**For a thousand years, the universe has done a marvelous job keeping its secrets to science.**

The ancient Greeks thought that the universe consisted of a fixed star orbiting the planets that orbited the planets orbiting the center of the Earth. Even Copernicus, who in the 16th century aptly replaced the sun with the Earth, considered the universe to be a single solar system surrounded by a star-studded outer circle.

But in the centuries that followed, the universe revealed another dimension. It had countless stars and galaxies, and they are now called galaxies.

Then, in the late 1920s, the universe revealed its most secret: It grew ever more significant. Rather than being stable and stable, the only permanent thing, the universe continues to grow. Remote observations of the galaxy showed the plane separately, suggesting that the present universe is an old celestial body born long from the explosion of a small energy cell.

It was a miracle that shook science to its foundations, subverted philosophical ideas about its existence, and ushered in a new era of cosmic science, the study of the universe. But even more surprising, in hindsight, that deep-seated secret was already blamed on the mathematician whose experts predicted the weather.

One hundred years ago this month (May 1922), Russian mathematician Alexander Friedmann wrote a paper based on Einstein’s theory of relativism, outlining the many possible histories of the universe. One such explanation was the expansion of the atmosphere from one location to another. Even without considering any astronomical evidence, Friedmann expected the Big Bang theory of the birth and evolution of the universe.

“Friedmann’s new cosmic vision,” writes Russian natural scientist Vladimir Soloviev in a recent paper, “has become the basis of modern cosmology.”

Friedmann was not well-known at the time. He graduated in 1910 from St. Petersburg University in Russia, studying mathematics and physics. In graduate school, he investigated the use of mathematics in meteorology and atmospheric dynamics. He used that technology to help the Russian air force during World War I, using statistics to predict the release of bombs from enemy targets.

After the war, Friedmann studied Einstein’s theory of relativism, describing gravity as a manifestation of spatial geometry (or, more accurately, space-time). In Einstein’s view, the masses distort the atmosphere, producing a period of “bending,” making the groups appear attractive.

Friedmann was particularly impressed with Einstein’s 1917 paper (and Willem de Sitter’s paper) which uses common sense throughout the universe. Einstein discovered that his early figures allowed the universe to expand or shrink. But he considered it unthinkable, so he added a word representing the disgusting (thinking) power that would keep the vastness of the universal constant. Einstein concluded that the universe had a beautiful curve (such as the surface of a ball), meaning that the universe was “closed,” or infinite.

Friedmann adopted the new term, called cosmological constant, but pointed out that the universe may reflect significantly different behavior with varying degrees of consistency and other assumptions. Einstein’s dry atmosphere was a unique story; the universe may also expand permanently, or extend for a while, then shrink to a point and begin to expand again.

Friedmann’s paper describing the ever-changing universe, entitled “On the Curvature of Space,” was approved for publication in the prestigious Zeitschrift für Physik on June 29, 1922.

Einstein refused. He wrote a dissertation in the journal claiming that Friedmann had made a math error. But it was Einstein’s fault. He later admitted that Friedmann’s figures were accurate while denying that they were physically fit.

Friedmann insisted.

He was more than just a pure mathematician, disregarding the literal meanings of his marks on paper. His deep appreciation for the relationship between mathematics and the universe convinced him that mathematics meant something real. He even authored a book (The World as Space and Time) that explored the intricacies of the geometry of geography and the movement of physical bodies. Physical bodies “translate” the “geometric world,” he said, enabling scientists to explore the possible geometric world in which humans live. Due to the association of physics-math, he denied that “it is possible to determine the geometry of the geometry of the earth by using observational studies of the physical world.”

So when Friedmann found Einstein’s mathematical solutions, he translated them into possible real-world interpretations. Depending on several factors, the universe may have grown out of nowhere or formed from the original but limited form. In one case, the universe began to slow down, but then it started to evolve, and then it began to expand rapidly. At the end of the 20th century, astronomers concluded that the universe had taken such a course, an astounding phenomenon almost as dramatic as the universe’s expansion. But Friedmann’s statistics had predicted that this would happen.