This post continues our discussion on Science and Creation, and will be the first of several posts from me looking at the point of view of mainstream science. Science is a major force within our society. Its advances have taken us to the moon, have opened entire new realms of medical treatments, and have brought us technologies that our ancestors could never had dreamed of. Science, perhaps because of its immense practical benefit, has come to occupy a venerated position within modern culture. However, sciences deals not only with the practical. Science provides tools and methods for attacking many of the questions of origin that have so long occupied men’s minds. Where did we come from? How did life originate? How did the earth and universe come to reach their present state? What are we made of? Many of these are questions for which religion also has answers – or at least they look a lot like questions addressed by religion.
Over the past century, science brought incredible technological innovation, but it also has made revolutionary discoveries that led to overarching theoretical frameworks within the fields that study origins. Perhaps the most important of these are big bang cosmology, plate tectonics, and DNA. In each of their respective fields, these discoveries have led to all-encompassing theories that are woven into intricate tapestries with vast explanatory power. Observation after observation bolsters the framework and adds another thread to the cloth. Because of its methodology, science really isn’t in the business of certainty, but theories with such explanatory power drive scientists to expound their certitude. As I present the scientific picture, I will only have space to touch on a few individual evidences, and it will be difficult to convey the full force of the overarching theories. The reader will have to understand that we are viewing only a few pieces of the expansive puzzle of the current scientific paradigm.
For ages humans have pondered the meaning of the starry night sky, but in the last 30 years the science of cosmology has converged on a coherent picture that explains the broad strokes of the evolution of the Universe since its inception. Cosmology has grown from a speculating theoretical science, where arguments were made only to an order of magnitude, into what is being deemed “precision cosmology,” where global properties of the Universe are known to within a few percent. The observed universe is full of evidence of antiquity, but I will share a few that I am most intimately familiar with.
In order to advance beyond the realm of speculation, observational cosmology had to address the major problem of determining scale within the Universe. That is, we can see all of these stars and galaxies out there, but how do we know how far away they are? This problem was solved over a long period of time with many different techniques that apply on various overlapping scales. This is referred to as the “cosmic distance ladder.” Each successive technique makes up a “rung” of the ladder that overlaps a bit with the previous technique, allowing us to ultimately measure very large distances. Near the base of the ladder is a technique called parallax. This is an easily demonstrated technique. Hold a finger out about a foot in front of your face and close one eye. Now switch and close the other eye. You’ll see that your finger appears to shift from one place to another. Now hold your finger way out at arm’s length and repeat the same process. You’ll see that it still shifts but not as much. By measuring this shift (and knowing how far apart your eyes are) you can calculate how far away your finger is. Astronomers do a similar thing with nearby stars. Except they use the solar system as their “face.” They take pictures of the night sky when the earth is in one location. Then they wait until the earth moves all the way around to the far side of the sun and take another picture of the sky. If the stars are close enough, then they will appear to move slightly from one picture to the next. By measuring these movements, astronomers can measure distances to the stars. However, this technique only works for stars that are pretty close. Most of the other techniques used to determine distances rely on what are called “standard candles.” Basically, there are certain types of objects that we know how bright they should be, either based on standard physics or on observations of many other objects of the same type. The further away an object is, the dimmer it will appear to us (falling off with the distance squared). Therefore, if we know how bright an object appears, and we know how bright it really is, then we can calculate how far away it is.
What cosmologists have found by applying these techniques is that the universe is a REALLY big place. The sun is about halfway between the center and edge of our galaxy, the Milky Way. The Milky Way is so big that it takes light 100,000 years to travel from one side to the other, and it takes 220 million years for the sun to make one orbit around the center of the Milky Way. The nearest galaxy similar in size to our own is the Andromeda Galaxy, which is 2.5 million light years away. That means that any light we are seeing now from Andromeda left the galaxy 2.5 million years ago. However, these galaxies just make up part of a small collection of galaxies called the Local Group. The Local Group is somewhat isolated from other galaxies, and the nearest “crowded” part of the Universe is the Virgo Cluster. The center of Virgo is roughly 60 million light years away. However, again this seemingly vast area of space is only a very small fraction of the observable universe. The edge of the observable universe is roughly 50 billion light years away (Note: This may confuse those who know that the Universe is only about 14 billion years old, but at such large distances the expansion of the Universe plays a large role such that there is no longer a 1-to-1 correlation between how many light years away something is and how long it took that light to get to us. You can think of it this way. The light is not violating its speed limit, but rather when the light was emitted, the object was much closer so the light really didn’t have to travel 50 billion light years). For a really cool movie that shows a fly-through of the stellar and galactic location data in the nearby universe see this link. The movie starts at earth, flies through several features in the Milky Way, and then goes up out of the disk of the Milky Way, flies by Andromeda, and ultimately makes its way to the center of the Virgo Cluster. This really helps one to appreciate what an incredible and huge place the Universe is. To me it is actually very inspiring. I will warn you that this is a really huge file (230 Mb), but it is worth the wait if you have a relatively fast connection. You can find a lower resolution version without music here.
There are countless processes observed in the universe that apparently require millions or billions of years to occur. My thesis work is on galaxy mergers, which typically take a few billion years to occur. There are many ongoing galaxy mergers that have been observed. Since they take so long, all we see are snapshots somewhere in the middle of the process. One of the neat things that happens in a galaxy merger is that tidal forces pull long “tidal tails” out of the galaxies. Much in the same way that the moon causes the oceans to bulge, one galaxy passing another galaxy will cause the stars in each galaxy to get pulled out. Unlike the daily tides in the ocean, because galaxies are so large, it takes hundreds of millions of years to raise tides. I think that merging galaxies are one of the most incredible sights to see in the Universe. Here is an image of two merging galaxies with tidal tails. These particular galaxies are called The Mice.
Computer simulations constructed using well-understood physics allow us to calculate the process of a galaxy merger. The most important influence is simple Newtonian gravity. Here is a computer simulation intermixed with comparisons to a number of observed galaxy mergers. As you can see, the simulation is capable of creating images that look almost exactly like what we observe.
In addition to ongoing galaxy mergers, we can also observe mergers that happened some time ago. If we look within the Milky Way we see long streamers of stars near the outskirts of the Galaxy. The stars in each group are moving all together, and we can tell that they don’t belong within the Milky Way. They are the ripped apart remnants of small galaxies that fell into the Milky Way a long time ago. It takes a long time for galaxies to be ripped apart like this. Remember, that one revolution around the Milky Way takes 200 million years, and the merging process would take at least several revolutions.
Modern cosmology has provided us with an overarching theory, that each year is confirmed by more data coming in from observational astronomers. It really is amazing the extent to which we now understand how galaxies form and change over time and also how the universe as a whole has changed over time. There are still many details to be worked out, but it seems unlikely that cosmology will see any other paradigm shifts. This leaves the young earth creationist with quite a hurdle to overcome. It is difficult to explain how light could have even gotten here from such distant locations, much less to come up with an equally successful overarching theory for how galaxies form.
Some young earth creationists have suggested that the speed of light may not be constant. Perhaps it was much faster in the past. However, the speed of light is intimately tied to many other processes in physics. If you change the speed of light by very much then the Universe as we know it would cease to exist. It seems that the only possible way out is to claim an “appearance of age.” God created the light from distant galaxies en route. While this can’t be disputed scientifically, it seems to me to be theologically unsatisfactory. All of this light is telling us a complex story of things that happened in the past. If it were created en route, then all of this story is fabricated. Not only that, but the character of light itself changes as it flies through the Universe. Light becomes stretched out from the expansion of space, and also becomes redder as it passes by more and more dust particles. We observe both of these effects in distant starlight. The further the light has traveled, but more we see of these effects. Thus, this created light not only would be showing us events that never occurred, it also would have to be modified to look like it had traveled very large distances. A God who creates with this sort of manipulation and deception doesn’t sound to me like the God of the Bible. As a Christian, I feel that I have to take both the Bible and the evidence within God’s creation seriously. As an astrophysicist, it is clear to me that creation tells us of its antiquity. In fact, I think the unexpectedness, the immensity, and the beauty of the observed universe speak to God’s boundless creativity, His awesome power, and His care for the creation.
-Matt, the elder brother