20

Any position of a standard cube can be solved in twenty moves or fewer, proved in 2010 by exhaustive computation across all 43 quintillion positions. The figure is known informally as God's number.

There are 20 primary teeth in a child (children before the adult set erupts).

There are 20 amino acids specified by the standard genetic code (almost all life; two more are used by some organisms). Selenocysteine and pyrrolysine bring the total to twenty-two in the organisms that use them.

There are about 20 seconds of retention in short-term memory without rehearsal (laboratory studies with rehearsal prevented). The range across studies is roughly 15 to 30 seconds. It is why a phone number survives the walk to the keypad and not the interruption on the way.

There are roughly 20 quadrillion ants alive at any moment. The estimate carries a wide margin and is derived from sampling. Figure as of 2022. A 2022 synthesis put the figure at about 20 quadrillion, with a total mass exceeding that of all wild birds and mammals combined.

There are about 20 thousand protein-coding genes in the human genome (humans). Before the genome was sequenced the expected figure was around 100,000. Being wrong by a factor of five is what led to the discovery that one gene can code for many proteins.

There are roughly 20 thousand species of bee. Most are solitary. The honeybee that the word usually calls to mind is one species out of twenty thousand.

There are about 20 thousand breaths taken in a day (adults at rest). Moving roughly 11,000 litres of air, almost none of which is noticed.

20 is the atomic number of calcium. Roughly a kilogram of it sits in an adult human skeleton as the mineral that makes bone rigid, and it is equally central to shells, limestone and cement.

There are 20 feet in the standard shipping container unit (worldwide, ISO). Port traffic is counted in twenty-foot equivalent units, so a forty-foot box counts as two. Containerisation is often credited with cutting the cost of moving goods by sea by more than an order of magnitude.

There are about 20 moving parts in a typical electric-car drivetrain (worldwide, approximate). An internal-combustion drivetrain has on the order of two thousand. The difference is most of the maintenance argument for electric vehicles, and most of the disruption to the parts industry.

The altitude of a GPS satellite is about 20 thousand kilometres. 20,200 kilometres, half a geostationary orbit and twice round the Earth a day. At that speed and altitude the satellites' clocks run measurably fast, and the correction is relativistic.

CWE-20 is improper input validation, a broad parent class. Its breadth is a recognised weakness of the taxonomy itself, since almost any specific defect can be described as a validation failure.

A 20-year anniversary is named for china in the modern gift lists. Porcelain in several European lists. Twenty is one of the years where national lists diverge most.

In the history of Maya and other Mesoamerican cultures, counting was done in twenties rather than tens, with place values of 1, 20, 400 and 8,000. Fingers and toes rather than fingers alone. Traces survive in French quatre-vingts for eighty and in the English score. This is a scholarly account rather than the tradition's own framing.

20/20 is the standard clinical benchmark for normal visual acuity; separately, 'a score' is a traditional English unit meaning twenty, as in Lincoln's Gettysburg Address opening 'four score and seven years ago'.

A dartboard carries twenty numbered segments, with 20 at the top. The ordering is deliberately hostile: high numbers sit beside low ones, so 20 is flanked by 1 and 5, and a narrow miss is heavily punished. The treble 20 is the highest score a single dart can achieve at 60.