One of the greatest advances in timekeeping was obtained by cancelling out the effect of temperature on the pendulum length of a clock.
When a clock is warmed the expansion of the metal pendulum makes the clock run slow. Cooler temperatures contract the pendulum and the clock runs fast .John Harrison, a famous 18th century watchmaker, designed a 'Grid Iron' pendulum to counteract the effects of expansion by maintaining the same length regardless of temperature.
The alloy metal known as 'Invar' was developed for the balance wheel in mechanical chronometers. This alloy neither expanded nor contracted with temperature making clocks and watches so stable that the determination of a ship's longitude became very reliable.
These clocks can be seen in the National Maritime Museum in Gereenwich, London.They are known as H1 to H5 after Harrison and were famously described in the best selling book 'Longitude' by Dava Sobell.
"What are the undesirable and unwanted effects in the medium?
Expansion and contraction can cause things to crack, as in the weathering of rock. They can cause a bi-metal strip to bend and straighten, which phenomenon is used in some thermostats. Expansion can cause the roadway of a bridge to buckle, so gaps have to be left. Obviously they cause the thread in a liquid-in-glass thermometer to get longer and shorter.
they get hy
Water has its smallest volume (for any given mass) at 4 degrees Celsius.
Expansion and contraction of rock material through which a wave passes is a characteristic of seismic waves generated during an earthquake. These waves cause the ground to shake as they travel through the Earth, creating various types of seismic effects.
No undesirable side effects have been reported.
These are the undesirable effects of drugs.
when the temperature of the body is lowered or raised, it contracts or expands accordingly. If this expansion or contraction is prevented, then a stress is produced called thermal stress
Water is most dense at 4°C/39°F. In absolute scale the temperature will be 277 K
true - they have undesirable effects
Thermal movement can cause expansion and contraction in building materials, leading to cracking, warping, or distortion. This can compromise the structural integrity of the building over time. Proper design and construction techniques that account for thermal movement can help minimize these effects.
On the contrary, side effects are undesirable. A good effect is the intended effect, not a side effect. It is the unintended, bad effects that are considered to be side effects.