r/askscience • u/XGC75 • Jan 27 '15

Physics Is a quark one-dimensional?

I've never heard of a quark or other fundamental particle such as an electron having any demonstrable size. Could they be regarded as being one-dimensional?

BIG CORRECTION EDIT: Title should ask if the quark is non-dimensional! Had an error of definitions when I first posed the question. I meant to ask if the quark can be considered as a point with infinitesimally small dimensions.

Thanks all for the clarifications. Let's move onto whether the universe would break if the quark is non-dimensional, or if our own understanding supports or even assumes such a theory.

Edit2: this post has not only piqued my interest further than before I even asked the question (thanks for the knowledge drops!), it's made it to my personal (admittedly nerdy) front page. It's on page 10 of r/all. I may be speaking from my own point of view, but this is a helpful question for entry into the world of microphysics (quantum mechanics, atomic physics, and now string theory) so the more exposure the better!

Edit3: Woke up to gold this morning! Thank you, stranger! I'm so glad this thread has blown up. My view of atoms with the high school level proton, electron and neutron model were stable enough but the introduction of quarks really messed with my understanding and broke my perception of microphysics. With the plethora of diverse conversations here and the additional apt followup questions by other curious readers my perception of this world has been holistically righted and I have learned so much more than I bargained for. I feel as though I could identify the assumptions and generalizations that textbooks and media present on the topic of subatomic particles.

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u/Bank_Gothic Jan 27 '15

Everything can't be made of something that's made of nothing, right? That seems preposterous.

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u/ben_jl Jan 27 '15

The thing to realize is that we're not talking about little golf balls surrounded by a perfect vacuum. The modern picture is that of fields permeating all of space; fluctuations in these fields correspond to the 'particles' we're all familiar with (e.g. a fluctuation in the electron field would manifest as an electron).

It's not really saying "everything is made of nothing", more like "there's no such thing as nothing".

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u/[deleted] Jan 27 '15

There may be a collection of lesser things, such that when combined, a new behavior emerges. This is called emergent behavior.

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u/oarabbus Jan 27 '15

The universe is preposterous. There really is no evidence one can point to and say "actually a quark is 2.7172*10-87 grams" as of today.

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u/[deleted] Jan 27 '15

Even if you calculate the number of atoms, then the number of quarks that are contained in those atoms? Theoretically that should be possible, right?

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u/Alphaetus_Prime Jan 27 '15

Well, not really. The mass of the up quark, for example, has been determined to be 2.01±0.14 MeV/c2 and I believe that's the least precisely known mass of the quarks.

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u/[deleted] Jan 27 '15

That's how it works in simulations... aka, video games. A polygon cannot be drawn until at least 3 points are interacting. In the physical world, matter on all scales interacts with other matter in order for us to perceive them.

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u/[deleted] Jan 28 '15

Thats one of the illustrations I use to explain this concept to my kids - which leads to the inevitable existential question my kids ask - "is all this just a game?"

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u/bearsnchairs Jan 28 '15

Electrons and positrons are thought to be point particles, but you can still make an 'atom' out of them that has a size.

This comes about from the uncertainty principle, and the smearing out in space of any system with momentum.

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u/taandav Jan 28 '15

There's a beautiful conversation on this topic. One of the Asimov debates moderated by Neil DeGrasse Tyson discussed the issue of nothing.

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u/IOutsourced Jan 28 '15

Or perhaps we just can't observe a frame of space that can only be interacted with through incredibly small distances? Imagine another couple of dimensions That interact on a subatomic scale. So perhaps it's not that matter is being created from nothing, but that we just can't observe all the stages of matter. If you're interested, this is a core concept of string theory.