In the beginning…

(a few people responsible for discovering how the universe began)

The way we design universes today, with the observational approach of modern science, may differ from the sacred metaphors of our ancestors, but we all do it for the same reason: to comprehend the universe the way that lets us feel at home in it.
-E. C. Krupp

 There was disorder and there was order, one day.
-Genesis 1:13

Once upon a time, some 13 1/2 billion years ago (that’s about as far back as you can possibly go, by the way, because that was the beginning of the universe), the entire universe was so small, it could fit in the palm of your hand.  Then, for some strange reason, nobody quite knows why, it expanded.  It did not really explode as some people think, but it just grew from that tiny speck and it grew and grew and grew. It is still growing to this day.

This is not a myth, legend, or another religious story about how the universe began.  This is really, truly how the universe began. How do we know? Well we have both a logical explanation and physical (empirical) evidence.  Logic and empiricism are the two central components of science, and science is the language we use to understand nature. If we have those two bases covered, we have a complete set of tools needed to uncovered nature’s secrets.

So what is the evidence? You could say it all starts with everyone’s favorite 20th century scientist, Albert Einstein.  Einstein did not discover the origins of the universe, but he came up with a logical explanation that describes how the universe is constructed. The logic here is based on math – really complicated math, like calculus.  Calculus was, in fact, invented to help describe how the Earth and Sun and other planets and stars interact and keep from crashing into each other or falling apart. In 1916, Albert Einstein wrote a paper in which he tried to correct some errors that earlier 19th century scientists, particularly Isaac Newton, made in their calculations that describe the structure of the universe. Einstein’s corrections revealed the gravity is not a mysterious force, as Newton kinda thought, but yet a property of space and time rationally explained by 4-dimensional geometry. This correction was known as the General Theory of Relativity.

The related Special Theory of Relativity that made Einstein famous was developed 11 years earlier (1905) and it is from the special theory that we get the famous E = mc2. This statement itself reveals some interesting facts about the universe.  Everything is either energy (E) or mass (m), and even this distinction is an illusory, because what E = mc2 essentially tells us is that every piece of mass contains within it an enormous amount of energy.  All of the mass and energy currently in the universe came from that initial blast of energy released from that tiny speck 13.7 million years ago.

Einstein, however, barely missed his chance at discovering the universe’s origins, because he believed what the ancient Greeks believed about the origins of the universe: that there was no beginning to the universe. It was static and eternal in both time and space.  Einstein believed the universe had always existed in the same form it exists now and will continue to exist forever.  He believed this so strongly that he incorporated a number, known as the cosmological constant, in his formulas that prevented the universe from expanding or contracting.

It was another person, a Catholic priest from Belgium by the name of Georges Lemaitre, who studied cosmology at the Massachusetts Institute of Technology, recognized this error, removed the constant that keep the universe from expanding, and provided the theoretical framework for the origins of the universe. The paper he wrote about this was first published in 1927 in the relatively obscure Annals of the Scientific Society of Brussels. Lemaitre was able to show, mathematically, that the universe began as a tiny speck that he referred to as the “primeval atom” or the “cosmic egg”.

Lemaitre and Einstein*

To most physicists and astronomers at the time who believed in Einstein’s ‘steady-state’ construction of the universe, this idea of an expanding universe was crazy. One of them, Fred Hoyle, a British astrophysicist, later mockingly referred to this idea as the “big bang theory”.  Now-a-days, not only have we come to love and accept this idea, but we have come to love the mocking description as well.  Georges Lemaitre is sometimes referred to as the “father of the big bang theory” as a consequence.

When theoretical scientists, like Einstein and Lemaitre, create logical models, those models, if they are good ones, will often make predictions about the behavior of nature.  This is where the empirical evidence comes in. With science, a lot of weight is placed on evidence that one can see, hear or touch. A scientific theory is never truly accepted as fact until there is hard physical evidence.  If the universe, for example, is expanding, then one should be able to see the stars and galaxies spreading away from us.  In 1929, two years after Lemaitre’s paper was first published, an astronomer by the name of Edwin Hubble at Mt. Wilson observatory near Pasadena, California did just that, sort of.  He did not actually see stars and galaxies moving away.  They are too small and too far away to observe that directly, but what he saw were galaxies behaving as one would expect them to behave if they were moving away.

Hubble, in turn, was in dept to the hard work of at least two other scientists, Vesto Slipher, the director of the Lowell Observatory in Flagstaff, Arizona and a computer named Henrietta Swan Leavitt at the Harvard College Observatory in Cambridge, Massachusetts.

Henrietta Swan Leavitt

Leavitt, the computer at Harvard, was responsible for formulating something called the ‘period-luminosity relationship’ of a particular type of stars known as Cepheid variables. This discovery essentially made it possible to determine how far galaxies are from us.  At the time, women were hired in mass to do the manual labor of recording data.  Before the non-human version of computers were invented, the word ‘computer’  referred to low-paid but highly educated assistants, most often women, who performed tedious calculations for scientists and engineers. Leavitt did her observations not through a telescope (as another of the indignities placed on the lowly computers was that they didn’t get to play with expensive equipment), but through thousands of photographs, primarily measuring the brightness of stars. Leavitt’s familiarity with the data led her to discover the cyclically varying brightness of certain stars (Cepheid variables) providing a way to measure the distances between galaxies, a sort of cosmological yardstick. Although she published her initial data in the Annals of the Astronomical Observatory of Harvard College, Leavitt’s ground-breaking discover of Cepheid variables was published by her employer, Edward Pickering, in a Harvard College Observatory Circular in 1912.  Leavitt had not been given much credit for it in her lifetime, but her discovery had played a significant role in changing our view of the universe.  Stars are not evenly spaced out from each as was thought in the 19th century, but are clustered into galaxies.

Vesto Slipher

The other person, Vesto Slipher, used a device known as a spectrometer to analyze the light coming of planets and stars.  Different elements, it turns outs, produce different wavelength patterns of light and these patterns can be measured with a simple device known as a spectrometer.  Slipher pointed this device at stars and planets and analyzed the spectral patterns (or spectral lines) coming from them. This is how we know what elements are on other planets of the solar system.  It is how we know our Sun as well as other stars are huge fusion factories were hydrogen atoms are combined to make helium.  Nobody has actually been to the Sun to find that out.  Slipher figured it out indirectly with the handy spectrometer. In 1912, Slipher also noticed that the light coming from far away galaxies ‘shifts’ toward the red-end of the color spectrum. This observation suggested that most galaxies are not standing still but moving away from each other at very, very fast speeds. Although he published his finding in the Lowell Observatory Bulletin in 1912 and in another article he wrote for Popular Astronomy some three years later, Slipher was somewhat of a recluse and avoided conferences that other scientists used judicially to promote their ideas and to advance their careers.

Image courtesy of USPS
When Edwin Hubble asked Slipher for his data, Slipher was more than happy to cooperate. To this day, it is Hubble who is remembered most for discovering the expanding universe, the key finding that led to the idea that universe began as a tiny speck some 13 1/2 billion years. Specifically, he discovered that a galaxy’s velocity is proportional to its distance (an observation predicted by Lemaitre’s mathematical theorizing). Galaxies that are twice as far from us move twice as fast. Another consequence is that the universe is expanding in every direction. This observation means that every galaxy has moved away from a common starting position at the same time in the very distant past.

Hubble is further remembered with a famous telescope currently orbiting the earth. He also has a cool postage stamp (left).  The telescope in the background is Mt. Wilson observatory, where Hubble was employed, not the Hubble Space telescope named after him. In addition, he have an asteroid and a crater on the Moon named after him. Interestingly both Leavitt and Slipher also have an asteroid and a Moon crater named in their honor, although Slipher has an addition crater on Mars named after him.

God seconding a sentiment once expressed by an Atheist?

Not everyone is comfortable with the big bang theory, however.  Usually the same people and the same groups of evangelical Christians who are opposed to biological evolution are also not happy with the big bang.  There is some irony to the fact that the father of the big bang is a Catholic priest.

The astronomer Fred Hoyle, the original opponent of the big bang theory who coined the phrase as an insult, was a committed hard-core Atheist, and spent a great deal of argument and effort trying to disprove it. To Hoyle, and a lot of other Atheists, the big bang was too similar to the idea of Biblical creation.

Fred Hoyle

Likewise, Pope Pius XII, the pope during and after World War II when the big bang theory was just starting to win acceptance, thought the theory was a validation of Christianity and the Biblical account of creation. Pope Pius XII would later accept evolution as well, and it all may because a Catholic priest’s role in discovering the big bang theory.  Lemaitre, himself, on the other hand, did not quite think the same way as the pope. Lemaitre had a very different take on the relationship between science and religion, regarding the two as separate, incompatible but equally valid domains. To him, the big bang theory did not vindicate religious faith, but rather the two had nothing to do with each other. He was an advocate of Stephan Jay Gould’s ‘”non-overlapping magisteria” (Noma)long before Gould coined the phrase in 1997. Shortly after the pope’s incorporation of the big bang into Catholic dogma, Lemaitre wrote:

Lemaitre and Pope Pius XII

“As far as I can see, such a theory remains entirely outside any metaphysical or religious question. It leaves the materialist free to deny any transcendental Being… For the believer, it removes any attempt at familiarity with God… It is consonant with Isaiah speaking of the hidden God, hidden even in the beginning of the universe.”

Further Reading (some primary sources).

Henrietta Swan Leavitt. 1908. “1777 Variables in the Magellanic Clouds” Annals of Harvard College Observatory. LX(IV):87-110

Edward C. Pickering. 1912. “Periods of 25 Variable Stars in the Small Magellanic CloudHarvard College Observatory Circular 173: 1-3.

Vesto Slipher. 1912. “The radial velocity of the Andromeda Nebula“. Lowell Observatory Bulletin: 2.56–2.57.

Vesto Slipher. 1915. “Spectrographic Observations of Nebulae“. Popular Astronomy: 21–24.

George Lemaitre. 1927 (1931 English translations). “Expansion of the Universe, A Homogeneous Universe of Constant Mass and Increasing radius Accounting for the Radial Velocity of Extra-Galactic Nebulae“. Monthly Notices of the Royal Astronomical Society. 91: 483-490

Hubble, Edwin. 1929. “A relation between distance and radial velocity among extra-galactic nebulae”Proceedings of the National Academy of Sciences. 15(3): 168–173

Further Reading (secondary sources)

Chris Impey. 2012. How It Began: A Time-Traveler’s Guide to the Universe. W W Norton & Company

George Johnson. 2005. Miss Leavitt’s Stars: The Untold Story of the Woman who Discovered How to Measure the Universe. Atlas Books

Harry Nussbaumer; Lydia Bieri; Allen Sandage. 2009. Discovering the Expanding Universe. Cambridge University Press.

Simon Singh. 2005. Big Bang: The Origin of the Universe. Fourth Estate.

*all images are from Wikimedia or Wikipedia unless otherwise noted.