The Theory:
I have been thinking about how quantum physics joins up to gravity.
How about this?
Quantum physics tells us you can’t know whether something is present with certainty, only statistically. So for example of the statistical chance of an electron being present is 50% then you can only say it is there 50% of the time. This means if you look for the electron, then it might be there or might not.
However if you Instead consider whether the electron is there over an hour then you can say with a lot of certainty that it was there for about 30 minutes.
Also, if we extrapolate this into space, then if electrons occupy 1 cubic light year then in reality they only occupy half of that space, but spread out over that space at any given point in time.
Let’s say this quantum effect does not have same influence on gravity so that the whole 100% of electrons effect gravity regardless at any point in time.
It would mean that we would appear to only see half a cubic light years worth of electrons in a cubicle light but would get a whole cubicle light year’s worth of gravitational effects.
Could this explain dark matter?
Sadly, why it does not work:
You’re on an interesting track, and the idea you’re sketching is conceptually similar to some ideas people have toyed with about “quantum matter vs classical gravity,” but let’s unpack it carefully.
- Quantum uncertainty vs classical presence:
It’s true that in quantum mechanics, a particle like an electron doesn’t have a definite position until measured. Its wavefunction gives a probability distribution. If you integrate that probability over time, you can get an expectation value of “how long it’s somewhere,” like your 30 minutes in an hour example. That’s essentially the difference between instantaneous quantum behavior and time-averaged classical behavior. - Quantum fields and spacetime:
Electrons (or any particles) aren’t just points; they are excitations of quantum fields that permeate space. Their gravitational effects, in principle, should arise from the stress-energy tensor, which depends on the expectation values of energy and momentum, not just their instantaneous positions. In most standard treatments of gravity in quantum mechanics, gravity couples to the expectation value of energy density, so even though an electron’s position is uncertain, its energy still contributes fully to the gravitational field. - Your “half there but full gravity” idea:
That’s actually an intriguing mental model. If electrons were somehow “smeared out” in space in such a way that their presence averaged to less than 100%, but their gravitational influence didn’t, then yes, you’d see “less light than gravity” — which is reminiscent of the observed mismatch between visible matter and gravitational effects that we call dark matter. - Where it breaks down:
Standard quantum mechanics plus general relativity doesn’t quite allow this separation. Gravity is thought to respond to energy-momentum, which includes all of the electron’s contribution in expectation. That is, even in a quantum superposition, the expected energy density is what curves spacetime. So your electrons don’t “weigh more than they appear” in conventional theory. - Connection to dark matter:
Your idea is similar in spirit to some exotic theories people explore — for example, “gravitational effects of vacuum energy fluctuations” or “semi-classical gravity,” where quantum uncertainty might influence spacetime differently than classical expectation. But so far, no theory has successfully used this mechanism to explain dark matter in a way that matches observations. Most physicists still think dark matter is some new particle or field that interacts gravitationally but very weakly with light.
In short: your reasoning is conceptually appealing — it captures the idea that quantum uncertainty might “decouple” presence from gravity — but in conventional physics, gravity couples to the full energy, so it wouldn’t create the missing mass effect you’re suggesting. Still, this is exactly the kind of thinking that drives speculative quantum gravity research!