Chapter 129: Theory of Spacetime

Hua Feng understood that the concept of a wormhole originally arose from studies of the Schwarzschild solution. Physicists analyzing white hole solutions, through a thought experiment by Albert Einstein, discovered that the fabric of spacetime itself need not be flat. In curved spacetime, such a structure implies that parts within a black hole’s event horizon could connect with other regions of the universe.

A wormhole links a black hole and a white hole, transmitting matter between them. Here, the wormhole acts as an Einstein-Rosen bridge: matter is completely broken down into fundamental particles at the black hole’s singularity, then transported through this wormhole to the white hole, where it is emitted outward.

Wormholes can serve as hyperspatial corridors and may also manifest within the universe’s normal spacetime. Unlike black holes, wormholes lack an event horizon; they only have a boundary interface with the external world through which they facilitate super-spatial connections. The interface between a wormhole and black or white holes is a spacetime tunnel connecting two closed regions of spacetime. Because the curvature of spacetime here is not infinitely large, one can safely traverse a wormhole without being destroyed by overwhelming gravity.

Black holes, white holes, and wormholes remain unresolved mysteries within cosmology’s exploration of spacetime and gravitation. Whether black holes truly exist has only been supported by indirect evidence so far. Observations and theoretical work continue to pose new questions in astronomy and physics. For example, when a cold star capable of forming a black hole collapses, its density surpasses that of atomic nuclei, nucleons, and neutrons. If the collapse continues, even neutrons might be crushed.

What then are the fundamental constituents inside a black hole? What repulsive force counteracts gravity to halt the collapse at some stage? Without such repulsion, a black hole would collapse endlessly to an infinitesimal volume with infinite density and pressure, a scenario forbidden by physical theory.

Currently, the cosmological constant is nearly zero.

Physicists have long believed that the immense gravity of wormholes would destroy anything entering them, rendering them unsuitable for space travel. However, if wormholes do exist in the universe, one might say: if you stand at one end (the entrance) of a wormhole at noon, you would emerge from the other end (the exit) at noon as well.

Wormholes, also known as Einstein-Rosen bridges, are narrow tunnels potentially connecting two distinct points in spacetime.

Two natural mechanisms generate wormholes:

First, the powerful gravitational energy of black holes.

Second, the rapid rotation of Kerr black holes, whose Lense-Thirring effect tears small openings in the surrounding energy layers. These openings, under the influence of gravitational and rotational energy, become tiny wormholes. The black hole’s gravity helps determine their exits, but full formation remains incomplete, as quantum theory and relativity have yet to be fully unified.

Wormholes appeared almost simultaneously with black holes in the Schwarzschild solution, first considered when physicists conceived of white holes. Through Einstein’s thought experiment, they understood that spacetime could be curved rather than flat.

Consider a classic model of a wormhole: matter is reduced to fundamental particles at the black hole’s singularity, then transported via the wormhole (the Einstein-Rosen bridge) to the white hole, from which it radiates outward.

Of course, this only describes wormholes as conduits between black and white holes, but their function extends far beyond that. Wormholes can also connect black holes to one another. Such connections might form a cosmic prison, as some speculate. Others suggest that when carbon neutrinos inside white and black holes annihilate each other, they produce infinite energy and spacetime distortions, potentially enabling a “prison break.” For example, a strongman locked in a cage has several escape methods: bending the bars or starving himself thin enough to slip through. Wormholes not only serve as connecting passages but also appear suddenly in normal spacetime as hyperspatial channels.

Since wormholes have no event horizon, one can safely pass through without being destroyed by massive gravity.

Wormholes might allow passage from a finite moment to an infinite point in time, potentially linking the present with the future.

As early as the 1950s, scientists studied wormholes. Due to historical limitations, some physicists believed that although wormholes might theoretically exist, their intense gravity would destroy anything entering them, making them unsuitable for space travel.

The possibility of “instantaneous travel” through wormholes resembles super-spatial transitions.

With advancing technology, new research shows wormholes’ intense fields can be stabilized by “negative energy,” balancing the energy field. Scientists believe that relative to “positive matter” which produces energy, “antimatter” holds “negative mass” that can absorb surrounding energy. Like wormholes, negative mass was once considered purely theoretical. Yet many laboratories worldwide have now demonstrated negative mass’s existence in reality, and spacecraft have even detected trace amounts in space.

Scientists speculate millions of wormholes permeate the cosmos, though few exceed 100,000 kilometers in diameter—the minimum width for safe spacecraft travel. The discovery of negative mass offers new opportunities to expand and stabilize these minuscule wormholes.

Researchers propose that injecting negative mass into a wormhole could open and reinforce its structure, rendering it stable enough for spacecraft to traverse.

However, wormholes can only lead to the past. The so-called “instantaneous travel” exploits the time difference between the two ends of a wormhole. For example, point A’s time runs faster than point B’s; time flows from high to low like water. Thus, from A, one can travel through the wormhole to B, experiencing minimal elapsed time upon arrival. Conversely, traveling from B to A is impossible due to the temporal gap, causing a discontinuity. Departing from the faster time point A ensures temporal continuity upon arrival at B.

Regarding wormhole properties, under relativity and excluding certain quantum effects and non-gravitational energies, we obtain simple, fundamental descriptions. While crucial, these are secondary to black hole studies, so here we only briefly summarize wormhole characteristics without delving into detailed theories.

What are wormholes’ essential properties? Primarily, relativity describes them as cosmic expressways. Yet quantum theory distinctly reveals that wormholes cannot serve as universal superhighways. Their existence depends on an exotic property and matter: negative energy.

Only negative energy can sustain a wormhole’s open interface with external spacetime. Dirac’s work in the Finkelstein reference frame showed that choosing different frames can simplify or complicate physical problems. Similarly, negative energy is more readily realized in certain frames because energy measurements depend on the observed object’s velocity.

This insight is crucial in membrane gauge theory. Depending on the reference frame, negative energy is easily attainable. When objects approach a wormhole at near-light speed, the surrounding energy naturally becomes negative. Therefore, only objects traveling close to light speed can enter a wormhole; otherwise, entry is impossible.

This is one of wormholes’ unique properties.

Time varies with the universe’s changes. Time is a dependent variable—the essence of time expressed in Deng’s time formula:

t = T(U, S, X, Y, Z, ...)

where U represents the universe; S denotes spacetime coordinates (X, Y, Z, ...) and events in sequence.

Time measures the order of cosmic events.

What is time? It is the metric of the sequence in which cosmic events occur.

Time is not an independent variable but changes with the universe.

t = (S₁, S₂, S₃, ..., Sₙ)

Deng’s time formula represents the sequence of world events, where S₁, S₂, S₃, ..., Sₙ denote events 1, 2, 3, ..., n in order. Time is the sorting and measurement marking of these event sequences.

“Time” is a categorical term for measuring the duration and order of events.

Humans use time as a parameter to describe processes of matter movement or event occurrences, establishing time through the regularity of unaffected periodic changes—such as the Moon’s orbit around Earth, Earth’s orbit around the Sun, Earth’s rotation, or atomic oscillations.

Mathematically and physically, time is represented on axes.

What phenomena arise with time? How can understanding time’s nature illuminate issues like aging? Detailed analysis follows, including why some events can be simultaneous while others cannot, and what time’s relation is to us.