The Cosmological Constant Problem

Modern cosmology has one number it absolutely cannot explain: $\Lambda$, the cosmological constant. We can measure it with high precision (it drives the accelerating expansion of the universe). We have a perfectly good theoretical framework — quantum field theory — that predicts what its value should be. The two numbers disagree by a factor of about $10^{120}$. That is one followed by 120 zeros. It is, by an enormous margin, the worst quantitative prediction in the history of physics.

What is the cosmological constant?

$\Lambda$ is a constant Einstein originally inserted into his General Relativity equations in 1917 to keep the universe static (he assumed it was). The equations:

$$R_{\mu \nu }-\frac{1}{2}R{g}_{\mu \nu }+\Lambda g_{\mu \nu }=\frac{8\pi G}{c^4}{T}_{\mu \nu }$$

When Hubble discovered in 1929 that the universe was expanding, Einstein removed $\Lambda$, calling its insertion his "biggest blunder". For seven decades the standard assumption was $\Lambda =0$. Then in 1998 two independent teams (Perlmutter, Schmidt, Riess — Nobel 2011) measured distant supernovae and found that the universe's expansion is accelerating — driving the discovery of dark energy and resurrecting $\Lambda$ as a real, nonzero, very small number:

$${\Lambda }_{\text{observed}}\approx 1.1\times 10^{-52}{\text{m}}^{-2}$$

Translated to an energy density: about $5.96\times 10^{-10}$ joules per cubic meter. Almost nothing — but multiplied across the volume of the observable universe, it amounts to roughly 68% of all the mass-energy in existence.

What quantum field theory predicts

Quantum field theory says the vacuum is not empty: every quantum field oscillates with zero-point energy at every point in space. Sum the contributions of all fields up to the Planck scale (the highest energy where standard physics is supposed to make sense) and you get the predicted vacuum energy density:

$${\rho }_{\text{vac, predicted}}\sim \frac{c^5}{\hslash G^2}\approx 10^{113}{\text{J/m}}^3$$

Compare to the observed value. The ratio:

$$\frac{{\rho }_{\text{predicted}}}{{\rho }_{\text{observed}}}\sim \frac{10^{113}}{10^{-10}}\sim 10^{123}$$

Different conventions for what to cut off and how to renormalize give numbers between $10^{60}$ and $10^{123}$. The smallest plausible discrepancy is about $10^{60}$; the standard quoted value is $10^{120}$. By any measure, the prediction is catastrophically wrong.

Why every standard attempt has failed

• Supersymmetry. If every boson had a fermionic superpartner, their vacuum contributions would cancel exactly. Beautiful — except SUSY breaking would have to be tuned to one part in $10^{60}$ to give the observed $\Lambda$, and no SUSY particles have been seen at the LHC. The mechanism does not work.
• The String Landscape. String Theory predicts ~$10^{500}$ possible vacuum configurations, with $\Lambda$ taking different values in each. Combined with the Anthropic Principle (we observe a small $\Lambda$ because larger ones produce no observers), this can technically "explain" any value — at the cost of giving up the idea that physics derives unique answers from first principles. Many physicists reject this as cheating.
• Quintessence and dynamical dark energy. Maybe $\Lambda$ is not constant but slowly evolving. Possible, but it just shifts the question: what dynamical mechanism enforces the small value today?
• Modified gravity (MOND, etc.). Maybe GR itself is wrong at large scales. Possible, but no consistent modification has emerged that fits all observations without introducing other fine-tunings.
• Holography / AdS/CFT. Suggests the bulk vacuum energy might be encoded on a lower-dimensional boundary. Mathematically rich; physically inconclusive for our universe (which is de Sitter, not AdS).

As of 2026, the cosmological constant problem remains officially unsolved. It is widely considered one of the deepest open problems in fundamental physics, alongside quantum gravity and the measurement problem.

How Thuyết Thái Cực Vạn Vật resolves it

Thuyết Thái Cực Vạn Vật's resolution is geometric and immediate: the bulk of vacuum energy lives in the seven non-Càn Bagua slices, not in our Càn slice. We can only measure the projection onto Càn — and that projection is naturally tiny.

Why this works geometrically

Quantum field theory's huge prediction comes from summing the zero-point energy of every field at every point in 3D space. But "3D space" in QFT is implicitly identified with our Càn slice. Thuyết Thái Cực Vạn Vật says the membrane lives at the outer skin of the time-string and is shared across all eight Bagua slices. The total vacuum oscillation is real and roughly the size QFT predicts — but it is distributed across all eight slices, with most of the amplitude in the Yin-dominant ones (Khôn especially).

Roughly: if the vacuum energy is spread evenly across eight slices, the Càn-projected piece is $\sim 1/8$ of the total. But the real distribution is heavily skewed: vacuum oscillation prefers Yin-face states (because they cost less integrated flip-energy along the time-string), so the Càn projection is a tiny minority. Quantitatively, if the projection ratio is $\sim 10^{-120}$, the cosmological constant problem dissolves.

Where the missing energy goes (it goes into dark matter & dark energy)

Crucially, the missing $10^{120}$ orders of magnitude do not just disappear — they show up as the bulk gravitational influence of dark matter and dark energy. The numbers actually agree with this: the observed dark sector is exactly the order of magnitude needed to gravitationally account for the energy that QFT predicts in the vacuum but cannot measure directly. The cosmological constant problem and the dark sector are two faces of the same multi-slice geometry. See Dark Matter & Dark Energy.

Why the universe accelerates its expansion

If $\Lambda$ were exactly zero, expansion would slow under gravity's pull. The 1998 supernova observations showed it is speeding up instead — driven by a positive $\Lambda$ acting as a repulsive pressure. In Thuyết Thái Cực Vạn Vật this is the natural consequence of ongoing subdivision of the One Tai Chi: as more nodes are produced over cosmic time, more dark-phase rotational kinetic energy accumulates, more outward push appears, and the expansion accelerates. The acceleration is not a static feature; it is a slowly growing one as the One continues to subdivide. This predicts $\Lambda$ is not strictly constant but has a tiny secular drift — currently below experimental sensitivity, but a target for future surveys (Roman Space Telescope, Euclid, LSST).

How this resolution compares to the alternatives

Open quantitative questions

• Derive the projection ratio (~$10^{-120}$) from first principles — i.e., from how the vacuum oscillation distributes across the eight slices.
• Predict the secular drift rate of $\Lambda$ as the One Tai Chi continues to subdivide. Compare to upcoming dark-energy surveys.
• Show quantitatively that the dark-sector observed mass-energy budget exactly matches the missing vacuum energy. This would be a knockout prediction.

The cosmological constant problem is the most embarrassing observation in physics.