Doodle Science - July 2011



Circulated to schools, organisations and individuals - covering primary science and related bits and bobs.

Sundog



























The above image is of a sundog, or mock sun.

These are caused by light being refracted by ice crystals in the high atmosphere, the differing shapes of the crystals can cause a varying effects.

The most spectacular of these phenomena are arcs across the sky ans one of the commonest is the circumzenthal arc.

These are apparently more common than rainbows but people do not see them as they spend their time looking down.

See Atmospheric Optics for pictures and information.

Great Dates in Sci and Tech for July
1st 1858 ~ Darwin and Russel's point paper on Natural selection is read to the Linnean Society.

3rd 1844 ~ the last pair of Great Auks is killed

also the 3rd in 1886 ~ Benz unveils the first purpose built car.

10th 1962 ~ Telstar is launched, the first communications satellite

10th again in 1997 ~ Scientists announce that DNA evidence supports the out of Africa theory of human evolution placing "African Eve" at between 100,000 and 200,000 years ago.

19th 1912 ~ a meteorite explodes over Holbrook Arizona and showers 16,000 bits on the town.

21st 1969 ~ Armstrong and Aldrin walk on the Moon.

25th 1978 ~ the first test tube baby is born.

Something to try

Making a mess with bubbles.

To make a good and inexpensive bubble mixture, take 100 ml cup of washing up liquid 1L water (soft water is best - if your water is very hard consider using distilled or bottled water) 2 tablespoons glycerine (available from a chemist).

You can substitute light corn syrup (not golden syrup!)

The more expensive washing up liquid works best I'm afraid.

Mix the ingredients together very carefully, so that you they don't get too bubbly. Pour into storage containers and, if possible, leave overnight to blend.

To make large bubbles, use a large plastic bottle and cut the bottom off to make a large spout.

To produce truly huge bubbles take string 60 cm long and thread two straws onto it and then tie into a loop. Dip into bubble mixture and then pull out holding by one straw. When gently wafted in the air it will produce massive bubbles.

Health and safety
Do not drink the mixture. Wash hands after handling.

Web site well worth a visit
is this DRB's Magnificent Trees feature

and have a look at Science Inquirer for useful things.