SCIENCE with Ms Lun
Today in Science
February
2nd. World Wetlands Day (UN)
Covering only around 6 per cent of the Earth’s land surface, wetlands are vital as 40 per cent of all plant and animal species live or breed in wetlands. Wetland biodiversity matters for our health, our food supply, for tourism and for jobs. Wetlands are vital for humans, for other ecosystems and for our climate, providing essential ecosystem services such as water regulation, including flood control and water purification. More than a billion people across the world depend on wetlands for their livelihoods (about one in eight people on Earth).
New Zealand has lost 90% of its wetlands. Once covering 2.4 million hectares, only about 250,000 hectares remain. Unfortunately, more wetland area was lost to the recent fire in the Kaimaumau wetland in Northland.
Many critically endangered bird and plant species rely on wetlands, such as the kōtuku (or white heron) and the Australasian bittern.
7th Periodic Table Day
Today, we celebrate the Periodic Table and all its 118 elements. In 1869, Russian chemist, Dmitri Mendeleev (sometimes written as Dmitry Mendeleyev) constructed a table of elements based on their increasing atomic weight. He noticed similarities within groups of elements and periodic law was born. Mendeleev also predicted the atomic weights of several missing elements, as his table only consisted of 63 elements. Here are some interesting facts about he periodic table:
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Our modern day periodic table, only the letters J and Q are not used. Until recently, Q was present in the name of the 114th element, Uuq or Ununquadium, which was officially renamed as Flerovium, symbol, Fl.
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All elements above 92 do not exist naturally. They are synthetic and all radioactive.
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NZ-born, Nobel Prize winning scientist, Ernest Rutherford, has an element named after him (#104, Rutherfordium, symbol Rf.)
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The most expensive, naturally occurring element is francium. Although it occurs naturally, it decays rapidly and cannot be collected for use.
Mendeleev's first published periodic table
This appeared in the a volume of General Chemistry, 1869
8th Feb. Dmitri MENDELEEV. Born 1834. Died Feb 2, 1907 aged 72.
What: Russian chemist
Famous for: Developing the periodic table of the elements and periodic law.
Mendeleev or Dmitry Ivanovich Mendeleyev was born in Siberia but moved to St Petersburg for his education. After he became Professor of General Chemistry at the University of St Petersburg in 1867, he struggled to find a decent textbook to teach inorganic chemistry. So what did he do? He wrote his own one (he'd already written a hugely popular one on Organic Chemistry in 1861). Published in several volumes over several years (1868-1871), it contained his version of the periodic table.
12th: Charles Robert DARWIN born 1809. Died 19 Apr 1882, aged 73
English naturalist famous for his study into evolution. He introduce the theories of "natural selection" and "survival of the fittest". In 1831, he embarked on a 5 year voyage on the HMS Beagle to chart the coastline of South America. He spent a lot of time on land doing geological investigations as well as collecting natural history specimens. He published a book titled "On the Origin of Species" in 1859 and went to publish many more (including books on coral and plants). In 1839, he married his cousin, Emma Wedgewood. They had 10 children but 2 died before age two and another, Anne, died aged 10. Despite being plagued by an undiagnosed illness in the last 22 years of his life, he still continued to work. Three of his children were successful in their chosen fields and received knighthoods.
15th: Galileo di Vincenzo Bonaiuti de' GALILEI born 1564. Died 8 Jan 1642, aged 77
Italian astronomer, physicist and engineer. He investigated speed and velocity; gravity and free fall; the principle of relativity; inertia; projectile motion and described the properties of pendulums and hydrostatic balances.
He invented the thermoscope and various military compasses. While he didn't invent the telescope, he made improvements to them (up to 30 times higher magnification) and through his observations, he confirmed the phases of Venus, observed the four largest satellites of Jupiter, observed Saturn's rings, and the analysed sunspots.
Above: Galileo portrait by Justus Sustermans (1636)
Below: The Sector, a compass invented by Galileo
Galileo believed in Copernican heliocentrism (the model proposed by scientist Nicolaus Copernicus in 1543 that the planets orbit around a central sun) but this went against the Roman catholic church beliefs and those of some fellow scientist. He was charged with heresy, became alienated from his former supporter the Pope, and lived the rest of his life under house arrest.
In 1718, a ban on publishing Galileo's work was lifted. Galileo is considered by some (including Albert Einstein and Stephen Hawking) to be the father of modern science.
