formation and recall, navigation, and other hippocampal functions.
Although less known in the West, the ancient Tamil literature is contemporary with the Vedas and rivals them in stature.