Finding tricky concepts hard to crack? This week’s SEE Snapshot simplifies VitalID, Non-deliverable derivatives (NDD), and galactic cosmic rays concept-focused way to give you an edge in UPSC Prelims. Don’t miss the infographics.
9 min readNew DelhiUpdated: Apr 29, 2026 06:39 PM IST
Here are three important topics from Science, Economy, and Environment decoded through the Prelims lens—focusing on concepts and clarity. (Image: AI generated)
Struggling with tricky and important concepts in UPSC Prelims? The exam increasingly tests your conceptual clarity and ability to apply core ideas, especially in the most dynamic subjects: Science, Economy, and Environment (SEE).
UPSC Essentials’ new initiative, UPSC Prelims ‘SEE’ Snapshot, brings you, every Wednesday, a quick, exam-focused revision of key concepts. In each article, we pick three important current themes from Science, Economy, and Environment and decode them strictly through the Prelims lens—focusing on concepts and clarity. Previously, we have covered concepts such as induction cooktops, tar balls, forex reserves, Nor’westers, Earth’s energy imbalance, and GDP rebasing, etc.
A new technology called VitalID promises to revolutionise how we log into different apps and websites, especially those offering an immersive digital experience. Instead of entering passwords or scanning our faces, we can use the subtle movements generated by our own bodies to log in. With the growing importance of emerging authentication technologies, knowing about VitalID and extended reality becomes important.
Core Concept:
— VitalID technology uses the vibrations generated by our breathing and heartbeats. These subtle movements travel through the neck and into our skulls. Because every person’s bone structure and tissue are slightly different, these patterns are unique— much like fingerprints.
— The system was introduced at the 2025 ACM Conference on Computer and Communications Security and is designed primarily for extended reality environments. According to researchers, it does not require any additional hardware. Instead, it relies on motion sensors already built into many modern headsets.
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— Extended reality: Abbreviated as XR, Extended reality comprises virtual reality, augmented reality, and mixed reality technologies. XR technologies combine the physical world with digital elements. XR technologies are mostly used in gaming platforms such as Viture, Meta Quest, and Oculus Rift. However, the use of XR technologies has been increasing.
📍UPSC Twist Points– VitalID vs Biometric
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— Biometrics: It refers to technology that identifies individuals using unique physical characteristics such as fingerprints, facial features, iris patterns, or voice. Biometric authentication is widely used for device unlocking, banking, and secure access systems, offering higher security and convenience compared to traditional password-based methods.
— Whereas VitalID uses internal physiological signals (heartbeat and breathing vibrations through the skull), captured via motion sensors, making it passive, continuous, and harder to spoof, Biometric Authentication relies on physical or behavioral traits (such as fingerprint, face, iris, or voice), which may involve active or passive scanning and are widely used.
VitalID uses subtle vibrations generated by breathing and heartbeats that travel through the neck and skull. Since every person's bone structure and tissue differ slightly, these patterns are unique — much like fingerprints.
Q 2 of 5
Where was VitalID first publicly introduced?
Researchers introduced VitalID at the 2025 ACM Conference on Computer and Communications Security, where it was designed specifically for extended reality environments.
Q 3 of 5
What additional hardware does VitalID require to function?
VitalID requires no additional hardware. It relies entirely on motion sensors already present in many modern XR headsets, making deployment simpler and more cost-effective.
Q 4 of 5
What does XR stand for in the context of this technology?
XR stands for Extended Reality — an umbrella term comprising virtual reality (VR), augmented reality (AR), and mixed reality (MR). XR technologies combine physical and digital elements and are used in platforms like Meta Quest and Oculus Rift.
Q 5 of 5
What is a key advantage of VitalID over conventional biometric authentication?
VitalID uses internal signals — heartbeat and breathing vibrations — captured passively and continuously. Unlike fingerprints or facial features, these internal signals are significantly harder to replicate or spoof.
The Reserve Bank of India (RBI) on Monday (April 20) partially eased curbs on certain rupee derivative trades that had been introduced earlier this month to prevent the currency from hitting successive record lows. On April 1, RBI has barred banks from non-deliverable derivative (NDD) contracts in the rupee, marking a decisive shift toward tighter control and transparency in the foreign exchange market.
Core Concept:
— Before knowing about the NDD, let’s first understand what derivatives are. ‘Derivatives’ refers to the financial instruments that derive their value from an underlying security or financial instrument. The underlying products can be equities, commodities, currencies, etc. Derivatives are primarily used by investors for hedging their position and minimizing the price risk.
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— NDDs, which are typically traded outside India in financial hubs like Singapore, Hong Kong, London or Dubai, allow participants to bet on the rupee’s direction without actual delivery of the currency.
— An NDD is a derivative contract where two parties agree on a future exchange rate for the rupee, but settle the difference in cash, usually in US dollars.
— The NDD market is widely used by foreign investors, hedge funds and global banks who cannot freely access and play in the Indian rupee market, as well as by firms looking to hedge currency risk. These trades take place offshore, outside the control of the RBI.
Non-Deliverable Derivatives (NDD) — Explained
FINANCE & ECONOMY — EXPLAINER
What are NDDs, who uses them, and how do derivatives like futures, options and swaps actually work? A primer for readers and UPSC aspirants.
What is an NDD?
A rupee bet settled in dollars — without ever touching rupees
An NDD is a derivative contract where two parties agree on a future exchange rate for the rupee, but settle the difference in cash — usually in US dollars. No actual rupees change hands. These trades happen offshore, outside RBI's control, in financial hubs like Singapore, Hong Kong, London, and Dubai.
Who participates in the NDD market?
◆
Foreign investors & hedge funds
Cannot freely access India's onshore rupee market. Use NDDs to take directional bets on the rupee's movement from offshore locations.
■
Global banks
Facilitate NDD trades for clients and manage their own currency exposure in markets where rupee convertibility is restricted.
●
Firms hedging currency risk
Companies with India exposure use NDDs to protect against adverse rupee movements without needing direct access to the Indian forex market.
Core Concept
Derivatives derive their value from something else
A derivative is a financial instrument that derives its value from an underlying asset — equities, commodities, currencies, and more. They are primarily used for hedging: a risk management strategy where investors offset the risk of adverse price movements by taking a strategic opposite position.
What can derivatives be based on?
▲
Equities & equity indices
Derivatives on stocks or indices like Nifty 50, allowing exposure to market movements without buying shares directly.
■
Commodities
Oil, gold, wheat and other physical goods. Producers and buyers use commodity derivatives to lock in prices and manage supply-chain risk.
●
Currencies & interest rates
Currency derivatives like NDDs help manage forex exposure. Interest rate derivatives help banks and borrowers manage rate fluctuation risk.
UPSC Focus
Three common derivatives every aspirant must know
Futures, Options and Swaps are the foundational derivative instruments. Each has a distinct structure and use case — frequently tested in UPSC Prelims and Mains (GS-III: Indian Economy).
Types of derivatives
F
Futures contract
An agreement to make or take delivery of a specified quantity at an agreed price on a future date. Both parties are obligated to fulfil the contract. Exists across commodities, equities, indices, currencies and interest rates.
O
Options contract
A right, but not an obligation, to make or take delivery of an underlying asset at an agreed price on a future date. The buyer can choose to exercise or walk away. Available on equities, currencies and interest rates.
S
Swap contract
An exchange of two streams of payments between two parties over a period of time. Commonly used for interest rate swaps (fixed vs floating) and currency swaps between institutions.
— The common derivatives are Futures, Options and Swaps.
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— A Futures Contract is an agreement to make or take delivery of a specified quantity at an agreed price on a future date in the underlying market. Futures contracts exist in commodities, equities, equity indices, interest rates and currencies.
— An Option is a right but not an obligation to make or take delivery of a specified quantity of an underlying asset at an agreed price on a future date. Option contracts also exist, just like future contracts, on different underlying assets or rates such as equities, currencies and interest rates etc.
— A Swap contract represents an exchange of two streams of payments between two parties.
Step outside on a clear night and look up. You’re watching light that has travelled billions of years to reach your eyes. But something else is raining down on you constantly, something you can’t see, can’t feel, and have probably never thought about: galactic cosmic rays. They are one of the most fascinating phenomena in nature. UPSC has previously asked questions on different environmental phenomena in its examinations. Thus, knowing about the galactic cosmic rays becomes important.
Core Concept:
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— Despite the name, cosmic rays aren’t rays at all. They’re particles: mostly protons, but also helium nuclei, electrons, and occasionally heavier atomic nuclei stripped bare of their electrons.
— They travel through interstellar space carrying enormous amounts of energy packed into something far smaller than an atom. When they slam into Earth’s atmosphere, they trigger cascades of secondary particles that shower down to the surface like invisible confetti. Roughly one cosmic ray particle passes through the palm of your hand every second.
— Where do cosmic rays come from? For the lower-energy variety, scientists believe the main culprits are supernova remnants, the glowing, expanding debris clouds left behind when massive stars explode. Within these turbulent remnants, magnetic fields accelerate charged particles like a cosmic game of pinball, each bounce adding more energy.
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— Because cosmic rays are charged particles, they don’t travel in straight lines. Magnetic fields – both inside our galaxy and beyond – bend their paths, scrambling their directions over the vast distances they travel.
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📍UPSC Twist Points– Solar cosmic rays and Cosmic ray shower
— Solar cosmic rays (cosmic rays from the sun) originate in the sun’s chromosphere. Most solar cosmic ray events correlate relatively well with solar flares.
— According to the National Oceanic and Atmospheric Administration, scientists have postulated that cosmic rays can affect the earth by causing changes in weather. Cosmic rays can cause clouds to form in the upper atmosphere, after the particles collide with other atmospheric particles in our troposphere.
— The process of a cosmic ray particle colliding with particles in our atmosphere and disintegrating into smaller pions, muons, and the like, is called a cosmic ray shower. These particles can be measured on the Earth’s surface by neutron monitors.
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Galactic Cosmic Rays: The Invisible Rain That Never Stops
Astrophysics — Explainer
High-energy particles from exploded stars and distant black holes pass through your body every second — silently, at nearly the speed of light. Here's what they are, where they come from, and why they're impossible to trace.
What Are They
The name is a misnomer — they're particles, not rays
Despite the name, cosmic rays are not rays at all. They are high-energy particles — mostly protons, but also helium nuclei, electrons, and occasionally heavier atomic nuclei stripped bare of their electrons. They travel through interstellar space carrying enormous energy packed into something far smaller than an atom.
What cosmic rays are made of
●
Protons
The most common type — hydrogen nuclei stripped of their electron, making up the bulk of all cosmic ray particles detected at Earth.
◆
Helium nuclei (alpha particles)
Two protons and two neutrons bound together — the second most abundant component of cosmic rays arriving at Earth.
→
Electrons
Fast-moving negatively charged particles, present in smaller numbers than nuclei in the cosmic ray flux.
★
Heavier atomic nuclei
Occasional heavier elements — stripped bare of all their electrons — arriving from deep space carrying extreme amounts of energy.
The Numbers
One particle per second — through your palm, right now
Cosmic rays are not a rare phenomenon. Roughly one cosmic ray particle passes through the palm of your hand every second. They travel at nearly the speed of light and pass through your body as though you barely exist — day, night, indoors, outdoors, without pause.
~1
Particle per second through your palm
~c
Speed — near the speed of light
1912
Year of discovery — Nobel Prize 1936
How They Were Discovered
A balloon ride that flipped scientific expectations
Austrian physicist Victor Hess climbed into a hydrogen balloon in 1912 and ascended to 5,300 metres. He expected radiation to weaken the further he got from Earth's radioactive crust — it did the opposite. Even a partial solar eclipse ruled out the Sun. He concluded the radiation was extraterrestrial, winning the Nobel Prize in 1936.
How They Form
Supernovae: the galaxy's most powerful particle accelerators
For lower-energy cosmic rays, the main culprits are supernova remnants — the glowing, expanding debris clouds left behind when massive stars explode. Within these turbulent clouds, magnetic fields accelerate charged particles like a cosmic game of pinball, each bounce adding more energy.
"Supernovae are the most powerful engines we know of in the galaxy — and cosmic rays are, in a sense, their exhaust."
— Astrophysicist, cited in summary of the field (source article)
Where ultra-high-energy cosmic rays may originate
◆
Active galactic nuclei
Supermassive black holes actively consuming matter at the hearts of distant galaxies — candidate sources for the most extreme cosmic rays observed.
★
Gamma-ray bursts
Some of the most violent explosions in the known universe, considered a possible origin for ultra-high-energy particles that arrive at Earth apparently intact.
●
The mystery: they shouldn't exist
At extreme energies, particles should lose energy interacting with the cosmic microwave background over long distances — yet they arrive at Earth apparently intact, suggesting a relatively close origin.
The Detective Problem
Magnetic fields scramble their paths — you can't trace them home
Because cosmic rays are charged particles, they don't travel in straight lines. Magnetic fields — both inside our galaxy and beyond — bend and scramble their paths over billions of years. By the time a cosmic ray reaches Earth, it's nearly impossible to trace back to its source. Physicists must work like detectives, piecing together indirect clues.
The detection toolkit
→
Atmospheric cascades
When cosmic rays slam into Earth's atmosphere they trigger cascades of secondary particles — "invisible confetti" raining down to the surface that can be measured at ground level.
★
Cosmic ray muon tomography
In 2017, researchers used muons — byproducts of cosmic ray collisions — to X-ray Egypt's Great Pyramid, revealing a previously unknown 30-metre void hidden for 4,500 years.
◆
The astronaut test
Astronauts aboard the ISS report seeing flashes of light with eyes closed — cosmic rays passing directly through their retinas, proof the universe passes through us.
"We are not isolated observers of the cosmos. We are part of it, immersed in it."
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Roshni Yadav is a Deputy Copy Editor with The Indian Express. She is an alumna of the University of Delhi and Jawaharlal Nehru University, where she pursued her graduation and post-graduation in Political Science. She has over five years of work experience in ed-tech and media. At The Indian Express, she writes for the UPSC section. Her interests lie in national and international affairs, governance, the economy, and social issues. You can contact her via email: roshni.yadav@indianexpress.com. ... Read More
(Image: AI-generated)
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