Chapter 147: The Greatest in the Universe

Amidst days that bordered on the monotonous and dull, the primary pillar of support for Hua Feng was the unwavering backing of Yunmeng by his side. He knew that for the sake of his family and the countless beautiful things in this world, he had to persevere with all his might.

I will try even harder! Hua Feng would silently tell himself this every single day.

It inherits all the achievements of the Big Bang theory and modern cosmology; it explains a series of problems that the Big Bang theory could not resolve, including why the temperature across the universe is so uniform, why space is so flat, and why high-energy remnants such as magnetic monopoles have not been found, among others. At the same time, it explicitly puts forward five testable predictions, four of which have already been confirmed. The only unconfirmed—and difficult to confirm—prediction is the multiverse.

Inflationary theory posits that inflation can cause space to expand exponentially and rapidly. This explains why our universe is so uniform and so immense. Once inflation ended, our universe became filled with matter and radiation—everything we observe in the Big Bang. The universe we have today was formed through sufficient inflation. However, according to the same theory, it can be deduced that around the regions where inflation has already ceased, there may still exist many areas where inflation has not yet stopped. This theoretically existent phenomenon is known as "eternal inflation."

There are three major criteria for determining whether a theory is mature and scientific. They are:
Whether it can reproduce the results of the original theory; whether it can explain results that contradict the original theory; and whether it can make new, testable predictions.

Because it cannot be verified, nor can it predict how to verify it, the multiverse is neither a scientific theory nor a scientific hypothesis, but rather a personal hypothesis. The multiverse theory in itself is not a scientific theory. It is actually a deduction made based on currently known laws of physics.

For the universe we inhabit, the multiverse theory offers little explanatory power. It cannot solve the problems we currently face. Worst of all, it fails to provide us with any testable predictions.

First and foremost, this means that if our understanding of this universe and its history is correct, the multiverse might genuinely exist. Yet, the Big Bangs that gave birth to these universes have no connection whatsoever to our own. At the same time, however, all of this remains surreal. Even in theory, it cannot be tested—unless we could recreate cosmic inflation and then send observers into different inflationary zones.

The multiverse theory will forever remain a physical deduction. It may well be an inevitable deduction, but until it is tested, it cannot be called science. In fact, we may never be able to test it at all. It is a meaningful theoretical conjecture, but not a scientific theory. And because the universe has imposed limitations upon us, the multiverse may never become a scientific theory. It belongs to a physics-based "metaphysics." We can learn information about the interior of this universe through scientific methods, but this universe itself is ultimately finite.

For instance, many people are fascinated by the "extremes of the universe."

The coldest place in the universe: Recent studies suggest that the Boomerang Nebula may be the coldest place in the universe, with a temperature of only minus 272 degrees Celsius. The Boomerang Nebula is located 5,000 light-years away from Earth.

The hottest planet in the universe: Kepler-70b is the hottest known exoplanet, with temperatures potentially soaring up to 7,000 degrees Celsius. Its orbit is also extremely close to its star, even closer than the distance from Mercury to the Sun.

The coldest planet in the universe: OGLE-BLG-390L is the coldest planet discovered to date. With a mass five times that of Earth, it is believed to be a rocky planet and is also one of the most distant planets from Earth, situated approximately 28,000 light-years away. Its surface temperature is a mere minus 220 degrees Celsius, lower than the boiling point of liquid nitrogen and approaching absolute zero (-273.15 degrees Celsius).

The largest star in the universe: UY Scuti is currently the largest known celestial body, a red hypergiant located in the constellation Scutum. Its radius is 1,708 times that of the Sun, meaning 1,708 Suns placed in a single row. It is located about 9,500 light-years away from Earth.

The fastest-spinning star in the universe: VFTS 102 is the fastest-spinning supermassive star discovered thus far. The star's equatorial region whirls around its axis at a blistering speed of 600 kilometers per second. Due to centrifugal force, this extraordinarily high rotational speed almost tears the star apart. It is extremely hot and highly luminous, shining 100,000 times brighter than the Sun, and is located in the Tarantula Nebula within the Large Magellanic Cloud.

The smallest scale of matter in the universe: The smallest known particles in the known universe are quarks. Unproven new theories suggest that superstrings (not yet a scientific theory), singularities, and space bubbles (not yet a scientific theory) are all roughly the size of the Planck scale. The Planck scale is $1.6 imes 10^{-35}$ meters.

The Planck scale is considered to represent the theoretical lower limit for measurable scales. According to the uncertainty principle, no instrument can measure smaller scales because within that realm, matter exhibits probabilistic and indeterminate characteristics. This scale is also regarded as the dividing boundary between general relativity and quantum mechanics. Scientists believe that all of the universe's smallest constituents are likely roughly the size of the Planck length.

The fastest transmission speed of information in the universe: Studies show that no matter how rapidly information is transmitted, its speed cannot exceed the speed of light. This suggests that Einstein's speed limit theory remains unassailable.

Quantum entanglement technology is a secure encryption technology for transmitting information and has nothing to do with faster-than-light travel. Although we know the speed at which these particles "communicate" is thousands of times the speed of light, we cannot utilize this connection to control and transmit information at such speeds. Therefore, Einstein's rule—that nothing can move faster than the speed of light—still holds true.

"Information" refers to any signal capable of acting upon an object or system; for example, a pulse of light can turn on an instrument. Researchers have proposed that even if some leading photons within a pulse of light exceed the speed of light, the pulse will only take effect once the majority of the photon cluster arrives. This means that leading superluminal photons cannot convey any information. Superluminal speeds that cannot transmit information are meaningless; for instance, cosmic expansion exceeds the speed of light, yet it cannot transmit information.

The brightest quasar in the universe: SDSS J0100+2802 boasts the largest black hole mass and luminosity among known distant quasars. Its luminosity is 430 trillion times that of the Sun, and it is located 12.8 billion light-years away from Earth.

The mass of its central black hole is approximately 12 billion solar masses, having formed about 900 million years after the Big Bang. It is currently the quasar with the highest luminosity and the largest black hole mass in the distant universe. By comparison, the black hole at the center of the Milky Way has a mass equivalent to only 3 million suns. Quasars are dazzling celestial bodies formed by central black holes violently devouring surrounding matter.

The largest planet observed in the universe so far: KR Pyxidis b is the largest observed planet (and brown dwarf), with a radius 6.8 times that of Jupiter, the "giant" of our solar system. It is located 320 light-years away from Earth. Its mass is 20 $M_J$, and this star is the only newly born planet ever directly observed.

The fastest-orbiting planet in the universe: The fastest-orbiting planet is SWEEPS-10, which maintains a distance of 1.19 million kilometers from its host star—three times the distance between the Earth and the Moon. This means that a single orbit for this planet takes a mere 10 Earth hours.

The heaviest black hole in the universe: OJ 287 is the heaviest invisible black hole observed to date, with a mass 18 billion times that of the Sun.

The brightest space object in the universe: The long-duration gamma-ray burst GRB 080319B erupted in March 2008 and could be observed with the naked eye from the ground. Its brightness was equivalent to 10 million ordinary galaxies, yet its distance from Earth is a staggering 7.5 billion light-years.

The fastest runaway in the universe: Star HE 0437-5439 speeds across the Milky Way at a velocity of 1.6 million miles (2.57 million kilometers) per hour.

The busiest galaxy in the universe: Astronomers have observed that galaxy GOODS 850-5 is the busiest galaxy, producing 4,000 stars per year during the early stages of the universe's formation, whereas the Milky Way generates only 4 stars per year.

The most distant galaxy in the universe: A 13-billion-year-old galaxy formed 700 million years after the Big Bang, yet the light from this most distant realm has only just reached Earth. The bright, star-forming state we currently witness represents the early epoch of this galaxy.

The smallest black hole in the universe: Using the quasi-periodic oscillation (QPO) method, astronomers discovered the smallest black hole known to date. It has a mass of only 3.8 times that of the Sun and is located within the galactic binary star system XTE J1650-500.

The largest and heaviest quasar in the universe: This is an extremely luminous, broad-absorption-line, radio-loud quasar named Ton 618. Its event horizon spans 384 billion kilometers, and its mass is 66 billion times that of the Sun, residing far away in the constellation Canes Venatici, 10.4 billion light-years distant. Contemplating this makes Sagittarius A* (the black hole at the center of the Milky Way) feel utterly minuscule.

The most hellish planet in the universe: Planet HD 149026b is a charcoal-dark world that absorbs massive amounts of radiation from its extremely close host star, driving its surface temperature to a scorching 3,700 degrees Fahrenheit, far above the boiling point.

The brightest supernova in the universe: Supernova 2005ap is 100 billion times brighter than the Sun and 300 times brighter than an ordinary supernova. Fortunately, this supernova is located 4.7 billion light-years away from Earth.

The theoretical highest temperature in the universe: When an object reaches ultra-hot temperatures, it emits diminishing wavelengths (corresponding to increasing frequencies and escalating energy). Theoretically, there is a lower limit to the wavelength of radiation (corresponding to an upper limit of energy). Planck's law posits that energy cannot increase indefinitely; otherwise, unimaginable rays would be generated. The limit point is approximately $1.416833(85) imes 10^{32}$ K, commonly referred to as the Planck temperature.