Sir Ali Raza's Learning Hub

Eid Mubarak

Rain in Karachi is almost certainly NOT toxic from Iran.
What people are saying has a small scientific basis, but the actual risk for Karachi is extremely low.

Recent attacks on oil refineries in Iran have released huge amounts of smoke and chemicals into the air. These include:
- Hydrocarbons
- Sulfur oxides
- Nitrogen compounds

When such pollutants mix with rain locally, they can form what is called: “black rain” or polluted rain

Distance dilution
Karachi is very far from Iranian refineries
Pollutants spread out and dilute heavily over distance

Deposition near source
Heavy particles (oil soot, ash) fall quickly near Iran
They do not remain concentrated over long travel distances

If polluted air from Iran moved toward Pakistan:
The first rainfall zones (Iran, nearby regions, western Pakistan) would remove most pollutants

By the time air reaches Karachi:
- It is much cleaner
-Most heavy toxic particles are already gone

Venice’s Floating Foundation: Key Facts
Foundation: Built on millions of wooden piles (alder, oak, larch) driven into lagoon bed.

Wood Durability: Alder resists rot underwater; petrifies in salty, oxygen-poor clay.

Scale:
St. Mark’s Campanile: ~100,000 piles.
Basilica della Salute: Over 1 million piles.
Piles spaced ~0.5m apart, driven ~2-3m deep by hand.

Why Water?
5th century: Barbarian invasions (e.g., Visigoths, Huns) pushed refugees to lagoon.
Lagoon’s shallow waters = natural defense.

Engineering: Lightweight brick buildings on piles; no bedrock foundation.

History: Symbolic founding ~421 A.D.; grew from refugee settlements.

Design: Harmonizes with lagoon; canals as streets, built for tides.

Why It Works: Ingenious adaptation, necessity-driven, resilient design.

Class 12 Physics 2024
Important topics

#2024