Dark Matter from before the Big Bang?
“In the beginning God created the heavens and the earth.” The Bible starts with a remarkable claim: the universe began to exist. However, a recent paper generated press that seems to undermine this important biblical statement.1 Various popular sources ran headlines like “Big Bang Bombshell: Did Dark Matter Come BEFORE Birth of Universe?,” “Dark Matter May Have Existed before the Big Bang, New Math Suggests,” and “Dark Matter May Be Older Than the Big Bang.” Some of the coverage even hints that scientists might not understand the universe as well as previously thought. Will science rebuff a biblical claim? Let’s look at this discovery and see what it tells us about the universe and how well the Bible describes it.
Isn’t the Big Bang the Beginning of Everything?
If the big bang is the beginning of the universe, how could dark matter originate before it? Well, the term “big bang” carries two meanings. According to scientists’ best understanding, the universe started in an extremely hot, dense state from which it expanded and cooled down over the last 14 billion years. Thus, the first meaning of “big bang” refers to the development of the universe from this initial hot, dense state without making any statement on how the universe came to be in this state. The big bang model provides the best explanation of how that initial hot, dense state transformed into the galaxy-filled universe that astronomers observe today.
The second usage of the term refers to the idea that, when running time into the past, one eventually encounters a singularity where the laws of physics break down. Stephen Hawking and Roger Penrose developed a powerful theorem showing that if a few conditions apply (like general relativity describing the universe and energy behaving a certain way) to the universe at all times, then the singularity genuinely exists and it represents the beginning of the universe. One should keep this distinction in mind when reading about whether the big bang means the universe had a beginning or not.
Specifically, the new discovery uses “big bang” with the first meaning in mind. Researchers have postulated a hypothesis that dark matter originated before the time when our understanding of physics gives us a relatively clear picture of how the universe behaves.
Inflation before the Big Bang
Many cosmologists and physicists would argue that the conditions necessary for the Hawking-Penrose theorem to hold don’t actually apply for two different reasons. The first reason concerns the condition that general relativity (GR) describes the universe. While GR has passed every observational test thrown at it, GR is inherently a classical, not quantum, theory. This means that GR likely gives way to a more fundamental quantum theory of gravity necessary to describe the initial hot, dense state. Proponents presume that the correct quantum theory of gravity will remove the singularity of GR, but for now we have no idea if this is true.
The second reason concerns the condition related to how energy behaves. Observations of the universe have affirmed the big bang model while revealing some issues known as the horizon problem, oldness-flatness problem, and magnetic monopole problem. Scientists also realize that an epoch of rapid, geometric expansion called inflation would solve these problems. However, this epoch of inflation occurs prior to the big bang models (as in the first usage). Additionally, how inflation works violates the energy condition required for the Hawking-Penrose theorem to hold. As such, incorporating inflation into big bang models appears to remove the big bang (second usage).
What about Dark Matter?
For over 80 years, scientists have made observations indicating that our universe contains an unusual form of matter that we detect only (currently) through its gravitational interactions. Because it emits no detectable light, scientists call this stuff dark matter. As of now, scientists have suggested numerous candidates to explain dark matter, but they possess no direct evidence for which explanation is correct. The research article behind all the headlines above simply proposed a new explanation for dark matter generated during the inflationary epoch. Obviously, future observations are necessary to see if this new proposal has any merit.
The Bottom Line
Simply positing a model where things happen before the moment when physics constrains our knowledge does not remove the evidence pointing to a beginning. Investigations of dark matter, inflation, quantum gravity, and the like represent the frontiers of scientific research. Consequently, these areas pose the most difficult—and most fun—scientific problems. I look forward to resolution of these problems and expect further affirmation of “In the beginning God created the heavens and the earth.”
- To explore all the issues regarding the scientific case for a beginning of the universe, check out my latest book, Escaping the Beginning? Confronting Challenges to the Universe’s Origin?.
- Tommi Tenkanen, “Dark Matter from Scalar Field Fluctuations,” Physical Review Letters 123, no. 6–9 (August 7, 2019): doi:10.1103/PhysRevLett.123.061302.