Color Me Purple Part 9 - The Science of Purple Quiz

Answer: non-spectral color

Of those listed, only non-spectral color is a real thing in the field of optics. While purple exists in the art world, and in other aspects, it's not a naturally occurring color. While many people consider purple as a base color, with violet being a variation, the color violet appears naturally and was described by Isaac Newton when he identified the colors with their own wavelengths. Purple does not.

(Question by Shadowmyst2004)

Answer: magenta

While displays use the RGB model that combines red, blue, and green light into the range of colors visible to the human eye, printers use the CYMK model. This means they use cyan (a greenish-blue color, also called aqua), yellow, magenta, and black inks. The magenta ink absorbs green light but transmits red and blue light. The cyan ink absorbs red light but transmits green and blue light. The yellow ink absorbs blue light but transmits red and green. Black ink, of course, absorbs all the light. The white paper on which the inks are printed reflects the transmitted red, green, and, blue light back to the eyes of the onlooker. In this way, varying combinations of inks produce a large range of the colors that humans can perceive.

(Question by gracious1)

Answer: hematite and manganese

Pigments of both hematite and manganese were used to create the colour purple, by Neolithic and New Stone Age artists. These minerals were finely ground before being mixed with fat, and finally moulded into sticks to be used for painting. Manganese was also later used by the Romans to colour glass purple.

Cadmium and chromium pigments were mainly used to provide the colour yellow, although cadmium was also used to create both red and orange. Mercury pigments were mainly used to create the bright red colour vermilion, whilst iron oxide provided various shades of red.

(Question by moonraker2)

Answer: photosynthesis

The word for species like purple bacteria is 'phototrophic', in that they use light energy to carry out metabolic processes, often by converting carbon dioxide into organic material. Unlike plants, they do not produce oxygen; in fact, they were the first bacteria discovered to use photosynthesis, without creating oxygen as a byproduct (some of them produce sulphur instead). Purple bacteria get their purple colour from bacteriochlorophyll, a photosynthetic pigment, and carotenoids, although they can be red, orange or brown as well.

(Question by Kankurette)

Answer: Nexium

All of the products listed were made by AstraZeneca. Prilosec is omeprazole, now sold over-the-counter (OTC). What the company did was not invent a new drug, but instead they isolated one of the isomers, esomeprazole, and marketed it as Nexium.

There has been much controversy about whether or not this deserved a patent, but it was granted one. With claims of improved results (there is controversy around these as well), Nexium would reap significant financial benefits for the company. Nexium too is now available over-the-counter.

(Question by mlcmlc)

Answer: foxglove

A native of temperate Europe, Digitalis purpurea belongs to the family Plantaginaceae. It is often cultivated as a garden plant because of its distinctive flowers, which grow in an elongated cluster and are typically purple, though other colours may also occur. The tubular flowers, whose inside surface is covered in spots, are reminiscent of fingers - hence the plant's common and scientific names. All parts of a foxglove are poisonous to humans and some animals because of the presence of digitoxin and digoxin, two organic compounds of of the class of cardiac glycosides, used to treat atrial fibrillation and heart failure. Both these compounds are highly toxic and potentially fatal.

The three incorrect choices are all poisonous plants with showy flowers.

(Question by LadyNym)

Answer: impurities in one of his chemicals

He was actually trying to produce quinine by oxidising aniline with potassium dichromate. The potassium dichromate contained several different closely-related aromatic compounds in the toluidine family. He therefore got a black solid instead of the desired quinine. Fortunately, as he was cleaning up, he noticed that the product dissolved in alcohol to form a purple liquid, and went on to investigate it. He quickly realised that this, one of the first aniline dyes, would make an excellent commercial proposition, patented his process, and set up a manufacturing plant. His original name for the dye was aniline purple; in 1859 it was renamed mauve, using the French name for a flower with that color. Chemists finally settled on mauveine, combining the color and the chemical class into a single word.

(Question by looney_tunes)

Answer: iodine

Like all of the choices listed, iodine is a halogen, or salt-producing element. Iodine is important in the prevention of health problems such as goiter (enlarged thyroid), and the introduction of iodized salt to the United States in the 1920s has been cited as a reason for a marked reduction of that ailment.

(Question by spanishliz)

Answer: Rayleigh scattering

Also known as atmospheric perspective, and noted as far back as the days of the great Leonardo da Vinci, the purple colour registered by our eyes is known as Rayleigh Scattering. This is because the colour blue (as in the sky) has what is known as a short wavelength, whereas red, for example, has a longer wavelength - and shorter wavelengths are scattered far more frequently by air. This allows more red light wavelengths to be received by the eye, particularly at dawn and sunset, thus making distant mountains appear purple.

(Question by Creedy)

Answer: hydrogen

Along with the presence of additional hydrogen, distortion of the crystal lattice also helps to give diamonds a purple tint. Purple diamonds can also be known by several other names including lavender diamonds or lilac diamonds. Purple diamonds can be found in both nature and man-made. The Argyle Mine in Australia is one of the more common (relatively speaking) sources of purple diamonds.

(Question by bernie73)