From: mk_thisisit
The universe is often described as a symphony, a reflection of emotions capable of creating new worlds [00:00:00]. God’s plan, in this context, would be cosmic music resounding in 11-dimensional hyperspace [00:00:21]. According to Michio Kaku, string theory can be summarized as an equation one inch long [00:00:41].
The Grand Challenge of Physics: Unification
For two thousand years, physicists have researched the nature of the universe, leading to two great concepts:
- Theory of Relativity: Describes great things like the Big Bang and quasars [00:02:01].
- Quantum Theory: Describes small things [00:02:10].
These two fundamental theories, quantum mechanics and relativity, are currently incompatible with each other [00:02:24]. This incompatibility represents the biggest problem in physics: how to combine the macroscale theory (relativity) with the microscale theory (quantum mechanics) [00:02:35]. Attempts to add quantum mechanics to relativity have historically caused theories to “blow up” [00:03:19]. The ideal scenario would be to combine general relativity with quantum mechanics [00:01:34].
String Theory as the Unifying Principle
Today, string theory is presented as the leading and only theory that could potentially combine both relativistic and quantum concepts [00:02:44]. It is a very controversial theory, as its correctness cannot be confirmed due to the inability to test it directly [00:02:54]. Despite this, it remains the only sophisticated theory available for this unification [00:05:05].
The purpose of physics, ultimately, is to find a unifying principle that explains many phenomena [00:09:03]. For Michio Kaku, this moment of understanding came when he realized string theory is a theory of music [00:09:09].
The Universe as a Symphony of Strings
In simplified terms, string theory is a theory of music [00:05:16]. Just as different notes can be played on a violin string, subatomic particles like protons, neutrons, and neutrinos are considered different vibrations of a tiny string [00:05:21]. Particles are essentially “notes” created by a vibrating string [00:05:41]. From this perspective:
- Physics embodies the laws of harmony of such vibrating strings [00:05:49].
- Chemistry is the theory of the interaction of these strings [00:05:53].
- The universe itself is a symphony of strings [00:06:05].
Albert Einstein spent his last 30 years attempting to find God’s plan, which, in this framework, would be cosmic music resonating in 11-dimensional hyperspace [00:06:12]. String vibrations are considered the only paradigm complex enough to explain the entire universe [00:09:47].
In 1968, when Michio Kaku began working on string theory, it was a collection of random equations [00:10:04]. He believed there had to be a “string field theory” to connect these equations, which he subsequently developed [00:10:22]. This string field theory connects all the equations that make up string theory, and Kaku refers to it as “my equation” [00:10:34].
Dimensions in String Theory
String theory suggests that space-time may have more dimensions than the three spatial dimensions and one time dimension we commonly perceive [00:04:09]. Early versions of the theory concluded that it only worked if space-time had 26 dimensions [00:04:09]. Later versions suggested 10 or 11 dimensions [00:04:30].
Unlike Newton’s laws, which can exist in any dimension, string theory is unique in that it dictates its own dimensions, being stable only in 10 or 11 dimensions [00:13:02]. Our current understanding suggests that the Big Bang may have occurred in 11 dimensions, not just three, and our universe is a “bubble” formed after this explosion, which happens to have three dimensions [00:13:44].
Multiverse and String Theory
The multiverse theory proposes an infinite number of universes, not just one [00:14:34]. The Big Bang, from this perspective, is understood as the collision of these “bubbles” or universes [00:14:26]. New universes are created at any moment, even during conversations [00:15:13]. This concept implies that string theory has an infinite number of solutions, each representing a different course of Big Bangs [00:15:01]. While compelling, there is currently no concrete evidence for the existence of the multiverse; these are still hypotheses [00:15:22].
Dark Matter and String Theory
String theory is not only a theory of electrons, protons, and neutrons; it is also a theory of music with notes “higher” than these known particles [00:15:43]. It is hypothesized that these higher notes are created by dark matter [00:15:54]. Most of the universe is not made of atoms but of a new substance, which string theory suggests could be another “octave” of the string [00:16:07]. The number of octaves a string has is infinite, similar to the infinite forms of matter that could exist, including dark matter [00:16:19]. String theory is currently the only theory developed enough to explain both normal matter and dark matter [00:16:40].
Limitations and Criticisms of String Theory
One significant limitation of string theory is that it cannot be tested directly [00:02:57]. The particles it describes have energy levels far exceeding what can be produced on Earth [00:07:21]. This means that humanity is currently too primitive to investigate string theory through experimentation; it can only be played with conceptually [00:07:26].
Despite Michio Kaku’s 17 years of work on the subject, including his doctoral thesis, he found that string theory did not answer the basic fundamental questions he had when he began his research [00:07:41]. He also noted that it “ruins the beauty” of the general theory of relativity, which he finds incredible [00:08:01].
However, the reality remains that while many great scientific minds, such as Heisenberg and Wolfgang Pauli, attempted to combine quantum mechanics with relativity, they failed, and only string theory has survived so far [00:08:18].
Consciousness and Quantum Mechanics
The question of whether human consciousness exists at the quantum level is a major mystery in science [00:33:30]. While some suggest ordinary mechanics can explain the brain through transistors and circuits, it’s also proposed that quantum mechanics plays a role, especially in relation to free will [00:34:03].
Free will is defined as the ability to be independent and creative, without external commands or a prepared scenario [00:34:15]. Robots, being mechanical and deterministic, lack free will [00:34:32]. If human consciousness involves more than just calculations, then artificial intelligence might never achieve consciousness [00:34:50]. Quantum mechanics introduces uncertainty, which allows for creativity, thinking, and consciousness [00:35:28]. Consciousness could be a by-product of quantum mechanics [00:35:35]. The “collapse of the wave function” in quantum mechanics, though not fully understood, is considered a potential source of this quantum element necessary for free will [00:36:05].
The Search for a Theory of Everything
At five years old, Michio Kaku was inspired by news of Albert Einstein’s death and his unfinished book – a “theory of everything” [00:23:20]. This “theory of everything” was meant to be an equation less than an inch long that would allow one to see God’s plan [00:24:16]. Kaku resolved then to be part of this great adventure and work on this project [00:24:33]. As a high school student, he even built a 2 million electron volt betatron particle accelerator in his mother’s garage, which often blew the house fuses [00:24:50]. This caught the attention of physicist Edward Teller, the inventor of the hydrogen bomb, and other physicists, leading Kaku to realize that technology “powers the universe” [00:25:39].
Kaku’s motivation to popularize science stems from his own childhood experience [00:44:11]. As a child, he sought information about the universe, the fourth dimension, and intelligent life but found nothing beyond comics [00:44:22]. He promised himself that if he became a physicist, he would share his knowledge with the next generation, making science more fascinating than comics and showing them the real cosmos [00:44:45].
The Future of the Universe and Civilization
Physics not only studies the beginning of the universe but also its end [00:17:49]. The Earth is projected to be absorbed by the sun in 5 billion years [00:17:57]. When the sun dies, it will not burn but freeze, an event set to occur in billions of years [00:18:02]. Other stars will similarly exhaust their nuclear energy and turn into ice [00:18:15].
If the multiverse theory is correct, our universe will likely freeze, leading to an eventual “freeze to death” for everything within it [00:18:39]. To avoid this, humanity might need to create a space-time “ark” or “lifeboat” to transport intelligent life from a dying universe to a young, new “bubble” [00:18:50].
Civilizations face a tendency towards self-destruction, with four main scenarios identified for Type I civilizations: nuclear weapons, biological weapons, global warming, and artificial intelligence [00:19:33]. Artificial intelligence, with its potential to harness all human technologies, could lead to self-destruction if used for the wrong purpose [00:20:02].
The concept of a time machine is theoretically possible, with time seen as a river with eddies that can even fork into multiple rivers [00:20:32]. Stephen Hawking argued that while travel to the future might be possible through time-space tunnels, travel to the past is problematic because it could create loops that accumulate energy and cause the time machine to explode [00:21:09]. However, if only one trip into the past is made, without an infinite loop, it might be possible given enough energy (Planck energy) [00:21:51].
Optimism for Progress
Michio Kaku maintains an optimistic view of humanity’s future [00:41:19]. While year-by-year history can seem depressing with disasters and wars, looking at progress over centuries reveals incredible advancements [00:41:46]. History, from a scientific perspective, shows a clear direction towards democratization and the spread of technology that can free humanity from hard work [00:42:22].
The internet, in particular, has revolutionized communication and knowledge sharing, empowering individuals globally [00:42:49]. Kaku believes science has a specific direction: democratization and sharing the fruits of technology [00:43:41]. This doesn’t negate future challenges, but the overall trajectory of history is one of progress [00:43:52].
Inspirations and Insights
Michio Kaku finds inspiration in scientists like Ed Witten, who have opened new mathematical worlds related to string theory [00:39:20]. String theory has even influenced mathematics, leading to the discovery of new forms and offering hope for a unified theory of mathematics, much like how string theory unified physics [00:39:42].
For a physicist, one of the hardest aspects of the career is the “hard seat” – the ability to sit for hours, analyzing hundreds of pages of calculations to find one working formula [00:40:22]. However, the satisfaction of seeing everything work after days or weeks of analysis is immense [00:40:43].