- Materialism is a form of philosophical monism which holds that matter is the fundamental substance in nature, and that all things, including mental states and consciousness, are results of material interactions of material things. According to philosophical materialism, mind and consciousness are by-products or epiphenomena of material processes (such as the biochemistry of the human brain and nervous system), without which they cannot exist. Materialism directly contrasts with idealism, according to which consciousness is the fundamental substance of nature.
- Rubidium (Wikipedia)
Rubidium is a chemical element; it has symbol Rb and atomic number 37. It is a very soft, whitish-grey solid in the alkali metal group, similar to potassium and caesium. Rubidium is the first alkali metal in the group to have a density higher than water. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope 85Rb, and 28% is slightly radioactive 87Rb, with a half-life of 48.8 billion years – more than three times as long as the estimated age of the universe.