Albert Einstein later called it ‘the greatest blunder’ of his life, at least that is how the story goes. At the beginning of the 20th century many astronomers assumed that the universe was static and unchanging. For good reasons. They had found the distances between stars to be mind-boggling and no evidence of them moving relative to each other. Einstein was developing his theory of gravity—general relativity—but ran into a conundrum.
His equations didn’t allow for a static, unchanging universe. If every object in the universe attracted every other object gravitationally, then it would all collapse together eventually. To avoid this, he introduced a repulsive energy term to balance the gravitational attraction. Basically, a fudge factor that he called the cosmological constant (Λ). For many years he even defended it against criticism, until contrary evidence began piling up.
An expanding universe
Astronomer Edward Hubble published groundbreaking astronomical observations a decade after Einstein published his theory. He and his team were observing astronomical objects with the Mount Wilson telescope, at the time the most powerful telescope in the world. One type of object they studied were the mysterious fuzzy patches of light known then as ‘nebula.’ First, they realized they were not fuzzy clouds but rather entire galaxies outside our own. Second, they realized that they were moving away from us at high speed. Furthermore, the further away the galaxy, the faster it was receding. The universe was not static but expanding.
Observations since then—including with his namesake telescope—have confirmed and refined Hubble’s findings. And they have found that there is a straightforward, pretty much linear relationship between distance and speed. If we extrapolate back in time, that implies that at one point in the past the universe was all concentrated in a small volume and expanded from there. Just the way we would expect if the universe began in a cosmic explosion.
Not all astronomers agreed with this interpretation. The term “the Big Bang” was originally used by opponents in a mocking way. New ideas in science frequently lead to passionate debates, which is a good thing. New ideas need to be scrutinized and tested by people trying to prove them wrong. Others proposed alternative theories, such as an eternally expanding universe with new matter appearing in the gaps. But perhaps the objections were not all strictly scientific.
Philosophical implications of the Big Bang
Underneath the scientific issues lay philosophical questions. In his book God and the Astronomers, astronomer Robert Jastrow opined that the opposition to the Big Bang theory stemmed in part from some scientists’ theological objections. The idea of the universe having a beginning was uncomfortably close to the Christian doctrine of creation.
For the scientist who has lived by his faith in the power of reason, the story ends like a bad dream. He has scaled the mountains of ignorance; he is about to conquer the highest peak; as he pulls himself over the final rock, he is greeted by a band of theologians who have been sitting there for centuries. (Robert Jastrow, God and the Astronomers)
The universe having a beginning has metaphysical ramifications. Both Aristotelianism and classical Greek Atomism believe the physical world was all there existed. No gods, cosmic minds or spiritual principles behind it. They both also asserted that the physical cosmos was eternal without a beginning. For a simple, logical reason, summarized here:
- All things that have a beginning have a cause.
- The universe had a beginning.
- Therefore, the universe has a cause.
Take a moment and think about it. Can you come up with any examples of something that just suddenly began to exist entirely on its own with no outside cause? Nor has anyone else. That means that if our cosmos has a beginning, as the Big Bang theory asserts, there must be something more. It must have a cause beyond the universe we can see.
Perhaps there existed some sort of predecessor physical reality from which it emerged. Maybe, though obtaining any real data about something outside or before our universe is pretty much impossible. And other objections have been raised. On the other hand the universe might have another type of cause. There are plenty of philosophies and religions that have asserted that.
An external must have certain characteristics. To avoid an endless series of causes, the ultimate cause must have always existed. (Whatever that means.) Furthermore, Einstein’s general relativity and Big Bang theory tightly link time, space and matter. That means an external cause would have to be non-physical and exist outside of space and time as we know them.
So how could an eternal, timeless entity cause an event to happen at one point in time? After all, if I exert an eternal force on a mass I will get an eternal acceleration. A valid solution is that this timeless entity is capable of making decisions. Like declaring, “today I’m going to create a universe.” Something that is starting to sound like Plato’s Demiurge, Islam’s Allah, or the Judeo-Christian Yahweh.
The 1964 discovery of the cosmic background radiation strengthened the case for the Big Bang. The tremendous heat of the cosmic explosion predicted the existence of a still-visible ‘afterglow,’ except shifted to much longer wavelengths. Arno Penzias and Robert Wilson were working with a supersensitive microwave antenna and found a source of noise they couldn’t explain. It turned out to be exactly what the Big Bang theory predicted. Our universe really does seem to have had a beginning. And if it had a beginning, it stands to reason that something—or someone—brought it into existence.
References
It is unclear if Einstein ever actually called the cosmological constant his greatest blunder, but it is plausible. See O’Raifeartaigh, C., Mitton, S. Interrogating the Legend of Einstein’s “Biggest Blunder”. Phys. Perspect. 20, 318–341 (2018). https://doi.org/10.1007/s00016-018-0228-9
Robert Jastrow, God and the Astronomers (Warner Books, 1978).
For a more extensive and rigorous discussion of this cosmological argument for the existence of a creator, see the third chapter of Reasonable Faith: Christian Truth and Apologetics (3rd edition) by William Lane Craig (Crossway, 2008).
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