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हिन्दी — Read in HindiPhysics, chemistry and mathematics in news
Physics, chemistry and mathematics as they reach the news: measurement and legal time, lasers and the physics of materials, chemistry, and famous problems in mathematics. Prelims has asked about the four fundamental forces and the Higgs boson.
Foundation note: The Large Hadron Collider and the Standard Model
Correct the Map resolution
Copy link to Correct the Map resolutionPrelims and Mains
- Map projection
- A way of drawing the Earth's curved surface flat, which always distorts area, shape, distance or direction.
- Rhumb line
- A course of constant compass bearing, crossing every meridian at the same angle, which sailors can steer without changing heading.
Correct the Map is a non binding resolution of the United Nations General Assembly that names the Equal Earth projection as more accurate than Mercator's.
- A globe cannot be laid flat without something being stretched, so a map projection keeps one property at the cost of the others.
- The right choice depends on what the map is for.
Every flat map distorts at least one of these
AreaHow large a landmass is relative to others
ShapeThe true outline of a country
DistanceThe actual space between two points
DirectionThe correct compass bearing between places
Mercator (conformal)
- Keeps angles and local shapes
- Rhumb lines are straight, so it suits navigation
- Inflates areas more towards the poles
- Greenland looks as big as Africa, which is 14 times larger
Equal Earth (equal-area)
- Keeps relative areas of continents true
- Shapes stretch near the poles
- Suits thematic maps of population, climate and resources
Winkel Tripel (compromise)
- Keeps no property exact
- Spreads error across area, distance and direction
What changed
5 Sep 2026
- The United Nations General Assembly adopted the non binding Correct the Map resolution, 164 to 1, with the United States alone against.
- It names the 2018 Equal Earth projection as more accurate than Mercator's of 1569.
- The case made was that the projection a map uses shapes how important a region looks, a matter of soft power.
- India voted for it but said the resolution authenticates no map.
- It said its territory, including Jammu and Kashmir and Ladakh, must be shown as in India's official map.
The Indian Express, 5 Sep 2026: UN adopts Equal Earth map: Why no flat map can accurately show the globe (opens in a new tab) · The Indian Express, 6 Sep 2026: India backs UN world map resolution, draws firm line on Jammu and Kashmir and Ladakh (opens in a new tab)
Legal Metrology (Indian Standard Time) Rules, 2026
Copy link to Legal Metrology (Indian Standard Time) Rules, 2026Prelims and Mains
- Traceability
- Linking a clock or any measurement, through an unbroken chain of comparisons, to a national reference standard, here the one kept by CSIR-NPL.
- Coordinated Universal Time
- The international reference time (UTC), maintained by the International Bureau of Weights and Measures (BIPM) from atomic clocks around the world.
- Legal Metrology
- The law of measurement: state rules that keep the instruments used in trade, health and safety accurate and verified, now extended to time.
Made under the Legal Metrology Act, 2009, these rules put Indian Standard Time on a legal footing for the first time.
Atomic clocks
CSIR-NPL's clock ensemble and primary frequency standard generate UTC(NPLI).
Link to UTC
UTC(NPLI) is kept within a few nanoseconds of Coordinated Universal Time.
IST
Indian Standard Time is UTC(NPLI) plus 5 hours 30 minutes.
Regional copies
Secondary time scales at Regional Reference Standard Laboratories, plus NavIC and National Informatics Centre (NIC) services.
Users
Banks, telecom, power grids and government systems synchronise and show traceability.
Why traceability matters
- A clock is only as good as what it is checked against.
- Traceability is the unbroken chain of comparisons that ties one to the national standard; until these rules nothing in law said which chain an Indian system had to be on.
- Many systems took time indirectly from GPS or a telecom provider, sources that can differ by seconds or even minutes.
- 2023 guidelines from the Indian Computer Emergency Response Team (CERT-In) already asked government systems to synchronise with NPL and NIC, because tracing a cyber incident needs trustworthy time stamps.
Who does what
- The CSIR-National Physical Laboratory (CSIR-NPL), India's National Metrology Institute, generates the national time scale with its atomic clocks, as the figure shows.
- The Legal Metrology Department enforces, as it already does for shop weights and petrol pump gauges.
What changed
1 Sep 2026
- The rules were notified: time dependent systems in government and in critical sectors must take Indian Standard Time from a traceable, authorised source and be able to show that traceability.
- They take effect 180 days after publication and serve the stated vision of One Nation, One Time.
The Indian Express, 1 Sep 2026: Why India is making IST legally enforceable: An expert explains (opens in a new tab) · The Indian Express, 31 Aug 2026: How India's new IST rules aim to put the country on one clock (opens in a new tab)
Background reading: PIB, 2 Sep 2026: Legal Metrology (Indian Standard Time) Rules, 2026 Notified: Major Step Towards "One Nation, One Time" (opens in a new tab)
UPSC has asked
- Prelims 2018: uses of GPS technology, including banking and power grids
- particle accelerator
- A machine that speeds charged particles to high energy and collides them, so that what comes out of the collision can be studied.
- radioactive beam
- A beam of unstable nuclei, used to study nuclei that do not survive long enough to occur naturally on Earth.
- beam catcher
- A block that safely absorbs the leftover high energy particle beam once an experiment has taken what it needs from it.
- Brout Englert Higgs mechanism
- The process by which particles acquire mass by interacting with a field that fills space.