In what language do people who have been deaf since childhood think?

If you have been deaf since birth, what language do you think in?

Elena Nelo, 10

Hearing people in humans, thinking is strongly based on spoken language. A deaf child also develops language if his family members use sign language. That’s where words are expressed with hand and finger positions and movements.

Deaf babies may then gesture to some extent even at the age of six months by repeating non-signs they see. They start to understand the meanings of signs at less than one year of age. Thus, they also learn to think in sign language.

The mother tongue of the deaf baby’s relatives is often the spoken language. In this case, the baby first learns to notice the movements of the mouth, facial expressions, gestures and the rhythm of the speech when the relatives speak. A baby can also get a cochlear implant already at the age of less than a year, when he learns spoken words and thinks in language, usually under the age of 2.

Teija Kujala

professor of psychology

University of Helsinki

Why doesn’t fresh corn on the cob turn into popcorn when cooked?

Nelli Korhonen, 11

Popcorn is created from dried corn kernels. They are hard-shelled seeds in which corn starch has been stored in small, dry and tight packets. A small amount of water has also remained in the grain during drying. When the grains are heated in a pot or, for example, in a popcorn machine, that drop of water starts to vaporize inside the grain.

However, the hard shell prevents water vapor from escaping from inside the seed, so the pressure in the seed increases and increases the hotter it gets. At some point, the pressure becomes too great for even the toughest shell, causing the corn grain to explode. The hot water vapor penetrates through the tight starch packages, which open in the steam stream and at the same time the starch ripens into the fluffy structure of the popcorn.

Fresh corn kernels have too soft a shell for the kernel to withstand the pressure of evaporating water nearly as well. Instead, the heating water slowly flows out of the grains, while the starch in the grains ripens into juicy ripe corn and not fluffy popcorn.

They are Hopi

professor of food development

University of Turku

How do people know what’s inside the Earth when it’s so big and no one has been there?

Varpu Haapala, 9

Anyone has not really been inside the earth, because even the deepest tunnel dug by humans reaches a depth of 12 kilometers. It’s just part of the Earth’s surface. Geologists and geophysicists studying the Earth have still found out many things about the interior of our home planet.

One way to find out the interior of the Earth is to study earthquakes. Strong earthquakes can cause rock vibrations that can be detected by measuring devices as far as the other side of the globe, and earthquake waves even travel through the entire globe.

The speed of seismic waves varies depending on the material they travel through. By studying them, it was already discovered almost a hundred years ago that inside the earth there is a core about the size of the planet Mars and composed of iron, and around it a rocky layer, called the mantle.

With the help of seismic waves, it is possible to take, as it were, transilluminated pictures of the Earth’s interior with current devices. With the help of those images, it can be seen, for example, that in some areas the substance of the Earth’s surface sinks into the depths. In other areas, hot currents rise from the boundary of the mantle and the core, i.e. from a depth of about 3,000 kilometers.

However, those images do not directly tell what substance the flows in question consist of. Therefore, the material composition of the Earth’s interior is studied with the help of volcanoes. In many volcanoes, lava rises from a depth of more than a hundred kilometers, and sometimes the lava material originates from the deepest updrafts.

The composition of the lava reveals, among other things, that there are diamonds deep inside the earth!

Arto Luttinen

Superintendent of Geology

Central Museum of Natural Sciences

Why are people different?

Alma Leppähaara, 3

Osa among people’s visible differences, there are some that they themselves can influence, such as hairstyle. The desire to express difference can come from wanting to stand out from others or, on the other hand, wanting to belong to a group where the custom in question is considered cool. Belonging to a group is usually important to people because none of us can do it all alone.

Some of the differences, on the other hand, are due to hereditary factors, i.e. the genes that a person has received from their father and mother – that’s why children often look like their parents. Hereditary factors also affect such differences that are not visible on the surface, such as the functioning of digestion.

The differences in heredity factors have originally arisen by chance. Genes that have somehow helped people survive in life have become more common over time. Some genetic factors have protected against, for example, motion sickness, which has killed many people in the past.

However, most differences due to genes do not make people better or worse survivors.

Many people think, for example, that people with a certain appearance can be more beautiful than others, but it’s just a matter of preferences and ways of thinking. Based on hereditary factors, it cannot be said that some people are more beautiful or otherwise better than others.

Elina Salmela

assistant professor of archaeogenomics

University of Turku

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