Explanation

• Wilhelm Conrad Rontgen discovered X-rays
• He was discovered on 8 November 1895.
• He got the Nobel Prize in Physics in 1901.

Additional questions

• The penetrating power of X-rays depends on their frequency

Last updated by NA on 05-11-2026

Explanation

• Inventors: Montgolfier brothers (Joseph-Michel and Jacques-Étienne).
• First public demonstration: 4 June 1783, Annonay, France.
• First passenger flight: 1783, near Paris.
• Known as: Pioneers of human flight.

Last updated by NA on 04-11-2026

Explanation

• John Napier was the discoverer of logarithms.
• He also invented the so-called "Napier's bones"
• He invented the logarithm in 1614.
• His purpose was to assist in the multiplication of quantities that were then called sines.

Last verified on 02-11-2026

Explanation

• Lewis Waterman invented the first practical fountain pen in 1884.
• He was an American inventor who improved the ink-feeding system.
• His design regulated ink flow and reduced leakage.
• The fountain pen stores ink in a reservoir and delivers it to the nib.

Last verified on 29-10-2026

Explanation

• First successful personal computer: Altair 8800
• Developed by: MITS
• Introduced in: 1975
• IBM PC launched: 1981

Last updated on 26 Oct 2026