Tricks Of Refraction
Part of: Secrets of Space
From: Pharaoh's Broker
The doctor figured out that we should be quite insensible to any weight
when we were seventy-five thousand miles from the Earth. At fifty
thousand miles I would still weigh a pound, and when we had finished the
first million miles, the entire projectile, with its two occupants and
all its dead weight, would weigh considerably less than an ounce. That
was a mere start on the enormous trip ahead of us; but when that
distance was reached, we could no longer count upon terrestrial gravity
for accelerating our speed. We must travel with our accumulated
momentum, unless by that time the Sun should have taken the place of the
Earth, and with his vaster forces continue to repel us Marsward.
As we sat talking the doctor grew weary, and soon unconsciously dropped
asleep. I left him to enjoy his rest, and, tossing a scrap of ham bone
to Two-spot, I went up to take my place at the telescope.
Mars seemed to be exactly in the right part of the field. I surveyed the
starry stretches ahead with a feeling a little akin to fear. I was
queerly affected by the vast expanse of loneliness outside, and by the
deathly quiet prevailing both without and within. There was not the
slightest whizzing or whistling now. We might be hanging perfectly
motionless in space for all I knew. The batteries made no sound either.
I could hear only the low, regular breathing of the doctor as he slept,
and the slight crunching of Two-spot on his bone. Presently I thought of
looking for the danger lights, but I looked through the telescope
instead, and saw the little red planet in his proper place.
What a vast distance we were from any planet! If anything were to happen
to us, no one on Earth or in the heavens would ever know of it. I had
never been homesick, but a very little would have made me Earthsick just
then. I did not like the upper end of the projectile because I could not
look back at the home planet. I wondered if it was all dark back that
way, or if those warning lights had begun to appear. That idea seemed to
haunt me. I touched the steering wheel just a little while I kept my
eyes on Mars. He moved slightly in the field at once. Then I turned the
wheel back until he took his former place. It was reassuring to know how
easily the projectile minded her great rudder, which was now fully
extended like an enormous wing. This made me feel that we were masters
of the situation, that all this vast space was as nothing to us, that
any planet in the heavens must mind us, and that though Earth was
driving us away, she must draw us back if we willed it. More than that,
she would warn us of all dangers. Perhaps she was sending that warning
now. I had promised to look out for it. I felt that I must go down. I
crept softly past the doctor and stooped over the port-hole. My eyes had
scarcely found the Earth in the darkness when I drew back quickly and
clapped my hand over my mouth to prevent a cry escaping me. Then I
looked again more closely. There was no small illuminated portion of the
surface this time, but a great smear of light just outside the edge of
the Earth. It was of a dull red colour, with rainbow tints around the
edges, and was much the shape of a great umbrella held just above one
quarter of her surface to westward.
I gave the steering wheel in my compartment a sharp turn in the
direction which should cause the light to disappear. Then I crouched and
looked again, but instead of being reduced in size the light broadened
and swelled. It was as if one edge of the umbrella were left against the
Earth's surface, and then the umbrella was being turned gradually around
until it faced me and formed an enormous disc, apparently a third as big
as the Earth. Then, as it slowly moved outward, its edge seemed to
cleave to the Earth's, as two drops of water do when about to separate.
Finally, it detached itself entirely, and stood as a great muddy red orb
a little to the west of and above the Earth. It filled me with dismay to
see all this happen after I had turned the rudder in the direction which
should have corrected our course. In desperation I gave the wheel an
additional hard turn and looked again. At last the great red patch was
shrinking; slowly it diminished, and finally disappeared. But just as I
was breathing a sigh of relief, I noticed the white sickle of light on
the east side that I had seen before; only it was increasing most
threateningly now. Yes, it was assuming the same umbrella shape and
detaching itself a little from the eastern edge of the Earth. There was
still a narrow rim of bright white light on the Earth, and this dimmer
umbrella shape was faintly separated from its edge. Its outlines were
marked by flashes of rainbow colours, as had been the case on the other
side. I sprang to the wheel and gave it several frantic turns back the
other way. Then I ran up to the telescope for a hurried view, and Mars
was nowhere to be seen! I hastened back to the wheel and gave it a
vicious additional turn. I was determined to prevent this umbrella from
opening at me! And true enough it ceased enlarging, and gradually shrank
and settled back upon the surface of the Earth. Then slowly it faded and
disappeared, as it had done before when the doctor had corrected the
course. I eased back the wheel and went to look for Mars again, but he
was not in the field. As I returned I brushed unconsciously against the
doctor in my excitement. He roused himself, sat up, and watched me
peering out of the port-hole. I was gazing at a new appearance.
"There it is again!" I cried, for below the Earth and to westward a pale
white disc came into view all at once, not gradually, as if emerging
from behind the Earth, but springing out complete and detached.
"Doctor!" I said, catching him by the arm and pulling him down to the
port-hole, "what is that?"
"That? That is the Moon, my boy. Has it excited you so much?"
"Yes; I have been trying to dodge it. But you had better look to the
wheel," I cried.
He ran up to the telescope, and I heard him exclaim, "Donnerwetter!"
half under his breath. But with a few careful turns of the wheel he
found the planet again, and moved him to the right part of the field.
Meanwhile the Full Moon shone on us with its pale glimmer. But a thin
rim of it next to the Earth gleamed brightly with rich silver light.
"I thought you said we had started in the dark of the Moon. I thought it
was behind the Earth," I interposed.
"That is the New Moon just emerging. It will probably not be seen on the
Earth until to-morrow night, but as we are at a greater distance we see
it first," replied the doctor.
"But that is not a New Moon, it is a Full Moon, which should not be seen
for fourteen days yet," I objected.
"Pardon me, it is a New Moon," he insisted. "That inner rim of
brightness is all the sunlight she reflects. The paler glimmer is
Earth-light, which she reflects. When she is really a Full Moon, she
will be perfectly dark to us."
Then I explained to him the first umbrella appearance, and its gradual
swelling and final disappearance.
"Rainbow colours around the edge and a gradual changing of the shape,
you say? That means refraction. The Earth's atmosphere has been playing
tricks on you. The umbrella of dull red light was a refracted view of
the Moon before she really came into sight. Rays of light from the
hidden Moon were bent around to you. Then, as she gradually moved from
behind the Earth, her appearance was magnified by the convex lens formed
by the atmosphere, bent over that planet. Presently it diminished and
went out altogether, you say?"
"Yes, but that was because I steered away from her," I replied.
"No; you could hardly lose her so easily," he answered. "Did you ever
try holding an object behind a water-bottle or a gold-fish jar? There is
a place near the edge of the jar where a thing cannot be seen, though
the glass and water are perfectly transparent. The rays of light from
the object are bent around, through the glass and water, away from the
eyes of the observer. It was like that with the Moon when she
disappeared. She was really drawing out from the Earth all the time.
Finally, when her light passed beyond the atmosphere altogether, she
became suddenly visible in a different place and shining with another
colour. What we see now is the real Moon in her true place. The other
appearances were all tricks of refraction."
"But when I had turned away," I explained, "there came a thin rim of
bright light on the other side of the Earth, and a gradually appearing
umbrella shape there too."
"Ah, then you steered far enough out of your course to see part of the
illuminated surface of the Earth. That was the real danger light. And if
it began to assume the umbrella shape, detached from the Earth, that was
due to atmospheric refraction of sunlight. This great shadow we are
travelling in has an illuminated core, which we shall encounter when we
have proceeded a little further. I tell you of it now, so it may not
give you another shock. Have you ever noticed the small bright spot
which illuminates the centre of the shadow cast by a glass of water?
That is partly the same as the core of light which exists in the heart
of this shadow. Rays from the sun, passing on all sides of the Earth,
are refracted through the atmosphere and bent inward. You must have
steered over into some of these rays just now, and then turned back from
them. Somewhat farther on all these refracted rays will meet at a common
centre, which they will illuminate, and we shall have an oasis of
rainbow-tinged sunlight in this great desert of shadow. The sun will
then appear to us to be an enormous circle of dull light entirely
surrounding the Earth."
"I don't fancy running into that at all," said I. "Can't we avoid it by
"Avoid it!" exclaimed the doctor. "We must investigate it, and
photograph the peculiar appearance of the sun. Light seems to have more
terrors for you than anything else just now. You must get over your
rush-and-do tendency; you must stifle your emotions and impulses, and
learn to think of things in a more calm and scientific manner."
"But that is not so easy for me, Doctor. Whenever I am left alone, a
feeling of dread possesses me. I am used to having many people, bustling
noises, and confused movement all about me. The silence of Space stifles
me, and the loneliness of the ether oppresses and overcomes me
"I prescribe a change of air for you," answered the doctor. "You will do
better in a rarer atmosphere. Let us send what we have been breathing
back to Whiting, and make a new one to suit ourselves."
Next: The Twilight Of Space
Previous: The Valley Of The Shadow