Concerning the Nature of ThingsHarper & Brothers, 1925 - 249 páginas |
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alloy aluminium angle argon arrangement atoms and molecules attraction balls bismuth body bubbles C. V. Boys carbon atoms cementite centimetre centre chemist chlorine contains copper crystalline Cullinan diamond curious diamond drop edge effect electricity electrons example experiment explain fact figure film forces gases give glass Gramophone needles H H H happens heat helium atom hexagonal hydrogen atoms iron layer lecture length light liquid air Lord Rayleigh Lucretius magnets matter ment mercury metal motion move movement naphthalene nature neighbours nitrogen nucleus observe outer oxygen packing paraffin particles pentane piece plane positive pressure prism properties pull quartz radium realise reflection ring round shape shown in Plate shows side slip soap sodium solid space speed stationary set structure substance suppose surface things track tube unit of pattern vessel water molecules waves whole X-rays
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Página 15 - what is the cause BSi of fluidness ? This I conceive to be nothing; else but a certain pulse or shake of heat ; for, heat being nothing else but a very brisk and vehement agitation of the parts of a body (as I have elsewhere made probable), the parts of a body are thereby made so loose from one another that they easily move any way and become fluid. That I may explain this a little by a gross similitude, let us suppose a dish of sand set upon some body that is very much agitated and shaken with...
Página 45 - We have to go a step further, and see how, at very slow speeds of approach, they may actually stick together. We have all seen those swinging gates which when their swing is considerable, go to and fro without locking. When the swing has declined, however, the latch suddenly drops into its place, the gate is held and after a short rattle the motion is all over. We have to explain an effect something like that. When the two atoms meet, the repulsions of their electron shells usually cause them to...
Página 42 - In each there is a nucleus which is positively charged; round the nucleus are electrons which are units of negative electricity. The positive charge of the nucleus is a multiple of a certain unit charge, equal to the charge on the electron, but of opposite sign. The number of electrons which every atom possesses under normal conditions is an exact balance to the positive charge on the nucleus, so that the atom as a whole is not charged; its positive and negative charges balance. Whether or no the...
Página 16 - ... twere) sinks to the bottom. Nor can ye make a hole in the side of the dish, but the sand shall run out of it to a level. Not an obvious property of a fluid body, as such, but this does imitate; and all this merely caused by the vehement agitation of the...
Página 15 - Nor can you bury a light body, as a piece of cork, under it but it presently emerges or swims as 'twere on the top ; nor can you lay a heavier on the top of it, as a piece of lead, but it is immediately buried in sand, and (as 'twere) sinks to the bottom. Nor can you make a hole in the side of the dish but the sand shall run out of it to a level.
Página 15 - ... very violently whilst it is empty; or on a very stiff drum-head, which is vehemently or very nimbly beaten with the drumsticks. By this means the sand in the dish, which before lay like a dull and unactive body, becomes a perfect fluid ; and ye can no sooner make a hole in it with your finger, but it is immediately filled up again, and the upper surface of it levell'd.
Página 45 - ... When the two atoms meet, the repulsions of their electron shells usually cause them to recoil; but if the motion is small, and the atoms spend a longer time in each other's neighbourhood, there is time for something to happen in the internal arrangements of both atoms, like the drop of the latch-gate into its socket, and the atoms are held. It all depends on some structure of the atom which causes a want of uniformity over its surface, so that there is usually a repulsion; but the repulsion will...
Página 45 - We have seen how it can happen that when two atoms approach each other at great speeds they go through one another, while at moderate speeds they bound off each other like two billiard balls. We have to go a step further, and see how, at very slow speeds of approach, they may actually stick together. We have all seen those swinging gates which, when their swing is considerable, go to and fro without locking. When the swing has declined, however, the latch suddenly drops into its place, the gate is...
Página 133 - X rays has increased our keenness of vision ten thousand times, and we can now see the individual atoms and molecules.
Página 1 - Nearly two thousand years ago, Lucretius, the famous Latin poet, wrote his treatise De rerum natura - concerning the nature of things. He maintained the view that air and earth and water and everything else were composed of innumerable small bodies or corpuscles, individually too small to be seen, and all in rapid motion. He tried to show that these suppositions were enough to explain the properties of material things. He was not himself the originator of all the ideas which he set forth in his poem;...