My Science School

Space tourism is human space travel for recreational purposes. It can be orbital, suborbital or lunar travel. In 2001, U.S. millionaire Dennis Tito arrived at the International Space Station (ISS) via a Russian Soyuz rocket, becoming the world's first space tourist. Since then, a handful of tourists have travelled to the ISS. There have also been many failed attempts by private players. But the recent developments in space tourism are something to watch out for.

In July 2021, space tourism gained a new boost as wealthy businessmen Virgin Group founder Richard Branson and former Amazon CEO Jeff Bezos, travelled to space as tourists in their company's VSS Unity spacecraft and Blue Origin's New Shepard rocket respectively. Virgin Galactic, Blue Origin, SpaceX and other private space firms have kick-started a commercial space race with each announcing their plans to launch more tourists into space. Already, people are buying their million-dollar tickets to space. As the industry is poised for major growth, environmentalists are worried about its carbon footprint. Will space tourism harm our environment?

When rockets launch into space, they require a huge amount of propellants to make them out of the Earth's atmosphere. Those fuels emit a variety of substances into the atmosphere, including carbon dioxide, and other chemicals. The carbon emissions from rockets are small compared to those from the aircraft industry, but they could get worse if space tourism becomes popular.

The emissions of a flight to space is of concern because just a few people hop aboard one of these vehicles, so the emissions per passenger are much higher. According to The Guardian, rockets emit up to 100 times more carbon-dioxide per passenger than aeroplanes.

Soot and heat

Roughly two-thirds of the propellant exhaust is released into the stratosphere and mesosphere, where it can persist for at least two to three years. The very high temperature during launch and re-entry also convert stable nitrogen in the air into reactive nitrogen oxides. These gases and particles have many negative effects on the atmosphere. They can eventually lead to depletion of the ozone layer, which guards life on Earth against harmful UV radiation.

Certain fuels used in rockets generate soot. Soot is a carbonaceous particulate matter that is 2.5 micrometres in diameter or smaller. Such fine particles are even smaller than dust and mould spores. It is comprised of a variety of pollutants, including chemicals, acids, metals, soils, and dust, which are suspended in the air after emission.

Carbon dioxide and soot trap heat in the atmosphere, contributing to global warming. A study from 2010 found that the soot released by 1,000 space tourism flights could warm Antarctica by nearly one degree Celsius.

At a time when the impact of climate change is quite stark, it is hard to ignore the contention that the huge money poured into space technology could instead be invested in making life better on our planet.

Picture Credit : Google

Classification

Elephants belong to the family Elephantidae, which also contains several extinct groups, including mammoths and straight-tusked elephants.

There are three different species of elephants - the African savannah elephant, the African forest elephant, and the Asian elephant. The savannah elephant is the largest of the three species- also the largest living terrestrial animal in the world.

Differences

• The easiest way to distinguish African elephants from their Asian cousins is to look at the ears. African elephants have larger ears that look like the continent of Africa, while Asian elephants have smaller, round ears. Asian elephants are smaller than African elephants.
• African elephants have concave backs, while Asian elephants have convex or level backs.
• Only some male Asian elephants have tusks, while both male and female African elephants grow tusks.
• African elephants live in sub-Saharan Africa, the rainforests of Central and West Africa, and the Sahel desert in Mali, while Asian elephants live in India, Nepal, Sri Lanka, and Southeast Asia in scrub forests and rainforests.
• There are minor differences between the African savannah elephant and the African forest elephant. The latter is a bit smaller than the former and has rounded ears. Forest elephants have tusks that are straight and point downward, while the savannah elephants have curved tusks.

Matriarchy

All three species are social and follow a matriarchal structure, with the eldest female elephant incharge of a herd. Herds consist of female family members and male offspring. Herds may include six to 20 members. Older males are often solitary.

The matriarch relies on her experience and memory to spot food, water, and shelter. Elephants in a herd build a strong bond by taking care of each other and protecting weak or injured members.

Intelligent animals

Elephants communicate using rumbling, low-pitched sounds that fall below the audible range of humans.

They demonstrate problem-solving skills, empathy, mourning, and self-awareness. Chasing, mounting, wrestling, and sparring are all considered part of play.

High Five

1. Wrinkles on an elephant's skin trap moisture and keep the animal cool. That's why African elephants have more wrinkles than their Asian counterparts.

2. African savannah elephants have four nails on the front feet and three on the back feet

African forest elephants have five nails on the front feet and four on the back feet Asian elephants have five nails on the front feet and four on the back feet

3. An elephant's trunk is actually a fusion of its nose and upper lip, used for smelling, breathing, trumpeting, and drinking. Asian elephants have a single "finger" on the end of their trunks, while African ones have two.

4. Ivory tusks are actually massive teeth. They serve a variety of purposes: digging, stripping bark from trees to eat, and for defence. The tusks also protect the trunk. Did you know elephant tusks never stop growing?

5. Elephants use their big ears to cool themselves down when they are hot. The heat is released as they flap them about. Some scientists think that the ears may funnel sound into their inner ear for better hearing.

Ecological role of elephants

• As keystone species, they help maintain biodiversity of the ecosystems they inhabit. They shape their landscape, and allow other animals, plants, and birds to thrive.
• When elephants eat, they create gaps in the vegetation. These gaps allow new plants to grow and create pathways for other smaller animals to use. This way they also help trees disperse their seeds.
• Elephants dig waterholes on dry riverbed when rainfall is low. The waterholes are used by other wildlife as well.
• Elephant dung keeps the soil fertile and disperses seeds.

Eating, pooping, and mudbathing

• Elephants eat all types of vegetation, including a variety of grasses, plants, and fruits. They spend 12 to 18 hours of a day in eating. They consume about 75 to 150 kg of food per day. This means, they also excrete a lot. Each elephant creates one tonne of poop per week.
• Elephants love to play in the water and mud. After a river bath, they smear mud all over their bodies to cool themselves. Mud is also their sunscreen!

Threats to elephants

Poaching for illegal ivory trade, habitat loss, and human-animal conflict are the greatest threats to elephants. Infrastructure development such as roads, railways, and other constructions are not only leading to habitat fragmentation but also putting the parchydem in danger of accidents.

The International Union for Conservation of Nature and Natural Resources (IUCN) classifies the Asian elephant as endangered and the African elephant as vulnerable.

Picture Credit : Google

Many state governments in India have announced plans to give e-mobility a push. While Karnataka made legal provisions for operating electric bike taxis, Maharashtra, Gujarat and Rajasthan announced financial incentives and schemes for purchasing e-vehicles and setting up charging stations. Earlier this year, the Delhi government launched the 'Switch Delhi' campaign to focus on adoption of electric three-wheelers, including e-autos, e-rickshaws, and e-carts.

The governments seem to have two dominant objectives - to control pollution and take the lead in an emerging industry. With fuel prices skyrocketing every day, people might look at e-vehicles as an affordable alternative to conventional vehicles.

E-vehicles are gaining popularity around the world. Many countries have pledged to become carbon neutral within a decade or two. Electric vehicles are seen as a way to reduce carbon emission from transportation. According to researchers at the International Monetary Fund and Georgetown University, more than 90% of all passenger vehicles in the U.S., Canada, Europe and other rich countries could be electric by 2040. If this becomes a reality, oil use will come down by 21 million barrels a day and CO2 emissions will be cut by 3.2 billion tons a year, they say.

What are electric vehicles?

Electric vehicles, such as e-cars, e-rickshaws and e-bikes, use electric motors for propulsion. EVs also include rail vehicles, surface and underwater vessels, electric aircraft and electric spacecraft. They are powered by rechargeable batteries installed in them. They can be charged at charging stations (like we do for conventional vehicles at petrol bunks) established at various places.

Lithium-ion batteries are predominantly used in electric vehicles. These batteries have become the industry standard over the last two decades of EV development. New graphene-based technologies that enable fast charging (say, in 15 seconds) are being tested. These are expected to supplement, not replace, traditional EV batteries.

How can the electric vehicles be charged?

The vehicles can be charged the same way one charges a cellphone. It can be done at home or at a public charging station. The time taken to charge EVS depends on its drivetrain capacity. There are two types of charging available for electric vehicles - Normal and Fast charge.

Normal charge: Depending on the vehicle and battery type and size, the charging duration can range between 8 and 14 hours. Fast charge: Again depending on the vehicle and model, this battery can be fully charged in a minimum of one hour.

How long does the battery last?

This too depends on the vehicle and battery type and how well the user maintains it. Like your phone battery, the one in your car will degrade over time.

In India, the cost of charging depends on the average cost of supply set by each State. The power ministry last year said that the tariff for a public charging station should not be more than 15% of the state's average cost of supply. On average, it will cost about Rs 40 to fully charge an all-electric car or a scooter.

When was the electric vehicle invented?

Electric vehicle is a not new concept. Professor Sibrandus Stratingh of University of Groningen, the Netherlands, built a small-scale electric car as early as 1835. The first mass-produced electric vehicles appeared in the U.S. in the early 1900s. Due to the limitations of storage batteries at that time, electric cars did not gain much popularity. However, electric trains did, because overhead lines met their electricity requirement. Electric train became common by the early 20th Century.

Interest in electric cars revived in the 1990s with mass production by General Motors, Chrysler, Ford, GM, Honda, Nissan and Toyota. But it soon died down due to the success of the conventional automobiles. It was the 21st Century that saw a resurgence of EVS, thanks to technical advancements and increased focus on renewable energy.

What are the benefits of EVs?

No emission: Electric cars do not emit toxic gases or smoke, while conventional vehicles that run on non-renewable fossil fuels such as petrol and diesel emit greenhouse gases. Electric vehicles get their power from a wide range of sources, including nuclear power, tidal power, solar power, and wind power, and not just from coal. Hence EVs are considered to have the potential to combat global warming. The vehicles are also much quieter and do not cause noise pollution.

Cost-effective: Though electric cars are more expensive than their fuel-powered counterparts, they are cost-effective in the long run. People can save on the fuel cost. Electric cars do not require much maintenance. Electric cars run on electrically powered engines, and hence there is no need to lubricate the engines with oil. Conventional vehicles consume fuel while idling, whereas energy is not wasted in the case of e-vehicles.

Prolonged lifespan: If maintained well, battery would be the only part that would require changing.

What are the shortcomings?

Not truly ecofriendly: Most countries generate electricity from coal and EVS use this electricity to charge the batteries. Hence, in most cases, energy to EVs indirectly come from fossil fuel, which is a major cause of global warming. Also, manufacturing an electric vehicle generates more carbon emissions than building a conventional car.

Fewer fuel stations: Not many places have electric fuelling stations in India. Short driving range and speed: Electric cars are limited by range and speed. They are not ideal for long journeys as of now, although this is expected to improve in the future.

Longer recharge time: While it takes a couple of minutes to fuel your petrol- or diesel-powered car, an electric car takes a few hours to get fully charged.

Power shortage: Electric cars may not be suitable for cities that face acute power shortage. Consumption of more power would hamper the city's daily power needs.

Danger of e-waste: The rise of electric cars could leave us with a huge pile-up of battery waste on our landfills.

What should governments do?

• Governments should focus on electricity generation from renewable sources so as to realise the environmental benefit of electrical vehicles.
• Bring down the cost of e-vehicles to make them affordable. This is being done by a few States in India.
• Increase provision for charging points at public places and workplace.
• Find a solution for the safe disposal and recycling of worn-out lithium-ion batteries.

Picture Credit : Google

A California wildfire that closed nearly 200 square miles of forest forced evacuations across state lines into Nevada recently as winds and scorching, dry weather drove flames forward through trees and brush.

The Beckwourth Complex - which began as two lightning-caused fires in Plumas National Forest - was intense. Hot rising air formed a gigantic, smoky pyrocumulus cloud that reached thousands of feet high and created its own lightning.

In north-central Arizona, increased humidity slowed a big wildfire that posed a threat to the rural community of Crown King.

Elsewhere, Cyprus saw one of the worse wildfires since the Republic of Cyprus was established in 1960. Wildfires destroyed 50 homes, damaged power lines and forced the evacuation of 10 villages. The blaze ripped through mountain forests and farmland, killing four people and destroying scores of homes.

Water-bombing planes from Greece and Israel and British aircraft from bases on the Mediterranean island helped douse the huge fire, which blackened 55 square kilometres (21 square miles) of the Troodos Mountains.

Climate change is considered a "key driver' of a trend that is creating "longer and more intense dry seasons that increase moisture stress on vegetation and make forests more susceptible to severe wildfire," the California Department of Forestry and Fire Protection said.

What is a wildfire?

An uncontrolled fire in an area of combustible vegetation which spreads quickly, wiping out large areas of land is called a wildfire. A wildfire can also be termed a forest fire, a grass fire, a peat fire or a bush fire, depending on the type of vegetation present in the area.

What causes wildfires?

Wildfires are common in Australia, Southeast Asia, southern Africa, Western Cape of South Africa, the forested areas of the United States and Canada, and the Mediterranean Basin. During summer, when there is no rain for months, the forests become littered with dry leaves and twigs, which could be ignited by the slightest spark.

Natural causes: Lightning is the most common cause of wildfire. There are three conditions for a forest fire to spread -fuel, oxygen and a heat source. In the forest, anything that is flammable is a fuel. This includes tall, dry grass, bushes and trees. High temperature, drought and dry vegetation are a perfect combination for igniting a forest fire.

Man-made disaster: Human neglect such as downed powerlines, sparks from tools or forest machinery, abandoned campfires and discarded cigarette butts can spark fires. People also tend to clear forests by setting them on fire to pave way for cultivation. Sometimes they set fire to scare away wild animals.

How is a forest fire put out?

Traditional extinguishing methods include water dousing and spraying of fire retardants from aircraft. To limit the spread of a fire, firefighters remove ground litter and bush.

What is a heatwave?

A heatwave is a period of prolonged abnormally high surface temperatures relative to those normally expected. Classifying a heatwave varies from country to country. The World Meteorological Organisation (WMO) defines heatwaves as five or more consecutive days during which the daily maximum temperature surpasses the average maximum temperature by 5°C or more.

What is the link between climate change and forest fires?

• Climate change has created conditions conducive to forest fires. Long summer, drought, and dry air and vegetation make forests more susceptible to severe wildfire.
• Climate change has led to frequent heatwaves across the globe. Hotter temperatures, again, mean parched land.
• Climate change has also lengthened the fire season in many parts of the world.

Why does California experience forest fires quite often?

California's climate: Wildfires are a natural part of its landscape. California has two distinct fire seasons- one that runs from June through September and another from October through April. While the first one is driven by a combination of warmer and drier weather, the second one is driven by dry winds which make wildfires spread rapidly and cover large areas.

Longer fire season: In the recent past, the fire season in California has been starting earlier and ending later. The length of the season is estimated to have increased by 75 days. Beetle infestation: Prolonged drought conditions leave behind a landscape of dead trees, which lead to infestation by bark-eating pests such as the mountain pine beetle. Outbreaks of pests weaken and kill trees. Beetle-killed trees are at a higher risk of fire.

Warmer weather: Heatwave is a major contributor to forest fires in California.

Picture Credit : Google