Blue Sky

The blue colour of the sky is due to the scattering of the sun’s light by molecules in the atmosphere. Known as the Tyndall effect or Tyndall scattering, is light scattering by particles in a colloid or particles in a fine suspension.

 As per theTyndall effect the shorter the light’s wavelengths, the more strongly it is reflected and scattered by these molecules. It is named after the 19th century physicist John Tyndall. He was the first to successfully answer the question “Why is the sky blue?”

Color receptors in the retina of the human eye are most responsive to wavelengths of red, green, and blue light. The wavelengths of blue light are shorter than those of both red and green light – therefore, the sky appears blue to the human eye.

Dogs and Chocolate

Chocolate chip cookies, chocolate candy bars, etc. are one of the most lethal substances a dog can ingest. Dogs love chocolate and once they have had it, even just a small amount, will begin to develop a craving for it no different from us humans! Most dogs have a sweet tooth and this is a perilous scenario when it comes to chocolate as they will seek it out if they smell it around the house, knowing that it is a treat that they have enjoyed before.

 Chocolate contains a natural occurring stimulant called theobromine found in the cocoa bean plant that makes chocolate. Theobromine is the poison as it affects the central nervous system, as well as the heart of the dog, throwing their system into panic which often manifests in the form of epileptic seizures.

Poison by chocolate can occur quickly if your dog had a large amount, but sometimes even small amounts will show signs of poisoning within a few short hours. Symptoms include vomiting and diarrhoea, restlessness and hyperactivity. Symptoms will progressively get worse from restlessness to arrhythmia and other muscle twitching. Frequent urination is common, a direct side effect of the toxin in chocolate.

To treat the dog of poisoning, first induce the vomiting. After that administer the charcoal. The sooner the dog ingests the charcoal, the sooner it will deactivate the dangerous effects of the poison.

The dirtiest item in the kitchen

The dirtiest item in Canadian homes is the kitchen towel, according to a study conducted by the Hygiene Council.

The study was conducted by the Hygiene Council, a group of international experts in microbiology, virology, infectious diseases, immunology and public health. Funded by Reckitt Benckiser, the makers of Lysol, the council makes recommendations to help improve hygiene in the home.

In an examination of 20 Canadian homes, the council's researchers found four contained kitchen towels that were highly contaminated with E. coli. The report recommends towels to be washed in water hotter than 60 C to kill the bacteria, which can cause severe cramping and bloody diarrhoea.

The council took various samples from 20 homes in each of nine countries, finding Germany and the U.S. had the cleanest kitchen towels, with 85 per cent of towels either spotless or at least satisfactory when it came to E. coli counts.

The council also assessed bacteria and mould, finding that they were most commonly found inside fridges and on seals around the bath or shower. People living in homes with high levels of mould report an increased incidence of asthma, respiratory infections and symptoms such as rhinitis, sore throat, cough and common cold.

The cleanest fridges were found in Canada and the U.S., where just five per cent had unsatisfactory levels of bacteria and mould.

Canada also ranked the highest in the bathroom seals category, with just 20 per cent failing the test for bacteria and 25 per cent failing for mould. The U.S. was the next cleanest for bathroom seals, with 40 per cent failing the bacterial test.

Aerogel




Aerogel is a manufactured material with the lowest bulk density of any known porous solid. It is derived from a gel in which the liquid component of the gel has been replaced with a gas. The result is an extremely low-density solid, with a notable effectiveness as a thermal insulator. It is nicknamed frozen smoke, solid smoke, solid air or blue smoke due to its translucent nature and the way light scatters in the material; however, it feels like expanded polystyrene to the touch.



Aerogel insulating a flower from a Bunsen burner flame



Aerogel was first created by Samuel Stephens Kistler in 1931, as a result of a bet with Charles Learned over who could replace the liquid in 'jellies' with gas without causing shrinkage.

Aerogels are produced by extracting the liquid component of a gel through supercritical drying. This allows the liquid to be slowly drawn off without causing the solid matrix in the gel to collapse from capillary action, as would happen with conventional evaporation. The first aerogels were produced from silica gels. Kistler's later work involved aerogels based on alumina, chromia and tin oxide. Carbon aerogels were first developed in the late 1980s.

Despite their name, aerogels are a rigid, dry material and do not resemble a gel in their physical properties; the name comes from the fact that they are derived from gels.

This exotic substance has many unusual properties, such as low thermal conductivity, refractive index and sound speed - in addition to its exceptional ability to capture fast moving dust.