Scattered Disc

Scattered disc is a distant circumstellar disc in the Solar System that is sparsely populated by icy small solar system bodies, which are a subset of the broader family of trans-Neptunian objects. The scattered-disc objects (SDOs) have orbital eccentricities ranging as high as 0.8, inclinations as high as 40°, and perihelia greater than 30 astronomical … Continue reading Scattered Disc


Displacement is an unconscious defence mechanism whereby the mind substitutes either a new aim or a new object for goals felt in their original form to be dangerous or unacceptable. The concept of displacement originated with Sigmund Freud. Initially he saw it as a means of dream-distortion, involving a shift of emphasis from important to … Continue reading Displacement

Quantum Key Distribution

Quantum key distribution (QKD) implements a cryptographic protocol involving components of quantum mechanics. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the best-known example of a quantum cryptographic … Continue reading Quantum Key Distribution

Monty Hall Problem

Monty Hall problem is a brain teaser, in the form of a probability puzzle. The problem was originally posed (and solved) in a letter by Steve Selvin to the American Statistician in 1975. The Monty Hall problem is mathematically closely related to the earlier Three Prisoners problem and to the much older Bertrand's box paradox. … Continue reading Monty Hall Problem

Large-Scale Brain Networks

Large-scale brain networks are collections of widespread brain regions showing functional connectivity by statistical analysis of the fMRI BOLD signal or other recording methods such as EEG, PET and MEG. An emerging paradigm in neuroscience is that cognitive tasks are performed not by individual brain regions working in isolation but by networks consisting of several … Continue reading Large-Scale Brain Networks

Solar Cell

Solar cell is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon. It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. Individual solar cell devices … Continue reading Solar Cell

The Cause of Radioactivity

Radioactivity is caused by emission of high energy radiation from unstable atomic nuclei. An atomic nucleus will be unstable if it has an excess of energy caused by an excess of either neutrons or protons. The nucleus will decay into a more stable atom (usually a different element) from the parent atom. ©Wikipedia An atom … Continue reading The Cause of Radioactivity

What is Apraxia?

Apraxia is a motor disorder caused by damage to the brain (specifically the posterior parietal cortex or corpus callosum) which causes difficulty with motor planning to perform tasks or movements. ©VeryWellHealth Apraxia is most often due to a lesion located in the dominant (usually left) hemisphere of the brain, typically in the frontal and parietal … Continue reading What is Apraxia?

Self-reconfiguring modular robot

Self-reconfigurable modular robots are autonomous kinematic machines with variable morphology. Beyond conventional actuation, sensing and control typically found in fixed-morphology robots, self-reconfiguring robots are also able to deliberately change their own shape by rearranging the connectivity of their parts, in order to adapt to new circumstances, perform new tasks, or recover from damage. For example, … Continue reading Self-reconfiguring modular robot

Seyfert Galaxy

Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei (very luminous, distant and bright sources of electromagnetic radiation) with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable. Seyfert galaxies were first detected in … Continue reading Seyfert Galaxy