Why do you feel like you’ve only slept for a while, even if you’ve slept a lot

Why do you feel like you’ve only slept for a while, even though you’ve already slept for many hours?

Kia Kuusivaara, 13

Up our environment usually shapes our sense of time, but when we sleep, that pacing effect disappears, so our sense of time becomes imprecise.

When sleeping, our sense of time also varies depending on the sleep stages and the length of the sleep period. In addition, it matters what time of the day you sleep and how dreams coincide with the body’s own internal clock.

Namely, sleep consists of falling asleep, light and deep NREM sleep and REM, or blinking sleep. When waking up from light NREM sleep, the sense of time is the most realistic.

Deep NREM sleep is the most restorative for the brain, but when you wake up during it, your sense of time is at its weakest. Waking up is then difficult, you may feel heavy and confused.

In this case, the time spent sleeping can seem much shorter. The feeling is probably due to the fact that the brain may still have sleep pressure, i.e. fatigue, to release and it strives to return to sleep. In this case, it often feels like you haven’t slept enough.

The brain evaluates sleep time more based on the restorability of sleep than the number of hours. If the night’s sleep is broken, you may not get enough deep sleep, even if the total duration of sleep is long.

That’s why, for example, 3-4 hours of continuous sleep that includes deep NREM sleep can sometimes feel as long as 7-8 hours of broken sleep.

Also, in terms of the circadian rhythm, a properly timed sleep period is the most restorative. If you sleep at the wrong time of day, sleep is often broken and less restorative.

The internal clock is most accurate when you wake up from a light sleep at the end of a sufficient period of sleep and at the right time for the circadian rhythm.

The vividness of the dream can also affect the sense of time. If you wake up from light NREM or REM sleep, you often remember that you dreamed. Depending on how long the bedtime story feels, the length of sleep may seem longer or shorter than what has actually been done.

Katja Valli

associate professor of psychology

University of Turku

How are worms able to move underground?

Ola Nylund, 5

Worms many kinds of crawling, limbless and small thread-like animals are called.

Most often, however, worm refers to earthworms, of which there are 14 different species in Finland. The most typical and largest of them is the earthworm. Earthworms and other earthworms are able to move underground with the help of their special body structure and muscles.

The body of earthworms consists of segments, i.e. successive parts of similar structure, with longitudinal and annular muscles.

When the ring muscles contract, the body becomes longer and thinner. On the other hand, when the longitudinal muscles contract, the body becomes shorter and thicker. Alternating contractions of the muscles create a wave motion that moves forward.

At the same time, the earthworm presses the earth against the walls created along its path.

Each division also has small stiff hairs that grab onto soil particles. They prevent the worm from sliding backwards and increase grip during movement.

When the earthworm moves, the fluid inside the body acts as a supporting structure. The pressure of the liquid helps it keep its shape and use the force efficiently.

When moving, the earthworm is also able to make passages more efficient by pushing its head forward and often eating soil at the same time.

The properties described above together make earthworms very efficient in moving even in dense soil. In addition, earthworms use their own and other earthworms’ network of corridors to help them move.

In winter, however, earthworms and other worms are mostly stationary in the ground, hibernating – usually below the frost line, i.e. below the frozen water in the ground.

Jaakko Kullberg

senior naturalist

Sitowise Oy

Does light have gravity?

Oiva Kämäri, 5

Light is a peculiar phenomenon. It has no mass, or in everyday language, weight.

Thanks to its masslessness, light always cools at top speed and never stops. Although light has no mass, it does have energy. In other words, it can kind of push and heat things up.

Mass and energy shape the universe.

According to the current knowledge of physics, gravity is not an invisible force that attracts things as previously thought, but heavy and energetic bodies or phenomena make dents in the universe – a bit like a bowling ball sinks into a soft mattress.

When light passes by a star, for example, its direction changes because of the hole.

Since light has energy, it also makes its own dent in the universe. However, the amount of light energy is usually very small, which is why it is imperceptible to humans.

Light therefore shapes the space, so the answer to Oiva’s question is yes.

Niko Jokela

university lecturer, docent

University of Helsinki and Institute of Physics

Do animals living in nature, for example reptiles or insects, get the flu?

Elvi Sulén, 6

With many animals living in the wild can have diseases similar to the human flu. They can be caused by many different viruses.

It is known that even reptiles, for example snakes, can have respiratory infections. However, they hardly have a fever, because their body temperature, as animals with an exchange temperature, varies very differently than, for example, us humans.

On the other hand, almost nothing is known about the flu symptoms of insects. They can’t have a fever. Their respiratory system is also such that respiratory tract infections are unlikely due to the absence of lungs, among other things.

Influenza viruses can cause more severe diseases in humans and other animals. There is more information about their occurrence in different animals.

Influenza A virus causes influenza in many seabirds and mammals, especially humans and pigs. B and C influenza viruses mainly infect humans, and D influenza virus cattle and pigs.

It is known that many birds can die from influenza. Predators that eat dead or sick birds can often also get infected. Influenza infection from seabirds has caused the death of many seals and sea lions.

Influenza viruses have also been found in horses, dogs and cats. Their symptoms include, for example, runny nose, coughing and fever, just like in humans. Viruses have also been detected in, for example, bats and whales.

Many monkeys have also been found to be infected with the virus after getting similar flu symptoms to humans. Studies have also found influenza viruses in crocodiles and even snakes, i.e. reptiles. Research on the exposure of insects to influenza, on the other hand, is only in the initial stages.

Lena Huldén

docent of applied zoology, entomologist

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