2019 Top Ten of Polemic for Nature

List of tectonic plate interactions

Tectonic plate interactions are classified into three basic types:Divergent boundaries are areas where plates move away from each other, forming either mid-ocean ridges or rift valleys. These are also known as constructive boundaries. Convergent boundaries are areas where plates move toward each other and collide. These are also known as compressional or destructive boundaries. Subduction zones occur where an oceanic plate meets a continental plate and is pushed underneath it. Subduction zones are marked

Square watermelon

Square or cube watermelons are watermelons grown into the shape of a cube. Cube watermelons are commonly sold in Japan, where they are essentially ornamental and are often very expensive, with prices as high as US$200

Mousetrap car

A mousetrap car is a small vehicle whose only source of motive power is a mousetrap. Variations include the use of multiple traps, or very big rat traps, for added power

Contact force

A contact force is any force that requires contact to occur. Contact forces are ubiquitous and are responsible for most visible interactions between macroscopic collections of matter. Pushing a car up a hill or kicking a ball across a room are some of the everyday examples where contact forces are at work. In the first case the force is continuously applied by the person on the car, while in the second case the force is delivered in a short impulse. Contact forces are often decomposed into orthogonal

Crest and trough

A crest point on a wave is the maximum value of upward displacement within a cycle. A crest is a point on a surface wave where the displacement of the medium is at a maximum. A trough is the opposite of a crest, so the minimum or lowest point in a cycle

Secondary research

Secondary research involves the summary, collation and/or synthesis of existing research. Secondary research is contrasted with primary research in that primary research involves the generation of data, whereas secondary research uses primary research sources as a source of data for analysis. A notable marker of primary research is the inclusion of a "methods" section, where the authors describe how the data was generated

Deposition (phase transition)

Deposition is the phase transition in which gas transforms into solid without passing through the liquid phase. Deposition is a thermodynamic process. The reverse of deposition is sublimation and hence sometimes deposition is called desublimation

Parable of the Lost Sheep

The Parable of the Lost Sheep is one of the parables of Jesus. It appears in the Gospels of Matthew and Luke. It is about a shepherd who leaves his flock of ninety-nine sheep in order to find the one which is lost. It is the first member of a trilogy about redemption that Jesus tells after the Pharisees and religious leaders accuse him of welcoming and eating with "sinners

Parent material

Parent material is the underlying geological material in which soil horizons form. Soils typically inherit a great deal of structure and minerals from their parent material, and, as such, are often classified based upon their contents of consolidated or unconsolidated mineral material that has undergone some degree of physical or chemical weathering and the mode by which the materials were most recently transported

Thermal pollution

Thermal pollution, sometimes called "thermal enrichment", is the degradation of water quality by any process that changes ambient water temperature. Thermal pollution is the rise or fall in the temperature of a natural body of water caused by human influence. Thermal pollution, unlike chemical pollution, results in a change in the physical properties of water. A common cause of thermal pollution is the use of water as a coolant by power plants and industrial manufacturers. Urban runoff—stormwater