WEBVTT

1
00:00:00.720 --> 00:00:06.280
<v Speaker 1>Section twenty three of Sun, Moon and Stars Astronomy for Beginners.

2
00:00:06.759 --> 00:00:10.599
<v Speaker 1>This is a LibriVox recording. All LibriVox recordings are in

3
00:00:10.640 --> 00:00:15.000
<v Speaker 1>the public domain. For more information or to volunteer, please

4
00:00:15.080 --> 00:00:20.839
<v Speaker 1>visit LibriVox dot org. Read by PROJECTA, Sun, Moon and

5
00:00:21.000 --> 00:00:27.719
<v Speaker 1>Stars Astronomy for Beginners by Agnes Gibbon, Chapter two, some

6
00:00:27.800 --> 00:00:32.679
<v Speaker 1>particular sense, The glory of the Lord shall endure forever.

7
00:00:33.399 --> 00:00:37.679
<v Speaker 1>The Lord shall rejoice in his works PSA. One hundred

8
00:00:37.719 --> 00:00:41.600
<v Speaker 1>and four thirty one. In the constellation of the Swan,

9
00:00:41.960 --> 00:00:46.679
<v Speaker 1>there is a little, dim, sixth magnitude star, scarcely to

10
00:00:46.719 --> 00:00:51.479
<v Speaker 1>be seen without a telescope. This star, sixty one Signy

11
00:00:51.640 --> 00:00:55.240
<v Speaker 1>by name, is the first whose distance from us it

12
00:00:55.399 --> 00:00:59.960
<v Speaker 1>was found possible to determine. We may think it's strange

13
00:01:00.200 --> 00:01:03.960
<v Speaker 1>that so faint a star was even attempted. Would not

14
00:01:04.120 --> 00:01:07.920
<v Speaker 1>astronomers have naturally supposed it to be one of the

15
00:01:07.959 --> 00:01:14.000
<v Speaker 1>farther distant stars. No, they did not, For though sixty

16
00:01:14.040 --> 00:01:17.920
<v Speaker 1>one Sidney showed but a dim light, yet his motion,

17
00:01:18.599 --> 00:01:22.319
<v Speaker 1>not the daily apparent motion, but the real motion at

18
00:01:22.359 --> 00:01:25.680
<v Speaker 1>scene from Earth, was found to be so much more

19
00:01:25.799 --> 00:01:29.920
<v Speaker 1>rapid than the motion of most other stars, that they

20
00:01:30.000 --> 00:01:33.640
<v Speaker 1>are rightly guessed sixty one Signey to be a rather

21
00:01:33.799 --> 00:01:38.439
<v Speaker 1>near neighbor of ours. Do not misunderstand me when I

22
00:01:38.560 --> 00:01:42.959
<v Speaker 1>speak of more rapid motion and of rather near neighborhood.

23
00:01:43.519 --> 00:01:47.519
<v Speaker 1>The real rate of sixty one signeys rush through space

24
00:01:47.879 --> 00:01:51.640
<v Speaker 1>is believed to be about thirty six miles each second,

25
00:01:52.239 --> 00:01:55.840
<v Speaker 1>or more than one thousand millions of miles each year.

26
00:01:56.719 --> 00:01:59.879
<v Speaker 1>All we can perceive of this quick motion is that,

27
00:02:00.760 --> 00:02:04.560
<v Speaker 1>in the course of three hundred and fifty years, sixty

28
00:02:04.599 --> 00:02:08.439
<v Speaker 1>one Signey travels over a space in the sky about

29
00:02:08.520 --> 00:02:12.240
<v Speaker 1>as long as the breadth of the full moon, little enough,

30
00:02:12.680 --> 00:02:15.840
<v Speaker 1>yet far beyond that detected in the greater number of

31
00:02:15.960 --> 00:02:19.520
<v Speaker 1>even the brightest stars. Then again, as to the near

32
00:02:19.639 --> 00:02:23.919
<v Speaker 1>neighborhood of this star, sixty one Signy is near enough

33
00:02:23.960 --> 00:02:27.719
<v Speaker 1>to have his distance majored. And that is saying a

34
00:02:27.759 --> 00:02:32.280
<v Speaker 1>good deal. Alpha Century, the nearest star of which we

35
00:02:32.439 --> 00:02:35.800
<v Speaker 1>know in the southern heavens, is more than two hundred

36
00:02:35.840 --> 00:02:40.159
<v Speaker 1>thousand times as far distant as the Sun. But sixty

37
00:02:40.199 --> 00:02:44.360
<v Speaker 1>one Signy, the nearest star of which we know in

38
00:02:44.439 --> 00:02:48.639
<v Speaker 1>the northern heavens, is nearly twice as far, or some

39
00:02:48.800 --> 00:02:53.120
<v Speaker 1>forty billions of miles away. We call sixty one Signey

40
00:02:53.199 --> 00:02:58.319
<v Speaker 1>a star, for so he appears to common observers. In reality,

41
00:02:58.759 --> 00:03:02.319
<v Speaker 1>instead of being only one star, the speck of light

42
00:03:02.520 --> 00:03:07.159
<v Speaker 1>which we call sixty months Signy consists of two stars.

43
00:03:07.800 --> 00:03:11.479
<v Speaker 1>The two are separated by a gap about half as

44
00:03:11.520 --> 00:03:15.680
<v Speaker 1>wide again as the wide gap between the Sun and Neptune.

45
00:03:16.319 --> 00:03:20.599
<v Speaker 1>Yet so great is their distance from us that to

46
00:03:20.680 --> 00:03:24.680
<v Speaker 1>the naked eye the two seem to be one. These

47
00:03:24.719 --> 00:03:28.360
<v Speaker 1>two sons might together make a sun perhaps about one

48
00:03:28.439 --> 00:03:32.879
<v Speaker 1>third as large as Arsun. These two sons might together

49
00:03:33.280 --> 00:03:37.159
<v Speaker 1>make a sun perhaps about one third as large as arsen.

50
00:03:38.400 --> 00:03:42.360
<v Speaker 1>They differ in sides, the quicker movements of one showing

51
00:03:42.439 --> 00:03:45.680
<v Speaker 1>it to be the smaller, and it is by means

52
00:03:45.719 --> 00:03:49.199
<v Speaker 1>of their known distance from one another and their known

53
00:03:49.319 --> 00:03:53.719
<v Speaker 1>rate of motion, that their size, or rather their weight,

54
00:03:54.400 --> 00:03:58.400
<v Speaker 1>can be roughly calculated. Of course, neither of the two

55
00:03:58.439 --> 00:04:03.719
<v Speaker 1>shows any actual major So much and so little is

56
00:04:03.840 --> 00:04:09.800
<v Speaker 1>withit tolerable certainty known about this particular pair of sins. Next,

57
00:04:10.039 --> 00:04:14.560
<v Speaker 1>let's turn to Alpha Centauri, named Alpha the first letter

58
00:04:14.719 --> 00:04:18.600
<v Speaker 1>of the Greek alphabet, because it is the brightest star

59
00:04:18.839 --> 00:04:23.360
<v Speaker 1>in the constellation of the Centaur, the second brightest star

60
00:04:23.560 --> 00:04:28.079
<v Speaker 1>in a constellation is generally called Beta, the third gamma,

61
00:04:28.560 --> 00:04:32.199
<v Speaker 1>the fourth delta, and so on, just as if we

62
00:04:32.199 --> 00:04:36.839
<v Speaker 1>were to name them ABCD in order of brightness. The

63
00:04:36.839 --> 00:04:41.199
<v Speaker 1>constellation Centaur lies in the southern heavens, close to the

64
00:04:41.240 --> 00:04:46.920
<v Speaker 1>beautiful constellation called the Southern Cross, and is invisible in England.

65
00:04:47.600 --> 00:04:51.240
<v Speaker 1>Of all the stars shining in the heavens around our Earth,

66
00:04:52.040 --> 00:04:58.360
<v Speaker 1>two only Sirius and Cannobus show greater brilliancy than Alpha Centaury,

67
00:04:59.399 --> 00:05:03.240
<v Speaker 1>as in the case of sixty one signy. Astronomers were

68
00:05:03.360 --> 00:05:07.959
<v Speaker 1>laid to attempt the measurement of Alpha Centauri's distance by

69
00:05:08.120 --> 00:05:11.160
<v Speaker 1>noticing how much more distinct were.

70
00:05:11.040 --> 00:05:13.839
<v Speaker 2>His movements than the movements of other.

71
00:05:13.800 --> 00:05:17.600
<v Speaker 1>Stars, though less rapid both to the eye and in

72
00:05:17.720 --> 00:05:22.519
<v Speaker 1>reality than those of sixty one signy. The distance of

73
00:05:22.639 --> 00:05:26.800
<v Speaker 1>Alpha Centaury from Us is more than two hundred thousand

74
00:05:26.839 --> 00:05:31.199
<v Speaker 1>times the distance of the Sun, or about twenty millions

75
00:05:31.240 --> 00:05:35.959
<v Speaker 1>of millions of miles. In other words, light traveling at

76
00:05:35.959 --> 00:05:39.439
<v Speaker 1>the rate of one eighty six thousand, three hundred miles

77
00:05:39.519 --> 00:05:43.920
<v Speaker 1>each second, takes four years to journey from Alpha Centaury

78
00:05:44.120 --> 00:05:47.439
<v Speaker 1>to Earth, and this, so far as we yet know,

79
00:05:48.079 --> 00:05:51.839
<v Speaker 1>is our Sun's nearest neighbor. In the heavens outside his

80
00:05:52.000 --> 00:05:56.920
<v Speaker 1>own family circle, Alpha Centaury, like sixty one signy, is

81
00:05:57.040 --> 00:06:00.759
<v Speaker 1>found to consist not of a single star, but of

82
00:06:00.920 --> 00:06:04.319
<v Speaker 1>a pair of stars. It is a two sun system.

83
00:06:04.480 --> 00:06:08.480
<v Speaker 1>Whether or no surrounded by planets cannot be told. The

84
00:06:08.560 --> 00:06:12.720
<v Speaker 1>two sons of the Alpha Centaury double star are separated

85
00:06:12.839 --> 00:06:16.399
<v Speaker 1>by a distance about twenty two times as great as

86
00:06:16.439 --> 00:06:19.759
<v Speaker 1>the distance of the Earth from the Sun. Yet to

87
00:06:19.839 --> 00:06:24.199
<v Speaker 1>the naked eye they show as a single star. Here again,

88
00:06:24.279 --> 00:06:28.160
<v Speaker 1>one is much smaller than the other, and the smaller

89
00:06:28.360 --> 00:06:32.680
<v Speaker 1>revolves round the larger in about eighty five years. It

90
00:06:32.800 --> 00:06:36.439
<v Speaker 1>is supposed that the two together might form a sun

91
00:06:37.000 --> 00:06:42.040
<v Speaker 1>considerably larger and heavier than our Sun. This belief is

92
00:06:42.160 --> 00:06:47.480
<v Speaker 1>trendant by the great brilliancy of Alpha Centauri. Our own Sun,

93
00:06:48.000 --> 00:06:52.360
<v Speaker 1>placed at that distance from us, would shine only about

94
00:06:52.399 --> 00:06:56.519
<v Speaker 1>one third as brightly as he does. Turning now from

95
00:06:56.560 --> 00:07:00.439
<v Speaker 1>the Sun whose distance was first majored, and from the

96
00:07:00.519 --> 00:07:05.160
<v Speaker 1>nearest star with which we are acquainted, let's think about

97
00:07:05.199 --> 00:07:09.839
<v Speaker 1>the most radiant star in the heavens, Serious, the bleazing

98
00:07:09.959 --> 00:07:14.959
<v Speaker 1>talk star of the ancients, named by one astronomer, the

99
00:07:15.079 --> 00:07:20.319
<v Speaker 1>King of Sins. First, as to the color of Serious,

100
00:07:20.439 --> 00:07:23.879
<v Speaker 1>he belongs to the order of white sons. And among

101
00:07:23.959 --> 00:07:28.279
<v Speaker 1>all the white sons known to us, Serious ranks as chief.

102
00:07:29.240 --> 00:07:33.360
<v Speaker 1>There may be many at greater distances, far surpassing him

103
00:07:33.480 --> 00:07:38.439
<v Speaker 1>in size and weight and brilliancy. But we can only

104
00:07:38.519 --> 00:07:42.800
<v Speaker 1>speak so far as we know. One ancient writer spoke

105
00:07:42.920 --> 00:07:46.800
<v Speaker 1>of Serious as a raid in you. Others followed suit,

106
00:07:47.279 --> 00:07:53.040
<v Speaker 1>but the original epithet was probably a copyist's mystic. It is,

107
00:07:53.199 --> 00:07:57.839
<v Speaker 1>at all events not to be depended on. Secondly, as

108
00:07:57.879 --> 00:08:02.079
<v Speaker 1>to the distance of Serious, like a few other stars,

109
00:08:02.360 --> 00:08:05.399
<v Speaker 1>Serious lies not quite so far away as to be

110
00:08:05.399 --> 00:08:10.040
<v Speaker 1>beyond reach of measurement. No baseline upon Earth would cause

111
00:08:10.120 --> 00:08:14.959
<v Speaker 1>the slightest seeming change of position in him. But as

112
00:08:15.040 --> 00:08:18.199
<v Speaker 1>our Earth journeys round the Sun, the line from one

113
00:08:18.240 --> 00:08:21.879
<v Speaker 1>side of her orbit to the other is found wide

114
00:08:22.000 --> 00:08:26.240
<v Speaker 1>enough a baseline of one hundred and eighty five millions

115
00:08:26.240 --> 00:08:31.160
<v Speaker 1>of miles does cause just a tiny seeming change. It

116
00:08:31.319 --> 00:08:35.480
<v Speaker 1>is very little even with alpha centaury, and with Serious

117
00:08:35.600 --> 00:08:39.480
<v Speaker 1>it is much less. The displacement of Serious is so

118
00:08:39.559 --> 00:08:44.240
<v Speaker 1>slight that to measure his distance with exactness is impossible.

119
00:08:45.120 --> 00:08:49.639
<v Speaker 1>Roughly calculated, Serious lies at a distance of about fifty

120
00:08:49.720 --> 00:08:54.919
<v Speaker 1>billions of miles Arson at the distance of Sirius would

121
00:08:55.000 --> 00:08:59.600
<v Speaker 1>shine merely as a star of the third magnitude. Light

122
00:09:00.120 --> 00:09:03.399
<v Speaker 1>which reaches us from the Sun in nearly nine minutes

123
00:09:03.919 --> 00:09:07.200
<v Speaker 1>and from Alpha Santauri in four years and one third,

124
00:09:07.919 --> 00:09:10.879
<v Speaker 1>cannot reach us from Serious in much less.

125
00:09:10.639 --> 00:09:11.720
<v Speaker 2>Than twenty years.

126
00:09:12.559 --> 00:09:16.840
<v Speaker 1>Thirdly, as to the size of Serious, here, of course,

127
00:09:16.960 --> 00:09:21.679
<v Speaker 1>we are in difficulties. Radiantly as Serious shines on a

128
00:09:21.720 --> 00:09:26.200
<v Speaker 1>clear night, and dazzling as he looks through a powerful telescope,

129
00:09:26.600 --> 00:09:30.080
<v Speaker 1>he shows no real disc or round surface.

130
00:09:29.799 --> 00:09:31.320
<v Speaker 2>Capable of being majured.

131
00:09:32.039 --> 00:09:35.919
<v Speaker 1>But although we cannot measure his size, we do know

132
00:09:36.080 --> 00:09:40.919
<v Speaker 1>something of his weight and of his extraordinary brilliance. The

133
00:09:40.919 --> 00:09:44.759
<v Speaker 1>brightness of Serious is so much greater than the brightness

134
00:09:44.840 --> 00:09:48.480
<v Speaker 1>of our Sun would be at that same distance that

135
00:09:49.120 --> 00:09:52.320
<v Speaker 1>it certainly seems to point to the fact of Serious

136
00:09:52.519 --> 00:09:55.919
<v Speaker 1>being very much the larger Sun of the two. The

137
00:09:55.960 --> 00:09:59.720
<v Speaker 1>only reliable method by which a star's probable weight can

138
00:09:59.759 --> 00:10:03.600
<v Speaker 1>be calculated each through the discovery of a companion to

139
00:10:03.639 --> 00:10:08.000
<v Speaker 1>the star and a knowledge of their relative distances, their

140
00:10:08.120 --> 00:10:12.360
<v Speaker 1>times of revolution, and the speed of either. For a

141
00:10:12.399 --> 00:10:16.960
<v Speaker 1>long while, since Sirius was not known to possess a companion,

142
00:10:17.320 --> 00:10:21.320
<v Speaker 1>this mode of computation could not be followed like other

143
00:10:21.480 --> 00:10:25.799
<v Speaker 1>sans Sirius has his proper motion, as it is called,

144
00:10:26.320 --> 00:10:29.919
<v Speaker 1>an outward world through space of more than one thousand

145
00:10:30.039 --> 00:10:36.879
<v Speaker 1>miles each minute, sometimes more, sometimes less. Mysterious irregularities in

146
00:10:36.960 --> 00:10:40.720
<v Speaker 1>the pace of Sirius were noted as long ago as

147
00:10:40.759 --> 00:10:45.200
<v Speaker 1>the year eighteen forty four, and by dint of careful thought,

148
00:10:45.639 --> 00:10:49.720
<v Speaker 1>a decision was reached that some large, disturbing orb must

149
00:10:49.879 --> 00:10:54.320
<v Speaker 1>surely belong to Sirious and revolve round him, a body

150
00:10:54.639 --> 00:10:58.720
<v Speaker 1>large enough and near enough to exercise a disturbing influence

151
00:10:59.159 --> 00:11:04.440
<v Speaker 1>over the greats now, hastening him on now pulling him back,

152
00:11:04.799 --> 00:11:08.679
<v Speaker 1>even as Jupiter and Saturn by turns hurry and delay

153
00:11:08.720 --> 00:11:13.679
<v Speaker 1>one another. There the matter rested during fully eighteen years.

154
00:11:14.000 --> 00:11:17.799
<v Speaker 1>Then one night the dim gleam of this companion was

155
00:11:17.840 --> 00:11:22.240
<v Speaker 1>actually seen, and having been once discovered, it was perceived

156
00:11:22.399 --> 00:11:26.360
<v Speaker 1>again and again. So the truth of the surmise reached

157
00:11:26.519 --> 00:11:31.039
<v Speaker 1>nearly twenty years earlier. Through simple exercise of reasoning power

158
00:11:31.320 --> 00:11:36.559
<v Speaker 1>was proved beyond question. Although this faintly shining second star

159
00:11:36.919 --> 00:11:40.919
<v Speaker 1>is so near to Sirius as greatly to affect the

160
00:11:41.039 --> 00:11:45.960
<v Speaker 1>movements of the latter, disturbing his regularity of speed to

161
00:11:46.000 --> 00:11:50.679
<v Speaker 1>an extent which could be noted forty billions of miles away.

162
00:11:51.399 --> 00:11:56.279
<v Speaker 1>Yet the distance between Serious and his companion is somewhere

163
00:11:56.399 --> 00:12:00.480
<v Speaker 1>about thirty seven times as great as our Earth's distance

164
00:12:00.600 --> 00:12:04.240
<v Speaker 1>from the Sun. The dim companion appears to be in

165
00:12:04.320 --> 00:12:08.240
<v Speaker 1>weight about equal to our sen while the bright star

166
00:12:08.559 --> 00:12:13.600
<v Speaker 1>Sirius is not much more than twice as heavy weight. However,

167
00:12:13.799 --> 00:12:18.279
<v Speaker 1>tells little as to size. The blazing radiance of Serious

168
00:12:18.639 --> 00:12:24.279
<v Speaker 1>is extraordinarily compared with the dimness of his companions. Probably

169
00:12:24.360 --> 00:12:28.919
<v Speaker 1>the latter is far cooler and consequently far denser and

170
00:12:29.080 --> 00:12:33.360
<v Speaker 1>smaller in make, while the dazzling Serious has doubtless a

171
00:12:33.399 --> 00:12:38.600
<v Speaker 1>photosphere of incandescent gases and glowing molten clouds like to

172
00:12:38.639 --> 00:12:42.919
<v Speaker 1>that of Arsun, but greatly exceeding it, either in size

173
00:12:43.120 --> 00:12:48.159
<v Speaker 1>or in actual brilliance, or probably in both. Fortunately, as

174
00:12:48.200 --> 00:12:52.240
<v Speaker 1>to the motions of Sirius, already touched upon, it was

175
00:12:52.360 --> 00:12:56.120
<v Speaker 1>long possible only to observe the movements of a star

176
00:12:56.679 --> 00:13:01.080
<v Speaker 1>when he journeyed sideways across the sky. A star coming

177
00:13:01.120 --> 00:13:05.480
<v Speaker 1>directly towards us, or passing straight away from us would

178
00:13:05.559 --> 00:13:10.639
<v Speaker 1>always appear to be at rest. Now, however, by means

179
00:13:10.639 --> 00:13:14.799
<v Speaker 1>of the spectroscope, it has become possible to perceive and

180
00:13:14.919 --> 00:13:19.159
<v Speaker 1>measure the aid on motions of stars to and from

181
00:13:19.279 --> 00:13:24.600
<v Speaker 1>our solar system, as well as their sideway journings. The

182
00:13:24.720 --> 00:13:29.360
<v Speaker 1>sideway motion of Syrias had been discovered before, but it

183
00:13:29.480 --> 00:13:33.840
<v Speaker 1>now appears that he does not move exactly sideways. He

184
00:13:33.960 --> 00:13:37.840
<v Speaker 1>rushes away in a slanting direction at the rate of

185
00:13:37.960 --> 00:13:42.039
<v Speaker 1>over one thousand millions of miles each year. Think how

186
00:13:42.080 --> 00:13:46.399
<v Speaker 1>many millions upon millions of millions of miles he must

187
00:13:46.440 --> 00:13:50.000
<v Speaker 1>now be farther off from us than in the years

188
00:13:50.039 --> 00:13:54.720
<v Speaker 1>of the engine. Yet he shines on with undeemed radiance,

189
00:13:55.240 --> 00:13:59.320
<v Speaker 1>still the most brilliant star in our sky. So small

190
00:13:59.360 --> 00:14:02.799
<v Speaker 1>a matter are all those millions compared with the sum

191
00:14:02.919 --> 00:14:07.360
<v Speaker 1>of his vast distance from Earth. It is an interesting

192
00:14:07.480 --> 00:14:11.279
<v Speaker 1>fact that while Sirius is moving away from us, we

193
00:14:11.399 --> 00:14:15.440
<v Speaker 1>are also moving away from him. Our first station ahead,

194
00:14:16.000 --> 00:14:21.080
<v Speaker 1>which seems to lie in or near the constellation of Hercules,

195
00:14:21.240 --> 00:14:23.879
<v Speaker 1>stands just in the opposite direction.

196
00:14:23.720 --> 00:14:25.240
<v Speaker 2>From the goal of Serious.

197
00:14:26.399 --> 00:14:30.919
<v Speaker 1>Fifthly has Serious a family or a system of worlds

198
00:14:31.080 --> 00:14:31.720
<v Speaker 1>like Arson?

199
00:14:32.519 --> 00:14:34.080
<v Speaker 2>He may have or he may not.

200
00:14:34.919 --> 00:14:39.039
<v Speaker 1>One companion he does possess in the shape of a companion,

201
00:14:39.159 --> 00:14:44.039
<v Speaker 1>Sin greatly inferior to himself in Leicester. Whether those two

202
00:14:44.080 --> 00:14:48.240
<v Speaker 1>sons possess a family of revolving words, we have no

203
00:14:48.399 --> 00:14:52.840
<v Speaker 1>power to see. If one asks why not, no reason

204
00:14:53.000 --> 00:14:56.519
<v Speaker 1>to the contrary can be given. But to say that

205
00:14:56.600 --> 00:14:59.840
<v Speaker 1>a thing maybe is not to say that it is.

206
00:15:00.559 --> 00:15:03.919
<v Speaker 1>Any star in the heavens may have such a family,

207
00:15:04.480 --> 00:15:08.399
<v Speaker 1>and any star may pursue his lonely path without an

208
00:15:08.480 --> 00:15:12.840
<v Speaker 1>attendant near when we do not and cannot know, it

209
00:15:12.919 --> 00:15:14.960
<v Speaker 1>is worse than useless.

210
00:15:14.440 --> 00:15:15.240
<v Speaker 2>To be positive.

211
00:15:15.759 --> 00:15:20.240
<v Speaker 1>Still, the discovery, after long ages of this diem huge

212
00:15:20.320 --> 00:15:24.480
<v Speaker 1>companion too serious, And the knowledge that a very slight

213
00:15:24.759 --> 00:15:30.399
<v Speaker 1>further increase of deemness or decrease rather of shining, would

214
00:15:30.440 --> 00:15:35.799
<v Speaker 1>have made that companion absolutely undiscoverable by us is.

215
00:15:35.720 --> 00:15:37.039
<v Speaker 2>Full of significance.

216
00:15:37.840 --> 00:15:42.679
<v Speaker 1>Even a faint star at that distance can barely be detected,

217
00:15:43.320 --> 00:15:47.799
<v Speaker 1>and a planet shining by borrowed light could not possibly

218
00:15:47.919 --> 00:15:54.120
<v Speaker 1>become visible. Such bodies may exist in countless billions throughout space,

219
00:15:54.759 --> 00:15:58.240
<v Speaker 1>where we see only the glimmer of a more radiant

220
00:15:58.240 --> 00:16:03.200
<v Speaker 1>sun dotting here, and they're the vast expanse. The mere

221
00:16:03.320 --> 00:16:09.639
<v Speaker 1>possibilities thus opened out to imagination are almost appalling. Lastly,

222
00:16:10.120 --> 00:16:14.440
<v Speaker 1>what is serious made of. Here again the spectroscope comes

223
00:16:14.480 --> 00:16:19.399
<v Speaker 1>to our aid. Before the discovery of spectrum analysis and

224
00:16:19.559 --> 00:16:24.480
<v Speaker 1>its application to astronomy, astronomers can scarcely be said to

225
00:16:24.559 --> 00:16:29.120
<v Speaker 1>have known with certainty that stars versons, and of the

226
00:16:29.159 --> 00:16:33.240
<v Speaker 1>composition of those stars, nay even of our own sin.

227
00:16:33.679 --> 00:16:37.480
<v Speaker 2>They were in ignorance. Now we have learned much.

228
00:16:37.799 --> 00:16:42.000
<v Speaker 1>Now the spectroscope, by breaking up and analyzing the slender

229
00:16:42.120 --> 00:16:47.639
<v Speaker 1>ray of light which travers earthword from each star, has

230
00:16:47.720 --> 00:16:50.960
<v Speaker 1>shown us something of the true nature of those far

231
00:16:51.039 --> 00:16:54.519
<v Speaker 1>off lamps of Heaven. Now I know that most of

232
00:16:54.600 --> 00:16:58.240
<v Speaker 1>the stars, not all of them, are like our sin,

233
00:16:58.679 --> 00:17:02.480
<v Speaker 1>great radiating machine for the giving fourth of light and

234
00:17:02.600 --> 00:17:03.600
<v Speaker 1>heat and power.

235
00:17:04.559 --> 00:17:05.279
<v Speaker 2>Like Arsen.

236
00:17:05.799 --> 00:17:10.240
<v Speaker 1>Each is surrounded by a brilliant photosphere formed in a

237
00:17:10.279 --> 00:17:15.359
<v Speaker 1>fairy atmosphere of heated and glowing gases in the white

238
00:17:15.359 --> 00:17:20.279
<v Speaker 1>sense of which serious is king and chi. While sodium,

239
00:17:20.359 --> 00:17:24.960
<v Speaker 1>magnesium and other metals do more or less exist, the

240
00:17:25.000 --> 00:17:29.759
<v Speaker 1>principal component of this dazzling envelope is found to be

241
00:17:29.839 --> 00:17:35.359
<v Speaker 1>incandescent hydrogen. Arsen belongs not to the first or Syrian

242
00:17:35.400 --> 00:17:39.440
<v Speaker 1>class of white sens, but to the second or solar

243
00:17:39.519 --> 00:17:43.720
<v Speaker 1>type of golden suns. In them, though hydrogen is abundant,

244
00:17:44.200 --> 00:17:49.480
<v Speaker 1>it is not so absolutely prominent. End of Section twenty

245
00:17:49.519 --> 00:17:53.640
<v Speaker 1>three