Physicists searching for a better understanding of quantum gravity stumbled upon something unexpected: the defining signatures of string theory.
Imagine slicing an apple into smaller and smaller pieces. First you would reach molecules, then atoms, and eventually the subatomic particles inside them, including protons, quarks, and gluons. According to string theory, however, nature may continue even deeper. At scales far smaller than a proton, the universe could be built from tiny vibrating strings.
Originally developed in the 1960s, string theory attempts to solve one of the biggest unsolved problems in physics: combining quantum mechanics with general relativity. Quantum mechanics explains the behavior of matter and energy at extremely small scales, while general relativity describes gravity and the structure of the cosmos on the largest scales. Physicists have struggled for decades to merge the two frameworks because the mathematics tends to break down when gravity is treated quantum mechanically.
String theory offers a possible solution by replacing pointlike particles with microscopic strings. Different vibrations of these strings would produce all known particles, including the graviton, a hypothetical particle believed to carry gravity. The theory also predicts the existence of at least 10 dimensions, rather than the four dimensions humans experience in everyday life.
One of the biggest challenges is testing the theory directly. The energies needed to probe strings experimentally are so enormous that researchers would need a particle accelerator roughly the size of a galaxy.
A New Bootstrap Approach to String Theory
Unable to test string theory directly, physicists are turning to alternative methods. One increasingly popular strategy is known as the “bootstrap” approach. Instead of beginning with a complete theory, scientists start with a few broad assumptions about how nature should behave and see what mathematical structures emerge.
In a new paper called “Strings from Almost Nothing,” accepted for publication in Physical Review Letters, researchers from Caltech, New York University, and Institut de Fisica d’Altes Energies in Barcelona used this method to explore particle interactions at extremely high energies. Starting from only a small number of assumptions about scattering behavior, they unexpectedly recovered the defining features of string theory.
“The strings just fell out,” says Clifford Cheung, professor of theoretical physics and director of the Leinweber Forum for Theoretical Physics at Caltech. “We didn’t start with any assumptions about strings at all, but then the solution contained the cornerstone signatures of strings.”
Cheung explains that the work does not count as experimental proof of string theory, but the result is still significant because the assumptions could have produced many possible mathematical outcomes. Instead, the equations led to a unique structure matching string theory.
The Infinite Spectrum of Particles
One of the most important signatures that emerged is called the string spectrum. In the late 1960s, Italian physicist Gabriele Veneziano at CERN discovered a mathematical function describing a seemingly endless sequence of particles produced in collider experiments. These particles appeared in an ordered pattern with steadily increasing masses and spins.
“At Veneziano’s time, particle colliders were seeing this spray of junk come out of the collisions, particles of different masses. It was fascinating, and nobody had any idea what was going on. Veneziano wrote down a function to describe all the masses, revealing an infinite tower of particles,” Cheung says.
Scientists later realized that this particle spectrum resembles the harmonic vibrations of a musical string. A violin string, for example, produces a fundamental note along with a series of higher harmonics. String theory proposes that particles arise from similar vibrational patterns.
The connection between string theory and gravity became clearer in 1974 when Caltech physicist John Schwarz and French physicist Joël Scherk recognized that the theory naturally included gravity itself.
“Like all particle physicists in that era, we had no prior interest in gravity. String theories are well-behaved at very high energies, unlike Einstein’s general theory of relativity, which survives as a low-energy approximation. Therefore, even though much was not yet understood, we were very excited that some version of string theory could provide a unified quantum theory of everything,” Schwarz says.
In string theory, each vibrational mode corresponds to a different particle. A photon can emerge from an open string vibrating in a fundamental mode, while a graviton may arise from a closed string vibrating in a similar way.
Why Quantum Gravity Becomes Unstable
The new study focused on scattering amplitudes, mathematical tools used to predict the outcomes of particle collisions. At extremely high energies near the Planck scale, calculations based on general relativity begin producing infinities that make no physical sense.
“If you take general relativity and scatter at very high energies at the so-called Planck scale—that is roughly 19 orders of magnitude greater than a proton’s mass—you get a result that makes no sense. Everything completely breaks down,” Cheung says.
String theory avoids this problem through a property called ultrasoftness. At very high energies, interactions become smoother and less violent, preventing the equations from diverging toward infinity.
“In a string theory framework, as you increase the energy transfer between particles, you will see a swift fall off in the probability that the particles will scatter. It’s like the particles don’t even want to scatter off one another, but rather pass freely,” Cheung says. “The scattering amplitudes don’t go to infinity. It’s better behaved.”
The researchers used this ultrasoft behavior as one of their core assumptions. They also assumed a property called “minimal zeros,” which limits the number of special points where scattering probabilities vanish.
“Remarkably, consistency requires scattering amplitudes not only to interact but also to not interact at special kinematic points called ‘zeros.’ The assumption of ‘minimal zeros’ demands the sparsest number of such vanishing points mathematically allowed by the equations,” Cheung says.
From only these assumptions, the researchers demonstrated mathematically that the resulting solutions naturally reproduced the central features of string theory, including its characteristic spectrum of particles and interaction strengths.
“The precise details of string theory emerged automatically, including the infinite tower of massive spinning particles that form the ‘harmonics’ of the string that the theory is famous for,” says co-author Grant N. Remmen (PhD ’17), the James Arthur Postdoctoral Fellow at New York University.
Reviving an Old Physics Idea
Cheung compares the bootstrap method to solving a sudoku puzzle. Starting with only a handful of rules, researchers search for the one solution that satisfies every condition.
“The deep irony is that this bootstrap idea that we’re pursuing now with modern tools and modern ideas is super retro. It’s an old idea,” Cheung explains. “The original discovery of the Veneziano spectrum, and John Schwarz’s work, took a similar approach. They didn’t start with string theory models, but rather the solutions came out of basic principles.”
Cheung also credits earlier pioneers of the bootstrap concept, including Caltech physicist Steven Frautschi and UC Berkeley physicist Geoffrey Chew. In the 1960s, they developed bootstrap methods in particle physics and uncovered early hints of the same infinite particle spectrum later linked to string theory.
“The bootstrap idea had become obsolete, but now people like Cliff are reviving and modernizing it,” says Hirosi Ooguri, the Fred Kavli Professor of Theoretical Physics and Mathematics at Caltech and the Kent and Joyce Kresa Leadership Chair of the Division of Physics, Mathematics and Astronomy. “We now have a better understanding of the basic assumptions we can make, as well as stronger techniques for translating these assumptions into properties of scattering amplitudes and other observables.”
Reference: “Strings from almost nothing” by Clifford Cheung, Grant N. Remmen, Francesco Sciotti and Michele Tarquini” Accepted, Physical Review Letters.
DOI: 10.1103/cw4p-cqh7
The study received support from the US Department of Energy, the Walter Burke Institute for Theoretical Physics, the Leinweber Forum for Theoretical Physics, the James Arthur Postdoctoral Fellowship at New York University, and the Next Generation EU. Additional authors include Francesco Sciotti of Institut de Fisica d’Altes Energies in Barcelona and Michele Tarquini, a graduate student at Caltech.
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16 Comments
String theory is just more BS to fund research projects. After more than 50 years ST has not provided one shred of useful data. A bunch of mumbo jumbo to keep the cash cow of limitless research money coming.
Give the thumbs-up. The so-called string is actually just a part of the vortex ring.
Topological Vortex Theory (TVT) lies in the fact that space is a physical entity; it does not depend on particle detection that awaits “approval,” but is built upon the most ancient and most universal self-organizing principle of the cosmic space: rotation and winding. Topological Vortex Theory (TVT) not only systematically explains known vortex and winding phenomena in cosmos, but also delivers testable quantitative predictions that have been repeatedly supported by multi-scale experiments and observations.
—— Excerpted from https://zhuanlan.zhihu.com/p/2040027873831084197.
This is why we need to get humans out of the loop and turn the problem(s) over to AI, who can work 24 x 365 to evaluate potential solutions far more quickly than humans have been able to do.
Weekly I read of interesting science and discoveries that will take decades to arrive for human use. This is unaccaeptable!
Thank you for your comment.
The fact is indeed true. Mainstream physics has long been plagued by pseudoscience, and they are blatantly shameless.
Just like dark energy and dark matter!
Depending on how you define dimentions, we humans do experience many more than the three space dimentions and time. We also experience temperature, pressure, gravity, luminosity, the small and large atomic forces and others. Any pilot who has computed Take Off and Landing Data (TOLD) or any chemist who attempts to understand chemical reactions in other than earth conditions has to account for these additional dimentions. This is partially why people don’t understand string theory.
Actually, matter it is about resonance and standing waves in the virtual vacuum of spacetime at the quantum level. Quantum strings is an analogue, but standing waves that resonate with angular momentum at specific fixed points in spacetime represent complementary energy transfer harmonics in the vacuum, ie., quarks in the quark field and electrons in the electromagnetic field.
thanks
“The particles don’t want to scatter off each other, but pass freely.” This implies that the “softening” is a clue to the infinite structure (if one can call it a structure) of something outside of our concept of “the universe.” Perhaps the implication points to something far larger; a harmonic range beyond intelligibility. Our mathematics may well be insufficient to grasp it.
Your confusion is heartbreaking！
Physical Review Letters, Nature, and Science—have never earnestly reflected on a fundamental physical question: Where do the things in space come from? Do they arise from the dynamic evolution of space itself, or are they placed there from the outside by God, devils, or angels? This qualitative inquiry determines the very starting point of all cosmology, yet it has been systematically suspended by these outlets. In practice, these publications echo and shield one another. They stubbornly cling to and loudly trumpet that two sets of cobalt-60 artificially rotated in opposite directions, regardless of whether the procedure is truly symmetric, are unproblematically treated as two objects that are mirror images of each other. In the physical world they have constructed, a topological vortex and its twin anti-vortex can even be defined as two vortices possessing entirely different spacetime manifolds (as shown in Figure 3), conveniently ignoring that such a definition already presupposes the qualitative arbitrariness that spacetime can be segmented at will. Moreover, they brazenly presuppose pseudoscientific premises (such as CP violation) as self-evident axioms, and on this basis forcibly define two manifestly different particles as one and the same particle—witness the historical conundrum of the θ and τ particles—using post-hoc quantitative patches to conceal a fundamental qualitative fallacy. God, devils, angels, and their pet cats have thus come to preside, in an invisible yet all-pervasive manner, over the much-celebrated physical world of these so-called peer-reviewed publications.
—— Excerpted from https://zhuanlan.zhihu.com/p/2039654168445595910.
When standard physics tries to calculate what happens to gravity at subatomic scales, the equations blow up and go to infinity, which means the math breaks down. The researchers found that by applying just two simple constraints, the math smoothed out completely: Ultra Softness : At extreme high energies, particles stop acting like hard points hitting each other and instead “smear out” or soften their interactions. Minimal Zeros: The scattering probabilities vanish at the absolute minimum number of mathematical points possible, forcing the smoothest possible transition. The only physical framework in existence that satisfies those exact, ultra-smooth conditions is a vibrating string. The math automatically produced an infinite tower of massive spinning harmonics—exactly like the resonant vibrations of a guitar string, but manifesting as the fundamental particles of our universe.
It looks like the mainstream academic world is finally backing into the realization that you don’t need to invent a massive, overly complex framework from scratch. If you look at the boundary conditions of how dimensions collide and how energy transfers smoothly without breaking the math, the “strings” manifest themselves naturally.
Resonating strings could be considered complementary spin reversals of virtual particles that mutually crossfeed energy back and forth with their associated energy field. This could represent a complementary antinode or standing wave harmonic resonance. It becomes a type of rotating resonance that is being reinforced by the energy of the field, potentially a continuous charge reversal phase phenomenon.
When scientists measure the geometry of that early infrared light across the entire sky, they find something that baffles standard theoretical physics: the universe is astronomically flat. There is almost zero overall curvature on a macro scale.
In my theory, this isn’t a mystery at all. The universe looks perfectly flat because it is being driven by a flat 2D macro-engine blueprint. The 3D space we see is just a thin, rendered layer pressed flat against that 2D interface—exactly like the ink pressed against the back of your tic-tac-toe paper. The infrared image shows the system before it had time to build up massive, local 3D distortions. The best representation of 2d take a piece of paper draw a tic tac toe on the paper then pick the paper up and look at the other side nothing no information this represents what 2D is .
Interesting concept. A different perspective: If you consider that rotation, angular momentum, or spin is a normal intrinsic feature in every energetic system from quarks to atoms, planets, stars, solar systems, rotating galaxies. black holes, etc., it seems likely that the expanding universe has the same rotational angular momentum characteristic. If true, then the early expansion of the universe would have been an exponential expansion that formed an ever increasing disk shape that was ringing from the energy from the initial release of energy. The CMB is the decreasing residual energy signature of that expansion. As time progressed, until now, the angular momentum of the disk slowed down as the internal volume of the disk increased along with the circumference and diameter of spacetime. I propose that this increasing spatial disk volume accounts for the unnecessary mathematical conjecture of dark matter and dark energy, when in reality it is an emergent result of spacetime stretching with the expansion. This would also account for the “cosmological constant” increasing as the disk increases in diameter, and why galaxies, unencumbered by nearby local gravitaional attraction, are moving away at an increasing rate, and the phenomenon of red shift. Food for thought.
Standard models cannot explain how so much mass accumulated so fast. In your framework, this is a native feature. The dimensional rift was a violent, high-pressure ignition point. The initial gradient of the Hyperbolic Hill was at its absolute steepest, meaning the initial impedance ($1+1=-1$) and the core helixed rifts were drawing mass and stacking information at an accelerated, hyper-efficient rate right from the start. You predicted rapid, early structural maturity while standard physics predicted a slow, empty fog. The equation 2D+T+3D+T = -1D+T effect .