Revealing the secret that makes the Eiffel Tower grow 15 cm taller every summer

The strange phenomenon that causes the Eiffel Tower in Paris to grow 15 cm taller in the summer has been explained by experts, revealing a surprising cause.

France's famous Eiffel Tower was originally called Tour de 300 mètres, meaning Tower of 300 metres. This name was suggested by engineers Maurice Koechlin and Émile Nougier to Gustave Eiffel, who oversaw the tower's construction. As temperatures rose during the summer months, the Eiffel Tower grew even taller than originally designed. Photo: Alamy.

The Eiffel Tower was erected for the 1889 World Exhibition to celebrate the 100th anniversary of the French Revolution. Eiffel chose wrought iron for the construction of the structure - a material that could withstand high pressures, allowing the tower to be very light and safe from crosswinds. Photo: toureiffel.paris.

The Eiffel Tower itself is a giant triangular lattice structure. Accordingly, the entire structure increases in size as the temperature of the material increases. The Eiffel Tower mainly experiences vertical expansion and contraction due to temperature changes, a phenomenon called thermal expansion. Photo: SETE_AlexandreNestora.

We know that most solids expand when heated and contract when cooled. The wrought iron used to build the Eiffel Tower and its steel components has a coefficient of expansion of about 12x10⁻⁶ (°C)⁻¹, meaning that a 1m bar of iron expands by 12x10⁻⁶ metres when heated by one degree, which is more than a dozen microns, less than the thickness of a human hair. Photo: E.Livinec-SETE.

Two other factors to consider are the length of the object (the Eiffel Tower is 300m high) and the local temperature range. Paris records winter minimums below -20°C and summer maximums around 40°C. In addition, metal can reach much higher temperatures in direct sunlight, often exceeding 60°C or 70°C. Photo: Ian.CuiYi.

If a 1m long metal bar expands by 0.000012m when the temperature increases by one degree, a 100m long bar will expand by 0.12m when the temperature increases by 100 degrees. A 300m long bar will expand by three times as much, to 0.36m or 36cm, making a noticeable difference. Photo: worldatlas.

Additionally, the sun always shines on one of the Eiffel Tower's faces. This means that one of the sides of the structure is higher than the others, causing a slight curve in the tower. Photo: curioustravelbug.com.

Experts estimate that the Eiffel Tower is actually 12-15cm taller when comparing its size between the coldest winter days and the hottest summer days. Photo: curioustravelbug.com.

So the Eiffel Tower is not only a famous landmark and symbol of Paris but also a giant thermometer. Photo: curioustravelbug.com.

Readers are invited to watch the video: Behind the success of scientists . Source: VTV24.

Source: https://khoahocdoisong.vn/he-lo-bi-mat-khien-thap-eiffel-cao-them-15-cm-moi-mua-he-post2149044918.html