Managing time when time doesn't exist

> The real productivity crisis emerged when physicists tried merging Einstein’s relativity with quantum mechanics. They discovered something that would terrify any time management consultant: the Wheeler-DeWitt equation—quantum gravity’s fundamental mathematics—contains absolutely no time variable.

Special Relativity and Quantum Mechanics have been merged since 1928 https://en.wikipedia.org/wiki/Dirac_equation That's the base of all the calculations inside the LHC and with some more technical details it has been tested in some cases with a lot of precision.

For General Relativity, we still don't have a good theory to merge it with Quantum Mechanics. The article cites https://en.wikipedia.org/wiki/Wheeler%E2%80%93DeWitt_equatio... but if you look at the equations it says

  g_μν dx^μ dx^ν = ...

  ... the Greek indices run over the values 1, 2, 3, 4 ...

The notation is confusing, but it's standard in the area. It means that "g" is a 4x4 matrix and "dx" is a 4 vector, and the labels of the coordinates are actually "t,x,y,z" something like [1]

                             ┌                      ┐  ┌    ┐   
                             │g_tt, g_tx, g_ty, g_tz│  │dx_t│   
  [dx_t, dx_x, dx_y, dx_z]   │g_xt, g_xx, g_xy, g_xz│  │dx_x│  =
                             │g_yt, g_yx, g_yy, g_yz│  │dx_y│   
                             │g_zt, g_zx, g_zy, g_zz│  │dx_z│   
                             └                      ┘  └    ┘

So it's a equation that has the time variable, just like the "Einstein’s block universe".

> The evidence keeps mounting from increasingly sophisticated timekeeping technology. Modern atomic clocks achieve accuracy where they’d only lose one second in 300 billion years—precision that makes your smartphone’s clock look like a sundial operated by someone with depth perception issues. These “tweezer clocks” combine atomic precision with quantum entanglement, revealing that time measurement itself has quantum foundations.

That just make no sense. Atomic clocks just measure the frequency of some process, some may use entanglement, but the clocks don't show that time is created by quantum entanglement.

> The Scientific Consensus: Time is a Group Hallucination

> What makes this development remarkable is unprecedented convergence across theoretical physics. String theory, loop quantum gravity, causal set theory, and emergent gravity models all independently conclude that time emerges from more fundamental quantum information structures. When rival physics theories actually agree on something, reality is definitely trying to communicate important information about its operational parameters.

There is no consensus about this.

[1] If you want too bee too technical, to label the index of dx you should use dx^t,... instead of dx_t,... They important part is that they are 4 numbers in a vector, but the _ or ^ have a slightly different technical meaning and there are some details in important for the calculations.

I made a significant error conflating different levels of the quantum gravity problem. Special relativity and quantum mechanics have indeed been successfully merged since the Dirac equation in 1928, forming quantum field theory that underlies all particle physics. That's well-established and experimentally validated.

The Wheeler-DeWitt equation is specifically an attempt to merge general relativity with quantum mechanics - quantum gravity - which remains unsolved. And you're correct that even the Wheeler-DeWitt equation does contain spacetime coordinates including time, as shown in your matrix breakdown.

The "timelessness" issue I was referring to is more subtle - it's about how when you try to quantize general relativity using the ADM formalism, you get a constraint equation (the Hamiltonian constraint) where the total Hamiltonian equals zero, leading to what looks like a "frozen" or timeless quantum state. But this is a technical issue in the formalism, not literally "no time variable exists."

I oversimplified this into "contains no time variable" which is just wrong, as you've demonstrated. The actual problem is much more nuanced and relates to how time evolution works in quantum gravity, not the absence of temporal coordinates.

>> That just make no sense. Atomic clocks just measure the frequency of some process, some may use entanglement, but the clocks don't show that time is created by quantum entanglement.

You're absolutely right - that's a complete logical leap that makes no sense. I conflated two separate things:

1. Atomic clocks are incredibly precise frequency measurements of atomic transitions 2. Some recent atomic clock experiments use quantum entanglement to enhance precision

But precise frequency measurement has nothing to do with proving time emerges from quantum entanglement. That's like saying "this really accurate thermometer proves temperature is created by the mercury inside it."

The fact that some atomic clocks use entanglement for better precision doesn't mean they're revealing that "time measurement has quantum foundations" in any deep sense about time's nature. They're just using quantum effects as a tool for more accurate measurement of whatever time actually is.

I was trying to connect recent atomic clock advances to the emergent time hypothesis, but there's no actual connection there. The clocks measure time precisely - they don't tell us anything about whether time is fundamental or emergent.

Thanks for keeping the physics accurate!

This is a science comedy podcast, so I’m hoping the 30K view I give my listeners on these topics encourage creative, but critical thought (sprinkled with humour).