Keys for tests

Appendix 1

Grammar Material

Indefinite Tenses. Active Voice.

Continuous Tenses. Active voice.

Passive Voice. (страдательный залог)

Irregular verbs

Appendix 2

IDIOMS, CONJUNCTIONAL AND PREPOSITIONAL PHRASES

according to – согласно

along with – вместе с, наряду

all over the world – во всем мире

a number of – ряд, несколько

apart from – кроме

as a matter of fact – на самом деле, фактически

as a result – в результате

as (close, etc.) as possible – по возможности (близко и т.д.)

as early as – еще (о времени)

as far as… is concerned – что касается

as far back as – еще (в), уже (в)

as follows – следующее, как следует ниже, следующим образом

as for – что касается

as is the case – как в случае с

as long as – пока, до тех пор

as soon as – как только

as to – что касается

as well – также

as well as – так же, как и

at any rate – по крайней мере, во всяком случае

at last – наконец

at least – по крайней мере

at once – тут же, сразу же

at present – в настоящее время

at the same time – в то же самое время

at times – иногда, временами

at will – по желанию

because of – из-за, вследствие

both… and – и… и, как…, так и

but for – если бы не

by all means – непременно

by chance – случайно

by means of – при помощи, посредством

by no means – никоим образом, ни в коем случае

by some means or other – тем или иным способом

by the way – между прочим

by turns – по очереди

consideration should be given to – следует обратить внимание на

do a world of good – делать много хорошего

do without – обходиться без

due to – благодаря

either… or – или… или

ever since - с того времени, с тех пор

first – прежде всего, сначала

for ever – навсегда, вечно

for example – например

for short – короче, для краткости

for the present – на этот раз

for the sake of – ради

for this reason – по этой причине

for want – из-за недостатка, нехватки чего – либо

from time to time – время от времени

give rise to – вызывать, иметь результатом

give way to – уступать

go into operation – вступать в действие

have nothing to do with – не иметь никакого отношения, не касаться

in addition to – кроме того, к тому же

in case – в случае, если

in certain respect – в некотором отношении

in comparison to – по сравнению

in effect – в действительности, в сущности

in fact – фактически, на самом деле, действительно

in its turn – в свою очередь

in no time – очень быстро, моментально

in order to – для того, чтобы

in other words – иными словами

in particular – в особенности

in question – о котором идет речь

in short – короче говоря

in spite of – несмотря на

instead of – вместо того, чтобы

in this connection – в связи с этим

in view of – ввиду

it goes without saying – ясно, само собой разумеется

it is high time – давно пора

it stands to reason – ясно, очевидно

it takes me (him, her) – мне (ему, ей) требуется

it was not until – лишь только в

keep in mind – иметь в виду, помнить

kind of – своего рода

last but not least – хотя и последний, но не менее важный

last but one - предпоследний

make use of – использовать

meet the needs (requirements) – удовлетворять нужды, отвечать предъявленным требованиям

more or less - более или менее

needless to say – нечего и говорить

neither… nor – ни… ни

no longer – больше не

no matter (how) – безразлично, неважно, независимо от

no sooner… than – едва, как только

not at all – вовсе нет, нисколько

not to speak of – не говоря уж о

no wonder – не удивительно

of course – конечно

on account of – из-за, вследствие

one and the same thing - одно и то же

one can’t help (gerund) – нельзя не…

on the basis of – на основе, на основании

on the contrary – наоборот

on the one hand – с одной стороны

on the other hand – с другой стороны

on the part of – со стороны

or so – или около этого

owing to – по причине, вследствие, благодаря

pay attention to – обращать внимание

put into operation – ввести в действие, в эксплуатацию

put into use – вести в действие

rather than – скорее, чем

result from – иметь результатом, приводить к

say – скажем

so far – до тех пор, пока

so to say – так сказать

take advantage of – воспользоваться

take into account – принимать во внимание, в расчет

take into consideration – принимать во внимание

take part – принимать участие

thanks to – благодаря

that is – то есть, т.е.

that is to say – т.е., иными словами

the former – первый из упомянутых

the latter – последний из упомянутых

the rest of – остальное, остальные

the… the – чем… тем

under consideration – рассматриваемый

up to – до

with respect to – по отношению к, относительно

ADDITIONAL READING

Text 1 ENERGY

What is energy? A scientist would say that energy is the ability to do work. You use energy when you walk. You carry your books with you to the Institute. It takes energy to carry books. You can do nothing without using energy. You wash with water warmed by energy. You put on clothes washed and ironed with energy.

There are many forms of energy. Each of these is useful to us. For example, we use heat energy to do a lot of useful things, namely, to heat our homes, to transport us from one place to another, and so on. Automobiles, trams, trains and airplanes are moved by changing heat energy to other forms of energy.

Electrical energy does many things for us. It is changed to other forms, such as: light, mechanical, heat, chemical, and others. When you watch television, you hear the sound and see the picture. The television (TV) set gets warm. Thus, electrical energy changes to heat, light and sound.

Many machines use electrical energy. They change energy from one form to another. Devices that are operated with electrical energy help us to work. Indeed, electricity plays an important part in our modern life.

Text 2 STEAM PRODUCES ELECTRICITY

Electrical power plants are needed in many places where water power is not available. At present only about 25 per cent of the power used in Russia is obtained from moving or falling water.

Great numbers of electric power stations throughout the country are run by the mechanical power of steam turbines.

These contain large wheels with blades attached to their edges. Hot steam under great pressure is directed through nozzles against these blades. The wheels can be made to turn very fast.

As many as 40 such wheels connected together may be part of a large steam turbine. A jet of high pressure steam hits the blades of one wheel, passes on to the blades of the next wheel, and so on, dropping in pressure and temperature as it progresses. The jet of steam comes in at speeds as high as 1,200 miles per hour and at a temperature of 900 degrees Fahrenheit. At this temperature the first metal wheel gets red hot. By the time the steam hits the last wheel and is ready to come out of the turbine, it has dropped to a temperature of 70 degrees Fahrenheit and to a pressure of less than the pressure of the air outside. The power of the steam is thus used up completely when it turns the turbine wheels.

The turbine wheels, traveling at speeds of 600 miles per hour have very great mechanical power. This power is used to turn large coils of wire between the poles of large electromag­nets in generators. When the coils of wire are rotated very rapidly, they can generate large currents of electricity. The mechanical power of hot steam under great pressure is thus converted into great, quantities of electrical energy.

How is this steam produced?

In almost all of these power plants coal or other suitable fuel is burned to heat water and turn into steam.

Text 3 STEAM POWER

Steam is the principal factor in producing usable energy because of the power created by its expansion. The discovery of the power in steam produced great changes in industry.

Steam power is used mainly in the generation of electricity. There are, however, many other examples of steam-operated machines. There are two main types of steam machinery: the reciprocating engine and the turbine. In the former, steam pressure pushes against a piston connected with a crank that converts the forward and backward movement into rotary motion. In the second or turbine type, the operation is similar to that of water turbine. Jets of steam under high pressure hit the blades on the turbine wheel causing rotation.

The reciprocating engine develops high power at low speed while the turbine develops high power at high speed. The reciprocating engine is often used to pump great quantities of wafer. The turbines are generally used in steam-electric generating plants where high speed as well as great power is necessary. The reciprocating engine is from ten to thirty per cent efficient. Turbines usually are much more efficient because they allow a more complete expansion of steam than do reciprocating engines.

Text 4 BOILING

If we heat some water in an open glass container, we can see that evaporation goes on from the top surface. This evaporation is indicated by the clouds forming where the vapour mixes with the colder air and condenses. We find that the temperature of water gradually rises until the thermometer registers 100°C. A little before this point is reached, bubbles appear on the sides of the container. They consist partly of gases driven from liquid and partly of water-vapour, for evaporation is directed into the bubbles.

Water is said to boil when vapour is formed both at the bottom of the container and at the top of it. The motion of the boiling water is caused by the bubbles of vapour rising through the water. The temperature of the boiling water is constant. This temperature is known as the boiling point of the liquid.

The boiling point of a liquid is the temperature at which it boils under some given pressure. When this point has been reached, further heating does not increase the temperature of the liquid, but only changes it into steam.

When water boils in a container we say that we see steam coming out of it. In fact what we see is not steam at all but fine water particles. Steam itself is invisible. It is the condensed steam in the form of fine particles of water that we see.

As liquids always increase in volume when passing into the state of vapour, an increase in pressure always produces an increase in the boiling point.

Just as solids may under certain conditions be cooled below their melting points without freezing, so liquids may be heated above their boiling points without boiling.

Text 5 LAWS OF BOILING

The principal laws of boiling are as follows:

1. When a liquid is heated, it begins to boil at a definite temperature, known as the boiling point, and on further heating the temperature remains constant at this value until the whole of the liquid is converted into vapour.

2. This temperature is constant for a given liquid if the pressure is constant.

3. The boiling point of a liquid increases if the pressure upon it is increased.

4. A definite quantity of heat is required to convert the unit mass of the liquid into vapour at the same temperature.

This is known as the latent heat of evaporation.

Text 6 THERMODYNAMICS

Thermodynamics is that branch of physics which deals with the conversion of mechanical energy into thermal energy and the reverse process of transforming heat into work.

The production of heat by mechanical means may be illustrated by the phenomenon of friction. For example, fire may be started while rubbing together two sticks of wood. Heat is developed when compressing a gas. The transformation of heat into work may be illustrated by operation of a steam or gas engine by means of which heat may be transformed into mechanical energy.

So a heat engine is a machine for transforming heat into mechanical energy, the most important of the practical heat engines being the steam engine and the internal combustion engines.

To transform energy from any of its numerous forms into heat is a comparatively simple process. To transform heat into work is a different matter. Experience shows that any actual physical process, as the change of state of a system, is irreversible and is accompanied by frictional effect. A strictly reversible frictionless process being an ideal, it may be approached but never attained. In the case of the ideal reversible process, there is no change in the quantity of available energy; but an actual irreversible process is always accompanied by a decrease of the amount of energy available for transformation. All transformations of energy are subject to two far-reaching laws:

1. The general law of conservation of energy, of which the following is a statement: the total energy of an isolated system remains constant and cannot be increased or diminished by any physical process whatever.

2. The law of degradation of energy. According to this law, the result of any transformation of energy is the reduction of the quantity of energy that may be usefully transformed into mechanical work.

The first law of thermodynamics is merely the law of conservation applied to the transformation of heat into work. It may be stated as follows: when work is expended in producing heat the quantity of heat generated is equivalent to the work done; and conversely, when heat is employed to do work, a quantity of heat precisely equivalent to the work done disappears.

The second law of thermodynamics is essentially the law of degradation of energy. Whereas the first law gives a relation that must be satisfied in any transformation of energy, it is the second law that gives information regarding the possibility of transformation and the avalability of a given form of energy for transformation into work. A general statement of the second law is: 'No change in a system of bodies that takes place of itself can increase the available energy of the system'.

Text 7 WHAT IS HEAT?

All matter is made up of tiny particles called atoms. Atoms combine with other atoms to form molecules. These atoms and molecules are continually moving. Movement is a form of energy. It is called kinetic energy. And heat again is a form of energy. It is produced due to the motion of electrons, atoms, and molecules.

The heat energy present in any object is connected with its temperature-which consequently depends on how briskly the atoms are moving. If the object gains heat energy, its temperature rises. And if it loses heat, its temperature falls.

There is an important difference between heat and temperature. Heat is a form of energy while temperature is the degree of hotness of a body. Heat is measured in joules or calories with an instrument called calorimeter, while the temperature is measured in units of degree- Celsius or Fahrenheit-with the help of thermometers.

Now the question arises how the substances become hot on heating.

When a pot of water is heated on a stove, the rapidly moving molecules of the gases in the flame collide with it. This collision causes free electrons in the metal of the pot to collide with their neighbours, accelerating them towards the water. Eventually this motion is imparted to the water molecules at the bottom of the pot. The hot bottom molecules now rise up and colder ones sink to take their place. This process is known as process of convection. When the water molecules are moving violently enough, bonds between them begin to break and as a result water escapes in the form of steam.

In general metals have many free electrons and hence act as good conductors of heat. Water and air have no free electrons, so they do not condupt heat, but they get heated by convection currents.

Heat can travel from one place to another by three different methods: conduction, convection or radiation. In conduction, the heat is transferred from one atom to another. Free electrons act as the carriers of the heat energy. Conduction mainly occurs in solids. When we put a metal cooking pot over fire, the handle of the pot also becomes hot, even though it is not in the fire. The atoms near the fire become hot and start moving quickly. They collide with nearby atoms and pass some of their heat energy. The energy is slowly transmitted through the whole body thus making it hot.

In convection, heated matter moves from one point to another. Heating of water is an example of convection. Air also gets heated by convection currents.

In radiation heat travels from one place to another without affecting the intervening medium. Sun's heat comes to earth by the process of radiation.

Heat has two common effects on material bodies. One is that it can cause bodies to change their states. For example, it can turn a solid into liquid or a liquid into gas. Another effect of heat is that it causes substances to expand. When a body is heated up, its atoms move more violently causing the substance to expand. Solids expand least, liquids little more and gases most.

Our most important source of heat is the Sun. Apart from this we get heat by burning fuels such as oil, coal, wood etc.

Text 8 STEAM TURBINE

Here is an example of an invention that had to wait many centuries before men discovered its practical application. We mean the steam turbine. More than two thousand years ago a man named Hero, who lived in Alexandria, Egypt, made the first steam turbine. It was a steam engine that produced rotary motion. It used neither a piston nor a cylinder as is the case in steam engines. The steam from a boiler was carried into a ball which had a pair of bent tubes. The steam forced the ball to rotate.

For almost two thousand years men did little with this idea. They did not know how to make the engine perform useful work. Then a few hundred years ago, men began to experiment with this device and came to a simple steam turbine. The rotor mounted on a shaft has many small blades around its outside edge. Nozzles direct jets of steam against these blades causing the rotor to rotate at high speed. This rotary motion can be taken off the rotor shaft by gears, to drive other machinery or an electric generator.

A modern turbine usually has not just one but a whole series of bladed discs, which together make up the rotor. They are all mounted on a single shaft so that all rotate togeth­er. Between each pair of discs there is a stationary ring in which a series of blades is set. The blades curve in the opposite direction from the blades in the rotor. After the steam has passed through the first disc and given the rotor a powerful rotary push, it reverses direction. It then goes through the curved blades on the stationary ring, which reverses its direction again, so that it can push against the blades in the second disc. In this way the steam goes through the turbine, pushing against the rotor blades and changing direction again in the stationary blades and so on. Most of the useful energy in the steam is utilized by the above process.

Text 9 PLASMA GENERATOR

As is well known electric current can be generated if a metal conductor continually crosses the lines of force of a magnetic field. This is the principal feature of all designs of modern electric generators and electrical engines.

However, a generator can be constructed with nothing moving inside, thus eliminating the need for a steam turbine. A copper wire acts as a conductor in ordinary dynamoes. However, the metal could be successfully replaced by a jet of gas heated to a plasma state. Plasma is a rather new term in. science and engineering. This term denotes another state of matter-the fourth state besides the solid, liquid and gaseous. It is caused by heating the matter to a temperature of 4000-5000° C and higher. In this case the so-called ionized gas is produced with a tremendous mass of free electrons forced away from the atoms. In this state a substance becomes an excellent conductor of current.

If a jet of plasma is directed between the poles of a powerful magnet, an electric current would result which could be carried elsewhere by special electrodes. Thus the rotor with the conductors, unlike the dynamo, is replaced here by a gaseous conductor continually crossing the magnetic field.

The efficiency of transforming the energy of fuel heat into electric current in a plasma generator can be brought to 55-56 per cent, and in some time possibly to 70 per cent.

Though there are many difficulties in the developing a plasma generator or, in other words, magneto hydrodynamic generator, Soviet scientists and engineers believe that it is a real task. To fulfill the task it is necessary to study the physical properties of the plasma and to find trie means of increasing its density and temperature.

Scientists and engineers are concentrating their attention on developing a power-generating installation based on a magneto hydrodynamic principle. Their success in this work will help our power engineering make a new contribution to our science.

Text 10 STEAM POWER STATION

A modern steam power station is known to consist of four principal components, namely, coal handling and storage, boiler house, turbine house, switchgear.

If you have not seen a power station boiler it will be difficult for you to imagine its enormous size.

Besides the principal components mentioned above there are many additional parts of the plant. The most important of them is the turbo generator in which the current is actually generated.

A steam turbine requires boilers to provide steam. Boilers need coal-handling plant on the one hand and ash disposal plant on the other. Large fans are quite necessary to provide air for the furnaces. Water for the boilers requires feed pumps. Steam must be condensed after it has passed through the turbines, and this requires large quantities of cooling water. The flue gases carry dust which must be taken away by cleaning the gases before they go into the open air.

A modern steam power station is equipped with one or more turbine generator units which change heat energy into electric energy. The steam to drive the turbine which, in its turn, turns the rotor or revolving part of the generator is generated in boilers heated by furnaces in which one of three chief fuels may be used-coal, oil and natural gas. Coal continues to be the most important and the most economical of these fuels.

Large installations with turbo-generators of 200,000 to 300,000 kW capacity are operating at a number of steam power stations in Russia. It is necessary to point out that our power machine building industry has started to manufacture even greater capacity installations for steam power stations of 500,000 and 800,000 kW.

A new steam power station will soon be put into operation in Konakovo on the Volga. As far as its capacity is concerned the station can be compared with such electric giants as Volgograd and Bratsk hydropower stations. Its eight generators will have an overall capacity of 2,400,000 kW. The station was planned to produce 16,000 million kWh of electricity annually. It is expected to meet power requirements of Moscow, Leningrad and some other industrial centers.

The Konakovo steam power station is the first station of such a great capacity to work on natural gas. The cost of the gas is one-tenth that of coal, therefore the Konakovo station is one of the most economic stations in the Russian Federation.

Text 11

Heat

Heat is the energy possessed by a substance in the form of kinetic energy of molecular movement, rotation, and vibration. It is usually measured in calories, transmitted by conduction, convection, and radiation. The chief observable, physical effects of a change in the heat content of a body may include rise in temperature; change of state from solid to liquid (melting), solid to gas (sublimation), and liquid to gas (evaporation and boiling); expansion; and electrical effects.

Expansion

Substances expand when heated; gases expand more than liquids, and liquids more than solids. Expansion is allowed for in railway lines and bridges; compensated in clocks and watches, utilized in the thermostat and in the shrinking of steel tyres.

The coefficient of linear expansion of a substance is the increase in length per unit length per rise of temperature of 1°.

Vocabulary:

• is allowed for – применяется в расчет

• to compensate – уравновешивать

• to shrink, shrank, shrunk – сжимать (-ся), садиться (о материи)

• linear – линейный, узкий, длинный

Text 12 NUCLEAR POWER STATION

Atomic energy was first, used for the explosion of the atomic bomb in 1945. Few people realized at first that the same energy which can destroy an entire city so easily can also be harnessed for the good of mankind.

The first practical realization of this came with the announcement in 1954, that a power station working on atomic energy had been put into operation in Russia. The effect of this was to make people realize that nuclear power was not something in the remote future but was quite possible, because the technical problems had been solved.

A nuclear power station is similar to ordinary power stations with the one exception, namely, instead of a coal-burning furnace it has a nuclear furnace, i. e., heat is produced by nuclear fission in a reactor.

As for the first in the world nuclear power station mentioned above, the fuel is uranium enriched 5 per cent with U-235. The pile is graphite-moderated and water-cooled. It generates 5,000 kW.

The pile can be cooled by many means, namely, by gas, water or liquid metal. The heat is applied to produce steam which in its turn is used to generate electricity.

The pile is controlled by a "moderator" that is, rods of cadmium or boron steel which absorb neutrons readily and so stop the chain reaction when they are inserted into the pile.

The reactors being built at present consist essentially of uranium bars which lie in a number of channels drilled through blocks of graphite. The purpose of graphite can be explained if we imagine the fission process starting in a bar of uranium somewhere at the centre of the pile. The first fission releases neutrons enough to carry on the process and establish the chain reaction but they are moving so fast that they escape out of the bar of uranium in which they were born without giving rise to any further fission. Outside the bar the neutrons find themselves surrounded on all sides by graphite. Graphite, like heavy water, is what is known as a "moderator", that is to say, it possesses the power of making neutrons lose energy, without absorbing them; so that by the time the neutrons have reached the other side of the graphite and come into contact with another bar of uranium, they are of just the right energy to promote fission within the bar. The graphite is made exactly of the right thickness for this purpose.

In our country it is the practice to enclose a large-scale reactor in a steel shell. Thus, if an accident should occur to the pile, there is no possibility of radioactive leakage. A further shell of concrete, the so-called biological shield, lies outside the steel shell. The function of this biological shield is to absorb radiation escaping from the pile so that no one should be injured by approaching the pile.

Text 13 EVAPORATION AND CONDENSATION

When enough heat is supplied to a liquid at standard atmosphere, the liquid evaporates to a gas. When heat being removed from a gas, it condenses to a liquid. The heat absorbed in the first process is called the heat of evaporation or vaporization and the heat evolved in the second, the heat of condensation. At any temperature the heat absorbed when a liquid evaporates equals the heat evolved when a gas condenses to a liquid.

At equilibrium the average translation kinetic energies of the molecules in the liquid and gas phases are the same, their potential energies, however, differing. Although strong intermolecular forces hold the molecules in a liquid, the attractive forces between gas molecules are relatively small. Hence, these molecules can collide within the liquid surface practically unhindered. The number of gas molecules striking the surface is directly proportional to this concentration. If they are to remain in the liquid, they must lose potential energy equal to the difference between their binding energies in the gas and liquid phases. Their loss of energy accounts for the heat of condensation. At the same time, the molecules evaporating from the liquid must absorb an equivalent amount of energy. This effect accounts for the heat of evaporation or vaporization.

Text 14 THE ATOMIC POWER PLANT

Atomic power plants are modern installations. They consist of several main units and a great numbers of auxiliary ones.

In a nuclear reactor uranium is utilized as a fuel. During operation process powerful heat and radioactive radiation are produced. The nuclear reactor is cooled by water circulation. Cooling water circulates through a system of tubes, in which the water is heated to a temperature of 250-300°C. In order to prevent boiling of water, it passes into the reactor at a pressure up to 150 atmospheres.

A steam generator includes a series of heat exchangers comprising tubes. The water heated in the reactor is delivered into the heat exchanger tubes. The water to be converted into steam flows outside these tubes. The steam produced is fed into the turbo generator.

Besides, an atomic power plant comprises a common turbo generator, a steam condenser with circulating water and a switchboard.

Atomic power plants have their advantages as well as disadvantages. Their reactors and steam generators operate noiselessly; the atmosphere is not polluted by dust and smoke. As to the fuel consumption, it is of no special importance and there is no problem of fuel transportation.

The disadvantage of power plants utilizing nuclear fuel is their radiation. Radioactive radiation produced in the reactors is dangerous for attending personnel. Therefore, the reactors and steam generators are installed underground. All their controls are operated by means of automatic devices. These measures serve to protect people from radioactive radiation.

But still there were some accidents, as it was at Chernobyl Atom Power Station in Ukraine. The radioactive radiation of that accident has spread over the vast territory.

Text 15 HEAT TRANSFER

Heat is a form of energy transported from one body to another because of a temperature difference. When two bodies at different temperatures are brought into contact, the warmer body will be cooled and the colder body will be warmed. In this case, heat is said to flow from the hot body to the cold body by conduction. The molecules of the hot body, being at a higher temperature, have a higher level of kinetic energy than do the molecules of the cold body. Thus, energy is transferred through the molecules from the hot body to the cold body. The energy being transferred is called heat while it is flowing from the hot body to the cold body. The energy received by the cold body increases its temperature and may be stored in its molecules as an increase in molecular or internal energy.

Heat may also be transferred from one body to another through space by means of radiation. Heat is received from the Sun by any body which is exposed to the rays of the sun. The molecules of any substance at high temperature emit waves of energy which travel through the air with the speed of light. They are known to differ from light waves only in their wave lengths. The radiant energy may be absorbed and reflected by a body upon which it falls. Upon absorption, the radiant energy is stored as molecular energy in the body and a rise of temperature takes place.

Heat may be transferred from one body to another body at a distance from the first one by means of convection. In this case, a fluid is heated or cooled by conduction through contact with one body after which the fluid flows to another place where heat is transferred between moving fluid and the second body. For instance heat is transferred by conduction from the hot metal surface of a stove to a stream of moving air, the temperature of which is increased. The heated air is then transported to a room in which the moving warm air transfers heat by conduction to the objects in the room. When heat is transferred by convection, a fluid transports the energy from one body to another through the movement of the fluid.

Text 16 CONSERVATION OF ENERGY AND MATTER

The Low of Conservation of energy means that no energy can be created or destroyed in any physical effects or transformations.

It has been shown however that matter can be converted into energy of radiation and that therefore the Law of Conservation of energy includes or implies also the conservation of mass.

Einstein has stated the rule for the equivalence of mass m in grams and energy e in ergs. It is e = m (3 x 10¹⁰)²or 1 gram =9 x 10²⁰ ergs. Where 3 x 10¹⁰ is the velocity of light m centimeters per second.

The fact that mass and energy can be changed one into another has given us means to explain the source of the energy radiated by the Sun for untold billions of years. It is from the melting away of the Sun's mass into radiation by degrees. The total energy radiated Tby-4he Sun as Light and Heat is 28 x 10²⁶ x 80*27 x 10⁶ = 2248 x 10³² ergs per minute. To obtain the equivalent in mass we have to divide this last number by 9 x 10²⁰ and we have 250 x 10¹² grams or 250 million tons as the amount of mass of the Sun melting away per minute to maintain the solar radiation.

No one needs be afraid we shall be left out in the cold for fence the mass of the Sun is 18 x 10²⁶ tons the annual loss of mass is a mere insignificant fraction of the whole mass of the Sun.