Let us consider a circle and a point that does not belong to it. Connect all points of a circle with the given point by line segments and draw perpendicular lines through their midpoints. These straight lines will fi ll a part of the plane as if bending round the untouched areas. In the case when the selected point lies inside the circle, the envelope boundary will be an ellipse, and if the point is outside the circle — a hyperbola. A similar operation can be performed with a straight line and a point that lies outside it. In this case, the boundary will be a parabola.

In Dan Browns novel Angels and Demons, villains steal a gram of antimatter from CERN and threaten to blow up Rome. Now we know that when a substance meets antimatter, both masses disappear, turning into radiation strictly according to Einstein's formula: E = mc2. As you can see, there is a monstrous magnitude in this formula — 300,000,000 meters per second, which is the speed of light, squared. This makes antimatter much more powerful than a thermonuclear bomb. Calculations show that the annihilation of that stolen gram of antimatter would be equivalent to 430 kilotons of TNT!

The brighter — the warmer? Life experience tells us that these two concepts are inseparable. however, the laws of chemistry refute this interdependence: matter can glow “cold,” with no heating at all. And what is most surprising — such phenomena occur literally everywhere. To illuminate a room, you can switch on a light bulb, but if you are in a dark grove, you will have to build a fire. The bigger the fire, the more light there is. You can also warm yourself up if the night is cold. In the morning, a natural light source will be back — the sun, heated up to 6000 K, giving Fluorite crystals can glow when heated — the process of thermoluminescence. Fluorite is a typical fluorescent mineral, but when it is warmed up or irradiated with ultraviolet light, it starts to phosphoresce. For matter to fl uoresce, an electron in its atom must reduce its energy, that is, move to a lower energy level, emitting the excess energy as a particle of light, a photon. But first, the electron absorbs energy and gets into an excited state. It stays there for a while and, at an arbitrary moment, jumps down, emitting a photon. There are many electrons, so photons are emitted almost at all times, and the substance glows continuously and gradually dies away while the number of excited electrons decreases.

The heart is an essential organ of the human body. Scientists say that with age, the heart increases in size directly proportionally to the growth of a persons own fist. Ancient people thought that the heart was the chief organ which controlled the whole body and so people used to believe everything related to the human condition and relationships was connected with the heart. Now, of course, we understand that this is the work of the brain. Certain expressions emerged, such as “stout-hearted,” “a warm-hearted person,” and “I love you with all my heart,” though it would be more accurate to say “I love you with all my brain.”

“Recognizing someone by the eyes” can be based on their retina or iris. These begin to form in the mother’s womb and then hardly change after that (in a healthy person). Iris scanners track the pupil’s response to light and take images of the coloured “ring” around it. This technology has one drawback, though: scanners can erroneously react to a dummy or a very high-quality picture of the eye. Retinal scanners highlight the blood vessels in the eye with infrared rays and copy the map of the capillaries against the background of surrounding tissues — it’s a slightly unpleasant procedure. The idea of scanning the retina was proposed in 1935 by doctors Carleton Simon and Isadore Goldstein in the New York State Journal of Medicine, but then, the technology could not support the realization of the idea. The first commercial model was released by Eyedentify in 1981 (and continues to do so to this day).