Children ‘s science questions Why are there northern lights in Lapland, but not in southern Finland?

Erika Kiviniemi, 9

Northern lights arises when particles from the Sun collide with particles in the Earth’s atmosphere.

Northern lights occur in the band-like zones around the poles of the earth. The earth is surrounded by a magnetic field that is like a large magnet. It pulls and directs particles there.

As a strong eruption of particles emanates from the Sun, the northern lights zone expands south from its usual place in Lapland. Northern lights are also visible in southern Finland, but not as often as in Lapland.

Approximately once a month there is an eruption during which northern lights spread to southern Finland. Once in a hundred years, they even reach the equator.

In the space of the Finnish Meteorological Institute, you can follow the forecasts of the northern lights from its website.

Currently, the Sun is activating. In the next few years, more northern lights are expected in southern Finland as well. They are best seen in autumn and spring on moonless and cloudless nights.

Compared to Lapland, there is also a lot of artificial light in southern Finland. It should be at least half an hour in the dark so that the eyes get used to seeing the dim light of the northern lights at all.

Minna Palmroth

Professor of Space Physics

university of Helsinki

Why sleep in the warm?

Vilhelmiina Ylönen, 10

Everyone even-temperature animals, including humans, need to keep their body temperature constant.

Body temperature drops naturally as a person goes to sleep. That’s when people usually curl up under cover. Many other animals seek a warm nest.

This will increase your body temperature. An increase in skin temperature, especially in the limbs, sends a message to the center of the brain’s thermoregulatory system. It signals to the rest of the body the need for cooling. At the same time, it triggers the onset of sleep.

Falling asleep is easiest when the body’s temperature drops at its fastest.

The phenomenon has been studied in the laboratory by warming the hands or feet in water of about 40 degrees. The researchers monitored how long it took to fall asleep. The phenomenon called a warm bath has the strongest effect in the evening because it is the most characteristic time for a person to fall asleep.

So when warm, you fall asleep because sleep and the body’s thermoregulation are tightly connected.

Henna-Kaisa Wigren

University Lecturer in Neuroscience

university of Helsinki

Which one has more parts, the car or the person?

Saara Kosonen, 5

Car consists of, inter alia, the body, tires, axles and engine. Large parts, such as an engine, consist of small parts, nuts and bolts.

Similarly, man is made up of organs such as skin, muscles, heart, brain and lungs.

The organs also form wholes. Such is, for example, the circulation of the heart and blood vessels. The organs, in turn, are made up of tiny cells.

If the small parts of the car are added together, there are about 30,000 of them. There are about 37 trillion cells in humans, or about 37 million. Thus, a person has many more parts than a car.

The larger parts, on the other hand, have about the same number in the car and the person, because they both need similar structures to function.

The car’s engine is largely responsible for the human heart, the tires on the legs and the fuel tank in the stomach. The car computer, in turn, controls the car in a similar way to the brain of the human body.

Mikael Segerstråle

University Lecturer in Physiology and Neuroscience

university of Helsinki

Are there similar numbers in each country as in Finland?

Lauri Karjalainen, 7

Yes, which have similar numbers in use.

So even if we don’t know a word of the language of a country, we can still understand the numbers on a piece of paper, for example.

In some countries, such as Japan and China, there is a completely different way to write, so numbers have their own characters. But alongside them, we study and use numbers that look exactly like ours.

Anyway, the math is the same in all countries. Therefore, students from many different countries study the subject at several universities.

However, there are also some groups of people who live well apart from the rest of society. Such groups live in the jungles, for example. Some of them may think completely differently about the figures.

Juha Oikkonen

Professor Emeritus of Mathematics

university of Helsinki

Where does that moon fall?

Toivo Hopia, 3

When The moon is falling, it is falling from the sky behind the earth invisible to us. It will remain hidden from us until it rises above the ground again. If you could look through the Earth, the Moon would still be visible as it sets.

The earth can be compared to a rotating carousel. At the same time, the Moon orbits it. The moon ceases to be visible when we move far enough away from it with the surface of the Earth.

Exactly how long the Moon remains invisible to the Earth and at what angle it will ever appear depends on two things. Firstly, where the Earth is the viewer, and secondly, where the Moon is orbiting the Earth at that time.

Now on Christmas Eve, the Moon rises to the sky in Helsinki from nine in the evening and sets off the next day at noon. After a week, the rise has shifted to more than nine hours later and the fall to half an hour later.

There are also places on Earth where the Moon sometimes does not rise or fall at all.

Sometimes the descending Moon is also called the reduction of its visible part from a full moon to a crescent or narrower. Then the Moon will not disappear anywhere, but the light of the Sun will only partially hit it.

Silja Pohjolainen

docent in astronomy and university teacher

University of Turku

Send the question, the full name and age of the questioner to [email protected]. The column will be edited by Touko Kauppinen and Juha Merimaa.