VI . LIGHT, MOTION, SPACE, AND ATTRACTION
Light
Light comes to us in the form of waves. Its rate is 186,330 miles a second.
These waves are motion in the ether
*, of which, in general view all space is full.
Without ether no account is possible of light -- or of some other things.
On making the light which we get go through a
prism1, it is broken up into
the colors : red, orange, yellow, green, blue, dark blue. The different colors are
caused by the fact that the different ether
waves are not equally long, the red being
the longest waves and the dark-blue the
shortest.
But on looking with attention we see
not only the colours, but dark lines in
them. These lines are caused by the
different substances which are sending
out the light rays, every substance having
its separate special lines.
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But this is not all. lf the star is moving
in our direction, the lines are seen moved
in the direction of the dark-blue end of the
colour band; if the star is moving away
they are seen in a position nearer the left
or red end of the band of colours.
The reason for the change of position is
that, when the star is moving in our direction,
we are meeting the waves and making
them shorter, in this way moving the
colour band with the lines to the blue end.
In the same way they are moved to the
red end, because the waves are made
longer, when the star is going away.
We are able to get a true measure of the
change of position of the lines, and this
gives the rates of motion of the stars in
our direction or away from us.
In this way we are not only able to say
which stars are moving in our direction
and which stars away from us, but even
to give their rate of motion.
This is quite in order when we get rates
of motion by this process which are in
agreement with the knowledge we have
got of star motions by other ways. That
is, when the amount of the motions may
go up to 200 or 300 miles a second.
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We will have something to say later
about star-clouds, which are masses of
stars or of star-dust, at very great distances,
hundreds of thousands of light-years away from us.
Some of these star-clouds, on having
their motion measured by the change in
position of their lines, give such values
that they seem to be going away from us
at thousands of miles a second.
Such a great motion is quite a new idea
and does not seem possible. It would
certainly be in need of very strong support
before we had any right to put it forward
as a certain fact.
But that is what is done, on no other
facts than this observation, by certain men
in authority like Professor Eddington,
who is a great supporter of the Theory of
Relativity. On that theory, however,
the rate of motion of light, about 186,300
miles a second, is the limit, and no motion
anywhere in space is greater.
How do these great men get over these
opposite statements made by them ?
1. The motion of light is the quickest ;
there is no greater.
2. The motion of the star-clouds is
greater.
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They might have said : No. Such a
rate of motion is impossible. Our knowledge
is not complete. We have no idea
of the conditions of substance in these
far-off star-clouds or star-masses, whose
feeble light takes hundreds of thousands
of years to get to us, or of what there
is in the space between us, or what other
conditions, of the ether for example,
which are quite new to us, may be in
operation, specially because when the
distance of the star-cloud (that is the
stretch of ether between it and us) is
greater, we see that the change of position
of the lines is increased.
In place of this they say, "Nothing"
(with a great ‘N’) " is stretching itself
out into a greater Nothing. It is able to
do so because it is nothing, and for that
reason does not come under the law of
relativity which we gave out as fixed and
certain a short time back, and which says
that the motion of light is the quickest
motion possible."
We have here an example of a strange
quality of man which makes him have a
desire to give out the law and the reason
for all things, without waiting for the
future and its additions to knowledge.
That is why his opinions are so frequently
laughed at later.
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And to give up, in this way, a statement
made a little earlier as to this limit by
by which everything is ruled, will not do
credit to astronomy.
From the lines of the substances in the
band of light from the stars, we see, in
addition, the surprising fact that the
greater number of the substances in the
stars are the same as the substances on
the Earth.
From this we are conscious that the
far-off suns are made up of the same
substances, and are ruled by the same
laws, as our Sun, and our Earth.
Motion, Space, and Attraction
In another part of this book, the
suggestion was made that Newton’s first law of
motion was not a law at all. It says that
motion of a body in space will go on for
ever in a straight line, if there is nothing
by which it is made slower or turned.
There are in this two statements :
1 . That the body will keep on moving
for ever at the same rate ;
2 . That it will
at all times be moving in a straight line.
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The fact that the motion keeps on is
dependent on stored-up energy, This
is clear, because, if the body is suddenly
stopped, the stored-up energy is turned
into heat.
Now, when talking of stored-up energy
in connection with electric forces, we have
a clear idea of the way in which it is
stored ; that is, by certain electrons taken
up in forming a special substance, which
are let loose when the substance is broken
up, giving an electric current.
When we make use of the words ‘ stored
energy ’ about heat, what we have in mind
is that the substance is in a condition
of very quick inner motion, giving ether
waves of a certain size (heat).
But it does not seem that anyone has
ever put the clearly necessary question:
In what form is the energy stored in the
body in motion ?
The great name of Sir Isaac Newton
has in some measure been responsible for
the fact that the need for looking into
this question has not been given any
attention. In fact, no one has seen that
there is such a question.
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The fact that we have so little knowledge
is covered up by our use, in a number
of languages, of a very high-sounding
name, ' the inertia of motion ', after which
we are no wiser than we were before.
Is any suggestion possible as to the way
in which the energy is stored? Possibly
some help may be got from the fact that
the force of motion (mass motion) is
changed into heat waves or motion of the
ether when stopped. It seems from this
that when motion is given to a body the
electrons or other smaller parts of which
it is made up go rolling or turning in the
ether, or pushing their way through the
ether and being pushed on by it, and that
when the ether is unable to keep on the
turning or pushing effect it lets off its
power in waves ; that is, heat.
The sense of such a statement is strange.
It is that space by itself has no existence ;
that in place of the words " space
full of ether " the right thing to say
would be simply " the ether ". Without
ether there is no motion. Would there
be distance ? To the writer it seems that
there would not. Distance is a stretch of
ether. The ether is the same sort of
thing, off the Earth, as the road on which
we go to any place on the Earth. It
gives the stones and mile-stones of which
that road is made up. Without it there
is no road.
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In addition, by this idea of the
connection of motion with the ether, the way
would be pointed for a clear account of
the Law of Attraction and its cause, by
which possibly the two forces viewed up
to now as opposite, the straight line
motion and the curved motion put down
to attraction, would be seen to be not two
separate things, but one only, a condition
of the ether.
There are strange theories now current
as to the form of space. To give an
example, it is said there is no reason why
space is limited to three-way space, long,
wide, and deep. There may be a fourth
measure, or even more. As an example
they give us this picture: Beings living
in a flat space which might only be
measured in two ways would say that
the idea of a three-way space (that is the
space in which we are living) is foolish,
because their minds would be unable to
get any picture of it. For that reason
we have to take care not to say that space
is limited to that of which we have knowledge.
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There is an error in this argument, but
it is covered up with great care ; it is that
the first step we have to take, of picturing
beings limited to moving in a two-way
space, is
itself not possible for our minds.
We are unable to have any idea of any
space which has not a third way, however
small. So that the argument is broken
down from the start.
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VII . THE FIXED STARS
The reader will, no doubt, be conscious of the fact that our Sun, with all his
planets, is only a star, and not even a very great one. Every one of the little points of
light in the night sky (other than the planets, is a sun, some of them far greater than ours.
The fact that they are seen only as points is the effect of their great distance
from us in space. The nearest is Proxima Centauri, in the Star-group of Centaurus.
Its distance is such that light, moving at
186,300 miles a second, takes about 3 years
and 7½ months to get to us. An idea of this
distance may be got by pointing out that
to get to the Sun from Pluto, the outer-
most planet, with its great distance of
3,700,000,000 miles, light takes about five
hours, and from the Sun to the Earth
498 seconds.
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The distances of about 1000 stars have
been measured, though naturally they
are not so certain as those of the planets.
This is done by angle measure in the same
way as was made clear in the account of
how our distance from the Sun is worked
out (see p. 42), but this time we have a
great base-line of 186,000,000 miles. The
position of the star is measured when we
are at two opposite points of our journey
round the Sun. But so great are the distances
that even with this far-stretching
base-line the angle is only ‘89 seconds for
the nearest star.
How small this is will be made clear by
the statement that it is equal to the angle
of a penny (which is one inch wide),
viewed from a distance of 6439 yards! And
this is the very nearest of the stars. One
of the farthest among the stars, numbering
about 100, the distances of which have
been measured up to now, is the great
Aldebaran, in the Star-group of Taurus,
which is about 54 light-years away.
1
Every one has seen the great Star-groups,
Ursa Major, Orion, and so on,
specially Orion, with its beautiful and
very bright stars stretching out over
a wide space in the sky, with the great
stars Rigel, Bételgeuse, and so on, having
a strange and deeply moving effect on the
mind, for which there is every reason,
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because these stars are, in size and power
of light and heat, among the greatest to
be seen in the sky and far greater than our
Sun. Some of the stars are so much
greater than the Sun that if we take
Bételgeuse, for example (in the Star-group
of Orion), we see that, though it is twelve
times farther away than the brightest of
all stars, Sirius, it is the second brightest
star. Bételgeuse is so great that the Sun,
with the Earth, might be placed inside
it, and the Earth would still have enough
room to make its journey round the Sun.
The stars are not truly fixed, but their
motion seems so small, because of their
distance, that present-day instruments
were needed for measuring it, and to the
eye of man they seemed fixed for thousands
of years. The star having the
quickest motion is a star in the group
Ophiuchus, which has a motion of more
than 10 seconds of angle every year. But
all the stars have some motion.
We see from this that, millions of years
back, in the young days of the Earth, the
sky seemed quite different, the Earth
being in quite a different part of the Star
system ; and if, as someone says, the wide
eyes of the great animals of the past had
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been able in death to keep a record of
their last view of the stars
1, we would
see groups completely outside our knowledge,
stars quite strange to us which have
now gone on their way into the great
deeps of space, and which the eyes of
man will not ever see. In the same way,
when the last son of man takes his last
look out on the Star-groups before falling
into his last sleep, the groups now before
our eyes will have gone for ever, every
star journeying to an end outside our
knowledge.
Great though the distance of the stars
is, we see that they are quite near to us
in comparison with other distances when
we go a little farther. Because it seems
that they, and we, are a part of that river
of light feebly seen on a clear night,
which is named the Galaxy. The soft
mist of the Galaxy is broken up, in the
telescope, into thousands of stars. The
only reason why we do not see them
separately is their very great distance.
There is no reason for doubting that, if
we were nearer, they would seem to be of
the same size and quality as the near
stars. It is our Star System, the Star-cloud
of which our Sun is one.
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But this is not all. As was said when
talking of the ‘ stretching ’ of space, here
and there in the sky we see through the
telescope other Galaxies or Star-clouds,
but at such distance in space that light
takes thousands of years to get to us.
Some of these star-clouds give the light
of stars, so that it seems certain that they
are other star systems like our Galaxy,
made up of thousands of stars. Others are
seen not to be star-clouds but are truly a
sort of thin mist, which even a telescope
of the very greatest power is unable
to do anything with. They give out a
feeble light, and, though stretched over
only a small part of our sky, their distance
is such, being numbered by thousands of
light years, that they would from a nearer
point, be seen to take up as much space
as a galaxy, and will no doubt undergo
development one day into millions of
stars. These new star systems in process
of birth are the places, possibly, where l
energy coming from all other parts of
space, is again changed into substance, so
that the great circle of changes may be
started again.
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Farther and Farther
Most of the stars whose distances have
been measured are less than two hundred
years journey, of light away from us.
These are, as one might say, quite near
to us. But what of the much greater
number which are at far greater distances ?
Are we able to get any knowledge as to
how far away they are ? Till quite a short
time back the answer to this question
seemed to be
No. There seemed to be no
process by which a measuring line might
be stretched across the great space between.
The knowledge seemed to be
shut off from us for ever. Then, suddenly,
as so frequently before in the history
of science, to our surprise the key to a new
door was seen to be in our hands, giving up
to us one more secret of the sky.
The knowledge came through certain
“ changing stars," that is, stars which are
not equally bright all the time, but become
regularly brighter or darker. These had
been under observation for a long time.
There were some in which the change
seemed to be accounted for by the theory
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that a great dark body, going round the
star as the Earth does round the Sun, took
away some of its light for a short time. A
planet, possibly, which we would not ever
be able to see. It was as if a voice came
to us suddenly from the far-off deeps of
space, saying " Though it is not given to
you to see us, to all you who have
come to knowledge in the wide-stretched
skies we send word that we are here."
One of these stars in which a change is
caused by a dark circling body is Algol,
the second brightest star in the star-group
of Perseus (between the Star-groups of
Taurus and Cassiopaeia) which is bright
for 2 days and 12 hours, then becomes
darker for 4½ hours, gets brighter again in
the 4½ hours after that, and then keeps
fully bright for 2 days and 12 hours again,
and so on. These changes are quite in
agreement with the theory that a great
body, a planet or dead sun, goes round
Algol.
But there are other changing stars in
addition. Such is Delta Cephei, the fourth
brightest star in the star-group of Cepheus
(a star-group high up in the North), which
goes through a complete circle in 5¼ days,
getting darker for 1¼ days and brighter
for 4 days. Stars of this sort are taken to
be masses of substance in gas form under-going
expansion and then again getting
smaller, at regular times.
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A number of these changing stars were
seen in the sky, completing their changes
in times up to 60 days. Some of them
were clearly very near to one another, because
they were in the same star-mist.
From these it was seen that there was a
fixed relation between the amount of light
they sent out and the time in which their
circle of change was complete. For
example, if a 1½ days’ circle gave a certain
amount of light, a 4 days’ circle gave twice
that amount, 8 days three times and so on.
In this way there was seen to be a completely
clear relation between time of
change and amount of light, for all such
stars everywhere in the sky. That was
the first step.
The second step was to get the distance
of one such star. This was done, with the
greatest care, by the old process. Then
it was noted how bright this star seemed,
by detailed measuring. When we have
the distance of a bright body, and take the
measure of how much light we get from it
at that distance, it is simple to see
92
mathematically how much light it is in fact
giving off. This gave the key to the distances
of all the other changing stars of
this sort. If the changing star had the
same time-circle as the one measured by
the old process, its greater or smaller
distance was got by seeing how bright it was
by comparison, all stars with the same
time circle being equally bright in themselves.
If it had a longer or shorter time
of change, it was possible to get its true
amount of light worked out by the rule of
the relation between times and amount of
light ; and again, by observation of how
much less or how much more it
seemed to
give, its true distance was worked out.
How surprising and new was the outcome
of this discovery may be judged from
one example : In the South half of the sky
there is a bit of star-mist named the Lesser
Megallanic Cloud. In it is a number of
stars of the changing sort were noted.
From their very feeble light it was clear
that they were at a very great distance.
The only hope of bridging such a distance
was by the new process. Strange indeed
was the outcome. It was that the light
from those feeble stars takes almost a
million years to get to us. By way of
comparison it may be said that the old process of measuring became of very little
value when the angle was less than say 1/5000th of a second, but the angle formed
by these stars in the Lesser Megallanic Cloud would be one of less than 1/300,000
of a second !
----------
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Deeply interesting as all these things will, it is hoped, be to the reader, the
limits of space make it necessary to put an end here to this little work, which will
have done its part if, after reading it, the desire is experienced by the reader to get
a fuller knowledge of these questions from some works of greater detail.
But it may be rightly said that all these questions of great size, great distance
and great heat are not truly important, and have no sense, if they do not have the
existence of living things, of mind as their purpose. Mind with its knowledge and
feelings and questioning, is the highest form, without which the stars are as
nothing. It will not be doubted, by the of thought, that the deeps of space
are full, not only of stars, but of planets giving birth to living things and at last to
thought and reason. But these beings are cut off from us for ever. It may be
that, like ourselves, looking out upon the sky of stars, they put the
the question to themselves : What is the purpose of it all,
and what is the hour which is now marked by the hand of the Great Clock of All
Time in the existence of all things?
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INTERNATIONAL: SCIENCE WORDS USED IN THE BOOK
| cone | parallax |
| dinosaur | planet |
| energy | pole |
| ichihyosaurus | relativity |
| magnetism | telescope |
In addition, the senses of these special words are made clear:
| canal | ether |
| candle-power | equator |
| comet | galaxy |
| cube | prism |
| diameter | satellite |
| eclipse | tide |
| electron | triangle |
| eclipse | |
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