What Does the Latest “Big Bang” Discovery Mean?
by Trent Horn
Filed under Cosmology
Over the past few days the world of cosmology and astrophysics has gone “supernova.” Researchers affiliated with the BICEP2 telescope in Antarctica announced that they had discovered empirical evidence for a key part of the Big Bang theory, cosmic inflation. One aspect of this discovery that I found really interesting is that it forms an almost perfect parallel to a discovery that was made sixty years ago.
The First Telescope Discovery
In the early twentieth century, the Belgian priest and physicist Georges LemaÎtre concluded that Einstein’s new theory of gravity, called general relativity, would cause a static eternal universe to collapse into nothingness. Since Einstein’s theory was sound, this only meant one thing: The universe was growing, and had a beginning in the finite past. Fr. LemaÎtre and Einstein would discuss the cosmic consequences of the theory while walking around the campus of Cal Tech, and although Einstein was skeptical at first, in 1933 he proclaimed that LemaÎtre’s theory of an expanding universe was one of the most “beautiful theories he had ever heard.”
Fr. LemaÎtre called his theory “the primeval atom,” but another physicist, Fred Hoyle, mocked the theory with the term “Big Bang.” Hoyle believed that theories of the universe beginning to exist from nothing were “primitive myths” designed to put religion into science. Fr. LemaÎtre’s status as a Catholic priest did not help the situation. In response to Fr. LemaÎtre, Hoyle argued for what he called the “steady state theory” of the universe and claimed that there was no empirical evidence for Fr. LemaÎtre’s model. Einstein was also skeptical that no “cosmic rays” or after effects from the Big Bang had ever been discovered.
However, in 1965 Bell Laboratory technicians Arno Penzias and Robert Wilson used radio telescopes to detect a faint, uniform “glow” of static coming from all directions of the sky. At first, they thought this uniform glow was merely bird droppings contaminating the telescope! But after a thorough cleaning, the static turned out to be radiation in the form of microwaves coming from deep space.
According to the Big Bang model, right after the “bang” the universe was a white-hot ball of plasma before it cooled and formed stars and galaxies. Particles that had been flying around since the very beginning of time cooled and turned into microwaves, traveling to fill the whole cosmos. Today, this radiation is called Cosmic Microwave Background Radiation (or CMBR, which is pictured below).
This discovery was so monumental that Penzias and Wilson won the Nobel Prize for it, and Fred Hoyle admitted it refuted his steady-state model of an eternal universe: “[It] is widely believed that the existence of the microwave background killed the “steady state” cosmology. . . . Here, in the microwave background, was an important phenomenon which it had not predicted.”
Enter Inflation
But this wasn’t the end of the story. As scientists studied the Big Bang they came across several problems that they weren’t sure how to resolve. One was the “flatness problem,” which couldn’t explain why the density of matter and energy in the universe almost perfectly aligned to a very precise value that gives the universe a “flat shape” (or one where parallel lines expand and never intersect). The other was the horizon problem, which could not explain why different parts of the universe possessed “equal temperatures” even though the universe was not old enough for particles from those different parts to interact with one another. Even if the particles were travelling at the speed of light, there would not have been enough time for them to cross our huge universe and mix together until their “temperatures” became even.
In the 1970’s an American cosmologist named Alan Guth proposed the idea that the universe did not expand at a slow, constant rate from the Big Bang. Instead, the universe expanded at an exponential rate from just a trillionth of a second after the Big Bang. Stephen Hawking says the expansion of the universe would be like a penny expanding to the size of the entire Milky Way galaxy (or 100,000 light years across) in a few seconds. This inflationary expansion would have “locked in” both the universe’s flatness and even temperatures while it was very small and then blown those features up to fill the entire universe we see today. But for decades this theory had the virtue of being elegant and explaining a lot, but it also had the vice of not being supported by empirical evidence . . . until now.
BICEP2 shows that there are distinct “gravity waves” in the microwave background radiation. These waves are the final “blown up” effects of very small “quantum disturbances” that made up the universe 13.7 billion years ago before the inflation event. What the Bell Labs radio telescope’s discovery was to Fr. LemaÎtre, the BICEP2 telescope’s discovery is to Andrei Linde, another pioneer in inflationary cosmology. A video team even captured the emotional moment when Linde learned that the theory he had been toiling over for decades had finally been confirmed with an empirical observation:
Any Religious Significance?
I’m glad that most news articles covering this story didn’t drudge up the tired “science vs. religion” trope. But, I could count on my local U-T San Diego newspaper to include this gem in their coverage of the discovery:
"The finding strengthens scientists’ support of the Big Bang theory, although it’s likely to be challenged by some theologians who see the hand of a divine creator in the rise of the universe."
Which theologians? Sure there are some Christians who think the universe was created at the same time the Babylonians were brewing beer, but the Catholic Church has affirmed that,
“The question about the origins of the world and of man has been the object of many scientific studies which have splendidly enriched our knowledge of the age and dimensions of the cosmos, the development of life-forms and the appearance of man. These discoveries invite us to even greater admiration for the greatness of the Creator, prompting us to give him thanks for all his works and for the understanding and wisdom he gives to scholars and researchers” (CCC 283).
This discovery does not disprove the idea that the universe requires a necessary being in order to sustain it nor does it disprove the idea that the universe began to exist in the finite past. Even if inflationary theory explains why some of the constants in the universe (such as the strength of gravity) have the life-permitting values they do, inflation alone does not overturn the conclusion that our universe’s life-permitting laws of nature were designed. Instead, it merely pushes the problem back one level. Resorting to inflation to explain the fine-tuning of the universe’s constants and conditions would be like saying that the case of a dart hitting a bull’s eye can be explained by “projectile theory” apart from the actions of any intelligent agent.
The fact is that this discovery has no bearing whatsoever on either the existence of God or any other Catholic teaching. It is perfectly compatible with the view that God created the universe from nothing for the good of intelligent creatures to come to know him.
Note: Our goal is to cultivate serious and respectful dialogue. While it's OK to disagree—even encouraged!—any snarky, offensive, or off-topic comments will be deleted. Before commenting please read the Commenting Rules and Tips. If you're having trouble commenting, read the Commenting Instructions.
