Why?

2023-05-16 14:00:41 WHY do humans live longer than other mammals?

Scientists may have just discovered a major key to the search for immortality by discovering that our lifespan is inextricably linked to the rate by which our cells undergo genetic mutations.

Although it is logical to assume that our probability of death increases as these mutations accumulate over time, such a hypothesis fails to account for an inconsistency known as the Peto paradox. If death depends on the accumulation of somatic mutations, then larger species with more cells should receive more mutations and therefore have shorter lifespans.

For example, the authors found that human cells undergo an average of 47 replacement mutations per year, giving us an average lifespan of 83.7 years. Открыть/Комментировать

2023-05-15 21:00:36 WHY do astronauts sleep near the ventilation system?

Basically, astronauts sleep in special modules in the form of horizontal and vertical cabins, similar to showers. A person in weightlessness feels indifferent to sleeping upside down.

However, the position is usually controlled by lightning bags attached by special cables to the walls.

Many astronauts use earplugs to sleep, as the station is always noisy. Also, there is a fan next to the sleeping area that creates the necessary air flow so that the astronaut does not sleep in the bubble of carbon dioxide that he himself creates. Otherwise, it would result in guaranteed oxygen deprivation and provide the person with a severe headache.

It is noteworthy that in space, the Sun rises every hour and a half, so astronauts have a clear daily routine that they are forced to follow. Открыть/Комментировать

2023-05-15 14:00:37 WHY does earwax form?

We occasionally have to clean the yellowish mass out of our ears. Where does it come from? The fact is that our external auditory canal has four thousand wax glands. These glands just produce a substance called earwax.

Since wax is so sticky, dust and dirt clings to it. Thus, it protects the ears from contamination, not allowing dirt to penetrate far inside. It is strictly forbidden to clean your ears with thin objects, such as matches. You could damage your eardrums. Some people produce more earwax than others.

If too much wax is produced, it can block the ear canals and cause hearing loss. In such cases, you should definitely see a doctor. Открыть/Комментировать

2023-05-14 21:00:30 WHY doesn't the filament in a light bulb burn out?

The thin metal wire in an incandescent bulb gets so hot when an electric current flows through it that it heats up and begins to glow.

Incandescent bulbs can burn for years, but the wire doesn't burn out. The fact is that the bulb has no oxygen inside, and without oxygen, no flame can arise. The bulb is filled with a gas mixture that quenches the flame. Small and weak bulbs, below 25 watts, have a vacuum inside them. When such bulbs break, air rushes into them at such great velocity that a quiet popping sound is heard.

And without the glass housing that insulates the filament from the oxygen, the metal wire would flash only for a moment and immediately burn up like a meteor. Открыть/Комментировать

2023-05-14 14:00:38 WHY can fatigue "attack" after an afternoon nap?

This kind of sleep doesn't always help you wake up. It's all about "sleep inertia," that is, the transition from sleep to wakefulness. "The longer you sleep, the more likely you are to 'fall' into deeper phases of sleep," explains Dr. Dawn Dor-Stites of the Sleep Disorders Center at the Michigan Medical Center.

"Waking up in the wrong phase can lead to sleepiness and irritability. Limiting daytime sleep to 20 minutes is key, so you'll wake up rested."

The exception to this is when you have enough time to take a nap during the entire sleep cycle, which lasts about 90 to 120 minutes. Открыть/Комментировать

2023-05-13 21:00:29 WHY do the old phones seem to get slower after a new model is released?

One of the reasons is that applications and the operating system are updated. With each update, applications tend to have more functionality, and consequently the RAM and CPU load increases - the phone has to perform more and more calculations.

When the RAM fails, slower flash memory helps, which also affects performance.

Another reason is the large amount of cache. Few people clean the app cache, but it can take up a serious amount of RAM, especially if you frequently use a browser or social networking apps where you often save music to listen to it offline.

Some apps can clear the cache on their own, but others don't, so do it yourself. Открыть/Комментировать

2023-05-13 14:00:42 WHY does the water in the glass change its taste overnight?

The first thing that affects taste is temperature. Most of the time, people fill themselves with cool water, and when it gets to room temperature, it doesn't taste as "fresh". However, it is an indirect cause, the main factor in the unpleasant aftertaste of water from the glass is the gases that dissolve in the water overnight. That's why if you pour water in a bottle, it will taste less unpleasant. Interestingly, the higher the temperature, the better the solubility.

Mostly carbon dioxide enters the water, and when it dissolves it forms carbonic acid, which can lower the pH of the water. In addition, acetone gases and aldehydes can dissolve in water.

Scientists say that even in 30 minutes the water can get an unpleasant taste. But if you forget a glass of water for a few days... you'll get all sorts of germs in it. Открыть/Комментировать

2023-05-12 21:00:33 WHY do hares need big ears?

Long hare ears are not only powerful hearing organs, but also cooling radiators. To escape predators, the hare has to run a lot and often, so it needs a powerful "cooling device".

If a hare would get rid of excess heat only by perspiration, it would consume a lot of water. And cooling by heat exchange allows it to survive in arid places and on scarce food like tree bark.

On the ears, right under the skin of these animals, powerful vessels pass (those who have fondled rabbits probably paid attention to this), the lumen of which is regulated in a wide range. Открыть/Комментировать

2023-05-12 14:00:44 WHY can't humans walk straight ahead without reference points?

Unlike some birds, humans do not have an organ to orient themselves according to the geomagnetic field. Nor do we have an analog of the gyroscope that maintains direction on ships and airplanes.

Our vestibular apparatus senses body turns, but to maintain direction they must be summed up, making sure that right and left turns together give zero.

With the many small turns that accompany walking, errors inevitably accumulate. Each subsequent step deviates by a small random amount from the previous one, and without external reference points, the movement deviates more and more from the original direction. Открыть/Комментировать

2023-05-11 21:00:29 WHY do you keep forgetting where you left your stuff?
⠀
Your brain has these hard-working cells that clean up unnecessary memories. These cells produce a hormone that makes sure you successfully forget everything "useless".
The greatest bursts of this hormone occur during sleep. Thus, it is rare that you can recall a dream.
⠀
One interesting fact is that memories are better preserved if they are triggered by active signals from the pleasure center in your brain. So, when you put your keys somewhere, don't forget to enjoy something in that place, so that you won't have to look for them for two hours. Открыть/Комментировать