Dreams are hallucinations or images that we see during certain stages of sleep. They could be pleasant, nightmarish or just random and disjoined thoughts. Dreams are the most vivid during REM (Rapid Eye Movement) sleep, which you might not have any recollection when you wake up. There are multiple theories regarding our dreams. However, the […]
Common name : Pennant fish, Threadfin trevally, Cobblerfish, Cuban jack Scientific name : Alectis ciliaris Family : Carangidae Native to : Tropical coasts around the world Conservation status : Least Concern This beautiful silvery, iridescent fish lives in depths of less than 100 metres feeding on crustaceans and small fish. Juveniles float with the ocean
Common name : Hair seal, Counsellor seal Scientific name : Neophoca cinerea Family : Otariidae Native to : Australia and Indian Oceans Interesting fact : Excellent rock climbers Conservation status : Endangered Australian sea lions are ‘pinnipeds’, i.e. they use their fins as feet. They have different breeding seasons which range from 5 to
Lightning travels down the side of the tree-trunk and then encounters the person standing next to the trunk. This person is made up of slightly salty water which is a better conductor. Instead of just the tree-trunk, lightning strike finds that a combination of the two is much better. So, a subsidiary strike connects to
Why shouldn’t you stand under a tree that has been struck by lightning? Read More »
Common name : Tongue worms Scientific name : Enteropneusta Family : Enteropneusta Interesting fact : Its skin secretes a bromide compoundthat keeps bacteria and predators away. Conservation status : Not Evaluated True to its name, the worm-shaped marine invertebrate has 3 parts–an acorn-shaped proboscis, a short fleshy collar and a long trunk. They live in
The touch-me-not plant’s leaves close on touching due to a touch stimulus known as ‘thigmonasty’. This is a mechano-sensory response in the plant. Generally, the water and cell contents apply pressure to the cell wall allowing the plant and leaf to have a rigid structure, in the process. However, when disturbed, certain chemicals are released
Why do the leaves of a touch-me-not plant close when we touch them? Read More »
Common name : Red-spotted surgeonfish, Redtail surgeonfish, Redspot surgeonfish Scientific name : Acanthurus achilles Family : Acanthuridae Native to : Pacific coral reefs of Hawaii and Pitcairn Interesting fact : The scaly spikes on its back resemble a surgeon’s scalpel, and so it’s called a surgeonfish! Conservation status : Least Concern This beautiful tropical fish
It is usually the female mosquito that bites. It bites into a tiny blood vessel, injecting its saliva into its prey’s bloodstream and then sucking its blood. The contact between the mosquito and the prey’s skin must be six seconds long to bring a reaction. Chemicals, enzymes and proteins present in the mosquito’s saliva prevent
The outermost part of our skin, known as epidermis, is bundled with several nerve endings. These nerve endings are responsible for analyzing the touch and thereafter informing us whether it was pleasurable or not. The parts of our body which have the least bones are the most sensitive parts like the stomach or our feet
When bees sting, they release a chemical called ‘melittin’, into their victims. It is venom that immediately triggers pain receptors, causing a burning sensation. The bee’s stinger is like a jagged sword, which sometimes gets stuck in its victim’s skin and gets dislodged from the bee’s body. As long as it stays stuck in the
There are many theories regarding why we grunt when we lift heavy objects. The most popular is that when we grunt, we activate the autonomic nervous system. It is responsible for controlling the body’s flight or fight response. It also releases the adrenaline rush in these scenarios. This helps the muscle contractions be more complete
Why do we make grunting noises when we lift heavy things? Read More »
The sun-rays play a big role in tanning our skin. They have two types of ultraviolet radiation that reach our skin – UVA and UVB. The UVB rays burn the upper layer of the skin, epidermis, and lead to sunburns. The UVA radiation, on the other hand, reaches under the lower layers of epidermis and
Venom is harmful only when it gets beyond the gut and gets circulated in the body. It is actually a mixture of proteins and if we were to eat the snake and the poison sack, it would just get broken down by the stomach’s enzymes. Snake-venom is actually stored in the snake’s glands and does
A space shuttle is made up of four parts – the orbiter, the external fuel tank, and the two white boosters. Only the orbiter has wings and can fly like a plane. But its engines are not powerful enough on their own to get it up to orbital velocity. Without wings, launching horizontally doesn’t work
Why don’t space shuttles take off like airplanes? Read More »
Paper is mostly manufactured with an even distribution of cellulose fibres with small pores. When we write in ink, it moves down into the pores of the paper, where it will remain to dry. To erase off ink-marks, it is difficult for the rubber to separate the intermolecular forces. Therefore, it has to be physically
Why is it easy to erase off pencil-marks from paper but not ink-marks? Read More »