Children ‘s science questions Why do trees bang when they burn?

Kalle Korhonen, 6

Worth to burns dried wood because it burns well.

When the wood dries, its pores, or kind of valves, close. The pores are between the cells of the tree, the tiny building blocks. Thanks to the pores, water travels from one cell to another through the roots of the tree to the top.

When the wood burns, its temperature rises, so that the water inside the wood and the resin do not get out but evaporate inside the cells. The pressure inside the tree increases. Evaporated substances eventually penetrate by force. This will break the cells. It creates a crackle and a bang.

Even if the wood has dried well before it is burned, it always contains a little water. Spruce and pine also contain resin.

The spruce when fired even more than a pine because its pores are small and close easily. Therefore, vaporized substances cannot easily escape.

Pekka Saranpää

leading researcher

Natural Resources Center

Where do all the long car queues start?

Emilia Mrena, 10

TeiDEN designers specify, among other things, the number of bands required, speed limits, and types of subscriptions.

The goal is to make roads safe as well as possible. If traffic on a section of road increases, the road’s ability to pass cars will not be enough and traffic will start to queue. In this case, it is also more difficult to join the road, which also causes queues for intersecting roads.

Of course, even for a section of road with normal capacity, queues may sometimes form. If the queues lengthen, traffic may momentarily stop completely.

In many cases, the temporary queuing is due to one of the above slow-moving vehicles. Often, road work, an accident, or a broken down vehicle also reduces driving speed and may reduce available lanes and cause queues.

In addition, the transmission capacity of the road is tested by various events. Then suddenly there will be significantly more traffic to a place than planned.

Teppo Vesalainen

training manager

Car Association

Are there traps in the pyramids? If so, what kind?

Eevi Nuorva, 5

Egyptin there were no actual traps in the pyramids. Their corridors and tunnels were mostly quite simple. Large boulders were used to block them.

However, the designers of some pyramids tried to keep intruders at bay by other means. This was done especially in the pyramids built in Egypt before the time of the 18th and 19th centuries.

There were corridors inside the Pyramid of Hawara, many of which led nowhere. The entrances were hidden, among other things, in the roofs of the tunnels.

However, such attempts to mislead and confuse robbers ultimately proved futile. All the pyramids of Egypt were plundered as empty in ancient times.

Anyway, the traps of the pyramids are primarily a product of the imagination. One hundred years of China’s first emperor Qin Shi Huangdin in the history of Shiji written after his death, I recount that in his pyramid-like tomb chamber inside the mound there would be a kind of trap.

Those traps would be mercury-filled ditches and loaded crossbows designed to kill robbers.

The concept has long been considered forged, but recent studies have found a large amount of mercury in the vicinity of the tomb, so the story may be true. The more than 2,200-year-old tomb of Emperor Qin has never been opened.

Sami Uljas

University Lecturer in Egyptology

Uppsala University, Sweden

Antti Lahelma

University Lecturer in Archeology

university of Helsinki

Why can’t man make honey from flowers?

Hertta Kaasinen, 4

Bees make honey from the honey produced by the flowers, a sugary liquid.

The task of the honey is to attract bees and other small useful insects such as butterflies, bumblebees and flower flies to the flower. The flowers hide inside the honey so that only insects can suck it with their little sucker.

During the flight in the flowers, bees and other insects also move the pollen from the flowers from one flower to another. This is how they pollinate the flowers. It helps flowers to make seeds and fruits and thus reproduce.

The bees transport the honey to the hive in their small hive. At the same time, they add their own enzymes and lactic acid bacteria to the honey. They are substances that help honey become honey.

Only a bee can make those special substances.

The mixture of honey, enzymes and lactic acid bacteria is dried in the honeycomb cells, where it turns into honey. The bees cover the finished honeycomb with beeswax. Honey is well preserved until they are used. Bees make wax in their wax glands under the stomach shields that humans do not have.

The special skill of bees in making honey has developed over millions of years. Over the years, man has developed other kinds of miraculous skills.

Anneli Salonen

research expert

Finnish Association of Beekeepers

What happens to another Siamese twin if the other dies?

Fanny Kristersson, 8

Maternal the embryo developing in the womb may divide during the first weeks into two embryos, each of which eventually develops into a child.

Those born in that way are said to be identical twins. Their inheritance is similar to each other. Identical twins are rarely born, about 3 to 4 thousand births.

Even less often does it happen that the embryos do not divide completely and identical twins get stuck together. They may be attached to the head, chest or hips. They tend to be called Siamese twins.

When Siamese twins are born, doctors try to cut them apart so that both can develop separately. Surgery is usually difficult and one or both of the twins may die. The less common blood circulation they have in common, the better the prognosis.

If Siamese twins were not cut, it would be very likely that they would not survive growing together. If one died, the other would die as well. This is due to the common circulation. If another Siamese twin dies, the best chance would be to try to quickly cut the other twin out of the other so he could live.

Jaakko Caprio

Professor of Genetic Epidemiology

university of Helsinki

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.