Night at the Museum
Even on sunny afternoons, one can find stars in a planetarium. A tour of New York's bright lights has included Times Square, the Christmas tree at Rockefeller Center, and Grand Central Terminal. American Museum of Natural History recently starred in NIGHT AT THE MUSEUM. The movie reminded us what an adventure this place is, for one could spend days here without seeing everything. Within the glass cube of its Rose Center for Earth and Space, a gigantic sphere marks Hayden Planetarium. The current show, COSMIC COLLISIONS, is narrated by Robert Redford and features breathtaking images of asteroids and meteors. Though New York lights drown out the stars, this place is a reminder of how Space can touch our lives.
The sphere's lower half is home to a circular Big Bang Theatre, with a show narrated by Maya Angelou. The winding exit ramp is a Big Bang Walkway with milestones of cosmic evolution marked along the tour. While "inflation" and "dark energy" are not on this guest list, Rose Center has at great expense built a model of our spherical Space/Time. Complementing this space are models of the planets, further reminders of the beauty of spheres.
We learn about the Greek Pythagoras via the straight sides of triangles, but he was also interested in spheres. He encouraged men and women to have many interests, making contributions to music and astronomy. As a musician, he is credited with the idea that “music of the spheres” described the planets. Reasoning that it was the most harmonious shape, he theorised that Earth was spherical. Today’s science seeks to explain the Universe from such principles.
To please his musician’s ear, Pythagoras sought a “cosmic harmony.” As a mathematician, Pythagoras was inspired to claim that “all is numbers,” meaning that everything in the world could be described by equations. This idea is the basis of modern physics. Pythagorean ideas began a quest that would last thousands of years, to find equations describing the Universe.
Everyone should own a book called "RELATIVITY: A Clear Explanation that Anyone Can Understand" by Albert Einstein. For about 6.95 US you will get a better view of the subject than any imitator book. In Chapter 31 Einstein dares to imagine the entire Universe. He tries to follow a Cosmological Principle that the Universe looks the same from all locations. Like Pythagoras, he reasons that the most harmonious shape is a sphere. Using General Relativity, Einstein predicts that enough mass will cause Space/Time to be curved into a sphere of 4 dimensions, of which our 3 dimensions are just the surface.
Einstein also realised that gravity would cause this spherical Space/Time to collapse, unless it were supported by some repulsive force. Taking the Cosmological Principle into 4 dimensions, he desired a Universe that looks the same at all times. Here Einstein made the blunder of introducing a "cosmological constant" to prevent the sphere from collapsing. Later Alexander Friedmann and Georges Lemaitre independently found solutions to Einstein equations indicating an expanding Universe. Edwin Hubble's observations of redshifts finally allowed Einstein to drop the cosmological constant
The simple expression R = ct predicts that the Universe expanded from a tiny point. When t was tiny, c was enormous and the Universe expanded like a Bang. Maya Angelou and a preponderance of evidence support the "Big Bang." According to one paradigm, faster-than-light inflation would have expanded the radius so much that its sphere would be to our perception flat. When pressed, even inflation theorists admit that on the largest scales the Universe must be spherical. It is not topologically possible for a tiny point to expand into flat Space. According to General Relativity, even the smallest mass will cause Space/Time to be curved.
Views of the Cosmic Microwave Background may also indicate a spherical Universe. By measuring distances between acoustic peaks, scientists hope to complete a triangle and determine curvature. When a changing speed of light is accounted for, the angles do not add up to 180 degrees and the triangle is not flat. Most telling, the scale of density fluctuations is nearly zero for angles greater than 60 degrees. Like a ship disappearing over Earth's horizon, the lack of large-angle fluctuations is smoking-gun evidence that the Universe is curved. Both lines of CMB data indicate that the curvature has radius R = ct.
According to fashion magazines, it was fashionable to believe that the Universe was flat, like the Earth. Large objects under the influence of gravity, even raindrops, tend to form spheres. The Universe is very, very large. The flat vs. sphere debate once raged about Earth, and everyone knows which side won. Even the work of mathematician Gregory Perelman and the Poincare Conjecture predict a spherical Space. The Universe model at American Museum of Natural History hints that the sphere will win again. The only missing ingredient is "GM=tc^3" written on the side.