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### What were Feynman's objection(s) to a cubic lattice universe? [duplicate]

In this video of Feynman discussing the scientific method, starting at around eight minutes and 30 seconds, Feynman describes the proposition that space consists of a cubic lattice of points (as ...
84 views

### Can a photon be captured in a grid space representation at a fractional Planck position? [duplicate]

Consider a photon, positioned in space in a finite portion of a grid. Any point of the grid is vertically or horizontally aligned, each distanced by a Planck unit. $l_P = 1.616 199(97) × 10−35 m$ ...
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### Quantum physics and constructable numbers [duplicate]

I do not know much about quantum physics. However, I do know it believes the world is discrete ( has quanta). This seems to contradicts the fact that we can create an object of length root 2 since you ...
82 views

### Isn't is far more likely that general relativity, and not QFT, is “wrong?” [duplicate]

At the risk/certainty of both sounding super ignorant and talking out of my arse, I have always wondered why there is some big mystery about why there are contradictions between the predictions ...
48 views

### If you have two Planck lengths extended from one point forming a right angle, whats the length of the hypotenuse? [duplicate]

Can we do measurements at this scale seeing that the length of the hypotenuse would have a value at a length that cant exist (1.4 Planck lengths)? Or is my interpretation of the Planck length ...
37 views

### Does having a minimum length in space violate Lorentz invariance? [duplicate]

I’m trying to understand different approaches to quantum gravity. One involves quantising space and time themselves, which i believe can result in there being a minimum possible length and time ...
23 views

### Update: Does the Planck scale imply that spacetime is discrete? [duplicate]

This question has already been asked Does the Planck scale imply that spacetime is discrete? however I'm wondering if there has been any change in the community since it was asked roughly 8 years ...
36k views

### Is time continuous or discrete?

I was coding a physics simulation, and noticed that I was using discrete time. That is, there was an update mechanism advancing the simulation for a fixed amount of time repeatedly, emulating a ...
23k views

### Is the Planck length the smallest length that exists in the universe or is it the smallest length that can be observed?

I have heard both that Planck length is the smallest length that there is in the universe (whatever this means) and that it is the smallest thing that can be observed because if we wanted to observe ...
23k views

### Is spacetime discrete or continuous?

Is the spacetime continuous or discrete? Or better, is the 4-dimensional spacetime of general-relativity discrete or continuous? What if we consider additional dimensions like string theory ...
4k views

### Does Quantum Mechanics assume space and time are continuous?

I was confused when I was listening to a Quantum Mechanics lecture online. Are space and time assumed to be continuous or discrete in Quantum Mechanics? I can see the question is vague, but this is ...
2k views

### Space-time in String Theory

I would like to understand how Physicists think of space-time in the context of String Theory. I understand that there are $3$ large space dimensions, a time dimension, and $6$ or $7$ (or $22$) extra ...
861 views

### Can physics get rid of the continuum?

Almost every physical equation I can think of (even though I don't actually feel comfortable beyond the scope of classical mechanics and macroscopic thermodynamics, as that's enough for dealing with ...