Nature

It has long been believed that ice becomes slippery due to the pressure from shoes or skis, which melts the thin surface layer, and also due to friction. However, a new study by scientists from Saarland University challenges this idea.

It turned out that ice sliding is caused not by pressure or friction, but by the interaction of molecular dipoles of water in ice with materials, such as shoe soles. Water is a polar molecule with partial charges, forming an ordered crystal lattice in ice.

When in contact with the surface of the sole, the orientation of the dipoles is disrupted, forming “frustrated” interactions that destroy the order and create an amorphous, liquid-like film. It is this that causes sliding even at low temperatures – down to -40 °C, where lubrication was previously thought to be impossible.

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The development of giant pumpkins is the result of selective breeding: pollen from the largest plants is used to pollinate female flowers, producing seeds that can produce even larger fruits. However, heredity is not the only factor. The right soil, sufficient water (up to 1,890 liters per week in summer), moderate lighting, and room to grow also play a decisive role.

Harvard scientists have studied the internal structure of various varieties of giant pumpkins and discovered that the record-breaking fruits have a particularly well-developed vascular system responsible for transporting substances inside the plant.

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The expedition will be the culmination of Walter’s Zero Emissions project, which aims to draw attention to human-caused climate change. The project has been ongoing for 17 years.

Walter is scheduled to set off from the port of Lagos in southwestern Portugal on September 15. He will first head south, through the Canary Islands and Cape Verde. Then he will head southwest along the Atlantic to his final destination, the port of Cayenne in French Guiana.

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Archaeologists in Israel have unearthed a mosaic floor with the inscription “Peace to the Elders” in Greek, dating to the late 4th to early 5th century CE. The fragment was found in the ancient city of Hippos in Galilee and likely belonged to a building that served as a home for the elderly, one of the first institutions of its kind in history.

The mosaic is decorated with images of Egyptian geese, cypresses, fruits and vessels, while the alpha and omega symbols indicate the Christian origin of the object. What makes the find unique is that it is not a church or a wealthy home, but a social institution reflecting the community’s care for the elderly outside of family structures, possibly linked to the birth of the monastic way of life.

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After five years of excavations, British archaeologists have discovered fragments of the 17th-century house where Isaac Newton’s mother, Hannah Ayscough, lived. It was located near Woolsthorpe Manor in Lincolnshire, the place where Newton was born and spent his childhood.

During the excavations, household items from that era were found: fragments of dishes, thimbles, buttons, parts of needles and bones with signs of meat processing. According to legend, it was under an apple tree near the house in Woolsthorpe that Newton came up with the idea of ​​gravity in 1666.

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