About dragons, chimeras and clocks - special questions and answers

Here are a number of interesting and unusual questions raised by 'Making History' listeners in a special episode dedicated entirely to questions and answers

(The article is taken from the program 'Making history!', A bi-weekly podcast about science, technology and history)

Lior Melamed asks: What would have happened if they had not stopped the hybridization between humans and animals and destroyed the resulting cells?

Before we answer the question 'what will happen if we don't stop the experiment and destroy the resulting cells?', it might be worth checking why these experiments are stopped at all. The answer to this question lies in the purpose of the experiments.

The scientists who perform genetic experiments in which human genes and animal genes are mixed, do not do them just to see what will come out. These experiments have a clear purpose. A group of British scientists, for example, implanted human DNA (DNA is our genetic material, which transmits our traits from generation to generation) into cow cells - with the aim of examining the response of the resulting cells to certain treatments for Alzheimer's disease. For the purpose of this individual experiment, there is no need to grow a perfect and mature creature - a few dozen cells in a test tube are enough. As soon as the experiment ends, the cells have done their thing and are destroyed.

In other experiments it is actually desirable to grow an adult creature. There are researchers who have changed the genetic material of goats to make them produce in their milk medicines that are good for humans: a sort of biological 'factory'. In this case, only the specific genes required to produce the additive in milk are changed. The goat still looks like a goat, acts like a perfectly normal goat, and eats what goats eat, which of course is goat cheese.

A distinction must be made between two different types of 'genetic mixing'. The first type is called a 'chimera', and is a situation where in the same organism there are two types of cells with completely different genetic material. For example, the heart is made from cells that contain one type of genetic material, and the liver from a completely different genetic material. To give a simple example, it's like a car that has a European transmission and a driver's seat of a Japanese car (may God have mercy on those who have such a car). In reality, chimeras may be very useful: for example, a pig in which a human liver is grown with strictly human cells, which can then be transplanted into patients without fear of rejection.

The name 'chimera' comes to us from Greek mythology, where the chimera was a terrible monster that was a combination of everything that scared the ancient Greeks: a lion's head, a goat's body, a snake's tail and other similar combinations. The chimera was destroyed by the hero Balerphon who was riding the winged horse Pegasus, but its name remains with us to this day.

The second type of genetic mixture is the creation of combined DNA - that is, in the same cell there is genetic material from the original animal, as well as human DNA. In that case, you get a creature that has features that are partly human and partly animal, such as the bacteria that produce insulin that I mentioned in the previous examples. If we take the idea one step further, into the field of science fiction, we may get an improved person (ParaHuman), a kind of Superman. For example, a sprinter with bursting power like a cheetah, or a dancer with feline flexibility. On the other hand, we might get something closer to the Ninja Turtles - who knows. This type of experiment is strongly opposed by people who claim that these combinations are immoral, but this is a complicated and complex discussion that should be left for another time.

Yaniv Dubovsky asks: Why did they divide the day into twenty-four hours, and the hour into sixty minutes, and the minute into sixty seconds? Does the origin of the name 'Second' come from the second division of the hour?

This is indeed a fascinating question. We are so used to the division of time into months, days, hours, minutes and seconds - a division that we grow into and learn from infancy - that it seems natural and self-evident. But when you look at our accepted time division, you find that it is very strange. We divide the year into twelve months, but the hour into sixty minutes. Our usual counting method, the method by which we count apples or money, is generally decimal. Why does this confusion exist?

This rush indicates the gradual development of the methods of dividing time since the dawn of history. The method we use today is the result of corrections, upgrades and additions of all those previous methods that our ancestors used since the cave days.
The division into days is clear: the sun rises and sets - one day. Three hundred and sixty-five days pass each year - this is easy to see by the path the sun takes in the sky: every year, the paths repeat themselves. The moon circles the earth once a month, twelve times a year - this is also a clear division.

indeed? Our ancestors got into a fair amount of trouble because of this "simple" division. It turns out that a year is not exactly three hundred and sixty-five days, but three hundred and sixty-five and a quarter days. The moon, unfortunately, orbits the earth once every twenty-nine and a half days, and not exactly every thirty days. These small deviations may seem insignificant to us, but over the years they accumulate and accumulate - until suddenly we discover that spring no longer comes in April, but in October!

Julius Caesar tried to solve this problem in 46 BC. He announced that once every four years another day is added to the month of February - this is a 'leap year' - thereby correcting the small deviation and spring returns to April.

But the problems did not end here. It turns out that the length of the year is not exactly three hundred and sixty-five days and a quarter, but a little less than a quarter. The small deviation slowly accumulated until fifteen hundred years after Julius, in the 14th century, they suddenly noticed that once again the calendar had gone completely wild. There was a deviation of ten days between the calendar and the sun, moon and seasons. The problem was that now there was no longer a powerful Roman emperor who could decide what the calendar would look like and those who dared to oppose him found themselves talking to the lions in the Colosseum. Europe was divided into small states and principalities that each did, basically, what they wanted.

The only substitute for Julius Caesar was the Pope. He wasn't as powerful as he was, but at least he had spiritual authority over millions of his believers around the world. Pope Gregory VIII decided to move the calendar forward ten days to close the gap with reality. He also added minor corrections to the Julian calendar, making it the Gregorian calendar.

The division of the day into twenty-four hours is older, and is attributed to the ancient Egyptians. They invented the sundials, and divided the day into twelve parts. Since the hours depended on the movement of the sun, they were not fixed in length: in the summer the day is longer and therefore the hours are longer. In winter the day is short and so are the hours. The ancient Greeks tried to remedy this problem but it was not until the invention of mechanical clocks in the sixteenth century that the hour became a truly fixed measure of time.

The division of the hour into sixty minutes, and sixty seconds into one minute, probably comes from the Babylonians. The Babylonians used the method of dividing by sixty because it is easier to calculate fractions in the head, without a page and paper: the number sixty is perfectly divisible into many numbers: 2, 3,4,5,6,10,12,15 and 30. The number ten, on the other hand, Divisible only by 2 and 5. This division was also preserved by the ancient Greeks, especially in everything related to navigation and astronomy. For navigation using the stars, they divided the sky into three hundred and sixty degrees. Each level was divided into sixty minutes. In Latin, this division is called Prate minute prima - the first small division. Minute means small, and we still say about something that is small that it is 'mini'. The division of the minute into sixty seconds is called Prate minute seconda, that is, the second small division. When the watches were invented that could measure time with a resolution of minutes and seconds, this division was also borrowed into the world of watches.

Ayalon Vakanin asks: What doesn't make sense to scientists about dragons? Have we already seen creatures with scales and dinosaurs with wings?

This is an interesting question. The immediate response to it is 'dragons? What nonsense!' After all, everyone knows that dragons are just an imaginary invention. But with a deeper observation, and familiarity with the vast variety of animals on Earth - the possibility of the existence of dragons somewhere in the mists of history cannot be dismissed without devoting at least a few minutes of thought to the matter.

There are several good reasons why dragons (or dragon-like creatures) may have existed in the past. First, dragons appear in folktales in almost all human cultures! Although in every culture the dragon is depicted differently, but the basic idea is the same. The described creature is reptilian (snake or large lizard), it has a large head with many teeth, a powerful tail and sharp claws on its feet. The differences between the descriptions in the different cultures mainly concern the mystical signs of the dragons: the European dragons spit fire, for example, and are described as evil creatures that like to eat mainly virgin girls. The Chinese dragon, on the other hand, is wise and good-natured, does not hatch lava from its mouth and has no culinary preference based on the victim's sexual history.

There are also physical differences: the European dragon is winged, while the Chinese dragon is wingless and has a lion's mane. Still, the fact that dragons appear in a wide variety of cultures suggests that there is something about this idea that makes it universal. Is it possible that our ancient ancestors knew real dragons in the past, and that the memory of the dragons passed from generation to generation to all of humanity? Were those the dinosaurs?

probably not. The big dinosaurs went extinct more than sixty million years ago, long before humans appeared on the scene or even before our ape ancestors debated whether getting down from the trees would be a wise move. There was no time when humans and dinosaurs lived side by side.
The matter of the fire coming out of the mouth is also problematic. Of all the animal species on earth, the only creature that makes use of fire is man. In order to produce combustion materials inside the body, the animal has to invest very large amounts of energy - because liquid fuel contains very concentrated energy. It is likely that from an evolutionary point of view, it is better to invest this energy in other survival tactics - like running faster, for example.

Where, then, did the dragons come to us? The answer is not clear, but it is likely that there is a combination of several interesting psychological phenomena here. The first is our deep and rooted fear of snakes and animals with large jaws, a fear that our ancestors developed over hundreds of thousands of years - perhaps the idea of ​​the dragon is a play of the human imagination against this fear. It is possible that the idea of ​​the dragon is a 'meme' - a piece of information that fits so well with the way the human brain works, that it is passed from person to person like a flu virus. Another possible reason is the dinosaur bones that have been discovered from time to time in different parts of the world, which combined with the previous reason encouraged the growth of legends about large and threatening animals.

The only real dragon known to science is the Komodo dragon - a terrible lizard, three meters long, that lives in the Indonesian islands. The Komodo is a predator - but its hunting method does not rely exclusively on its agility. Extremely deadly bacteria grow on the Komodo dragon's teeth. The Komodo bites its victim, and after a few days the prey falls to the ground - dead as a result of a severe bacterial infection. It does make a little less noise from the flames through the nostrils - but admit it, it's no less impressive.

(The article is taken from the program 'Making history!', A bi-weekly podcast about science, technology and history)