Tag: science & technology

An equinox is the date when day and night are approximately equal in length worldwide. This occurs twice yearly - around March 20 (vernal/spring equinox) and September 22 (autumnal equinox). Solstices mark the longest and shortest days, not equal days.

Benjamin Franklin invented the lightning conductor (lightning rod) in 1752 through his famous kite experiment demonstrating lightning's electrical nature. This invention protects buildings by safely conducting lightning strikes to the ground. Franklin was a polymath scientist, not primarily known for physics like Einstein or Newton.

The Pleistocene epoch (2.58 million to 11,700 years ago) is when Homo sapiens evolved and spread across the globe. This epoch was marked by repeated glaciations (ice ages) and the emergence of modern humans. The Holocene began after the Pleistocene (10,000 years ago to present), Mesozoic was the age of dinosaurs, and Cambrian was much earlier (541-485 million years ago).

Ammonia (NH3) is widely used as a fertilizer because it contains nitrogen, an essential nutrient for plant growth. NH3 can be directly applied to soil or used to produce other nitrogen fertilizers like urea. The other options (CO, O3, CO2) are not used as fertilizers - CO is toxic, O3 is an air pollutant at ground level, and CO2 is not a direct fertilizer though plants need carbon.

Agent Orange was a herbicide used by the US military during the Vietnam War that contained dioxin (specifically TCDD) as a dangerous contaminant. Dioxin is highly toxic and caused severe health problems and environmental damage. The other options are toxic chemicals but were not components of Agent Orange.

Heron of Alexandria created the aeolipile, the first known steam engine, in the 1st century AD. Newcomen built the first practical steam engine (1712), and Watt improved it (1769). The question claims Heron is correct.

Aryabhata (476-550 AD) is credited with developing the concept of zero as a number in ancient Indian mathematics. The other options are unrelated - Agatharchos (Greek artist), Galileo (astronomer), Engel (unknown context).

Saint Gyandev, a 13th-century Indian saint, is traditionally credited with creating Snakes and Ladders as a moral teaching game called Moksha Patam. The question claims this is correct.

Dr. Martin Cooper, working at Motorola, made the first handheld mobile phone call in 1973 and is widely credited as the inventor of the modern mobile phone. Joel Engel was a rival at Bell Labs, while Thomas Savery and Newcomen were steam engine inventors from centuries earlier.