Why is it cold at bedtime?

Why does a person get cold when he goes to sleep?

Hilla Saari, 9

Cold many things can affect the feeling when going to sleep. First, when the sun goes down, the ambient temperature often drops. When a person is still, the muscles also produce less heat, which makes it easier to get cold.

The feeling of cold can also be related to the fact that the body is preparing to fall asleep. When the evening approaches, the so-called internal clock of the brain starts the decrease in body temperature. In this case, the blood vessels of the skin expand, allowing heat to escape more easily from the body to the environment.

In deep sleep, the temperature of the brain and the rest of the body is at its lowest during the day. Appropriate cooling is an important part of both falling asleep and good quality sleep. Some animals help it by building nests, and humans do the same by snuggling under a blanket. Falling asleep is often easiest in a slightly cool room, as long as there is a warm enough blanket.

The drop in body temperature at bedtime can also be related to the functioning of the body’s immune system, i.e. the defense system, and it also slightly reduces energy consumption. So far, however, no exact explanation is known as to why falling asleep, sleep and temperature regulation are so closely connected.

Samuel Kohtala

docent of neuropharmacology, University researcher

University of Helsinki

Why do bubbly drinks sting in the mouth?

Venni Laakio, 4

Bubble drinks the bubbles are formed from carbon dioxide. The carbon dioxide is dissolved in the drink, but when the bubble drink bottle is opened, the pressure inside the bottle tends to balance with the outside air, and the carbon dioxide starts escaping into the air. Carbon dioxide can easily feel a tingling sensation in the mouth.

The tingling sensation occurs because there are mucous membranes on the surfaces of the mouth, which are sensitive areas. The information about the bubbles travels from there along the trigeminal nerve to the area dealing with the sense of touch in the brain, whereupon the perception and experience of a tingling sensation is formed.

It’s about the so-called chemosensation, i.e. chemically activated sense of touch. A chemical sensation is awakened when the generator of the tactile sensation is a substance, such as carbon dioxide itself, and not, for example, touch, pressure, heat or pain.

Over the years, it has been important to be able to sensitively recognize tingling and other sensations with the help of mucous membranes on the surfaces of the mouth. In this way, it has been possible to identify useful and harmful substances for the body.

Bubbles are formed in drinks, because many people enjoy the sensations they cause. However, different people experience bubbles in different ways. Some people can’t even tolerate them.

Carbon dioxide is usually produced for lemonades and other sparkling drinks with a carbonation device with the help of pressure.

Bubbles can be produced in other ways as well: for example, in mead they are made with the help of a fermentation reaction caused by yeast, while an effervescent tablet is made to cause bubbles among the liquid when the acidic and alkaline substances it contains react with each other.

Sweet Roukka

university teacher of food sciences, researcher

University of Helsinki

How are people’s names invented?

Kerttu Holopainen, 6

In all of them countries and cultures give names so that people can be distinguished from each other. No such culture is known in human history where people were not given names. As long as people have had some kind of language, they have also had names.

Names are often formed from words in one’s native language. In Finland, for example, we have first names like Snow or Onni.

First names have also been adopted from other languages. A common boy’s name in Finland, Leo, is Latin and means lion. The girl’s name Sofia, on the other hand, is Greek and means wisdom.

A lot of names have also been derived from people in the Bible, such as Maria of Jesus from mom. In Finland, Maria has often become Maija, Mari, Marja or Marjukka.

Names have also been adopted from literature and movies. For example Astrid Lindgren Mio, my son Mio is the boy’s name Mio from the book Mio and the Frozen movies have made the name Elsa popular.

Often, children are also given names after relatives. Grandparents may have been named Eino or Hilma, for example. Sometimes names have also been given after famous people. So skier Iivo in Niskase there are many namesakes named Iivo in Finland.

Surnames are also formed based on one’s own language, such as Järvinen or Vuorela in Finland. Some Finnish surnames are also in foreign languages. For example, the Swedish surname Lindberg means linden mountain. You usually get your last name from your parents or spouse, but you can also come up with it yourself.

Immigrants have also brought with them first and last names from other cultures, which has greatly enriched the countries’ nomenclature.

Minna Saarelma-Paukkala

name day specialist

Almanac Office of the University of Helsinki

Where did oxygen originate on Earth?

Jooa Lampila, 8

Size the universe’s oxygen was originally created by fusion in stars. Fusion means an event that takes place in the immense heat of stars, where lighter elements such as helium become heavier.

When the fuel used by the star, i.e. hydrogen, finally runs out, it ejects its outer part into space, causing the oxygen to spread as well. For example, Lyra’s ring fog was born that way. The blue-green color created in that and other star nebulae comes from oxygen.

Most of the oxygen that came to Earth from the stars is bound to rocks. For example, quartz is a compound of oxygen and silicon. Most of the oxygen in the earth’s rocks is in the mantle, i.e. inside the earth between the crust and the core.

Atmospheric oxygen, i.e. the oxygen we can breathe, is only less than one millionth of the total oxygen on Earth. Atmospheric oxygen has been created as a result of the so-called contact between plants and cyanobacteria, i.e. blue-green algae. When combined, the plant forms sugars and oxygen from water, carbon dioxide and sunlight.

Oxygen began to accumulate on Earth about 2.4 billion years ago. At first, it happened mainly thanks to the association of cyanobacteria.

Pekka Janhunen

research manager

Department of Meteorology

Send the question, the questioner’s full name and age to lasten.tiedeskö[email protected]. The column is provided by Touko Kauppinen.