Children ‘s science questions Why were drugs invented?

Alma Vehkasalo, 9

People have utilized various plants and their parts for thousands of years. They cure diseases, increase endurance and lift mood.

In some religions, priests have also used mind-boggling herbs in an effort to connect with the spirit world.

The use of mind-boggling plants and substances made from them was a concern in the late 19th century. Non-medicinal use became more widespread and international trade in substances began. It was feared that widespread use would pose a risk to human health and increase bad behavior.

An international agreement was reached in The Hague, the Netherlands, in 1912, in which states decided to restrict the manufacture, import and sale of certain plants and substances made from them.

Plants and substances subject to these restrictions began to be called drugs.

Drugs were thus coined to describe plants and substances that people do not want to use. Due to the disadvantages they cause, their manufacture, import and sale are severely restricted.

Mikko Salasuo

docent, responsible researcher

Youth Research Network

What is the smallest plant in the world? What size seed does it have?

Eeli Vuorenoja, 8

World the smallest plants are called water lentils.

Very many of them are very small in size. The smallest of all is called Wolffia globosa, but especially Wolffia arrhiza and Wolffia australiana are almost as small.

The diameter of one water lens is only about half a millimeter. They are thus roughly the same size as the nonpareils known as desserts, or sugar granules.

Water lenses have no leaves, stems or roots. They are oval and green balls that float on the surface of the water. They grow as carpets of several hundred thousand individuals.

Water lenses only rarely bloom. Then their smallest flower, fruit and seed will form on their side. The fruit and seeds are so small that it is impossible to see them without a magnifying glass or microscope.

The fruit is only about 0.1 millimeters in diameter, slightly smaller than the salt salt. The seed inside it is apparently about 0.05 millimeters in size.

Wolffia globosaa occurs wild in Asia. Other water lenses are also growing in Central and Southern Europe, for example.

Small mites, among other things, are also very small plants. However, they are clearly larger than water lenses, about 1.5 to 5 millimeters in size.

Roosa Laitinen

Assistant Professor of Genomics-Based Plant Biology

University of Helsinki

Can Pluto become a planet again?

Robin Silén, 4

Student Clyde Tombaugh found a small dot in his photographs of the starry sky in 1930. It began to be considered the ninth planet, Pluto.

In 1978, its moon Kharon was found near Pluto. It was soon possible to calculate that the mass of Pluto was tiny, only five-hundredths of the mass of the Earth.

When celestial bodies of the same size and size began to be found near Pluto in the 21st century, Pluto’s fate was sealed. It got a new name: dwarf planet.

Four other celestial bodies in our solar system have also been named dwarf planets. They differ from the planets precisely in that orbits like them can move and even collide with other orbits of significant size.

The name Pluto will remain a dwarf planet in the future. The difference between the planets is so fundamental. Nor can Pluto evolve back into a planet.

Instead, there are still planets previously unknown to us. About 5,000 of them have already been found outside our solar system.

Harry Lehto

docent of astronomy

University of Turku

Can I talk with my eyes?

Elmeri Ahokas, 2

All people are unable to produce speech with their mouths. However, they can control with their eyes a computer that is made to speak for them.

The camera of the machine closely monitors the movements of the eyes. This allows a person to compose messages by pointing at patterns, words, or letters on the screen.

Then the machine produces speech. Then you can say that you can talk with your eyes.

Eyes, by the way, play a very important role in how we communicate with other people. When we both talk and listen, we often look the other person in the eye for a while.

From the direction of the gaze one can deduce what the other is paying attention to, and the obvious how he feels in the eyes.

Studies have shown that many emotions can be inferred by eye observation alone.

So you can tell from the gaze how the other person feels, even if you don’t say anything. In addition to humans, other animals also use their eyes to communicate.

Satu Saalasti

University Lecturer in Speech Therapy and University Researcher

university of Helsinki

Is there any way to make a plane made of gold fly?

2nd grade of Heikkilä school, Kirkkonummi

To fly well and in order to be able to carry cargo and passengers the aircraft must be very light in size.

Therefore, airplanes are usually made of materials that are very light yet durable.

Today, a large proportion of new aircraft are made of so-called fiber-reinforced plastics, or composites. Aluminum is the most commonly used metal.

One liter, a piece of aluminum the size of a milk jar, weighs only about 2.7 pounds. A piece of gold of the same size weighs about 19.3 pounds.

So gold weighs, and an airplane made from it would inevitably become very heavy. It would need a very powerful and heavy engine. This would provide sufficient thrust for flying.

Gold is also soft and easy to shape. From a sphere about five millimeters in size, gold can stretch two kilometers of wire.

Wings made of gold would ultimately not withstand the weight of the machine. So a golden plane would not be able to fly.

Gold is used in aircraft and space technology because it conducts electricity very well and does not oxidize. In electrical connectors connecting electrical parts, gold is used as a very thin layer on the surface.

Jussi Aaltonen

Research Manager in Automation and Mechanical Engineering

University of Tampere

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.