If a
comet moved in a direct line toward the center of the sun, there would
be no curve to the tail. But taking Donati's comet of 1858 as an
example, the tail of which was said to be about 200,000,000 miles long,
a ray of light traveling at the rate of 192,000 miles per second would
be about twenty minutes in going from the nucleus to the end of the
tail.
But during that time the comet would move in its orbit, say, 50,000
miles, and as light moves in a straight line, and other rays are
constantly emerging from the nucleus as it moves along in its course,
the result is that the tail has a curved appearance.
I have no data at hand regarding this comet, but what I have said will
serve to illustrate my ideas. Again, referring to this comet, I remember
to have read the statement of an astronomer that, after passing round
the sun, a new tail was formed opposite the original one. Now, it seems
to me that that is just what would happen, for in moving round the sun
the comet would travel say 3,000,000 miles; the greater portion of the
tail then, would extend millions of miles upon one side of the sun,
while from the nucleus upon the opposite side of the sun a new tail
would appear to be formed.
Pages:
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171