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Planck length, planck time, and planck rotation? [duplicate]

given that there is a fastest speed at which anything can travel in our universe,299,792,458 meters per second, that seems to imply there may be a smallest distance in our universe, so first of all, ...
44 views

How Einstein thought experiment clock works in quantum world? [duplicate]

According to Einstein's thought experiment, imagine a clock but this time the distance between mirrors is one Planck length $\ell_p$. If we move the spaceship (with clock on board) at velocity $v$. ...
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Quantization of length [duplicate]

Plank length is considered to be smallest length possible in the universe. But since it is derived only from some known constants and it's value is derived from dimensional analysis, it doesn't ...
21k views

Does the Planck scale imply that spacetime is discrete?

On a quantum scale the smallest unit is the Planck scale, which is a discrete measure. There several question that come to mind: Does that mean that particles can only live in a discrete grid-like ...
15k views

How to get Planck length

I know that what Planck length equals to. The first question is, how do you get the formula $$\ell_P~=~\sqrt\frac{\hbar G}{c^3}$$ that describes the Planck length? The second question is, will any ...
6k views

If energy is quantized, does that mean that there is a largest-possible wavelength?

Given Planck's energy-frequency relation $E=hf$, since energy is quantized, presumably there exists some quantum of energy that is the smallest possible. Is there truly such a universally-minimum ...
9k views

Is there a maximum possible acceleration?

I'm thinking equivalence principle, possibilities of unbounded space-time curvature, quantum gravity.
6k views

Can a photon have a wavelength less than the planck length?

Well? Maths if necessary, please. Would the photon effectively have no wavelength?
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Are laws of nature absolute or are they just very good approximations? [closed]

Newton's second law, for example, states that $F=ma$. Is this absolutely true, down to the smallest possible unit of measurement? Or is it just a handy approximation that happens to work extremely ...
1k views

Is the Planck length the limit below which our physics does not make sense? And if so, why is that true?

I've been reading Physics SE answers on Planck units such as this one and this one. The general picture I get is that much of what is said about the Planck length (and the associated Planck units) is ...
1k views

How far apart do two objects have to be for there to be negligible force between them?

Inspired from the commentary on this question. How far apart do two objects have to be for the gravitational force between them to be negligible? By negligible I mean, that it could never be ...
2k views

What things are smaller than the Planck length?

I recently read Is the Planck length the smallest length that exists in the universe or is it the smallest length that can be observed? The general agreement is that the idea that the Planck length ...
501 views

Is the minimum mass of a black hole the planck mass?

Leonard Susskind said "It's thought to be the mass of the smallest black hole that can form" (or something like that when referring to the planck mass in his string theory lectures) and I've always ...