On the Origin of Time Summary

Why does our universe seem perfectly designed to support life, and could it have been any other way?

1. The Universe Appears Tailor-Made for Life

Stephen Hawking proposed that the universe seems uniquely suited for the existence of life, raising the question: why does it seem this way? The laws of physics align to create conditions where life can thrive, but it didn’t have to turn out like this. If those laws were just slightly different, life as we know it would be impossible.

For instance, gravity plays a pivotal role in the formation of stars. If its pull were slightly stronger, stars would burn out too quickly for life to develop. Conversely, if gravity were weaker, stars might not form at all. Another example is the temperature variations in the early universe. Tiny differences helped form galaxies; larger differences would have led to black holes, while smaller ones would have prevented galaxies from forming at all.

Even the tiny difference in mass between protons and neutrons is vital. If their weights were reversed, neutrons would have decayed moments after the Big Bang. Without neutrons, atoms could not form, and neither could planets or living beings. Such fine-tuning highlights a deeper mystery about the universe and its laws.

Examples

• Stars rely on perfect gravity to sustain themselves for billions of years.
• Small temperature differences in the early universe enabled galaxies to form.
• The minimal weight difference between protons and neutrons made atoms possible.

2. Current Explanations Fall Short

Two competing explanations for the universe’s fine-tuning have dominated: the idea of a divine creator and the multiverse hypothesis. Hawking rejected both for similar reasons: neither can be scientifically tested or proven.

The divine creator hypothesis posits that an intelligent being designed the universe with specific laws to support life. While many believe this, it falls outside the realm of science because it cannot be falsified. On the other hand, the multiverse theory suggests there are infinite universes with varying laws, and ours happens to support life. But how can we verify or explore universes beyond our own, which are inaccessible to us?

Hawking wanted a testable, scientific theory. He knew that both these ideas couldn’t answer the core questions under the lens of scrutiny that science demands. His dissatisfaction pushed him to seek a new answer to how the universe operates.

Examples

• The divine creator idea lacks scientific proof or experimental support.
• Multiverse theory rests on speculation, not observable or testable phenomena.
• Karl Popper’s falsifiability principle highlights why these ideas fail rigorous scientific standards.

3. Time as the Fourth Dimension

Einstein's theories revealed time as more than just a concept; it is a dimension like up, down, forward, and back. Hawking expanded on this idea with the no-boundary proposal, which stated that time itself didn’t exist before the Big Bang. Time emerged from a quantum process alongside our spatial dimensions.

Hawking believed everything started as a tiny, dense point containing all the energy and matter of the universe. When this point began to expand, it also gave rise to time. In this view, there’s no “before” the Big Bang because there was no time to mark events. Time and space are intertwined, springing into existence together.

Over the years, Hawking began to revise his earlier beliefs, questioning whether the laws of the universe were eternal. Instead, he suggested these laws evolved along with the universe, shaped by time and quantum phenomena.

Examples

• Time was mathematically proven as a fourth dimension by Einstein.
• The no-boundary proposal posits time originated with the Big Bang.
• Hawking’s theory connects the emergence of physical laws with the evolution of the universe.

4. Physics Operating Like Evolution

Hawking realized that the universe's laws might have evolved similarly to how species evolve in biology. Just as natural selection shapes life, quantum phenomena might have shaped the universe’s laws just moments after the Big Bang.

He proposed a shift in focus from fixed, eternal laws to evolving, adaptable ones. Laws like gravity or electromagnetism could have emerged as probabilities solidified in the quantum chaos of the universe’s infancy. He began to view physics through the lens of biological evolution, moving beyond the earlier notion of immutable rules.

This perspective allowed Hawking to see the laws of the universe as contingent, not inevitable. It also opened the door to understanding how present observations might influence our understanding of past events.

Examples

• Evolutionary biology inspired Hawking’s view of physics.
• Laws of gravity and electromagnetism might have emerged as probabilities firmed up.
• Rejecting immutable rules allowed for more dynamic theories of cosmology.

5. Quantum Physics and Probability

In quantum physics, particles exist as probabilities rather than fixed points until measured. This idea fascinated Hawking and Hertog, who linked it to the evolution of the universe’s laws after the Big Bang.

For example, an electron does not have a predetermined location. Instead, it exists as a cloud of probabilities until observation fixes its position. Similarly, Hawking argued the laws of physics themselves may have existed as probabilities until the conditions of the early universe "chose" them through quantum selection.

Quantum rules defy normal logic, but they offer a framework to understand how our complex universe emerged from seemingly random possibilities.

Examples

• Electrons exhibit probabilistic behavior unless observed.
• quantum laws influenced early choices in the cosmic evolution of rules.
• Probability helped explain shifts in physical laws post-Big Bang.

6. Top-Down Cosmology Challenges Traditional Thinking

Hawking and Hertog introduced top-down cosmology, a view that human observation plays a role in fixing the universe’s past. This perspective flips the traditional approach to cosmology, which only focuses on how events move forward in time.

In top-down cosmology, observing the universe’s current state helps define what came before. It means the past is not completely independent of the present. This approach connects human observation with the existence of the laws that govern the cosmos.

The strange implication is that the act of studying the universe contributes to shaping its story, linking human perception directly to the early moments of cosmic evolution.

Examples

• Bottom-up cosmology focuses on forward-moving time; top-down involves observation influencing the past.
• The universe’s observed laws are “fixed” by scientists’ studies.
• Human role in cosmology extends beyond passive observation to active influence.

7. The Holographic Universe

Hawking embraced the idea that our universe could be a hologram. This means the three-dimensional world we perceive might be a projection of higher-dimensional data stored on a two-dimensional surface.

Evidence for this concept comes from black holes. Their immense gravitational fields store incredible amounts of information. Strangely, math shows this information corresponds not to the black hole’s three-dimensional volume, but to its two-dimensional surface area.

This theory helps explain how higher dimensions might influence our universe, offering a strikingly different way to think about space and matter.

Examples

• Black hole information aligns with surface area, not volume.
• Holographic principles suggest three dimensions are projections.
• Higher dimensions might influence our universe in imperceptible ways.

8. Running Out of Information at the Big Bang

Hawking and Hertog compared the universe to a digital image. As you zoom closer to the Big Bang, you “run out of pixels," or information, much like an image getting blurrier as you magnify it. This marked the limit of physics and time itself.

Approaching the Big Bang in their equations revealed that nothing existed before it—not even time. This ultimate blur suggests that the dimensions of existence only came into being when the universe began to expand.

Their findings offer an extraordinary perspective: before the Big Bang, there was no "before."

Examples

• Universal bits of information diminish as you approach the Big Bang.
• The Big Bang marks the beginning of time and space.
• Time ceases to exist in quantum calculations before the Big Bang.

9. Questioning Timeless Laws

Hawking’s final theories dispelled the idea that physics is immutable. Instead, he saw the laws as adaptable, shaped by quantum realities and evolving in tandem with the universe.

This dynamic perspective helps address why our universe seems so perfectly calibrated for life. Rather than being arbitrary or fixed, physics could have “selected” the conditions leading to life from among countless probabilities.

This opens exciting avenues for understanding life’s place in the cosmos and the true nature of physical realities.

Examples

• Hawking rejected eternal immutability in physics.
• Quantum probabilities determined the physical constants of the universe.
• Evolving laws of physics explain life-friendly universal conditions.

Takeaways

1. Reconsider fixed assumptions about reality. Explore the possibility of evolutionary and adaptable systems in science and beyond.
2. Develop curiosity about cutting-edge ideas like quantum mechanics and holography, even if they challenge long-held beliefs.
3. Embrace the concept that observation plays an active role in shaping the world, both in science and daily perspectives.