Magnetism Vs. Gravity

Gravity and magnetism are two fundamental forces that affect almost every phenomenon in nature. While we owe it to gravity, to keep our feet firmly grounded on Earth, it is due to magnetism that devices like electric generators, motors, fans, hard drives and countless other electronic gadgets help make our life comfortable. Both magnetism (as one aspect of the electromagnetic force) and gravity are two fundamental forces of nature, which mold matter at the microscopic and macroscopic scales. Gravity is the force which determines the large-scale structure of space time by clumping together matter from planetary scales to galactic clusters, determining the ultimate fate of the universe. On the other hand, at microscopic scales, electromagnetic force determines atomic structure, determining the properties of materials. While the force of gravity felt by a particle is purely dependent on mass, electromagnetic forces are mediated by charge.

Ex. 46. Fill the gaps with the words from the list below. Be ready to interpret the text.

Maglev, magnetism, diamagnetic, atom, ferromagnetic, electric current, angular momentum, conductors, magnetic field, paramagnetic.

… is the tendency of any material to react to any applied … with attraction or repulsion. For example, when a magnet is passed over iron nails, they stick to it due to attraction. All substances are either … (repulsed by applied magnetic field), … (weakly attracted by applied magnetic field) or … (strongly attracted to applied magnetic field) in nature.

Every magnetized object has two poles, which are labeled as north and south poles (as they are attracted to the north and south poles of the Earth's magnetic field). Like poles of magnetic objects repel each other, while unlike poles attract. The Earth itself behaves like a large magnet, with the magnetic north and south poles directing compass needles towards them. The magnetic property of a substance arises due to the orbital motion of electrons around the atomic nucleus and intrinsic spin ….

In fact, wherever there's an …, there is a magnetic field. The degree to which magnetism is expressed in a material is largely dependent on the electronic configuration of its constituent atoms. More the number of unpaired electrons in an …, more is the probability of the atom showing magnetism. Every atom of the material is a small magnet. In most materials, these small magnets are aligned in such a way, that they cancel each other out. In some ferromagnetic materials like iron, these small atomic magnets tend to be well aligned in the same direction, giving rise to pronounced tendency to be magnetized.

All … with an electric current flowing through them, have a magnetic field around them, making them 'electromagnets'. Magnets are used in countless electronic gadgets like audio speakers, doorbells, computer hard drives and in the construction of 'Magnetic Levitation (…) trains'. Most importantly, electric power generation is made possible by the giant magnets placed inside power plant dynamos.

Ex. 47. Find the definitions for the words from the list below. Be ready to interpret the definitions.

Heisenberg's Uncertainty Principle, Newton's laws of motion, general theory of relativity, Archimedes' Buoyancy Principle, Laws of Thermodynamics, Newton's law of universal gravitation, theory of natural selection,

1. The three laws proposed by Sir Isaac Newton to define the concept of a force and describe motion, used as the basis of classical mechanics.

2. The principle that two particles attract each other with forces directly proportional to the product of their masses divided by the square of the distance between them.

3. A geometrical theory of gravity developed by Albert Einstein in which gravity's effects are a consequence of the curvature of four-dimensional space-time.

4. The four laws which define fundamental physical quantities (temperature, energy, and entropy) that characterize thermodynamic systems.

5. The law that states that a body immersed in a fluid is buoyed up by a force equal to the weight of the displaced fluid.

6. The principle which says that random genetic changes that are beneficial to survival are 'selected' and passed to descendants.

7. The scientific principle stating that it is impossible to determine with perfect accuracy both the position and momentum of a particle at any given point in time.

Ex. 48. Fill the gaps with the words from the list below. Be ready to interpret the text.

Mass, universal law of gravitation, pulls, force, inversely, pull back, gravity, gravitational constant.

One of the most important scientific breakthroughs of all times is Sir Isaac Newton's …, all thanks to the falling apple. … is an invisible force that pulls all matter together. Sir Isaac Newton studied the reason behind the falling apple and defined it as the law of universal gravitation, "Each particle of matter attracts every other particle with a … which is directly proportional to the product of their masses and …proportional to the square of the distance between them."

Gravity is the reason behind, things staying on the Earth's surface as also for the formation and movement of all the planets and other heavenly bodies.

Standard Formula of Gravity is Gravitational force = (G * m₁ * m₂) / (d₂) where G is the …, m₁ and m₂ are the masses of the two objects for which force has to calculated, and d is the distance between the centers of gravity of the two masses.

Let's consider the two objects; the Earth and us. As we move around the Earth's surface, it … us and we …. Mass is the amount of matter in any object, since the Earth's mass is more compared to us, we get pulled towards the Earth. Besides the amount of…, gravity also depends on how far you are from a particular object. This is probably the reason why we don't get pulled towards the Sun, which has more gravity than the Earth.

Ex. 49. Translate the following text into English.

На відміну від короткодіючих сильних і слабких взаємодій, електромагнітні і гравітаційні взаємодії мають властивість дальньої дії: їх дія виявляється на дуже великих відстанях. Усі механічні явища в макроскопічному світі визначаються виключно гравітаційними й електромагнітними силами. Між фізичними тілами діє сила взаємного притягання. Такі явища, як падіння тіл на Землю, рух Місяця навколо Землі, планет навколо Сонця і інші, відбуваються під дією сил всесвітнього притягання, які називають гравітаційними. Аналізуючи закони Кеплера і закони вільного падіння тіл на Землі, Ньютон дійшов до висновку, що сили притягання мають існувати не лише на Землі, а й у космосі. Закон, який характеризує сили притягання, уперше сформулював Ньютон в 1687 року під час вивчення руху Місяця навколо Землі. Цезакон всесвітнього тяжіння: будь-які дві матеріальні точки притягуються одна до одної із силою, прямо пропорційною добутку їх мас і обернено пропорційною квадрату відстані між ними.