Type: Prelims Only

Engineers in the US have created what they are calling the whitest paint yet.

What is the whitest paint?

• The researchers created an ultra-white paint pushing the limits of how white paint can be.
• This older formulation was made of calcium carbonate, while the new one is made up of barium sulphate, which makes it more white.
• The newer paint is whiter and keeps the surface areas it is painted on cooler than the formulation before this could.
• If this new paint was used to cover a roof area of 1,000 square feet, it may be able to get a cooling power of 10 kilowatts.
• Most ovens use up about 2.3 kilowatts to run for an hour and a 3 ton 12 Seasonal Energy Efficiency Ratio (SEER) air conditioner uses up about 3 kilowatts to run for an hour.

The researchers have claimed that this paint may be the closest equivalent to the blackest black paint called “Vantablack” which is able to absorb up to 99.9 per cent of visible light.

What determines if a colour absorbs or reflects light?

• To understand how this works one needs to note that whenever an object is seen by the eye, it is either because of sunlight or the artificial light in the room.
• This light is made up of seven different colours (Violet, Indigo, Blue, Green, Yellow, Orange and Red or VIBGYOR).
• Specifically, light is made up of wavelengths of different colours.
• If an individual is looking at a sofa that is green, this is because the fabric or material it is made up of is able to absorb all the colours except green.
• This means that the molecules of the fabric reflect the green coloured wavelengths, which is what the eye sees.
• Therefore, the colour of any object or thing is determined by the wavelength the molecules are not able to absorb.

Try this PYQ:

Q.Rainbow is produced when sunlight falls on drops of rain. Which of the following physical phenomena are responsible for this?

1. Dispersion
2. Refraction
3. Internal reflection

Select the correct answer using the codes given below:

a) 1 and 2 only

b) 2 and 3 only

c) 1 and 3 only

d) 1, 2 and 3

What determines which wavelength of light will be reflected and absorbed?

• This is dependent on how electrons are arranged in an atom (the building block of life, an atom is made up of electrons, protons and neutrons.
• These three particles make up everything in the known universe from mountains, planets, humans to pizza and cake).
• In contrast, if an object is black, it is because it has absorbed all the wavelengths and therefore no light is reflected from them.
• This is the reason that darker objects, as a result absorbing all wavelengths tend to heat up faster (during absorption the light energy is converted into heat energy).

So, what makes the paint so white?

There are two features:

1. One is the paint’s high concentration of a chemical compound called barium sulfate, which is also used to make photo paper and cosmetics white.
2. The second feature is that the team has used different sized particles of this chemical compound, which means different sizes scatter different amounts of light.

In this way, the varying size of particles of the compound makes sure that the paint can scatter more of the light spectrum from the sun.

The Tiki Formation in Madhya Pradesh, a treasure trove of vertebrate fossils, has now yielded a new species and two genera of cynodonts, small rat-like animals that lived about 220 million years ago.

Tiki Formation

• The Tiki Formation is a Late Triassic geologic formation in Madhya Pradesh.
• Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.
• Phytosaur remains attributable to the genus Volcanosuchus have also been found in the Tiki Formation.
• The genera Tikiodon, Tikitherium and Tikisuchus and species Rewaconodon tikiensis, Hyperodapedon tikiensis and Parvodus tikiensis have been named after the Tiki Formation.

Findings of the new study

• The fossil teeth were studied for size, crown shape, structure of the cusps and compared with previously reported cynodonts.
• Cynodonts are important in evolutionary studies as this group ultimately gave rise to the present-day mammals.
• By studying their molar and premolar teeth, we see how they slowly evolved and modified.
• Their crown shape shows that these animals are actually intermediate forms that are very near to the mammalian line of evolution.
• Cynodonts and living mammals both belong to a group of egg-laying vertebrates (amniotes) called synapsids.
• The close relationship of cynodonts with living mammals is seen in their bones.

Azhdarchid pterosaurs, the giant reptiles that flew in the skies nearly 65 million years ago, had necks longer than that of a giraffe (i.e. more than 6fts).

What are pterosaurs?

• Pterosaurs are reptiles that are close cousins of dinosaurs, the first animals after insects to evolve powered flight.
• Some pterosaurs were as large as an F-16 fighter jet, while others were as small as a paper aeroplane.
• Pterosaurs went extinct about 65-66 million years ago (end of the Cretaceous period) and while they did not leave any of their descendants behind.
• One reason for this is that few pterosaurs lived in places where fossils tend to form, because of which their bones are preserved poorly.

Revise the geological timescale from your NCERT textbook.

Azhdarchid pterosaurs

• They are one type of pterosaur and one of the distinguishing characteristics about them is how big they were, especially their long necks.
• Some of these pterosaurs were the largest animals to have flown in the sky, with wingspans greater than 30 feet.
• The name azhdarchid, as per a blog on Scientific American comes from Azhdarcho, a Central Asian form named by Russian ornithologist and palaeontologist in 1984.

What have the researchers found?

• Researchers involved in this study were curious about how the reptile’s long neck functioned and how it was able to support the pterosaur’s body, allowing them to capture and eat heavy prey animals.

Researchers have described a pterosaur species with opposable thumbs, which could likely be the earliest-known instance of the limb.

Monkeydactyl

• The pterosaur species were reptiles, close cousins of dinosaurs and the first animals after insects to evolve powered flight.
• They evolved into various species; while some were as large as an F-16 fighter jet, others were as small as paper aeroplanes.
• The new pterosaur fossil was discovered in the Tiaojishan Formation of Liaoning, China, and is thought to be 160 million years old.
• It has now been described by an international team of researchers from China, Brazil, the UK, Denmark and Japan, and has been named Kunpengopterus antipollicatus, also dubbed “Monkeydactyl”.

What has the team found?

• “Antipollicatus” in ancient Greek means “opposite thumbs”, and it was attached to the name because the researchers’ findings could be the first discovery of a pterosaur with an opposed thumb.
• Researchers suggested that K. antipollicatus could have used its hand for grasping, which is likely an adaptation for arboreal life.

What makes it special?

• Opposability of the thumb enables the species to “simultaneously flex, abduct and medially rotate the thumb” in a way that one is able to bring the tip of the thumb to touch the tips of the other fingers.
• Along with humans, some ancient monkeys and apes also had opposable thumbs. Humans, however, have a relatively long and distally placed thumb, and larger thumb muscles.
• This means that humans’ tip-to-tip precision grip when holding smaller objects is superior to non-human primates.
• This is the reason that humans are able to hold a pen, unscrew an earring stopper, or put a thread through a needle hole.
• The grasping hands of primates developed as a result of their life in the trees — an opposable thumb made it easier for the common ancestor of all primates to cling on to tree branches.

Try this PYQ:

Q.Some species of plants are insectivorous. Why?

(a) Their growth in shady and dark places does not allow them to undertake sufficient photosynthesis and thus they depend on insects for nutrition

(b) They are adapted to grow in nitrogen deficient soils and thus depend on insects for sufficient nitrogenous nutrition

(c) They cannot synthesize certain vitamins themselves and depend on the insects digested by them

(d) They have remained in that particular stage of evolution as living fossils, a link between autotrophs and heterotrophs