4 ms·

A Breakthrough in Measuring the Building Blocks of Nature

zer0gravity 6y ago
This makes me ask the question: Is it possible for a cellular automata to measure its state in one region without getting inconsistent results, since the simple act of measuring means changing its state?
- fsloth 6y ago
  I don't think the word 'measurement' has any meaning in a context without a memory. And without consistency you can't have a memory. In other words in cellular automata context aren't the concepts of 'memory' and 'measurement' isomorphic. I.e. a cell pattern {c} can be copied from region 1 to region 2, and from there any number of times. Or have I misunderstood something?
sanxiyn 6y ago
If you are interested in this ongoing saga, you can start at https://en.wikipedia.org/wiki/Proton_radius_puzzle https://en.wikipedia.org/wiki/Proton_radius_puzzle.
- JumpCrisscross 6y ago
  How did we eliminate the possibility of a proton in the midst of a muon being smaller than one near an electron?
  - sanxiyn 6y ago
    We haven't. It is in fact one of alternatives considered. The problem is just that the direction doesn't work well.
  - jfengel 6y ago
    They didn't. But they did measure electron hydrogen in a different way, and got a similar result to the radius with muonic hydrogen. That makes the other measurement the odd man out. There could still be something unexpected going on with the proton radius in the presence of muons vs electrons, but it's more likely that the larger measurement is simply incorrect for some unknown reason. That discrepancy could still reveal new physics, but it's more likely an unrealized problem with the apparatus.
deleted 6y ago
[deleted]
l33tman 6y ago
On a (somewhat) related matter, I find the experimental search for inconsistencies in measurements in different directions in space and quantization of length scales very interesting as well. There are some experiments done constraining the level of anisotropy or space quantization in our universe. These are of course interesting for the "universe could be a simulation" crowd; basically searching for limitations and/or bugs in the code..
mikewarot 6y ago
I have this suspicion that in the coming decades, the rush to make all of our standards based on the "unchanging constants of the universe" might turn out to have been a bit presumptive. For instance, assuming that the speed of light is constant and uniform in all directions, might be a mistake.
- TooKool4This 6y ago
  I believe there would be minimal practical impact in any case. In the case of anisotropy of the physical constants, it would have to be so small that to date independent labs around the world haven’t detected a difference outside of the measurement uncertainty. In terms Of time variance a similar logic can apply. I would also add that variation of the physical constants over the span of a few decades is not very likely in the grand scheme of the universe. It’s the same reason that nothing in your life materially changed when we switched the definition of the kilogram last year, unless you are a metrologist ;). The variations being discussed here have to fundamentally be below our current measurement uncertainties and our current measurement uncertainties are very very small.
zvrba 6y ago
What I don't understand is why Higgs' boson wasn't discovered before LHC: its mass is 125GeV, which is way smaller than that of the top quark at 171.2GeV... Yet the top quark was discovered in 1995.
- ssivark 6y ago
  It’s not just about the mass, but how strongly it couples to the things we can directly manipulate (typically, protons, electrons, muons and occasionally their anti-particles, and photons). The top quark, being a third generation quark turns out to be far easier to produce (if you work out the details of the standard model) than the Higgs. Yes, the heavier mass might act as a suppressor but stronger couplings act as an enabler. So, a “dark matter” particle at even few GeV could have gone hitherto undetected, because it hardly talks to anything we can directly manipulate/sense (hence the “dark” moniker).

This makes me ask the question: Is it possible for a cellular automata to measure its state in one region without getting inconsistent results, since the simple act of measuring means changing its state?

fsloth 6y ago
I don't think the word 'measurement' has any meaning in a context without a memory. And without consistency you can't have a memory. In other words in cellular automata context aren't the concepts of 'memory' and 'measurement' isomorphic. I.e. a cell pattern {c} can be copied from region 1 to region 2, and from there any number of times. Or have I misunderstood something?

sanxiyn 6y ago

If you are interested in this ongoing saga, you can start at https://en.wikipedia.org/wiki/Proton_radius_puzzle https://en.wikipedia.org/wiki/Proton_radius_puzzle.

JumpCrisscross 6y ago
How did we eliminate the possibility of a proton in the midst of a muon being smaller than one near an electron?
- sanxiyn 6y ago
  We haven't. It is in fact one of alternatives considered. The problem is just that the direction doesn't work well.
- jfengel 6y ago
  They didn't. But they did measure electron hydrogen in a different way, and got a similar result to the radius with muonic hydrogen. That makes the other measurement the odd man out. There could still be something unexpected going on with the proton radius in the presence of muons vs electrons, but it's more likely that the larger measurement is simply incorrect for some unknown reason. That discrepancy could still reveal new physics, but it's more likely an unrealized problem with the apparatus.

deleted 6y ago

[deleted]

l33tman 6y ago

On a (somewhat) related matter, I find the experimental search for inconsistencies in measurements in different directions in space and quantization of length scales very interesting as well. There are some experiments done constraining the level of anisotropy or space quantization in our universe. These are of course interesting for the "universe could be a simulation" crowd; basically searching for limitations and/or bugs in the code..

mikewarot 6y ago

I have this suspicion that in the coming decades, the rush to make all of our standards based on the "unchanging constants of the universe" might turn out to have been a bit presumptive. For instance, assuming that the speed of light is constant and uniform in all directions, might be a mistake.

TooKool4This 6y ago
I believe there would be minimal practical impact in any case. In the case of anisotropy of the physical constants, it would have to be so small that to date independent labs around the world haven’t detected a difference outside of the measurement uncertainty. In terms Of time variance a similar logic can apply. I would also add that variation of the physical constants over the span of a few decades is not very likely in the grand scheme of the universe. It’s the same reason that nothing in your life materially changed when we switched the definition of the kilogram last year, unless you are a metrologist ;). The variations being discussed here have to fundamentally be below our current measurement uncertainties and our current measurement uncertainties are very very small.

zvrba 6y ago

What I don't understand is why Higgs' boson wasn't discovered before LHC: its mass is 125GeV, which is way smaller than that of the top quark at 171.2GeV... Yet the top quark was discovered in 1995.

ssivark 6y ago
It’s not just about the mass, but how strongly it couples to the things we can directly manipulate (typically, protons, electrons, muons and occasionally their anti-particles, and photons). The top quark, being a third generation quark turns out to be far easier to produce (if you work out the details of the standard model) than the Higgs. Yes, the heavier mass might act as a suppressor but stronger couplings act as an enabler. So, a “dark matter” particle at even few GeV could have gone hitherto undetected, because it hardly talks to anything we can directly manipulate/sense (hence the “dark” moniker).