WHY does the Eiffel Tower grow 15 centimeters in summer?
It’s all about temperature compensators. Thanks to them, steel can expand and contract without being damaged.
When steel heats up, it begins to stretch and occupy a larger volume. It is known as thermal expansion. Conversely, a drop in temperature leads to a decrease in volume.
WHY do human fingernails and hair keep growing after death?
The nails do not grow, yet the skin around them dries out and pulls back, making the nails appear longer.
Moreover, the dead person’s skin loses moisture and shrinks, exposing a previously invisible part of the hair on the male chin.
WHY does motion sickness occur?
It is caused by a malfunction of the vestibular apparatus, responsible for keeping us firmly on feet.
It reacts to changes in the position of the head and body in space, as well as to acceleration.
When a person’s body moves and sways in a car or on a boat, the brain receives conflicting information from the different senses, which causes nausea, dizziness, and headaches.
WHY are there no thunderstorms or lightning in winter?
In order for a thundercloud to form, warm, moist air rises. Humidity increases as the temperature goes up.
All the particles of precipitation: rain, and hail, are electrically charged. When they gather in large numbers, this charge increases.
Wet summer air has a greater conductivity of electricity, and the discharge of the potential difference is accompanied by thunder and lightning.
WHY does the wind blow up a fire, but not a match?
Burning wood begins with gasification (evaporation of combustibles by high temperature). In the case of a match, the flame provides heat. However, the wind takes away the heat, and the match goes out.
A fire is kept burning by coals. The gasification of wood in them occurs in the inner layers when there is a lack of oxygen. The wind replenishes it: the smoldering of coals accelerates, the heat release grows, and the fire is ignited.
WHY do stars twinkle?
The cause of flickering is the Earth’s atmosphere, through which star rays must pass before reaching the eye. Starlight, in this case, has to penetrate not a homogeneous medium, but gas layers of different temperatures, different densities, and therefore different refractivity.
Light rays undergo numerous deviations from the straight path, now concentrating, now scattering. Hence the frequent changes in the brightness of the star. And since refraction is accompanied by color scattering, along with fluctuations in brightness, changes in coloration are observed.