When I taught astronomy I favored the naked eye approach in my classroom. What could be seen with the naked eye? What could we learn by observing and interpreting the skies without a telescope? Students responded favorably to visual stimuli in order to discover the nature of sky object movement, including the movements of the Earth, Moon, and planets. Subsequent challenges of astronomy involved distinguishing real motion from apparent motion with respect to what we visually observed.
Telescopes were an exciting add-on after a few weeks of introductory instruction in astronomy. Whenever we presented an outdoor “star watch,” telescopes were supplements to the lessons of astronomy already learned from naked eye observations. Premature use of telescopes, however, could complicate introductory concepts of astronomy. We illustrate by citing early use of microscopes and telescopes for very young children. Parents may be wise to use neither device before children are reasonably able to process their observations according to everyday visual experiences.
We are confident the lessons of our last seven posts have increased readers’ knowledge of naked eye astronomy. But what of telescopic revelations of our magnificent macrocosmos? We have not dealt with these revelations. Our preliminary near Earth discoveries do not instruct us concerning the wonders of the magnificent distant universe. Visualizing distant celestial objects farther away and smaller than our unaided eye can see is only the beginning of discovery. Enhanced knowledge gained with advanced telescopes leads us to deeper inquiry about how the universe began, how the universe developed, and how it presently works.
As a classroom teacher, occasionally I challenged my students with a puzzling riddle. I claimed, “I really don’t see any of you. I merely see the light coming from your bodies!” In the ensuing discussion students acknowledged that the light reflected from their bodies to my eyes consumed travel time, albeit a very short time. Even at the speed of 186,000 miles per second, some time was necessary. When I observed the students, I perceived them with slightly “old” light. Therefore, I was observing a past event, I claimed. An analogy from the world of sound transmission helped students understand the riddle. It is common knowledge that the sound of thunder needs time to travel to us after the cause of the thunder—the bolt of lightning. When we hear thunder we sense sound energy generated by a past event. We may calculate the distance to the bolt of lightning if we know sound travels at 1116 ft/sec and how long the sound was in transit.
Knowledge of speeds, distances, and times operating today on earth help us derive information about our vast universe. For example, knowledge of any two enables us to calculate an unknown third factor. Telescopes enable us to see objects which sent their light to us very early in the history of the universe. In a sense we are looking at the past just as I observed my classroom students with slightly “old” light. Telescopes today, whether an inexpensive one purchased at Walmart or an advanced telescope such as the Hubble Space Telescope (HST) help remind us that observed light coming from objects in distant space is very old. Since that light was generated, many events have taken place including the ongoing expansion of the universe.
We close with an invitation to contemplate a startling fact of our universe. In the past few decades our telescopes such as the HST have enabled us to discover the vastness of the universe we observe and calculate how massive it really is. Hugh Ross in his 2008 volume Why the Universe Is the Way It Is (Baker Books) states, “The Universe that exists today is different from the universe that astronomers actually observe. Astronomers look back in time when they look at distant objects because light (even though it’s very fast moving) takes time to travel through space. Thus, the universe astronomers observe is the universe of the past. The farther away astronomers look, the farther back in time they see…”
Ross continues, “In a continually expanding universe, the universe of the past is spatially smaller than the universe of the present…The actual universe of the present must be at least an order of magnitude (a factor of ten) larger than the universe they observe via telescopes.”
There are over a dozen scripture passages that reference the stretching out or expansion of the heavens, including Isaiah 40:22 (NIV), “…He stretches out the heavens like a canopy…” Even if we view such verses as metaphorical, astronomers have discovered that the universe has been stretched out (expanded), is being stretched out, and will be stretched out until the onset of the New Creation.