In 1900, what scientists understood about the universe was limited to a small part of the Milky Way and most scientists, including the two giants in physics, Isaac Newton in the 1500s and Albert Einstein in the first three decades of the 1900s, considered what they saw of the universe was an orderly stable affair with no beginning or end.

Cracks in that view came in the 1920s from theoretical physicists such as Lemaitre, who, after examining Einstein’s equations for general relativity, realized that far from a stable affair, the universe was expanding.

Then observations by the astronomer Erwin Hubble revealed that galaxies close enough to see with one of the largest telescopes of the day were speeding away from one another and faster, the further away they were, all carried by an expanding universe.

If so, it was reasonable to suggest that the universe must have been very much smaller at one time, a hypothesis which led some theoretical physicists to suggest that the universe had a beginning with a sudden violent burst of energy.

That moment became popularly known as the Big Bang, a term derisively coined by the famous astronomer Frank Hoyle, who vigorously opposed the whole notion of a Big Bang. At this point, theoretical and experimental physicists were stuck.

The first solid scientific evidence for the Big Bang and subsequent expansion of the universe began when Arno Penzias and Robert Wilson, working then at Bell Labs, were frustrated by faint radiation in the microwave range seemingly emanating from all directions in the universe, which was interfering with their unrelated projects.

The two men systematically and scrupulously excluded any earthly sources for the radiation but had no idea what was causing the radiation. They shared their finding with James Peebles and colleagues, who immediately grasped the significance of the findings because that’s precisely what they were looking for as evidence for the Big Bang.

Here, many billions of years later, was evidence of the radiation created in the Big Bang, now cooled to a few degrees above zero Kelvin and stretched by the expanding universe into the microwave range — what became known as the cosmic background radiation.

Key to the Big Bang theory was accompanying evidence that there were significant random variations in the distribution of that residual heat consistent with variations in the distribution of matter in the earliest universe for gravity to work on and create the earliest condensations of matter and stars.

Arno Penzias and Robert Wilson received a Nobel Prize for their observation and James Peebles and colleagues for recognizing its importance as solid evidence of that long ago violent explosion of energy and heat.

The evidence for the Big Bang hypothesis was now solid and consistent with George Gamow and his associates, who suggested that synthesis for all natural elements except hydrogen, helium and lithium took place in stars.

Since then, a blend of observational and theoretical studies has led to a model for the beginning of the universe and subsequent development of stars, galaxies and planets, which incorporates dark energy as the engine driving the universe’s expansion and dark matter.

Becauase it’s six times more common than the matter we’re familiar with, it must play a key role, together with giant black holes, in shaping gaseous clouds of hydrogen and some helium into stellar matter and planets, as governing the shape of whole galaxies and groups of galaxies.

Then along came the James Webb Space Telescope, which was designed to see light in the infrared range and thus much farther back in time than Hubble.

The standard model suggested that it would take more than half a billion years to create mature galaxies and stars capable of creating heavier elements such as carbon.

To the surprise of many astronomers and theoretical physicists, this telescope revealed some large galaxies half that age or less, which suggests that they might have begun to form hundreds of millions of years earlier.

The observation of early galaxy and star formation raises several questions.

Is the standard model wrong, if so, what’s assumptions were wrong or left out, or as some wilder cosmologists suggest those, perhaps those “too early” galaxies might belong to an earlier more mature galaxy?

Many theoretical physicists speculate that there might be many galaxies.

The 2020 Nobel laureate, Roger Penrose, suggests that universes might be serial, ours followed the end of a previous galaxy and one that will follow the demise of our galaxy or as others suggest, there might be many, many other galaxies overlapping with one another in time — or does time even matter with speculations like that?

Some of those questions will never be answered if only because the universe is so much larger than the “observable” universe and well beyond any tools now available to search as well as the limits imposed by the speed of light.

This brief summary of the revolution in cosmology traces for little more than a century the scientific journey from set beliefs to massive changes in how we understand the universe writ large and the role of quantum physics in determining those earliest changes, which later created stars and thus all the elements and life itself.

That’s perspective on a grand scale.

Dr. William Brown is a professor of neurology at McMaster University and co-founder of the InfoHealth series at the Niagara-on-the-Lake Public Library.