exchemist
Valued Senior Member
Quarks
- Thread starter Beaconator
- Start date
Beaconator
Valued Senior Member
So a photon is larger than the Higgs because the Higgs only covers a point within the nucleus
No.
Beaconator
Valued Senior Member
So they are both the same size except mass
What do you mean by "size"? Volume?
How do you propose to measure the volume of a photon or a Higgs boson? Bear in mind that both of these are quantum objects. They are not very much like solid little balls of stuff. They have all the usual quantum "weirdness". You can't measure both their position and velocity at the same time. They can spread out over a volume of space. They exhibit wavelike interference effects and other wavelike properties.
Why do you think it matters what "size" a fundamental particle is? When does that ever become relevant?
Beaconator
Valued Senior Member
If volume of space they take up is different. They are different volumes.
We can measure the space a particle appears in and by that estimate it’s density.
I really don’t think it matters but I know it’s possible.
is there such a thing as the density of a wave? Oh yes there is but it only applies to galaxies…
DaveC426913
Valued Senior Member
That would require having a physically meaningful boundary between what is, and what is not, particle.
It's a little like the question of "What is the radius of Earth's gravitational influence?"
Well, that depends on how you define it. Technically, the answer is "the radius of the universe".
Their "volume" is a probability, not a fixed quantity.
Beaconator
Valued Senior Member
The volume of the universe can be quantified.
So can the volume of a sugar cube. But the volume of an atom is a probability, not a fixed quantity. "Sizes of atoms" can only be compared if you establish a "standard probability" - e.g. 60%.
Beaconator
Valued Senior Member
That doesn’t make any sense. 60% of what?
DaveC426913
Valued Senior Member
A sphere around the nucleus wherein there is a 60% (or greater) probability of an electron being measured at any given time.
If you decided you wanted the probability threshold to be 30%, or 10%,then you would measure atoms to be larger than if you set the threshold at 60%.
But there's no upper limit. You could set the probability limit so low that the atom could be a light year in diameter.
This is a poor analogy, but give it some thought.
What is the diameter of the Earth, including its atmosphere?
Well, you can find molecules of Earth's atmo at thousands of miles height - even as high as the Moon, if you look carefully enough.
So we have to define Earth's diameter in terms of the density of atmosphere molecules (the likelihood we detect a molecule) - a value we choose arbitrarily.
If we decide we don't consider it atmosphere when it's at less than 50% density, that occurs at 18,000 feet. So Earth's diameter is (24,902 + 3.5x2) miles.
If we decide we should only have a 0.1% chance of encountering an air molecule, in order for it to be considered part of Earth, then Earth is much larger.
The reason this is a poor analogy is because the molecules of Earth's atmo really do exist, whether we measure them or not. If we lose track of one, we can always pick it up farther along its path.
Not so for electrons. The do not actually whiz around the nucleus of an atom. We cannot say what they are doing unless and until we measure - and then, all we can do is say "we found an electron at this location". It says nothing at all about what it was doing before or after we measured it.
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Also pretty hard to determine which nucleus it "belongs" to.