Al Owski’s Reviews > On the Origin of Time: Stephen Hawking's Final Theory > Status Update

“if determinism, the probabilistic predictability of the universe on the basis of scientific laws, were to break down in the presence of black holes, how could we be sure it doesn't break down in other situations? How could we be sure of our own history, and our memories? "The past tells us who we are" Stephen noted pointedly. "Without it, we lose our identity." ”

“As such the black-hole information paradox became a beacon in the search for a unified theory. Physicists felt that if they could disentangle Hawking's knot and understand what happens to the hidden information when black holes cease to be, they'd be well on their way to marrying the principles of relativity and quantum theory into a single coherent framework.”

“The paradox of the fate of information locked inside evaporating black holes became the most vexing puzzle in theoretical physics of the late twentieth century, bedeviling not one but two generations of physicists. It is in some ways the contemporary analogue of the Mercury anomaly in the nineteenth century, the wobble in Mercury's orbit that defied Newton's theory.”

“This was the first glimmer of holography in modern physics: The storage capacity of black holes isn't determined by their interior volume but by the area of their horizon surface. It is as if black holes do not have an interior but are holograms.”

“Bekenstein and Hawking's entropy formula predicts that black holes have a truly gigantic information storage capacity. Black holes are likely the most space-efficient storage devices in the universe indeed. According to their formula, Sagittarius A, the huge black hole of 4M sun masses lurking in the center of the Milky Way—the shadow of which was first imaged in the spring of 2022—can store no less than 10^80 GB.”

“Hawking's formula exhibits the interplay of different areas. By combining principles from quantum theory and general relativity, Hawking had taken a mathematical risk, but he was rewarded with an insight that neither relativity nor quantum theory alone could ever have provided: Black holes radiate.”

“Today, whenever Planck's spectrum shows up in nature, physicists take this as a telltale sign of an underlying quantum process. This was precisely the sort of process Hawking considered. Stephen looked at black holes from a semiclassical angle, studying the quantum behavior of matter moving about in the classical, warped geometry of a black hole.”

“The 2.7 Kelvin cosmic microwave background radiation, for example, is black-body radiation. It tells us that even the entire observable universe behaves like an ordinary radiating body. In the year 1900, Planck's theoretical derivation of the spectrum of black-body radiation marked the dawn of the quantum revolution.”

“In A Brief History of Time, the early (bottom-up) Hawking famously wrote, "Even if we do find a theory of everything, it is just a set of rules and equations. What is it that breathes fire into the equations?" The answer of the later (top-down) Hawking was: observership. We create the universe as much as the universe creates us.”

“We started out searching for a deeper explanation of the universe's fitness for life in the physical condition at the origin of time. But the quantum cosmology we developed to this suggests we were looking in the wrong direction. Top-down cosmology recognizes that, much like biology's tree of life, physics tree of laws outcome of a Darwinian-like evolution that can only be understood backward in time.”