The insects find it difficult to breathe as they grow, there may once have been giant insects in times when the proportion of oxygen in the air was greater
It was very hot in the summer months. Sometimes, in the evening, we preferred ventilation over air conditioning and opened the windows. The incident happened and a huge cockroach, disgusting and scary brown, called an American cockroach (because it originates in South America and it came to our places and many other places via ships), found its way into the room, either by flying (and it was a male) or by running along the walls. Some of the members of the house tried to panic and shout terror and the brave ones took care of him, with an insecticidal spray or chases that ended in the successful case with a trampling or a shoe kick.
Such a cockroach may reach a length of 33 mm from the tip of its abdomen to the tip of its head (without the tentacles).
And now, those who are really afraid of cockroaches, better skip the next section.
As huge and scary as the cockroach is, imagine the same cockroach ten times bigger - that is, its length will reach 33 cm, which is longer than the size of a tile, not a normal 20x20 tile, but more like a 30x30 living room tile, or like a tile An especially large living room, the length of three of which together is one meter. Imagine such a cockroach running on the floor and approaching you. A shoe won't help here and it seems to me that neither will a spray - he will simply run away, or attack you before the relatively tiny dose of the spray affects him. As an omnivore, he will surely try to bite you. Remember the movie Men in Space (and also Men in Black)? The script will not be far from that.
Fortunately for us, there are no such cockroaches. And actually can they be? The answer is no and let's see why.
There were huge dinosaurs. Today the elephant is the largest land animal. Their legs and muscles are adapted to their size. In the sea there are giant octopuses that reach a length of 15 to 20 meters and the largest creature today and ever since is the blue whale that reaches a length of 30 or even 35 meters. At sea, for obvious reasons, it's not a problem to be big.
But on land, our giant jock won't do. First he won't be able to fly. If it is ten times longer than it is, its wing area will indeed be a hundred times but its weight will be a thousand times, that is, ten times heavier than what its wing design is capable of carrying. He will not be able to walk on the walls or the floor because the ratio between the contact area and the weight also happens tenfold and if he tries - the gravity will knock him down. He will also have a problem running on the floor - the large weight relative to the contact friction with the floor will not allow him to run fast. In short, a hard life. But he will have another problem - he will not be able to live at all. As you know, the breathing of insects is done by pulsation. They do not have an active respiratory system that draws in the air. Their breathing is passive - the air enters through the tracheas - the breathing openings and flutters to the rest of the body. If it is too big and fat - the air will not be able to reach the internal parts of the body and in fact breathing will not take place and there will be no metabolism.
So it is true that tens of millions of years ago there were giant dragonflies whose wingspan reached sixty cm. But their bodies were thin and long - so they had no problem breathing and the area of the wings was large enough for the weight of the delicate body.
You can relax somewhere - no mutation can create giant insects as we saw in science fiction movies from the fifties and if we had giant dragonflies today - maybe we would get along with them because they are not disgusting and there is no fear that they will attack us - they do not eat at all in the adult stage. And by the way, the explanation is that the development of such giant dragonflies was possible at the time, because then the air was richer in oxygen.
And now for something completely different, which is also related to the summer heat, which we mentioned at the beginning.
You may have noticed that babies, toddlers and small children suffer from the heat less than us adults. This is indeed so and this is because the surface area of their skin is relatively large relative to their body mass. This is similar to the cockroach thing we mentioned earlier.
In general - if an adult is several years taller than a child, then his skin area is four times larger, but his weight is eight times larger. This means that the same child will have twice the skin area per kilogram of weight, than the same adult. Since the skin is, among other things, the radiator of the body, it is clear that the child manages to cool himself better. This is also the reason why fat people suffer more from the heat and you can see them flushed and dripping with sweat, while for their thin friends, the situation is less severe.
What about the cold? Well children are more sensitive to cold. The large area of the skin relative to the body emits heat, so their body is less able to maintain its heat. This is why in winter it is important to keep the ambient temperature of babies warm.
Being in the summer in Barakah, we noticed that toddlers who have been in the water for a long time, their lips turn blue and when they get out of the water - they tremble, while the adults suffer less from these symptoms.
It should also be noted that the percentage of children who survive after prolonged drowning in very cold water far exceeds that of adults. The reason why the large body of adults is not enough to cool down and they drown. Children, on the other hand, get cold quickly and therefore, even though their lungs fill with water, the body's processes slow down and they last a relatively long time and can be successfully thawed. It must be emphasized that this is not about freezing (as in the stupid belief that people can be frozen and revived in many years), because in freezing, the physiology of the cells is destroyed and the cells of the body actually explode.
The relatively low weight of children is in their favor even during falls. When a child falls, the injury is much easier than in a similar fall in an adult. The impact from which the child suffers is lighter because the weight of the body hit in a certain area is less than that of an adult.
