Category Science

Which period did dinosaurs first appear?

Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago, although the exact origin and timing of the evolution of dinosaurs is the subject of active research.

All continents during the Triassic Period were part of a single land mass called Pangaea. This meant that differences between animals or plants found in different areas were minor.

The climate was relatively hot and dry, and much of the land was covered with large deserts. Unlike today, there were no polar ice caps.

It was in this environment that the reptiles known as dinosaurs first evolved. Reptiles tend to flourish in hot climates because their skin is less porous than, for example, mammal skin, so it loses less water in the heat. Reptile kidneys are also better at conserving water.

Toward the end of the Triassic, a series of earthquakes and massive volcanic eruptions caused Pangaea to slowly begin to break into two. This was the birth of the North Atlantic Ocean.

 

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Do animals sweat?

Sweating or perspiration is a natural way for the body to regulate its temperature. Humans have sweat glands in many parts of the body. What about animals? Sweat glands are found in most mammals. But they do not produce large amounts of sweat (exception being horse). For instance, dogs and cats produce small amounts of sweat through their paws. The overall distribution of sweat glands varies among primates – while the rhesus monkey has them on the chest, some macaque species and baboons have them over the entire body. But they do not sweat as much as humans, as their fur serves as the temperature regulator.

Mammals also resort to other methods to regulate body temperature. Pigs and hippopotamuses roll in the mud to cool themselves, while dogs pant.

Have you ever wondered about the secretion on the skin of the hippopotamus? It is not sweat.

Hippos secrete a reddish oily fluid, sometimes called blood sweat, from special glands in their skin. This fluid functions as a skin moisturiser and antibiotic.

 

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What is the importance of digital detox?

Ever since gadgets entered our lives, we have been addicted to them. Checking the mobile phone as soon as we wake up has become part of our daily routine. Similarly, thanks to the pandemic, today our mornings begin with online classes.

While the computer is highly useful for academic purposes such as project work, it is also used as a means of entertainment. However, constant use of the computer can take a toll on our health and leave us feeling tired and exhausted.

The need to detox

Using the computer for long periods of time can affect the eyes as well as the body. The harsh light emitted by the monitor can tire your eyes and leave you with dark circles. The light is also said to affect sleep. Besides, in the absence of physical activity as a result of being confined to the house, your body will feel much weaker than it is.

Prolonged use of the computer can also lead you to develop a poor posture that can result in back and neck pain. Many people also complain of headaches and disorientation.

Another major health problem encountered by many of us today is obesity. Sitting in front of the computer for hours together can lead to weight gain. This in turn affects our heart and mind.

Ways to detox

The best way to stay away from the computer is to keep yourself occupied with other interesting things. Here are a few ways to detox and recharge yourself.

Take regular breaks:

Take a sand clock or set a reminder on your phone and place it on your computer table to remind yourself to get up and move around every half hour. During these small breaks, do simple stretches to relax your muscles before getting back to work.

Take power naps

You could feel exhausted with all the things you need to do during the day. So, to relax, take power naps instead of playing games on the computer or the Playstation.

Listen to music

Music helps us relax and destress. There’s a tune for every mood. So, start listening to your favourite songs in your free time.

Allocate time for play

Even if you can’t go out, you can still play at home. There are a lot of games you can play with your family. You could also invent a game.

Reward yourself

It can be difficult to detox. A reward is a good way to keep yourself motivated. Every time you do something other than using the computer, reward yourself with something useful.

 

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What are the threats to sloth bears?

Threats

Increasing human population is said to be the greatest threat to these bears. This leads not only to the loss and degradation of the bears habitat but also human-bear conflict. And, this is not good news. Sloth bears tend to avoid humans. However, they can also be intolerant of them when the two meet face to face. And their aggressive behaviour coupled with powerful claws and canines don’t help. So, a human-bear conflict may not end well. For instance, a media report says that “in Odisha, between 2014 and 2018, 716 attacks by sloth bears on humans were recorded. Out of the 716 attacks recorded, 627 humans were left grievously injured – with many victims severely impaired for life”. Which means, there are retaliatory killings too. Other worrying factors include hunting and poaching for meat and body parts for medicinal purposes. It is said that there are no specific numbers for the deaths of sloth bears. This is of concern because there are only rough estimates for their population, meaning we may not know exactly how many bears live and die, and what sort of conservation mechanism should be put in place to save this vulnerable species. Another reason for concern is that these animals have traditionally been captured and made to perform “dances” for human entertainment. Though this has been largely brought down in India and some of the animals have even been rehabilitated, it is believed to be continuing in places such as Nepal.

Though sloth bears are found in Sri Lanka, Bhutan, and Nepal too, India hosts its largest population in the world. They appear to be extinct in Bangladesh since no sightings have been confirmed in the region for years now. Within India, they are found in many States, including Karnataka. Tamil Nadu, Kerala, Gujarat, Rajasthan, Chhattisgarh, Odisha, and central India. Among the sanctuaries for the species are Ratanmahal Sloth Bear Sanctuary and Jessore Sloth Bear Sanctuary in Gujarat, and Daroji Sloth Bear Sanctuary in Karnataka. According to the Red List of the International Union for Conservation of Nature, it is a “Vulnerable” species.

Sloth bear facts

  • Sloth bears are small bears, and usually have a black coat (and sometimes, a brown coat). What helps identify them is their distinctive whitish or yellowish chest patch in the shape of a wide U or Y.
  • They are a lowland species, and occupy different types of habitats such as wet and dry tropical forests, savannahs, scrublands, and grasslands.
  • These omnivores feed primarily on termites, ants, and fruits. Apparently, they are fond of honey too.
  • Cubs stay with their mothers for roughly two-odd years, and for about nine of those months, they ride on their mother’s back.

 

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How the Moon can block the light from the big star?

In the event of a total solar eclipse, the Sun’s light is completely blocked by the Moon. But have you wondered how the Moon, which is about 400 times smaller than the Sun, can block the light from the big star?

It’s a matter of distance

The distance between the Earth and the Sun, and the Earth and the Moon is at the crux of this answer.

Objects that are closer to us appear much larger than objects that are much farther away. For example, the stars in the sky might look like tiny objects but are actually much larger than the Sun. they appear so because their distance from the Earth is much more than the Sun’s distance from Earth.

Thus, though the Moon is 400 times smaller than the Sun, because it is much closer to Earth, it appears to be the same size as the Sun from Earth. So, when the Moon comes between the Earth and the Sun, it appears to completely block the light from the Sun.

An end to total eclipse?

Total solar eclipses won’t be around forever because the Moon’s orbit is changing. The Moon’s orbit grows about 1.5 inches larger every year. And as the Moon’s orbit takes it farther away from the Earth, it will appear much smaller than it does currently. Once the Moon’s growing orbit takes it approximately 23,500 km farther from Earth, it will be too far away to completely block the light from the Sun.

The good news though is, if you look at the maths, this won’t happen for the next 600 million years, at least.

 

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What is an overhead kick in soccer?

Kinetic energy largely dominates the beautiful game of football as players cover a number of kilometres in a 90-minute game, in search of goals that separate the competing sides. But one of the more dramatic moments produced on the football field depends mainly on the potential energy of a player.

Energy and forces

The overhead kick, also known as the bicycle kick and scissors kick based on minor differences, sees the player utilising potential energy to carry out the acrobatic move. There are also forces in action as a player needs to contend with centrifugal and gravitational forces while trying to kick the ball overhead.

Three main phases

The overhead kick can be broadly broken down into three phases. The first, and most obvious phase, is the jump. The player places himself such that their centre of gravity is a little behind their impulse foot. This enables the player to gain rotational momentum by applying pressure on the ground. The jump phase is thus similar to the back somersault.

There is very little separating the second and third phase as it all happens really quickly in reality. The second phase is the kicking movement done by the player once completely air-borne. With other forces in action, the player needs great strength in their thighs and muscles to carry out this phase.

Changes direction and spread

The third and final phase is the moment of impact, when the player’s foot strikes the ball. When struck properly, the ball not only change direction, but also gains considerable velocity.

While all these happen within seconds, what really matters for the player is what happens next. What we have just described might seem like poetry in motion for those who love physics, but for footballers, their goal with these kind of shots is to find the ball in the back of the net!

 

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