5 Questions that still remain unexplained by science #3

3. Ghosts and Paranormal Activities

Who doesn’t like a good ghost story? Ghost stories and horror films are sure to have one on the edge, biting one’s nails and waiting anxiously for the next thrilling moment. And the thrill is amplified by the much-expected sounds of creaking doors, whistling winds and ghostly groans and moans.

Many a time, people report strange occurrences that cannot be easily explained. But when one investigates further, most of these happenings have perfectly scientific explanations.

Here are some of the common reasons behind ghostly activities

Common reasons behind Ghosts and Paranormal activity

Abnormal Sounds

An online search for ghostly places often leads to images of tall buildings. The presence of multiple tall buildings leads to, what is called, the urban canyon effect. Any sounds in the lower parts of the building get amplified and heard as strange whispers, bangs and otherworldly sounds.

Helmholtz Resonance is another reason for sound amplification. There is a much-publicized case of a haunted building where mysterious ghostly whistling constantly occured. It was later found that disgruntled workers had embedded glass bottles on the roof which resonated the sound of wind passing over them causing eerie noises. Something similar also happens in the case of buildings with long narrow windows . Many old buildings with high ceilings fall in this category.

The vibratory hum of machinary, air conditioning units etc are also sometime perceived as abnormal sounds.

Abnormal Sensations

Infrasound, sometimes referred to as low-frequency sound, refers to the sound waves with a frequency below 20 Hz. It lies at the lower limit of human auditory ability. Many animals, however, can perceive this sound.

Infrasound, as per some studies, is said to cause varied sensations such as anxiety, headache, general discomfort and even abnormal sensations like being elsewhere (probably due to effects on the cerebellum). Effects on blood pressure and heart rate have also been reported in some experiments. The resonance of our internal body organs at very low frequencies of infrasound is said to cause them to vibrate leading to the symptoms.

While some studies have explored this angle, we do not have definitive proof yet. With more studies targeted at this, things might get clearer in time.

Many psychotropic drugs, psychological conditions, toxins and gases like carbonmonoxide can also lead to abnormal sensations as well as hallucinations.


Many psychological conditions, alcohol and hallucinogenic drugs and toxins can lead to the perception of visions and apparitions.

A relatively high concentration of Electromagnetic radiation has been found in haunted places. The source of electromagnetic radiation could be different type of equipments. How it effeccts the human physiology and psychology to produce is yet to be fully understood.

Moving objects

Objects moving or falling off their own accord is a source of much debate and discussion. Many such cases can be debunked by understanding the physics behind such occurances.

Sometimes, such events are deliberate or are easy to execute pranks too.

All in all, many cases of ghosts and paranormal can be debunked scientifically. Some are being studied and we will have answers in time. Some, however, are still a mystery and science is in a constant quest to find answers to these.

5 Questions that still remain unexplained by science #2

2. What happened before the Big Bang?

Big Bang

The universe came into existence approximately 13.799 billion years ago. Its origin is still shrouded in mystery. Many theories have been proposed and none has been able to completely explain the events that led to the formation of the universe as we know it today.

Big Bang and Cosmic Inflation

The current explanation relies on the Big Bang Theory. In simplified terms, the universe initially existed as a hot and dense mass of energy that expanded and subsequently cooled. This initial hot, dense state is called the Plank Epoch that lasted a mere 10-43 seconds. Scientists have suggested a phase of initial exponential spurt called ‘Cosmic Inflation’ before gravity modified the expansion to its present state.

Big Bang and No Boundary Proposal

Stephen Hawking and James Hartle proposed the ‘No Boundary Proposal’ that indicated that the cosmos was shuttle-cock shaped and the universe expanded from the tip that had zero diameter. They derived a formula that described the whole shuttle-cock called the ‘wave function of the universe’ covering the past, present and future all at once. Therefore, Hawkins is said to famously have said that asking what came before Big Bang was like asking what lies South of the South Pole. There is no notion of time as per this theory.

Chaotic Inflation Theory


As per this theory, there exists a multitude of universes. Each universe births out inflationary bubbles, each of which becomes a universe and this process repeats endlessly creating an immeasurable multiverse.

Black Holes

Some scientists believe that our universe was created inside a black hole and the black holes we see in our own universe are a source of more universes. Theoretically, hence, our universe is a white hole derived from a black hole in another universe. A white hole, hypothetically, is an opposite of a black hole, releasing energy and matter instead of drawing it inwards.

Black Hole

Big Bounce

This theory suggests that a small smooth universe gradually expands and becomes warped and clumpy. After a point it will start to collapse on itself going back to its original smooth shape and size and the cycle will repeat.

Big Bounce

We have always been intrigued by our origins. We hope that the advances in science and technology will someday give us the answers we desire. Till such time we must focus on sustaining and promoting life on our planet that is but a speck in the vast expanse of the universe.

5 Questions that still remain unexplained by science #1

1. Why Do We Dream?

Much remains unknown about the process and purpose of dreams. Although it is a part of our everyday lives, we rarely think about it once we are awake. Sleep itself is a complex series of events that leaves us fresh and energised day after day. These different stages of sleep also occasionally lead us to creative and incredible solutions to problems that normally seem unsolvable.

Many research projects about dreams have been undertaken to understand the science behind them. The current view is that the same specific areas of brain that control activities we dream about when awake are activated while dreaming. Our memories, managed by the hippocampus, also play a major role in the process of dreaming.

Why do dreams contain fragments of our memories?

Hippocampus, in simple terms, helps form memories. It also uses memories to create scenarios. This could be a reason that fragments of our memories are a part of our dreams which then get simple or strange to downright bizarre, fantastic overlays that define dreams.

Some of the proposed purposes of dreaming include the following

  • Processing, analysing and consolidating past experiences and memories.
  • Cognitive simulation of events and experiences gathered when awake.
  • Understanding and reflecting on niggling subconscious issues.

5 stages of sleep have been described

  1. Stage 1: 4-5% of the sleep time. This is the period of light sleep with slow eye movements when muscle activity reduces.
  2. Stage 2: Around 50% of sleep happens in this stage. The eye movements now stop and brain waves become slower. There are sporadic bursts of rapid waves called sleep spindles.
  3. Stage 3: Slow brain waves called delta waves start appearing in this stage. This is a short phase comprising of around 4-6% of the sleep time.
  4. Stage 4: Stage 3 and 4 are the periods of deep sleep when there are no eye movements or muscle action. If woken from this stage, a person can experience disoriented for a few minutes to adjust to wakefulness. The brain produces delta waves. 12-15% of total sleep occurs in this stage.
  5. Stage 5: This comprises of 20-25% of sleep time. It is also called the REM or Rapid Eye Movement stage. As the name suggest, the eyes seem to move jerkily and quickly along with other features such as rapid, irregular breathing, rise in heart rate and blood pressure.

While it was thought that dreaming was restricted to this REM phase, a new study from scientists at the Wisconsin Institute of Sleep and Consciousness, however, has shared findings which indicate that dreams can occur during both REM and non-REM sleep equally.

Dreams are not always remembered. However, when remembered, they include vivid visual and emotional content. Many studies have been undertaken to pinpoint the regions of the brain activated during dreaming to help decipher their purpose.

The Wisconsin Institute study led to the inference that the same areas that fire during wakefulness are triggered while dreaming about the relevant activities.

Functional Parts of the Brain – Simplified diagram

All in all, this is a subject of much intrigue and interest and is yet to be fully understood.





Stay Tuned for part 2 of this series – What happened before Big Bang?

15 Simple steps to reduce your Carbon Footprint

Carbon Footprints

The total amount of greenhouse gases like carbon dioxide, methane, nitrous oxide and fluorinated gases generated by our actions is known as Carbon Footprint. We all create a carbon footprint as a result of our day to day activities.

To ensure that global temperature doesn’t rise over 2˚C by 2050, the per capita carbon emissions need to be below 1.87 tonnes for every country on earth.

This is a tall order considering that countries like USA, Canada and Australia are at over 15 tonnes. Countries like China and UK are at over twice the recommended value. In terms of absolute annual emissions, China at 9.8 billion tonnes needs to aggressively work on controlling Carbon emissions. USA and Canada are at a high 5 billion plus too.

India’s per capita Carbon emission is at 1.84 tonnes and total annual emission is at 2.46 billion tonnes.

Data on Carbon Emissions

2017 Data
Source -https://ourworldindata.org/co2/country/united-states?country=USA~GBR~CAN~IND~AUS~NGA~CHN

2017 Data
Source -https://ourworldindata.org/co2/country/united-states?country=USA~GBR~CAN~IND~AUS~NGA~CHN

The highest carbon footprint generator in the present day is the energy production sector which accounts for over 70% of the Carbon emissions. This is followed by Agriculture at 11%. Deforestation and Industries together produce around 12% of the total emissions.

The world is in a critical stage, very near a point of no return. Now, more than ever, it is important for every person to contribute to the cause of environment protection. What can we, as common citizens, do to reduce our Carbon Footprint?

Here are some simple steps that we can easily make a part of our lives.

Steps to reduce energy consumption

  • Switch off lights, fans, laptops, air conditioners and other appliances when not in use. A computer that is turned off uses at least 65% less energy than that left on idle.
  • Unplug appliances when not in use. Many electronic devices like chargers, televisions, printers etc. continue using energy even when powered down.
  • Switch to Solar appliances wherever possible for heating, lighting and other purposes – It is renewable, abundant and free.
  • Use energy efficient appliances – check for star rating. Star rating indicates the energy efficiency of electrical appliances. The higher the number of stars, the more efficient it is. The star rating system was devised by the Bureau of Energy Efficiency (BEE) India, with a range of 1 to 5 stars.
  • Use LED for lighting – They are more energy efficient and environment friendly than CFL and other options. They also last longer and emit less heat.
  • Walk, cycle or use car pools and public transport as far as possible.

Steps to reduce wastage

  • Reduce – Reuse – Recycle – Around 3% of the global carbon emissions are a result of waste disposal. Higher amount of emissions result from products that need advanced methods of disposal. Be it plastic, cloth, paper, metal or any other household waste, try reusing, donating or recycling it to contribute in your own way to reduce global warming.
  • Carry a cloth or jute bag when you go shopping instead of picking or buying a plastic bag with every purchase.
  • Save water – treating and pumping water requires energy. Additionally, getting safe water is also a challenge in many geographical areas.
  • Reduce food wastage and compost vegetable and organic waste as far as possible.

Tackle Deforestation

  • Save trees – Each year about 15 billion trees are cut – leading to increase in greenhouse gases and soil erosion. Deforestation also impacts local ecosystem of the forest area.
  • Save and recycle paper and wood furniture as much as possible.
  • Participate and volunteer in reforestation drives and tree planting activities in the community.
  • Restrict use of disposable plates, cups and cutlery and switch to reusable utensils.

Spread the Word

  • Finally, You can be a champion of environment protection by just spreading awareness about these simple steps to reduce Carbon Footprint and save our planet.

Why Go Nuclear – Top 5 Reasons

Nuclear Energy – The Fuel of Tomorrow

As concerns on Global warming and depletion of Non-Renewable sources of energy mount, the quest for safe, renewable and abundant alternative source of energy has gathered momentum.

A front-runner in this energy race is Nuclear Power. Countries such as Slovakia, France, Ukraine, Hungary and Bulgaria already produce over 40% of electricity through nuclear power plants. With the available reserves, it is projected that energy needs for the entire world can be covered for hundreds of years through nuclear energy.

Top Countries by Nuclear Energy Production
Top Countries by % of Power Generation through Nuclear Energy


Here are the top five reasons to switch to Nuclear power.

Low Carbon Footprint

A clear goal of the ‘Paris Agreement’ is to limit the rise in Global temperatures to under 2 Degrees Celsius. Greenhouse gases are significant contributors to Global Warming.

Nuclear power plants, unlike conventional power plants, do not produce greenhouse gas emissions during operation.

CO2 Emissions from different Power Sources

Over the course of its life-cycle, nuclear power is equivalent to wind energy in terms of CO2 equivalent emissions per unit of electricity and one-third compared to solar energy.

It is reliable

The production of nuclear power is more reliable, consistent and more predictable than renewable sources such as Wind and Solar power which are subject to climatic variation. In some studies it has also proven to be more reliable than Hydroelectric and other power plants.

Nuclear power plants run 24/7. They are designed to operate for long operating time and refuel every 1.5 – 2 years. A study in the US has shown that Nuclear power plants have a 92.3% Capacity Factor compared to under 40% for Solar and Wind Power.

Capacity factor is a measure of what percentage of the time a power plant actually produces energy.

It is Safe

Contrary to popular belief, Nuclear power production is safer as it generates less amount of waste than other thermal electricity generation technologies. Safe and effective methods are available to dispose nuclear waste.

In fact, hydrocarbon led industries also produce radioactive material as waste product. This material from the oil and gas industry is called ‘technologically enhanced naturally occurring radioactive materials’ (Tenorm). The largest Tenorm source is coal ash of which around 280 million tonnes is produced every year globally. It contains uranium-238 and thorium-232.

Stringent guidelines to dispose radioactive waste are followed by the industry players.

Radioactive waste is classified as low-level (LLW), intermediate-level (ILW), or high-level (HLW) based on its level of radioactivity. Radioactive elements with longer half-life (time taken for half its atoms to decay and become non-radioactive) are easier to handle and emit Alpha and Beta rays. Those with short half-life emit Gamma rays which are more penetrative and need to be handled carefully. Half-life may vary from a few hours to thousands of years for different materials.

Before disposal, processes of segregation, characterisation, handling, treatment, conditioning and monitoring are done to ensure proper disposal. The methods preferred for Radioactive waste disposable in India are as follows.

Delay and Delay

Dilute and Disperse

Concentrate and Contain

Recycle and Reuse

While their safety has been well established for decades and countries like France have used it for generating a substantial portion of their overall power generation, there are reservations about their safety. A number of research projects are underway to improve this technology further. Small modular reactors are being developed to take care of the safety as well as resource aspect of Nuclear energy. Newer processes of manufacturing, better, safer and more efficient fuel types are also being developed.

Options to Recycle

Used nuclear fuel can also be used as resource for other purposes. Once uranium or thorium is used as fuel in a reactor, it can be treated and used in another reactor as fuel. Processes like Closed Fuel Cycle and Breeder Fuel Cycle allow for recycling of nuclear fuel.

Many isotopes are used for preparing radio-pharmaceuticals for diagnostic and therapeutic usage. Some like Cs -137 are used for irradiation of food, sewage sludge, blood etc as a better option to Co-60. Some by-products like Sr-90 and Ru-106 are also used in cancer treatment.

Fuel material Available in abundance

Uranium is a relatively common element found in Earth’s crust. it is a part of most rocks and found abundantly in the sea as well. It is expected that 4.5 billion tons of Uranium can be extracted from sea water at 10 times the current price of Uranium.

Thorium can also be used as nuclear fuel. It is available in much larger quantities than Uranium (around 3 times more).

Very small quantities of fissile material are needed to produce energy. One Uranium fuel pellet produces energy equivalent to one ton of coal.

While there are still concerns about cost of setting up a plant, technological challenges, cost of operating and maintenance and safety, the future seems bright for Nuclear Power. With research ranging from developing smaller, safer and more efficient reactors like the Small Modular Reactors (SMEs), to developing better fuel and manufacturing processes, it will not be long before Nuclear power becomes the first option for clean renewable energy worldwide.







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UFOs – Are they Real?

We humans have always been intrigued by extraordinary events unfolding in the night sky – be it eclipses, meteor showers, comets or UFO sightings. An oft explored but unexplained subject is the sighting of UFOs or Unidentified Flying Objects. As the name suggests, these are merely unidentified objects but we nearly always equate them with extra-terrestrial visitors. They are defined as any aerial phenomena that cannot immediately be identified or explained.

There are many theories and conspiracies surrounding UFO sightings. Many sky-gazers report unexplained objects and lights that fall under this category. As exciting as they may seem, many of these sightings have a perfectly scientific and earthly explanation.

Here are some of the common objects and phenomena that can be mistaken for UFOs

Low orbiting Satellites

As of 1st January, a UCS (Union of Concerned Scientists) reported 6542 satellites orbiting Earth. Of these, 3372 were active.

Satellites orbiting low enough can appear like UFOs and many such cases have been documented.

ISS captured as a hovering object on a mobile camera
Various uses of Satellites


Drones are a part of our lives now and single or multiple drones travelling across the sky can sure appear like UFOs especially at night. They are commonly used for purposes like surveillance, photography and even for recreation. As their numbers rise, the suspected UFO sightings are likely to rise.

Weather Balloons

We all know that the official answer for most UFO sightings in the past has been Weather Balloons, and rightly so. These common and harmless meteorological devices have been mistaken UFO sightings for decades. With varied shapes and sizes and carrying instruments, some of them traverse to high altitudes and stay for long periods. They can appear as strange hovering objects.

Optical Illusions

Some common illusions that appear like floating lights include Lens Flares, Parhelia and Lenticular Clouds.

Meteorites, Comets and Planets

It is not uncommon to mistake this beautiful natural phenomenon for something more sinister. A multitude of flares lighting up the night sky can be mistaken for descending UFOs by untrained observers. Occasionally Venus, that appears like an unusually bright object in the sky, can also be a source of confusion.

Falling Rocket parts, Space Debris

There are approximately 23,000 pieces of space junk of notable size orbiting the earth. According to NASA, one catalogued piece of debris on an average per day has fallen to Earth in the last 50 years.

These include dead spacecrafts, launch vehicle stages like boosters and other equipment. Although most debris burns up in the atmosphere, larger objects can reach the ground. These generally add to some of the UFO reports by observers who capture them on camera.

Some of the recent space debris cases include uncontrolled re-entry of a Long March 5B rocket over Africa in 2020 and a Falcon 9 second stage re- entry over Washington state in March 2021 producing Light Show that many people observed.

Experimental Vehicles

Many agencies across the world are developing futuristic airborne manned and unmanned vehicles that are not really disclosed to the general public. These could be anything from regular transport vehicles to military aircrafts. Owing to their futuristic designs, they could be reported as UFOs by casual watchers.

Contrails from Jets

Lines made from Contrails or vapour clouds from Jets can be mistaken for a passing UFO occasionally.


Ball lightening is an unexplained phenomenon where luminescent spherical objects are seen during thunderstorm. They vary from pea-sized balls of lightening to those several meters in diameter. They can be a reason for some of the UFO sightings reported.

For now, there is no clear evidence that UFOs have visited us and many of the sightings can be easily explained.

However, it is more probable than not that life exists on one or many of the exoplanets dotting the universe. While there are no definitive answers yet, a recent report states that the odds of finding an intelligent extra-terrestrial life lie at a promising 50%.

Therefore, it is not wrong to assume that it is possible that some of them might visit us some day.





Five inventions that will change the world

The world is changing like never before. Every change brings its own set of benefits and challenges. Here is the #TSIFUNLEARN list of inventions that will change the world for the better.

Artificial Sun

This is an attempt to recreate the nuclear fusion reactions that occur in the Sun and generate limitless clean energy in the process.

EAST, or Experimental Advanced Superconducting Tokamak experiment is underway in China and is backed by 35 countries including India, USA, Japan and Russia.

Once fully operational, it is slated to reduce the dependence on fossil fuel and put an end to the energy crisis. Nuclear fusion using Deuterium found abundantly in the sea will be used to generate energy.

Deuterium, (D, or 2H), is also called heavy hydrogen. It is an isotope of hydrogen with a nucleus consisting of one proton and one neutron, which is double the mass of the nucleus of ordinary hydrogen (one proton). Immense amount of heat and pressure applied to Deuterium atoms initiates a fusion reaction. This results in emission of a vast amount of energy that can be harnessed.

Bio degradable plastics

Bio degradable plastics are plastics that are broken down or degraded by microbes and prevent plastic pollution. They are produced from renewable sources such as vegetable oils, corn starch, straw, woodchips, sawdust and even recycled food waste.

Around 8 million tons of plastic waste escapes into the oceans every year. Plastic production increased from 2.3 million tons in 1950 to 448 million tons by 2015 and the last two decades have seen a steep rise. The environmental impact includes production of greenhouse gases, impacting wildlife and marine ecosystem. More importantly, microplastics find their way into the human food and are a health hazard. Many studies are underway to evaluate their role in endocrine, neurological and cardiovascular disorders, cancer and even autoimmune diseases.

Biodegradable plastics, once fully scaled up will greatly help reduce plastic pollution and will be counted as one of the most impactful developments to save the environment.

Examples in use include polyhydroxyalkanoates (PHAs), Polylactic acids (PLAs), Starch blends and Cellulose based plastics.

The top benefits include environmental safety and lowered cost of treating waste.

Artificial Intelligence and Machine Learning

AI is already a much in use technology and it is only going to be bettered over time. It has revolutionised nearly all industries, offering easy solutions for everything from predictive planning to process improvement to deriving avenues for profitability and most of all, an incredible customer experience.

Over time, we have started getting used to AI based personalized suggestions for what to read, what to buy, what to eat, what to watch, even whom to friend or follow on social media.This technology will revolutionize even expertise-based fields such as judiciary, healthcare, education, fashion, creative writing etc.

Hyperloop Public Transportation

This is a futuristic technology at various stages of testing and is most likely the closest to being available for public use. Many players are working on developing feasible models of this technology.

The technology is based on the principle of using a system of tubes maintained at low air pressure that reduces friction or air resistance increasing speed of the transport pods. With speeds at par with air travel will help make this a highly energy efficient and one of the fastest means of public transport.

Many other routes around the world are planned in India, USA and Europe.

Malaria Vaccine

Nearly 50% of the world’s population lives in areas at risk of malaria. In 2019, malaria caused an estimated 229 million cases and 409,000 deaths.

We are in the midst of a Covid 19 pandemic and the current priority is to get over it. However, malaria has continued to cause significant morbidity and mortality for thousands of years and we are yet to find a suitable and sustainable preventive measure. The earliest fossil evidence of the parasite is 30 million years old. However, significant human infestation is known to have occured about 10,000 years ago coinciding with the start of agriculture.

The only approved vaccine as of now is Mosquirix (RTS,S). It needs four shots and is of relatively low efficacy. A new trial with a vaccine called R21, underway with 450 children aged 5–17 months. This vaccine has shown up to 77% efficacy at preventing malaria over the course of one year in preliminary trials — Higher than the 75% effectiveness target set by the World Health Organization. Both the vaccines include a protein secreted by the malaria parasite at the sporozoite stage when it enters the human body along with an adjuvant to stimulate a sufficient antibody response.

We are nowhere near eradicating Malaria yet but a multipronged approach targeting the parasite and mosquitoes will get us there in the near future.

Read more about eradication of Malaria in our previous edition –

Simple Steps to Save Water

97% of water on earth is not potable. Only 3% of the world’s water is fresh water and even from that, only one third is available for use.

Currently one in ten people have no access to clean water. People, mostly women, spend 200 million hours every day to fetch water for daily use. Over 800 children under 5 years of age die every day across the world from diarrhoea due to contaminated water and poor sanitation.Fifty percent of world’s population could be living in areas with scarcity of water by 2025.

World bodies and governments are working on plans to conserve water and provide safe water to all. But what can we, as average citizens, do to make a difference and save this precious resource?

Around 30% of water we use in our households can be saved by just taking small steps in our day-to-day life. Some of the direct benefits are –

  • Direct saving on water bills.
  • Prevents greenhouse gas emissions involved in water treatment and distribution.
  • Reduction on soil saturation and thus extending the life of septic systems.
  • Makes available incremental water for use by society as a whole

Easy steps to conserve water at home.

  1. Leaks – This is one of the unnoticed losses which can be easily addressed by maintenance of household plumbing and taps
  2. Overflow – This needs some difficult changes in habits but the effort is well worth it. Loss during brushing, shaving, washing utensils and vegetables a can be prevented by not keeping the tap running during these activities
  3. Optimise quantity – Installation of Dual Flush modes for low and high water need, choosing water conserving washing machines and dishwashers also helps.
  4. Water saving equipment – Water saving low flow aerator in shower heads and taps.
  5. Recycling water – Watering plants with water used for washing vegetables or grains.
  6. Water from RO purifier can be used to flush toilets.
  7. Water harvesting – Rainwater can be harvested to build up soil reserves.

So armed with these simple but effective measures, everyone can contribute in saving the environment and be a Hero.

Ghosts Debunked

This week TSI debunks the common incidents reported as Ghost stories or Paranormal events.

Science has answers to most of the cases. Everything from structural acoustics to psychiatric conditions and psychotropic drugs can give rise to such phenomena.Watch the video for more information.

Many mysteries remain and the quest for answers through science continues.

Don’t forget to post any experiences or comments related to this subject.


Team TSI

Metamorphosis –

Some fascinating insights into this evolutionary magic trick.

By Elizabeth Jane


When you look at an elegant butterfly flitting across the landscape, flapping its delicate wings, resting briefly to feed on nectar from flowers, it’s almost impossible to imagine the real story of its evolution- that it has only recently wriggled out of a pupa- a mummy-like sarcophagus where it underwent an unbelievable transformation from being a caterpillar. And that as a caterpillar, it may have moulted upto five times, shedding its continuously expanding outer body, as a gluttonous crawling insect, decimating host plants, to fatten up, and reach its optimum size. And before taking the shape and form of a caterpillar, it was a tiny maggot-like grub that emerged from a miniscule egg, laid by a butterfly just like the one you’re looking at.

As an amateur entomologist and nature photographer, I have over the years observed various creatures around me and marvelled at them, without really being able to either fathom the evolutionary link or understand the reasons and purposes of their development stages.

I found answers to many of these mysteries in a Science Weekly podcast of The Guardian, curated by Natalie Grover. She explores a range of aspects about that fascinating thing called ‘Metamorphosis’- where a creature remodels itself between life stages; one of the most astounding and bizarre feats of biology. While we might presume this is a relatively rare phenomenon, she says, it’s surprisingly common, as explained by experts- Stuart Reynolds, a professor at the University of Bath and Anjali Goswami, a research leader in life sciences at the Natural History Museum, London, and honorary professor in palaeobiology in the Department of Genetics, Evolution and Environment at University College London.

While I share pictures of some wonderful caterpillars from my neighbourhood, I thought, I’d also share some of the insights from the podcast, to put their evolutionary story in context. 

So, what are caterpillars? Why do animals bother undertaking this huge transformational change, called metamorphosis? And how do they rebuild their bodies from one form to another?   


Prof Stuart Reynolds explains that metamorphosis is something people have been fascinated with ever since Aristotle. The way we usually use the word is to describe “an abrupt and quite quickly accomplished change in the shape of the animal concerned and the fact that the two different forms have very different behaviours and habits. It’s as if they occupied different niches” but he clarifies that “actually there are two different kinds of metamorphoses that insects undertake. There are some insects like grasshoppers that hatch out looking like little adults except that they don’t have wings, but there’s another kind of metamorphosis, which a majority of insects undertake. The difference between the immature form and the adult is very great. The immature insects look like little grubs or maggots or caterpillars and they’re totally different from the adult. The difference in shape is so great that you have to have a stage interposed between them and we usually call this a pupa or a chrysalis. During the time that an insect is a pupa, it’s going to have to undergo very great changes in its body form.”

In a nutshell, what is the typical journey from egg to adult in one of these extreme cases? 

Prof Reynolds explains, “The insect lays an egg, the creature that develops inside that egg turns into a larva, like a caterpillar. The caterpillar is highly adapted to eating and growing. In fact it eats like crazy. It does absolutely nothing else. It periodically has to replace the hard exoskeleton on the outside because its inextensible. It can’t be stretched anymore. So the insect actually grows a new cuticle- a new skin inside the old one. And  then the old one splits and the new caterpillar comes out. And we go through a series of moults like this. Maybe five moults- is pretty typical for a butterfly caterpillar and then somehow, the caterpillar knows that it’s big enough. And it stops eating. It stops growing and instead of moulting into another caterpillar, it moults into something that looks a bit like an adult but actually isn’t very mobile. We call this a pupa. And at this time a great deal of restructuring has to take place. The pupa has things that look a bit like wings but they aren’t flappable. They wouldn’t be able to fly with them. It has things that look like adult legs but it couldn’t walk on them. And lots of other structures have to be reorganised. New muscles have to be grown. Bits of nervous system have to be put in place, so the adult insect will be able to know where it is and what it’s doing. All of this time, during the life of the pupa, there’s a great deal of breaking down of the old tissues that has to go on, and it takes almost as long as the caterpillar spent growing in size  to turn the fully fed caterpillar into a proper adult and that is the pupal stage. Sometimes the pupa lives inside a silken cocoon, sometimes it lives under the ground, but the changes that go on at that time are pretty similar… and eventually the pupa is now ready to emerge as an adult. So, it moults again and what comes out is an adult that we would easily recognise as being a proper butterfly. And as an adult, it has a completely different lifestyle. Instead of being concentrated on growing, it is interested really only in sex!”

Insect Eggs

Not a bad life at all, for a creature most of us view dispassionately, as gorgeous, fairy-like winged beings, just passing through…

So, how does the turning point present itself to a caterpillar, to decide that today is the day, that it will change itself completely and irreversibly?

Turns out that the answer is not all that clear. But, Prof. Reynolds says, this could partly owe to the fact that caterpillars have “stretch receptors inside its body that say- oh, you’re getting a bit fat now. And so, they know that they’re big enough. But actually when you think about it, the way that the stretch receptor works, is that it’s stretched between two bits of the outside of the body. And every time the insect moults, they’re going to be reseting their ideas of how big is big. So somehow, the insect has to know how many times it’s already moulted as well, and we really don’t have a very good idea about that. So the basic idea is that the insect knows how big it is and then it decides it’s going to moult. And what it does then, I think is utterly fascinating. It turns out the insect has a hormone, which it stops releasing when it’s big enough. It’s called the juvenile hormone. The role of this hormone is to stop metamorphosis from happening. As you can imagine quite a lot of people since the 1930’s have heard about the juvenile hormone and thought it would be great if you could put it in a bottle and sell it. But of course it’s a hormone that’s really only found in these jointed-limb animals- the arthropods, that is basically crustaceans and insects.”

Natalie Grover says that for insects, once this gatekeeper- the juvenile hormone stops being produced the process of metamorphosis can begin. For the most extreme cases like a caterpillar turning into a butterfly, in the pupal stage the insect needs to disassemble itself and rebuild a totally different form- reallocating materials and turning them into new legs or muscles or wings. She asked Prof. Reynolds about the role of genetics in this biological reprogramming.

According to Prof. Stuart Reynolds, when insect biologists first got interested in this at the start of the 20th century, “it was speculated that an insect having three markedly different body forms- larva, pupa and adult, might actually need three whole separate sets of instructions on how to form those three different kinds of bodies. The idea was you’d have three separate genomes, all combined into one, because that’s what genes do. They tell the body, how it should develop, what activity should be going on. So the idea wasn’t a completely stupid one. But actually it turns out to be wrong. It turns out, that the larva, the pupa and the adult- they’re using the same set of instructions to make their respective bodies. If you think about this, in a simple human analogy, if you’re a building firm, you employ the same set of builders and the same kinds of building tools, to make a house or a factory or a skyscraper. The techniques are all the same. The blueprints are a bit different- they just tell you what to do and when to do it. So, the tools that you actually need to make the larva, the pupa and the adult are all the same. What really is different is that there’s a master gene in each case, that then feeds down onto a very complex interacting system of feedbacks that gives you the use of all of these different tools and instructions.”

Anjali Goswami says, metamorphosis is surprisingly widespread, and not just in insects. It is “much more common than most people realise. Something like half of the animals actually go through metamorphosis. Some of the most famous examples are the amphibians- the frog’s life-cycle is a really classic example of metamorphosis- They’re very much like a fish in their earlier phases and then they transform into an animal that has limbs and in many cases it’s on land and honestly if you found these different forms and didn’t actually witness that they actually transformed into each-other, then I think it would be really hard to match up larval forms to their adult forms. It’s a problem when we think about fossils where we don’t actually capture that transition. So, it’s extremely common in the animal kingdom but it’s also really extreme in terms of the amounts of change that happen between their larval forms and their adult forms’, she says.  

This begs the question about why animals undergo this change? Why even bother going through this huge transformation?

Goswami says, “Why metamorphosis is so common is a really interesting question. You’d think that it would be really uncommon because it’s so difficult. The idea for why it is so common is because of competition. The competition specifically between the young of a species and its adult stages. So, you can imagine if the juveniles or the babies are living and eating in exactly the same way as the adult forms, there could be a lot of competition between them for the same resources. Obviously, it really disadvantages the young, but by having a completely different lifestyle it means that they can specialise for a very different life, diet, habitat- it removes the competition between different life stages of the same species.” 

Of course, this implies a downside, “to be one organism and then transform into essentially another organism. You have to basically rebuild your body from scratch twice, and that’s really energetically expensive. Our natural inclination is to think, that’s a pretty crazy thing to do”, Anjali Goswami says. 

As far as eliminating competition, Anjali and her team investigated if metamorphosis could also play a role in evolution, using salamander skulls from the natural history museum collection, Anjali and her team measured skull shapes of a 148 species to learn about how salamanders evolved, depending on their developmental stages.            

Using micro CT scanners to create 3D scans of various salamander species, Anjali Goswami and her team made some amazing discoveries. She says her research was “able to show with our salamander data set that, species that are direct developers- that is the ones that have lost that metamorphic phase- they all cluster together… and the ones that do go through metamorphosis also cluster together and show similar shapes in skulls. So just by looking at skull shapes we get really strong signals of how these different animals develop, which is really interesting… it’s really difficult to tell an aquatic salamander from one that lives in the trees, from one that lives in the ground. We have a much better chance of guessing or figuring out how they developed just from the shape of the skull.”

Turns out metamorphosis offers a clear evolutionary advantage to animals: “In fact, what we found is that the species that are metamorphic and also the species that are pedomorphic, meaning they stay in their larval form- evolve much faster and show much more diversity than the ones that are direct developers- so when they lose that metamorphic phase altogether. So that’s really interesting and surprising how much slower these direct developers are evolving, compared to the metamorphic forms.”

Finding that different parts of the skull don’t always evolve in the same way, and particularly for species that undergo metamorphosis, demonstrated to Anjali and her team that this transformational change was having a significant impact on their evolution and their diversity.

“In terms of how metamorphosis might be shaping the evolution of different species – there’s a lot of potential there in terms of why that could be. Why it could be a promoting factor. One is that by separating life stages into different bins, maybe you can specialise more as an adult into a certain habitat, because you’re not limited by what your young form has to do. You can basically, completely change what you’re doing and that could give you a lot more flexibility. And one thing we were able to show is, when you look at different parts of the skull- you can break it up into different bones that form the skull- and within the metamorphic species, we are able to show that different parts of the skull are able to evolve more independently. So you might have certain things that are influencing the evolution of parts that are related to the mouth, that are evolving really independently of the parts that are involved in say the brain case or the attachment to the neck. The species that are metamorphic seem to show more independence in the evolution of skull parts than the ones that don’t go through metamorphosis. And maybe that means that those metamorphic species are just evolutionarily more flexible, and that’s interesting because you can use that to understand, well, as the environment is changing rather quickly these days, as we go through this biodiversity crisis- are there some species that can do better than others? Basically how quickly they can evolve, how adaptable they may be.

The issue of a biodiversity crisis, set into the context of climate change and destruction of habitats caused by human activity creates a whole lot of questions about the future of creatures that might adapt and those that might perish. Anjali Goswami is not very optimistic about the pace at which species might manage to adapt and survive, given the velocity of habitat destruction unleashed by humans. She says, “metamorphic species have essentially two completely different lifestyles that need to have a habitat preserved, and as we go through this period where due to human activity we are decimating a lot of habitat and really getting rid of areas where animals live, things that really need complex or multiple habitats might have a harder time than things that just have a simple or single habitat. Now, I don’t know if that’s the case but it’s a hypothesis that I can think about and test. Whether or not, even though these metamorphic species seem to evolve more quickly in the past, whether these extreme changes that are going on right now, because of human activity, are quite different from the changes that happened in the past, in terms of the environment, and by of course fragmenting and destroying large areas of natural habitat, it would have quite a severe impact on metamorphic species. Hopefully they’ll be ok, being adaptable, as they are metamorphic. But, I’m not sure that’s going to be the case.”

Given the miracle, that the process of metamorphosis is, and the mysteries of nature that the human mind is always grappling to unravel, it might be worth our while to pause and ponder over these fantastic phenomena, especially at a time that we’ve been brought to our knees by microscopic germs. I hope you enjoy my pictures of a few caterpillars from my neighbourhood for now.

You may listen to the Science Weekly podcast- ‘How do animals undergo metamorphosis and why’, here:


About the author

Elizabeth Jane combines over 14 years of experience in a range of roles across media sectors. She has been a journalist for the bulk of her career, covering news from the field as a reporter, while also offering analytical perspectives on developments from the studio, as a Senior Anchor. She has worked with India’s national broadcaster DD News in Delhi, with the BBC World Service in London, TV 18 Network and the India Today Group.

Before moving to India’s news-capital, New Delhi, Elizabeth spent more than five formative years in the Maximum City, Mumbai, where she assisted Prahlad Kakar on making ad-films and also worked on TV serials and documentaries with directors like Vikas Desai and Ajay Kartik. At Banyan Tree Communications, she worked as a Senior News Editor/ presenter, handling political news in the South-Asian region for an internet radio station and also wrote pilot scripts for fiction formats on radio.

Elizabeth gained a Masters Degree in Communication Studies from Pune University after graduating in Psychology, English Literature and Journalism, from Mount Carmel College, Bangalore.

Recently, following a sabbatical to raise her child, she turned to flexitime work options. She worked as Senior Editor with Trans Asia News Service, a portal offering news and analysis from an Asian perspective, where she interviewed the Dalai Lama.
Most recently, she brought to bear her collective experience to manage the Communications and Media management services for a Tata Trusts initiative called Social Alpha. At this Bangalore-based startup specialising in the ‘social business’ sector, her work entailed content creation, copywriting, PR and media relations, as well as communications strategy for internal and external stakeholders & events.

Elizabeth is an animal-lover, is passionate about plants, enjoys photography, and is keenly interested in health & fitness.

Durum Wheat – Uses and Importance

Dr. Amit Gautham

When we relish the upma or pasta in our plates, we seldom think about how the ingredients make their way into these sumptuous dishes.

One of the most used cereals worldwide is wheat. It is one of the most durable and dependable crops after rice and maize and is grown under diverse Agro-Climatic conditions.

We will take a look at a variety called Durum wheat that is the raw material that goes into our daily food items. Durum wheat is used to prepare numerous food products such as macaroni, pasta products and semolina and plays a part in the nourishment of the world’s population including India.

Durum wheat (Triticum durum L.) is an economically important crop grown worldwide including India. It is being cultivated in 10 to 11% of world area and accounts about 8% of the total wheat production.

In central India it is being cultivated in Malva regions, Sourastra and Kathiaward in Gujarat and Kota, Bundi, Jhalaward and Udaipur regions of Rajasthan, Bundalkhand region and west Maharastara from a long time and its traditional food products like Bati, Bafla, Dalia, Churma, Lapsi, Upma etc. are being consumed as staple food.

Due to susceptibility to rust and limited production in 1960s the cultivation in mid India declined and farmers stopped growing Durum wheat varieties. Now, due to the development of highly tolerant and high yielding varieties the area, production and productivity of Durum wheat has increased day by day and central India is now called a hub for Durum wheat.

Durum Wheat 1 kernel copyPic: Durum Wheat kernel

Advantages of durum wheat cultivation

More Production in less irrigation

Durum (Malvi) wheat needs less irrigation as compared to bread wheat. Some varieties like Malav Ratan and Malav Karti can give 35-40 quintals/ha. in one or two irrigations, depending upon the availability of water. Varieties like Malav Shakti and Poshan gives around 50-60 quintals/ha. in three to four irrigations.

Durum Wheat 2 crop stages copy

Pic: Durum Wheat crop stages

Durum Wheat 3 crop stages

Nutrient security:

It is found that as compared to rice and aestivum (variety of wheat) nutrient value of Durum wheat is more, because it contains protein, micronutrients like iron, copper and zinc in large amount comparatively.

Table 1: Comparison between quality characters of popular Bread wheat (Lok-1) and Durum wheat (HI 8627)

Varieties Hectolitre weight (kg) Protein (%) Total carotene (ppm) Iron (ppm) Zinc (ppm) Copper (ppm)
Malav Karti (durum) 82.3 11.0 5.7 49.6 42.1 6.0
Lok-1 (aestivum) 80.1 10.6 2.3 35.5 27.2 4.5

From the above table, it is clear that, as compared to the most popular bread wheat (Lok-1) in central India durum wheat (Malav Karti) contains more values of total carotene (two and half % more), protein and micro nutrients. In addition, it contains vitamin B complex i.e., Riboflavin, Lysine and Thiamine in good amounts. It contains folic acid, calcium, vitamin E and antioxidants in good amounts as compared to bread wheat. Total carotene which is a precursor of vitamin A, helps to keeps eyes healthy and is useful in the development of immune system.

Security to rust and other disease:

Research showed that Durum wheat has different levels of rust resistance as compared to common bread wheat. Many Durum wheat varieties are resistant to brown rust, which is very prominent in bread wheat in India. Durum wheat can protect wheat cultivators not only in central India but also all over India where wheat is cultivated. It is also resistant to black rust (Ug 99) so it avoids the dispersion of Ug 99 race in India. Durum wheat is also resistant to seed borne disease like Karnal blunt and Kayama (Loose Smut) which gives seed born disease free wheat varieties.

Durum Wheat 3A rust copy

Pic: Field view of Brown rust on Wheat

Job Orienting:

Durum wheat is mostly used in fast food like noodles, spaghetti, lasagna, vermicelli, macaroni, pasta and many other products.

Keeping in view the increasing demands of these products, many fast food production plants can be set up , providing jobs to many people.

Durum Wheat 4 products

Possibility of International business:

There is a wide competition in the export of bread wheat as compared to the Durum wheat. Since Durum wheat is a more profitable crop as compared to bread wheat, farmers can make good money by supplying disease free nutrient filled Durum wheat. In addition, they can get good market of processed food manufacturing in India.

New developed varieties of Durum wheat:

There are many Durum wheat varieties developed for different irrigation conditions, India Agriculture Research Institute, Regional station is working in very effective way for the development of many Durum wheat varieties for different irrigation conditions and improving its quality level. All the developed varieties are rust resistant, have high level of water use efficiency, drought and heat tolerable and contain high level of quality nutrients.

Therefore, the cultivation of Durum wheat makes great economic sense today as compared to other crops.

It surely is an opportunity for farmers in India to make use of indigenous technologies and crop varieties available for increased profitability and a fulfilling farming career!

Author :

Dr. Amit Gautham RA

Indian Agricultural Research Institute

Regional station Indore

Environment and Us

A Poetic Take

TSI presents shortlisted poems on ‘ Environment and Us’ to celebrate the International Forestry day and World Poetry day on 21st march 2023.

Sameer Gudhate is an avid reader with a passion for books and is interested in different perspectives, cultures, and ideas. He is a book reviewer with a keen eye for what makes a great story. He believes that books have the power to transport us to different worlds, introduce us to new perspectives and leave a lasting impact on our lives. His collection of Poems is soon to be published. He also runs a literary online Magazine.

Manvi Mehta is a Poet, Economist and a Mental Health Activist based in Jaipur, Rajasthan. She has published two poetry books and working on her fiction debut.