弦论自1968年问世后已过58年，在众多批评中仍是最有分量的理论一体论候选。批评者认为它难以检验，因为其预言涉及约10^-36公分（=10^-38公尺）以下的次结构，且在21世纪初已知至少有10,500种六个额外维度的紧致化配置，每一种对应不同宏观宇宙。即便如此，在许多顶尖大学的高能理论圈中弦论仍是主流；近期的bootstrap计划将论战重心从“美学上成立但不可测”转向“哪一些一致性假设被强制采用”。
1968年提出的Veneziano振幅最初为强子散射公式，后被解读为开弦振动，成为弦论的起点。弦论要求10维时空（4个可观测维度加6个紧致维度），到1984年Green与Schwarz发现手征异常可相互抵消后，理论声望大幅提升；1996年Strominger与Vafa以D-brane堆叠得到与Hawking与Bekenstein的黑洞热力学熵公式一致的结果，提供少数与既有理论可对接的定量成功。之后又出现多重对偶关系与更深层的数学结构，既增加统一性也扩大争议。
近期Cheung、Elvang等人的bootstrap工作尝试在特定原理下把弦论近乎必然化。2025年8月《Strings from Almost Nothing》在ultrasoftness等假设下推出Veneziano与Virasoro–Shapiro振幅；2026年1月Elvang的《String Theory From Maximal Supersymmetry》在假设QFT及N=4最高超对称（外加两项技术条件）下，得到Veneziano作为UV completion的树阶近似结果。支持者认为高能极限可能唯一收敛到弦；反对者如Eichhorn与Boyle质疑UV是否仍可谈平直时空散射与局域性，若量子重力在高能表现为非平坦、强涨落或分形，结论会改变。多数作者仍持保留态度，但普遍把弦视为与Penrose tilings、四元数与八元数等同级的特殊数学对象。
Fifty-eight years after string theory first appeared, it remains the leading theory-of-everything candidate despite persistent criticism. Critics argue it is untestable because it invokes structure at scales below 10^-38 metres (10^-36 cm) and allows a vast landscape: by the early 2000s at least 10,500 compactifications of six extra dimensions were known, each yielding a different large-scale universe. Yet in many top academic high-energy departments, string research remains mainstream, and the bootstrap program reframes the argument from “beautiful but untestable” toward “which consistency assumptions are forced.”
The field originated from the 1968 Veneziano amplitude, first a hadron formula later reinterpreted as open-string vibrations. String theory’s ten-dimensional spacetime requirement (4 observable plus 6 compactified dimensions) gained dramatic support after Green and Schwarz showed chiral anomalies could cancel in 1984. In 1996, Strominger and Vafa used stacked D-branes to count states and matched the Bekenstein–Hawking black-hole entropy result, giving one rare quantitative link to established physics. Later decades added string dualities and deeper mathematical structure, which strengthened unifying promise while widening the controversy.
Recent bootstrap papers by Cheung, Elvang, and collaborators aim to make string-like behavior nearly forced under specific principles. The August 2025 work “Strings from Almost Nothing” derives the Veneziano and Virasoro–Shapiro amplitudes from ultrasoftness and related assumptions. The January 2026 “String Theory From Maximal Supersymmetry” derives the Veneziano tree-level ultraviolet completion from QFT assumptions plus N=4 maximal supersymmetry and two technical conditions. Proponents take this as evidence for uniqueness in the UV, while critics such as Boyle and Eichhorn question whether flat-space scattering and locality are valid at quantum-gravity scales if spacetime is highly fluctuating or fractal. Most authors stay agnostic but increasingly treat strings as special mathematical objects alongside Penrose tilings, quaternions, and octonions.