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The stems of succulent plants have a low surface to volume ratio and store large amounts of water. These plants are common in desert environments.

The leaves of most succulents form a fibonacci (golden mean) spiral.

A tree is a living structure in nature that has undergone 9 or more levels of fractal complexity.

Tubers are swollen regions of stems that store food for subsequent growth. The potato is an example. It is a stem because it has many nodes called eyes with spaces between eyes known as internodes. Potato tubers develop at the end of swollen underground stem structures, rhizomes.

Eyes of potatoes are really axillary buds which contain several small buds at each site. These buds can expand to form shoots which grow on to make whole plants. Although the common potato is a stem, the sweet potato is a modified root!


In physics, the zero-point energy is the lowest possible energy that a quantum mechanical physical system may have and is the energy of the ground state. The quantum mechanical system that encapsulates this energy is the zero-point field. The concept was first proposed by Albert Einstein and Otto Stern in 1913. The term "zero-point energy" is a calque of the German Nullpunktenergie. All quantum mechanical systems have a zero-point energy. The term arises commonly in reference to the ground state of the quantum harmonic oscillator and its null oscillations.

Zero-point energy is sometimes used as a synonym for the vacuum energy, an amount of energy associated with the vacuum of empty space. When the term is used in this way, sometimes it is referred to as the quantum vacuum zero point energy. In cosmology, the vacuum energy is one possible explanation for the cosmological constant. The variation in zero-point energy as the boundaries of a region of vacuum move leads to the Casimir effect, which is observable in nanoscale devices.

A related term is zero-point field, which is the lowest energy state of a field; i.e. its ground state, which is non-zero.