Science questions for kids | Why does wool warm even when wet?

Luna Suvanto, 9

Clothes the warming effect is based on the fact that they act as heat insulators, i.e. they conduct heat poorly. In this case, less heat is transferred from the skin to the outside air.

The ability of fabrics to insulate heat comes from the air they contain. Air pockets remain between the fabric fibers. The curly structure of wool fabric fibers ensures that it contains a lot of air. That is why it is a very warm material in clothes.

When the fabrics get wet, the air pockets are partly filled with water. Water is not a good insulating material at all. Wet clothing usually doesn’t insulate at all. On the contrary, it feels very cold, which is further increased by the gradual evaporation of the water.

However, wool fiber is a material that absorbs moisture. In this case, the gaps between the fibers remain dry and therefore the fabric continues to act as an insulator.

Absorbing moisture from wool also has a small drawback: Washed woolen clothes dry slowly, so drying must be done carefully.

Wool fiber is mainly keratin, i.e. horn substance. So it is the same substance as our hair and nails.

Tom Kuusela

University researcher in physics

University of Turku

Why is the teddy bear the most important soft toy for most children? Why not a cat or a dog?

Armi Saalasti, 10

Teddy bear is the first figure toy brought to the mass market.

It began to be mass-produced after the President of the United States Theodore Roosevelt refused to shoot a bear brought in front of him on a hunting trip in March 1902. The story spread to the international media and inspired toy companies.

Since then, Nalle has had strong ties to the media. It has inspired writers and music songs and movies have been produced about it.

Teddy bears have become hugely popular. Nalle has a well-established position in the toy world. It is no wonder that it is still a toy for many children.

Teddy bears, which have already been favored by several generations, have been found to bring security and create hope, for example, in the midst of health crises, wars or other difficult times.

In the early days of the corona pandemic, the teddy bear challenge that spread on social media was precisely about our trust in teddy bears as safety toys and ambassadors of good cheer.

Teddy bears have broken away from their original role model of a bear and have become more human-like, sweetened and comforting characters.

Toys featuring cats, dogs and other real animals are popular. However, over the years, they have not become as widely marketed and bought as guardian figures as teddy bears.

Katriina Heljakka

toy and play researcher

University of Turku

Are there sounds in space?

Topi Martikainen, 8

Popular the saying goes that in space no one can hear your scream. The saying is usually true.

Sounds are wave motion that need some medium to travel. There are very few particles in space, i.e. matter acting as a medium. It’s almost a complete vacuum.

In space, a sound wave cannot normally travel, which means that no sounds can normally be heard there. Be it a scream or some other sound.

However, the American space agency NASA has released the eerie sounds of the black hole at the center of the Perseus galaxy cluster.

There was enough gas around it for sound waves to travel. When the frequency of sound waves was raised considerably and processed in other ways, we humans could hear it.

Similar places suitable for the passage of sound waves can be found here and there elsewhere in space.

Emilia Kilpua

professor of space physics

university of Helsinki

The sounds of the black hole in the Perseus galaxy cluster can be heard on the NASA website.

Do all animals have brains in their heads?

Sofia Nurmi 6

Animal the head usually has a brain, but not all animals have a head.

In headless animals, the brain is elsewhere, and there may be several brains.

For example, a jellyfish that lives in seas and lakes has a round body, i.e. a swimming bell, with catch compartments attached to its edges everywhere.

The swim watch also has eight small protrusions (rhopalium), each of which has an accumulation of nerve cells corresponding to an eye and a brain. These correspond to the brain of a jellyfish.

If an animal has a head, it has eyes or other sensory organs. For example, a snail has two pairs of sensory horns on its head, and the associated nerve ganglia, i.e. the primitive brain. This allows the snail to see and smell things.

The brain is part of the nervous system of animals. The brain is the part where the senses of hearing, sight, smell and taste come from, and where thinking and learning take place. Because the brain is so important, it is usually protected by the skull.

The head has originally developed around the mouth. Because it is good for an animal to know what it is putting in its mouth, senses such as sight and smell have developed around it.

Summer Viranta

associate professor of paleobiology

university of Helsinki

Send the question, the questioner’s full name and age to [email protected]. The column is edited by Touko Kauppinen and Juha Merimaa.