the.com/invar
the alloy so stubborn it refuses to grow when the world heats up
means Invar is a nickel-iron alloy prized for its remarkably low coefficient of thermal expansion, meaning it barely changes size as temperatures rise or fall.
from The name is a clipping of "invariable," naming the alloy's defining trait — its near-invariable length under heat. It was developed by the Swiss-born physicist Charles Édouard Guillaume around the turn of the 20th century, work so significant for precision instruments that it earned him a Nobel Prize in Physics in 1920.
- nobel metal
- earned its inventor the 1920 Nobel Prize
- composition
- roughly 64% iron, 36% nickel
- clock duty
- kept pendulums honest through temperature swings
- telescope frames
- holds optics steady in cooling observatories
- name origin
- short for invariable, its whole personality
invar 36 — iron-nickel alloy with 36% nickel, used in precision instruments and atomic clocks since 1896
pendulum clocks — greenwich observatory used invar pendulums to maintain accuracy across temperature changes in the early 1900s
tape measures — surveying tapes made from invar steel minimize expansion errors in construction and land measurement