*

“Physicist John Archibald Wheeler once speculated that perhaps the reason all electrons are alike is that there’s really only one electron, careening back and forth from the ends of time, weaving the fabric of the universe by crossing its own path innumerable times.”^{i}^{[1]}

***

“The *three-body problem* is the problem of taking the initial positions and velocities (or momenta) of three point masses and solving for their subsequent motion according to Newton’s laws of motion and Newton’s law of universal gravitation. A complete solution for a particular three-body problem would provide the positions for all three particles for all time given three initial positions and initial velocities. Unlike the two-body problem, in general, no closed-form solution for the three-body problem exists, and the time evolution of the system is believed to be chaotic.” ^{[2]}

***

“*Neutronium* is a hypothetical substance composed purely of neutrons. The term was coined by Andreas von Antropoff in 1926 for the conjectured ‘element of atomic number zero’ (with zero protons in its nucleus) that he placed at the head of the periodic table, denoted by a dash rather than a normal element symbol. Neutronium would have no electronic structure due to its total lack of electrons and could be classified as a noble gas. However, the meaning of the term ‘neutronium’ has changed over time. From the second half of the 20^{th }century onward, it’s also been used to refer to the extremely dense material theorized to exist in the cores of neutron stars, referred to in scientific literature as ‘*neutron-degenerate matter*’.” ^{[3]}

“A *neutron star* is the collapsed core of a giant star that had a total mass of between 10 and 25 solar masses. They result from a supernova explosion combined with a gravitational collapse, which compresses the core density to that of atomic nuclei*. *Due to such extreme conditions, electrons and protons combine to produce neutrons. Consequently, these stars consist almost entirely of neutrons, with fewer and fewer protons and electrons present the closer one moves toward the core. Neutron stars are the smallest and densest (non-theoretical) stars, having a radius on the order of 10 kilometers and a mass of about 1.4 solar masses. They’re so dense that one teaspoon of the star’s material would have a mass of approximately 6 billion tons, equivalent to about 900 times the mass of the Great Pyramid of Giza.” ^{[4]}

***

“At the center of a black hole is a gravitational singularity, a region where the spacetime curvature becomes infinite. This region is a single point, having zero volume, and although it has a finite mass, it can be thought of as having infinite density.” ^{[5]}

***

“Black holes are *punctures *in the fabric of spacetime.” ^{[6]}

***

“It’s been proposed that when a black hole forms, a white hole forms on the ‘other side’. Energy entering the black hole exits the white hole. Physicist Lee Smolin takes it a step further and suggests that the resulting white hole is the Big Bang of a new baby universe, and that in fact our universe was formed that way.”^{i[7]}

***

“What if the sun disappeared? It’s not going to happen ― matter and energy don’t vanish ― but let’s discuss it anyway as a thought experiment. Light from the sun takes eight minutes and twenty seconds to reach earth. So for a little over eight minutes after the sun disappeared, we’d have no idea. The sun’s gravitational grasp on our planet would also take eight minutes and twenty seconds to end. This is because gravity waves propagate at the speed of light. So the very moment we saw our sun disappear, we’d also lose its gravitational influence, and earth would fly out in a straight line tangent to wherever it was in its orbit.” ^{[8]}

***

“Perhaps it’s better to think of it ― not as the speed of light ― but as the speed of causality.”^{i[9]}

***

“What binds us to spacetime is our rest mass, which prevents us from flying at the speed of light, when time stops and where space loses meaning. In a world of only light, there are neither points in space nor moments of time. Beings woven from light would live nowhere and nowhen. Only poetry and mathematics are capable of speaking meaningfully about such things.” ^{[10]}

***

“Perhaps our universe is an elementary particle in a higher universe.” ^{[11]}

***

“Even if there is only one possible unified theory, it’s just a set of rules and equations. What is it that *breathes fire* into the equations and makes a universe for them to describe?” [Steven Hawking]

***

“Max Tegmark’s *mathematical universe hypothesis, *also known as the *ultimate ensemble theory,* is that the physical universe isn’t merely described by mathematics, but *is* mathematics ― all structures that exist mathematically exist ‘physically’ as well. Observers, including humans, are ‘self-aware substructures’. In any mathematical structure complex enough to contain such substructures, they’ll subjectively perceive themselves as existing in a physically ‘real’ world. Tegmark claims that the hypothesis has no free parameters.” ^{[12]}

This is how I’d phrase the idea. Our universe is described by one ‘set of rules and equations’ (or ‘mathematical structure’) out of the infinitely many sets of rules and equations that could possibly be expressed. Tegmark’s theory is that *every one of these* describes a universe ― all equally real ― one of which is ours. Not only that, these mathematical structures are *the only thing* that ultimately exist ― they *are* the universes. Our intuition that our universe is special ― that it has genuine, physical existence while all others are merely possible/imaginary ― is, in an important sense, an illusion.

***

“We might imagine that the quantum world ― delicate and dynamic ― is just too skittish for our clumsy instruments to pin down, like trying to locate a swiftly moving wasp that wants to avoid our caliper’s jaws. This, however, fails to do justice to the quantum description.

Quantum theory suggests that before we measure the wasp (the particle), it’s not a particle at all but something as big as a whale (a wave). However, if we think of the wasp as analogous to a measured quon and the whale as analogous to an unmeasured quon, then this still misses *the flavor* of a quantum measurement, because a wasp and a whale are still both physical objects. In the quantum description, an unmeasured quon *does not enjoy the same style of existence* as a measured quon. An unmeasured quon dwells in a more attenuated state of reality than the quons which appear on our phosphor screens.

While the wasp is real, imagine that the whale dwells not in the real world but *on the spirit plane*. Now we’re closer to the sense of the quantum description. Whenever a measurement occurs, something like a *ghostly* whale (immense, insubstantial, permeable, and wave-like) turns into something like a real wasp (minute, substantial, and particle-like).”^{i[13]}

*

*

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**Citations**

- Dennett & Hofstadter
- Wikipedia’s
*Three-Body Problem*article - Wikipedia’s
*Neutronium*article - Wikipedia’s
*Neutron**Star*article - Wikipedia’s
*Black Hole*article - (various sources)
- (source lost)
- Michael Stevens
- Matt O’Dowd
- Yuri Manin
- T. G. Cowling
- Wikipedia’s
*Mathematical Universe Hypothesis*article - Nick Herbert