Category Science

How solar cells can play as an energy source?

You must have learnt quite a bit about solar panels in school. An electrical device that converts the energy of light directly into electricity, solar cells or photovoltaic cells tap solar energy. As the energy is produced from a renewable source, our sun, they offer huge potential in helping us move away from energy generated by burning fossil fuels (non-renewable sources)

Given the important role solar cells can play as an energy source, there is plenty of research on to figure out if we can make the process more efficient. Among these are research that aim at increasing the light captured, as it directly influences the energy produced

Design innovation

An innovation suggested by a team of scientists late in 2020 stands to more than double the light that can be captured by solar cells when compared to conventional solar cells. The team, comprising scientists from the U.K., Portugal and Brazil, discovered that etching a simple pattern could lead to this considerable gain.

According to their study, a shallow pattern of grating lines in a chequerboard design on solar cells can increase the current generated by as much as 125%.

Chequerboard pattern

In their attempt to try and trap more sunlight, the researchers experimented with this design along with other designs (vertical grating lines, crossed lines, etc.) and a conventional plain solar cell. Results showed that the chequerboard pattern with random rotations of the repeating units far outperformed the other competing cells and the conventionally used plain one as well.

While the results might not be as impressive when implemented in the real world with the fabrication measures, the change could well lead to positive impact in the design of new solar cells as a whole. Only time and more experiments can tell us if the chequerboard design does yield the results that we yearn for.

 

Picture Credit : Google

On January 31, 1961 who became the first hominid in space?

 

Hominids are any of a family (Hominidae) of erect bipedal primate mammals, including extinct ancestral forms. To put it simply, any member of a group that consists of humans, chimpanzees, gorillas and orangutans, or an early form of any one of these is known as a hominid. So while Americans Neil Armstrong and Buzz Aldrin remain the buzz words when we are talking about astronauts (as they were the first to land on the moon), and Soviet Union’s Yuri Gagarin was the first human ever in space, none of them can claim to be the first hominid in space.

That record goes to Ham, a chimpanzee. While other animals, including dogs, monkeys, mice, rabbit and fruit flies, had been sent to space from late in the 1940s, Ham became the first hominid when he achieved the feat on January 31, 1961.

Chimps turn astrochimps

Born in 1957 in the French Cameroons (now part of Cameroon) in West Africa, Ham was captured by trappers and the male chimpanzee was then sent to the Miami Rare Bird Farm in Florida, the U.S. He was sold to the U.S. Air Force in 1959, who then transferred him to Holloman Air Force Base in New Mexico.

Ham (after Holloman Aerospace Medical Center), who was merely “Number 65” at that time, was one among 40 chimpanzees chosen for the space programme that was to serve as the springboard for human spaceflight. The fact that both chimps and humans are hominids and that humans share more DNA with chimpanzees than any other animal meant that they were much more closely related, and hence chosen for the task.

The 40 chimpanzees chosen were put through the paces as they received their astrochimp training. They were taught to pull levers in response to light and sound and were awarded (with banana pellets) or punished (with mild electric shocks on their feet) based on their responses. Just like their human Mercury 7 counterparts who were training for years, these chimps too were subjected to g-forces and microgravity.

As the training progressed, the number of chimpanzees was first brought down to 18 and then to six – four females and two males. With their training complete, the Air Force sent the six finalists to Cape Canaveral in Florida on January 2, 1961.

The chosen one

The six were split into two groups of three in order to ensure that germs do not spread to everyone in case one of them became ill. The training sessions continued, and all six of them remained in contention until the day before the scheduled launch on January 31. Ham, who was said to be particularly feisty and in good humour, got the nod along with another female chimp, who served as backup.

Those traits probably served him well as Ham went to space aboard the Mercury spacecraft, boosted by a Mercury-Redstone 2 rocket. The flight didn’t go exactly as planned as the Mercury capsule unintentionally carried him to an altitude of 157 miles (252 km) and a speed of 5,857 mph (9,425 kmph) as opposed to the original targets of 115 miles (185 km) and 4,400 mph (7,081 kmph).

Ham experienced weightlessness for 6.6 minutes during his 16.5-minute flight. Even though there was a partial loss of air pressure as well, there was no damage done as he remained encased in his pressurised capsule. The lever-pulling exercise was also a success, as Ham performed only mildly slower than how he had during training. This success was significant as it showed that human beings too could perform physical tasks while out in space.

Instant popularity

Ham’s capsule splashed down in the ocean a little over 16 minutes after it was launched. Ham was calm and in good spirits when retrieved by the recovery ship and was only agitated later on when he had to pose for the photographers and TV crews after returning to the hangar.

Fatigue and dehydration apart, Ham was fine according to the medical examination that followed. He instantly gained celebrity status as he featured in numerous documentaries, articles, magazine covers, television shows and cartoons.

After living at the Smithsonian’s National Zoo in Washington, DC until 1980, he was moved to the North Carolina Zoological Park in Asheboro. Following his death in 1983 aged 25, his skeleton was sent for further investigation, while his other remains were buried at the International Space Hall of Fame in Alamogordo, New Mexico. A plaque at the grave site in New Mexico reads “Ham proved that mankind could live and work in space.”

 

Picture Credit : Google

What is GPS and how it is connected to space?

Over the years, GPS has played an important role in getting people to places at the touch of a button. But what is GPS and how is it connected to space?

What is it?

GPS or Global Positioning System is a system of navigation satellites circling Earth that helps people identify where they are and how they can get to some place. GPS is accessible to people as an independent device as well as through features on their smartphone.

How does it work?

The GPS system is made up of three parts – satellites, ground stations and receivers. Thirty-one navigation satellites orbiting Earth are tracked and monitored by ground stations located in different places in the world. These ground stations check if the satellites are where they are supposed to be in orbit so that the signal received from them are accurate.

The receiver, such as the one found on a smartphone or the GPS device in some cars, constantly listens to signals from the navigation satellites. Once it manages to calculate its distance from four or more satellites, the receiver knows exactly where it is placed.

This system can help users determine where they are within a few metres of their actual location. Based on the strength of the receiver, the location’s accuracy increases. So, more advanced receivers can be accurate in determining location down to a few inches.

 

Picture Credit : Google

Of globes, triangulation and camera obscura

A box, room, or device (a darkened enclosure) that has a small hole (an aperture, maybe with a lens) through which light from external objects enters to produce an image on an opposite surface is called a camera obscura. Also referred to as pinhole camera at times, the basic optical principles of these have been known for a long time. While the earliest written observations can be dated back to over 2,000 years, the oldest known published drawing of a camera obscura is found in a 1545 book De Radio Astronomica et Geometrica.

The author of this book was a physician by the name Gemma Frisius. Apart from being a practising physician, he was also a mathematician, cartographer, philosopher, astronomer and instrument maker.

Teaches medicine and mathematics

Born Jemma Reinierzoon in Dokkum, Friesland, a town in modern Netherlands, in 1508, he lost his parents at a young age. While Gemma is a Latinised onomatopoeic version of his birth name, Frisius is the toponym for Friesland. Despite the fact that he was born into a poor family and was also orphaned early in his life, he not only earned a medical degree while studying at Leuven (a city in Belgium), but also stayed on to study mathematics and astronomy.

After he had obtained his MD degree in 1536, he practised medicine in the city for the rest of his life. He also remained in the faculty at Leuven’s University and as one of the leading theoretical mathematicians of the time, also taught mathematics.

Triangulation for surveying

Even before he got his MD degree, he had probably made one of his finest contributions. In 1533, Frisius described for the first time using triangulation for map-making. Even though the technique of triangulation (formation of or division into triangles) had been known since antiquity, it was Frisius who proposed to employ it for the purpose of surveying lands.

In this technique, one chooses a base line of known distance and from its endpoints the angles of sight to remote points are measured. Using basic trigonometry, the distance to this point from either endpoint can now be calculated. The two distances measured are then used as base lengths and the process is repeated until the entire area to be surveyed is broken down into a network of triangles. This method proposed by Frisius is still widely used for surveying.

Gemma’s rings

As a cartographer, Frisius built and improved a number of instruments. He had set up his workshop to produce globes and mathematical instruments while he was still a student and went on to create terrestrial and celestial globes that became famous.

He even designed astronomical instruments and one of them, astronomical rings, is also called as Gemma’s rings. Frisius is also credited with a method of determining differences of longitude by transporting an accurate clock or time-pieces.

As an astronomer, Frisius observed natural phenomena with gusto. It was during an annular solar eclipse, which took place on January 24, 1544, that Frisius utilised a camera obscura to study it.

He then described his method of using camera obscura to study the solar eclipse along with an illustration in his 1545 book De Radio Astronomica et Geometrica. This diagram is the first known picture of a camera obscura.

Frisius died in 1555, aged 46, at Leuven. By then, he had left his influence in a number of fields, some of which lasts even now, over 400 years later.

 

Picture Credit : Google

How do animals help each other?

Animal Partners

Hungry crocodiles usually try to eat birds that come near them. But one kind of bird can walk among crocodiles safely. In fact, this bird can lay its eggs in crocodile nests!

A bird called the water dikkop eats insects that disturb crocodiles. The bird gets an easy meal and the crocodile becomes more comfortable. So the birds are really helping the crocodiles. Maybe that’s why the crocodiles don’t harm them.

Little fish called wrasses help many other bigger fish. Tiny worms often fasten themselves to a fish and make sores on its body. When this happens, the fish goes to a coral reef where a wrasse lives. The little wrasse hunts all over the fish’s body and eats the worms.

A European fish called a bitterling teams up with certain freshwater clams. The female bitterling lays her eggs in the clam. When the baby fish leave the shell, clam larvae are buried in their skin. After the clam larvae have grown a bit, they leave the fish and sink to the bottom of the pond or river. The clam provides a safe place for the fish to lay its eggs, and the fish helps spread baby clams along the pond bottom.

The water dikkop, the wrasse, and the bitterling all get something from the animals they help. Some get food as a reward for getting rid of annoying pests. Others help each other reproduce.

Picture Credit : Google

Why do animals make sounds?

Warning!

Have you ever wondered what animals is “saying” when they tweet, squeak, mew, or bark?

Sometimes, animals make sounds to find a mate. But other sounds are calls for help or cries of danger. A dolphin that is hurt makes a high whistling noise to get the attention of other dolphins. The other dolphins use their backs and flippers to keep the injured dolphin near the top of the water so it can breathe.

Some animals “talk” without using any sounds. Deer and many other animals mark their territory by rubbing a special scent on trees or bushes. Glands in the faces of some male deer give off a scent that warns other males to stay away.

Other animals communicate by changing their body positions. Whenever two wolves in the same family meet, they use their bodies to show which wolf has a higher rank, or position. The high-ranking wolf stands straight, holds its tail high, and points its ears forwards. A low-ranking wolf crouches, holds its tail between its legs, and flattens its ears.

Picture Credit : Google