FIRST YEAR SCIENCE 



another of the stars, it takes light about 180 years to 

 reach us, and from others very much longer. Sometimes 

 from this outer space comets visit our solar system. Thus- 

 we see that our little earth is only a speck in the universe. 

 In the space between the planets Mars and Jupiter, 

 there has been found a group of small bodies which are 

 called planetoids or asteroids. The brighest of these is 

 Vesta, not more than 250 miles in diameter. 



A famous theory, called the Nebular Hypothesis, was 

 suggested many years ago to account for the formation of 



our solar system. This 

 theory supposes that the 

 materials of which the 

 members of the solar 

 system are composed 

 once formed a cloud or 

 nebula of finely divided 

 matter filling an enor- 

 mous space, and that 

 this matter, by reason 

 of the mutual attrac- 

 tion of the particles, 

 gathered together into 

 what is now our sun 

 with its planets and 



their satellites. Man is unable to comprehend how matter 

 originated or how matter can either be created or destroyed. 

 But we do know many of the properties of matter. 



3, Properties of the Matter Composing the Universe. Experi- 

 ment 1. Pull out the handle of a compression air-pump or bicycle 

 pump. Close the exit valve or stop up the end of the bicycle pump. 

 Now try to push in the handle. What keeps it from movrag easily? 

 Try to shove an inverted drinking glass into a pail of water. Why 

 does not the water fill the glass ? 



DIAGRAM OF THE SOLAR SYSTEM. 



Showing roughly the positions of the 



various planets and their moons. 



