In my opinion, the speed of an electron's movement in the electron cloud cannot be determined by direct measurement (electrons are too small for that), but we can use an analogy from astronomy — for example, the Moon orbits the Earth at a speed such that the magnitude of the centrifugal force is equal to the gravitational force ...

Just like with everything in our surroundings, it is necessary to determine under what conditions we want to measure the temperature in. For example, water can be at 4 °C in the refrigerator, 95 °C in an electric kettle, and around 300 °C in a power plant (typically nuclear) ...

So far, outer space in the solar system is a peaceful place where no one is shooting at anyone, but we can feel free to entertain hypotheticals about what if we needed to. Maybe that astronaut doesn’t want to shoot another astronaut, but a creepy alien monster ...

Freezing is a process in which a liquid state changes to a solid state. Solid crystals begin to grow in the liquid and more and more molecules of the freezing liquid are added to them. Eventually, one solid block is formed. In water, we call it ice. In order to freeze, the molecules need to get rid of the energy that prevents them from getting a firm grip in the crystal bonds ...

When we heat water, it starts to evaporate. At first, it evaporates only from the surface, and when it reaches the boiling point, it evaporates from its entire volume. The water changes from a liquid to the gaseous state called steam. At some point, an equilibrium is established. As many molecules evaporate from the water as condense back into it. The steam thus obtained is called saturated steam ...

Human beings have always longed to be invisible. Fables and myths are full of potions, incantations and cloaks of invisibility. H. G. Wells attempted to grasp the idea of invisibility a little more scientifically in his novel The Invisible Man. In it, the hero invents a substance that makes all the cells of his body transparent ...

The ability of dinosaurs to construct radiation detectors, take measurements, and record the results has not yet been proven, and it is quite likely that they did not actually do any such thing. Yet we know the half-lives of elements that are longer than the time that dinosaurs ruled the Earth. In order to explain how this is possible, it is first necessary to clarify what the half-life is ...

Photons are particles with zero rest mass moving in a vacuum at the speed of light. As bosons, they are not constrained by the Pauli Exclusion Principle and can pass through each other or occupy the same quantum state ...

The nucleus of each atom is made up of protons with the addition of more or less neutrons. It is thus theoretically possible for an element to exist with any number of protons in its nucleus. Perhaps a thousand or a million. But protons, as charged particles, repel each other, and the more there are in the nucleus, the harder it is to keep the nucleus together ...

The fission chain reaction in a nuclear reactor takes place when a neutron flies to a uranium-235 atom and collides with it, splitting the nucleus into two or three fragments. Several neutrons fly out of the whole process, slow down appropriately, collide with other uranium atoms, and so on. Each fission of uranium generates neutrons, which cause other uranium nuclei to fission ...

You may not like it, but people crowding outside the exit of a concert hall are subject to the Venturi effect. The same physical principle applies to water flowing through a pipe or wind blowing through a canyon. The fluid flowing through a pipe must obey the laws of conservation of energy. The total energy of the fluid, i.e ...

The short answer is yes, they can, but it is extremely unlikely. Photons are quanta of electromagnetic waves. When you turn on a light bulb, it starts producing billions and billions of these particles that whizz through your living room at the speed of light. They’re pure energy. They have no rest mass. Photons are a type of quantum particle called bosons ...

Hopefully, it will never be necessary. To answer your question, let’s first look at what radioactivity is, and how it is measured. Radioactivity is the process by which unstable atoms produce ionising radiation. This radiation can also reach us from space, where it is produced by stars and dramatic processes in the cores of galaxies. Ionising radiation is divided into several types ...

By quickly peeling off the adhesive tape, you not only caused a flash of visible light, but even a brief pulse of X-rays. Don’t worry, you are not in any danger and you can keep using the tape. This phenomenon is called triboluminescence. In some substances, the mechanical energy to which they are subjected, say during crushing or scrubbing, is converted into its internal energy ...

In a container filled with hydrogen under normal conditions, i.e. at room temperature and atmospheric pressure, hydrogen molecules (H-H, H₂) collide quite normally. However, nothing at all is formed — only their temperature and momentum change as they collide. In order for hydrogen to become a different isotope, a change must occur in its atomic nucleus ...

Depending on the distribution power lines of the country in which the bird lives, it can choose to sit on lines with a voltage of 100—400 kV, in some parts of the world even up to 800 kV. Electricity with such a high voltage has low transmission losses and is easier to transport over long distances from power plants to cities and factories. Here it is transformed to lower voltages ...

The most common way to draw lightning is a zigzag line from the cloud to the ground. However, this is not the only way lightning can strike. This relates to the rather complicated way in which lightning is produced in a storm cloud. Even though it is made up of only water, a storm cloud is a huge structure, ranging from a few kilometres above the ground to 12 kilometres up ...

Water is a compound of hydrogen and oxygen. A water molecule contains one oxygen atom and two hydrogen atoms bonded to it at an angle of 104.45 degrees. In order for water to appear in the universe, these two basic elements had to be present first. Hydrogen was created at the very beginning of the universe ...

Hydrogen is the lightest element in the known universe. It consists of just one proton orbited by a single electron. It would seem, therefore, that nothing could be lighter. Theoretically, it would be possible to create an artificial element from subatomic particles, for example muonium ...

Some materials or products are said not to be “earthly”. It’s certainly possible, but I’m not aware of any irrefutable evidence for it. Astronomers are convinced that there must be more than 1 planet in the universe to support life as we know it (which is understandable with billions of star systems) ...