Chess is a complicated game. The computer program views it as a tree
structure of all possible moves corresponding to every possible move of the opponent. But, this entire tree
would consist of 10^120 board positions. Just as a comparison, the age of the universe from the Big Bang is
only 10^26 nanoseconds. Hence, even powerful computers create only 10 to 20 moves into the future. An
evaluation function might assign points to each chess piece depending on its value. The program then tries
to maximise the total points on the board compared to the opponent to win the game.
Pitcher plants have prey trapping mechanism and are known as
carnivorous plants. The leaves get modified into a pitfall trap which helps in grabbing insects and other
small organisms. The rim of the pitcher is slippery and possess nectar which attracts the insects. The plant
has waxy scales with circular folds inward to ensure that the insect cannot climb out. Gradually the insect
body gets dissolved in the pitcher. These plants naturally grow in soil which lack minerals or if the soil
is too acidic.
The popcorn seed or kernel consists of a semi-permeable shell (called
pericarp), sufficient water content and starch. These three components work together to make popcorns pop
when heated. When we heat the popcorn kernels, the water inside it converts into steam and starts to expand,
and the starch inside it turns into a gel-like substance. The steam, being enclosed within the shell, cannot
go out. When the shell can no longer withstand the pressure, the kernel explodes - POP - releasing the steam
and the gel. When this gel comes in contact with air, it rapidly solidifies forming fluffy popcorn.
Rovers are one of the several different types of spacecraft sent to
Mars. A rover can drive around different areas, studying different chemicals, rocks, and soil, which may
also give us evidence for extraterrestrial life. Until now, NASA has sent four rovers - Sojourner, Spirit,
Opportunity, and Curiosity. These rovers come equipped with toolkits which are used to study precisely
different things. Rovers derive their power from the solar panels attached to them. The new Perseverance
Rover launched on 30 July 2020, is expected to reach the Jezero crater on Mars on 18 February 2021.
They lose their tail to defend themselves from predators. When a lizard
detaches its tail, the tail whips around and wiggles on the ground.Sometimes the tail keeps moving for
half-an-hour as the nerves are active and are still communicating with each other. This behaviour helps to
distract the predator. When the new tail grows back, it is a bit different from the earlier one. The new
tail is made of cartilage, so it takes time to regrow. Some squirrels also lose their tail, but their tails
don't grow back again.
The Northern Lights are most visible in the night from the belt which
connects Central Alaska, Canada, the southern tip of Greenland, Iceland and the Northern parts of
Scandinavia. The sun produces solar winds consisting of a large amount of erupted gas that is hurled out
into space. The particles of the solar wind get deflected by the earth's magnetosphere towards the poles.
These high-speed beams of particles collide with the Nitrogen and Oxygen atoms in the earth's atmosphere and
excite them to the state that they start emitting colourful dazzling lights. This phenomenon is called the
Rapid Antigen Test detects the presence of viral nucleoproteins
(antigens) expressed by COVID-19 virus in the nasal swab sample within 20 mins. The swab is processed with
reagents to disrupt the particles of the virus and expose the antigens. If the target antigen is present in
sufficient concentration, it will bind to the antibodies fixed in the test strip and produce coloured lines
confirming the presence of COVID-19. However, this test can detect less than 60% of all positive cases.
Therefore, if the rapid antigen test result is not positive, it has to be followed by the slower RT-PCR
What are the different sleep stages and how does the cycle
The three sleep stages are - Rapid Eye Movement (REM) Sleep, Deep Sleep
and Light Sleep. Light and deep sleep are about 20% while REM is 50% of the night. You stay awake for the
remaining 10%. Every sleep cycle ends with REM, the stage where you dream and the body paralyses itself as a
defence mechanism. However, sleep talking and walking are not dreams but part of your deep sleep. This stage
is mostly in the first half of the night. It induces immunity and growth hormones and is the most important
part of the cycle. Never wake up a person from deep sleep.
Shanghai Maglev, the fastest train, reaches a whopping operational
speed of 430 km/hour. The word maglev comes from 'magnet' and 'levitation'. The train doesn't run on wheels
on tracks but floats over a magnetized coil running along the track, called a guideway. The maglev track
allows the train to float with repelling magnets. A constantly alternating polarity of the magnetized coils
creates a unique magnetic field in front of the train to pull the vehicle forward, and another magnetic
field behind the train adds more forward thrust. The aerodynamic design and lack of friction help Maglev
trains reach such high speeds.
It is the aquatic eight-legged 'Tardigrade' which is microscopic and
can survive an apocalypse or mass extinctions. Hence, they belong to the category of animals called
extremophiles. They exhibit a survival strategy called cryptobiosis, where they can become dormant until
conditions improve. They can live without food and water for up to 30 years, tolerate extreme temperatures
and even survive in the vacuum of space. They contain a unique protein known as Dsup (damage suppressor)
that protects their DNA from harmful radiations. They have survived for 600 million years, preceding
dinosaurs by about 400 million years.
On November 3rd 1957, the Soviets launched the first-ever living
creature to space. It was Laika - the space dog. Picked from the streets of Moscow, Laika was a small and
calm dog. The mission was a guaranteed suicide mission as there was no technology to de-orbit her back to
Earth. The Russians sent her on the Sputnik-2 spacecraft. The main aim was to see how long a living creature
could survive on Earth’s orbit. Unfortunately, the cooling system inside the spacecraft failed; and the
temperature increased, which Laika couldn’t withstand. Laika paved the way for other cosmonauts with her
The twin paradox is an interesting thought experiment involving two
identical twins, one of whom moves through space in a high-speed spaceship (86.6% of the speed of light)
returns and finds her twin who stayed on earth has aged more. For the twin travelling in the spaceship, her
biological processes like heartbeats and her rate of ageing will also slow down. The very perception of time
will change. The faster you move through space, the slower you move through time compared to an unmoving
observer. This phenomenon of slowing down of time is known as 'time dilation'.
We know that loss of sleep makes people ill-tempered and depressed. A
recent study showed that less sleep is better than longer periods of interrupted sleep for our positive
mood. The experiment concluded that interrupted sleep lacked slow-wave sleep, which is associated with the
reduction in positive mood. In interrupted sleep, any interruptions can break into our sleep cycle
unpredictably at random times, thereby disturbing the regular sleep pattern. However, if we wake up at the
end of each sleep cycle, the impact on our mood won't be that adverse.
According to Einstein’s general theory of relativity, when an object
moves faster, its mass increases and length decreases. As an object approaches the speed of light, its mass
would become infinite and length nearly zero - an impossibility. So, an infinite amount of energy would be
required to speed up the object to the speed of light. Light is composed of massless photons, which possess
natural energy as they travel in waves. This makes it possible for light to reach a speed of 299,792,458 m/s
in vacuum. Paradoxically, the Universe expands at speeds greater than the speed of light.
Mother spiders make the ultimate sacrifice for their young ones. Not
just mothers, but other female spiders also go to extreme lengths to save the colony's young ones. After the
eggs hatch, the mother and the other female spiders begin producing a nourishing fluid, which consumes
almost all their resources. In the end, the female spiders start to liquefy. The off-springs will finally
crawl onto the depleted mother and start eating her. This process is known as 'matriphagy' and is an
effective means of survival for these species. It is a rare behaviour found in some spiders, insects and
Plants require sunlight to make their food, but they also need
protection from its harmful rays. If plants are exposed to harsh ultraviolet radiations daily, then it may
cause damage to the plant DNA. Plants can make their chemical sunscreen, which protects plants from harmful
solar radiation (sunburn) and allows them to carry on photosynthesis. These natural sunscreens protect the
plants much in the same way that sunscreen lotions protect the human skin from the dangerous effects of
ultraviolet light exposures.
Wireless charging works by transferring energy from the charger to a
receiver on the back of the device via electromagnetic induction, which discovered by Michael Farraday in
1831. Charging pads work on the principle that a time-varying magnetic field induces a current in a coil.
There are three types of wireless charging: tightly-coupled inductive, loosely-coupled resonant and
uncoupled charging. Charging pads that are in usage today use the first two methods. The third method
promises the possibility of contact-less wireless charging in the future. It can work just like a wifi
network and charge all our devices.
Helium is an inert gas and is used to inflate blimps and balloons. For
a Helium-filled balloon to rise in the atmosphere, it must be lighter than the weight of the volume of air
displaced by it. This phenomenon is called buoyancy. Gravity pulls the heavier air displaced by the balloon
towards the Earth, and hence the Helium balloon goes up. In the absence of gravity, there would be no
specific direction for the balloon to move. As the balloon ascends, the pressure of the surrounding air
decreases and the Helium inside expands. Finally, the Helium balloon bursts.
Every virus evolves to target a particular species. So, after the
initial evolution, the virus tends to jump from the host to a target species. When the virus passes to the
new host (a process called zoonosis), it often causes more severe diseases. Because viruses and their
initial hosts have evolved together, the initial host has had time to build up resistance. However, the new
host species might not have evolved the ability to tackle the virus. Thus, if humans come in contact with
animals bearing the virus, humans may develop deadly diseases, while those animals are themselves less
Lying makes the heart race, drives up the blood pressure, and makes
people sweat. The polygraph uses these physiological changes to detect lies. The machine needs to baseline
the vitals, and hence it needs to be calibrated with some “control” questions. The polygraph compares these
reactions to those of the relevant questions. A simple way to beat the lie-detector is to induce stress
while answering the control questions and keeping calm while answering the relevant ones. Biting the tongue,
imagining a fall from a building, or trying to solve a difficult math problem can distort the baseline
A virus such as COVID-19 can spread like wildfire when no one is immune
to the virus. When a fraction of the population becomes immune through natural exposure to the virus or
vaccination, the spread slows down. Herd immunity is a state where immune individuals will protect
non-immune individuals from the virus by slowing it down. Herd immunity depends on the reproductive rate of
the virus (R0), which is the average number of people that an infected person could spread the virus. Herd
immunity happens when (R0 - 1)/R0 fraction of the population becomes immune to the virus.
Mayflies are aquatic insects with the shortest lifespan of about 24
hours. Actually, they consume algae in the larval stage for 1-2 years to emerge as winged adults. After they
shed their larval shells, they have only 24 hours to take to the air, find a mate, breed and die. Adult
mayflies don’t have functional mouth and don’t eat. They emerge in summer months in large numbers and are
hence known as ‘mayflies’. Mayflies can only survive in clean water environments. The presence or absence of
Mayfly larvae is an important indicator of water pollution.
Quarks are one of the most fundamental units of matter. They are the
smallest thing in the universe. They are bound together by strong force carried by hypothetical particles
called gluons and form ‘hadrons’ such as pions, neutrons and protons. Quarks sometimes pair with
anti-quarks, which are identical to quarks but with some opposite nature. The evidence for their existence
came from a series of inelastic electron-neutron scattering experiments carried out at the Stanford Linear
Accelerator Centre. Until now, six types of quarks have been discovered: up, down, strange, charm, top, and
Pigeons were used for sending messages because they could fly over 1600
miles at 60 miles per hour. A particular breed of pigeons called "homing pigeons" is especially suited for
carrying messages. Pigeon post was widely used by the military, newspapers, and stockbrokers. Pigeons were
transported by land over long distances in cages and attached with messages. Because of their natural homing
abilities, they could fly back to their homes with the piece of parchment. Scientists believe that pigeons
follow the Earth's magnetic field for guidance. Recent research shows that pigeons might be able to use
low-frequency infra-sounds to find their way home.
Tortoises are entirely land creatures. They are a type of turtle that
lives on land but are not equipped for living in water. Unlike turtles, who are omnivores, tortoises are
vegetarians. The latter have shells that are large dome-shaped and are heavier than turtles, whose shells
are mostly flat and streamlined. Tortoises have limbs with short bent legs that are designed for tucking
around on land. But turtles have webbed feet with long claws. So, all tortoises are turtles but not all
turtles are tortoises.
What is the largest living structure on the Earth?
The Great Barrier Reef in Australia is the world’s largest coral reef
comprising of over 3000 individual reef systems. It is known for its breath-taking beauty and is called one
of the seven natural wonders in the world. Spanning over 2300 km, it is larger than the Great Wall of China
and is the only living structure that is visible from space. It is one of the richest and most complex
natural ecosystems and is inscribed as a UNESCO World Heritage. Rising water temperatures, water pollution,
severe cyclones, and starfish outbreaks have weakened the reef’s resilience and threatened its very
Sea sponges are one of the simplest organisms and belong to the phylum
Porifera meaning 'pore-bearer'. They are multicellular organisms
without any nervous system, brain or heart. They have bodies full of pores and channels, allowing water to
circulate through them. Though they can't move, they are considered aquatic animals and not plants. This is
because they lack cell walls and cannot produce food through photosynthesis. They capture tiny microbes and
planktons from the surroundings. They are one of the most primitive organisms on earth with fossils dating
more than 635 Million years ago.
During the smallpox outbreak in the 18th century, people used to huff
powders made of smallpox scabs or insert pus into their skin. They hoped that they would only get a milder
version of smallpox and become immune. However, these methods were not full-proof. People still suffered
from full-blown smallpox. Edward Jenner, a scientist, realised that milkmaids hardly ever got smallpox. He
discovered that milkmaids were routinely exposed to a similar yet milder kind of disease called cowpox. So,
Jenner inoculated a boy with cowpox; and, to his surprise, the boy became immune to smallpox too. Thus,
vaccination came into existence.
Honeybees sting when they sense a threat to the hive as a defensive
mechanism. However, it stings only when it feels a physical threat while foraging. When it stings, it dies.
It cannot pull its barbed stingers back as it gets stuck in the victim's skin. Thus, it leaves a part of its
digestive tract, nerves and muscles along with the stinger. This massive abdominal rupture kills the bee.
The worker bees that die by stinging don't reproduce. They defend their reproducing relatives inside the
hive. So, this sacrifice does make sense from an evolutionary perspective.
Ever wondered about the trails left behind by jets? These trails are
basically called condensation trails called contrails. When jet fuel is burned, one of the products of
combustion is water in vapour form. The temperature at 37,000 feet above the ground is below -40°C. So when
water vapour exits the high temperature exhausts, it comes in contact with the very cold atmosphere and
undergo rapid condensation. These water droplets soon turn into ice and thus we see contrails left behind.
We see them some distance apart from the engine because condensation takes a slight amount of time.
Some new born birds or animals follow the first object they see. This
is called 'imprinting' and it explains why some birds and animals behave exactly the way they do. They learn
to recognise and mimic the actions of the first thing they see which is mostly their mother. The young ones
have an instinct of following moving objects and learns from experience what object to follow. This is how
young ones stay safe close to their mother and follow her everywhere. Did you know that birds can also
imprint humans? So first impression is sometimes the last impression.
Onions belong to the Allium Family and produce tasty bulbs in the first
year of its life-cycle to store energy. To stop predators from eating the bulb, it has a defence mechanism
for its survival. Onions release a volatile chemical called propanethial S-oxide, which is also known as
lachrymatory factor (LF). When onions are chopped, the cells within them are broken and release this
eye-stinging volatile chemical. It quickly evaporates and reaches the eyes producing a small amount of acid.
Reflexive tears well up as our defence mechanism to remove this pesky irritant from the eyes.
Voyager 1 - a space probe launched by NASA is the farthest artificial
object from the Earth. Till now it has travelled a total distance of 17.9 Billion kilometres since its
launch from Florida on 5th Sep 1977. Light takes around 16 hours to travel from the probe to us. The probe
is still moving with a velocity of 17,087 m/s (38,200 mph or 61,400 km/h). Most of its scientific equipment
have already been shut down due to lack of power. In a few years, it will no longer be able to power its
Although stars have a constant brightness, we see them twinkle. This is
because of the earth’s atmosphere. Light from the distant stars acts as a point source and passes through
various layers of the atmosphere differing in temperatures and densities. Each of the boundaries between
these layers refracts the light bending it in a slightly different direction every moment. This makes stars
twinkle. Interestingly, planets don’t twinkle that much as they are much closer. The light bouncing off from
planets are in the form of a disc and not a single point like the distant stars. This averages out the
Yes. Blind people can have dreams too. The subconscious mind starts
functioning in our sleep and they are not an exception. However, the amount of visual dreams depend on what
age they lost their sight. But people who are born blind mostly dream the same way as us with the other
senses - touch, smell, hearing and taste. They do not have visual dreams. Not just humans, but do you know
animals have dreams too? They dream about their day to day life, like grazing, hunting and surviving.
Gravitational attraction causes a large amount of interstellar gas
(mostly Hydrogen) to collapse in on itself. This causes the atoms to collide at great speeds generating
enormous heat. This heat causes the Hydrogen atoms to merge while colliding, forming Helium atoms. The
fusion of Hydrogen into Helium releases massive heat and light which makes the stars shine. This additional
heat creates enough pressure of the gas to balance the gravitational force that prevents the star from
collapsing. The whole process takes more than 10 Mn Years. Thus, a star is born.
The bodies of electric eels have electric organs that are made up
of electrolytes. These organs are lined up and stacked allowing them the ability to store power, much like
small batteries inside a torch. Hence, each cell adds to a potential difference and a current of ions can
flow through them. Electric eels, with their electric ability can communicate, navigate and stun their
preys. They can discharge upto 860 volts and one ampere of current.
Jellyfish aren’t really fish but gelatinous zooplankton; composed of
95% water. The remaining 5% is structural proteins, muscles and nerve cells. They are made of a jelly-like
material 'Mesoglea'. They got no brain, heart, bones or blood. They came 500 million years back, primitive
to even dinosaurs. Some are even bioluminescent, producing their own light. Heard of Box jellyfish? The most
venomous marine animals in the world! A type of jellyfish, Turritopsis Dohrnii is the only animal in the
world that can reverse its lifecycle and hence called immortal.
Colliding particles of water vapour and ice inside clouds create
electrical charges. Heavier negative charged particles sink to the bottom of the cloud and positively
charged particles accumulate at the top. When these electrical fields become large enough, a giant spark of
electric discharge is created. This causes lightning. Most lightning occurs between clouds but a few occur
between clouds and the earth. A flash of lightning contains up to 1 billion volts of electricity and can
heat the surrounding air to temperatures 5 times hotter than the sun’s surface.
Sunlight is made of different colours of light which have different
wavelengths. The atmosphere of the earth is composed of very small molecules of Nitrogen, Oxygen, Water
Vapour, Carbon Dioxide, Argon and traces of other gases. These molecules scatter the shorter and
higher-energy wavelengths of light more efficiently than other wavelengths. Though violet light is scattered
more than blue light, our eyes respond more strongly to blue light and hence the sky appears blue.