A placebo is a medicine or treatment intended to appear genuine, but actually have no pharmaceutical effect, such as inert sugar pills. The placebo effect is a genuine psychobiological phenomenon in which the mere expectation of improvement from a placebo can lead to some actual physiological changes. Modern studies find that placebos can affect some outcomes such as pain and nausea, but otherwise do not generally have important clinical effects. There is also the effect called a nocebo effect. The nocebo effect is falling ill simply by consciously or subconsciously anticipating a harmful event. Both placebo and nocebo effects are presumably psychogenic but can induce measurable changes in the body.
Energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. The law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be conserved over time. In the case of a closed system, the principle says that the total amount of energy within the system can only be changed through energy entering or leaving the system. Special relativity shows that mass is related to energy and vice versa by E = mc2, the equation representing mass–energy equivalence, and science now takes the view that mass-energy as a whole is conserved. This implies that mass can be converted to energy, and vice versa.
Hormones play a very large part in the physiological processes of the body. The endocrine system consists of numerous glands throughout the body that produce and secrete hormones of diverse chemical structure, including peptides, steroids, and neuroamines. The nervous system and the endocrine system are linked in a process known as neuroendocrine integration. The neuroendocrine system is the mechanism by which the hypothalamus maintains homeostasis, regulating reproduction, metabolism, eating and drinking behaviour, energy utilization, osmolarity and blood pressure. Neuroendocrinology is the branch of biology (specifically of physiology) which studies the interaction between the nervous system and the endocrine system; i.e. how the brain regulates the hormonal activity in the body.
Meganeuropsis permiana was considered the largest insect of all time, it was a dragonfly relative with an estimated wingspan of around 710 mm (28 in). It existed before the dinosaurs, during the Artinskian age of the Permian period, 290.1–283.5 million years ago. There are several theories as to why insects were so big during this time. One theory was that oxygen levels in the atmosphere were significantly higher than today, although there is some controversy regarding this theory. Another theory was that insects at the time were at the top of the food-chain, with few predators.
Meganeuropsis Werner Kraus, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons
In psychology, cognitive dissonance is a phenomenon where people unknowingly or subconsciously hold fundamentally conflicting cognitions (mental processes). Being confronted by situations that create this dissonance or highlight these inconsistencies can cause stress (discomfort) and motivates change in their thoughts or actions to reduce this dissonance. Persons who experience internal inconsistency tend to become psychologically uncomfortable and are motivated to reduce the cognitive dissonance in several ways, such as: rationalization (justifying the behavior), using a just-world fallacy, using selective perception (ignoring some info), or avoiding information (resulting in confirmation bias).
