How small can you go

[fakts]

Title says it all, and it has been in my head forever
How small can you go? As far as I know, the smallest known this is what makes a proton which called quarks? but still, a quark must be made of other things and those things are made of even other things and so on.. But till where? infinity?
I can't imagine there is such thing as smallest and no smaller than that, at least that's what I think.

Can someone with white beard help me get some sleep?

Thanks

If this has been discussed before please link me and I apologize

[Borek]

still, a quark must be made of other things

Must?

[fakts]

Well, you get the idea

[DavidSnider]

It's quarks all the way down.

[jnorman]

an electron is a point particle - it has no volume - that's about as small as you can get. same thing with quarks - point particles, no volume. that pretty much covers everything...

[fakts]

Ok, and what makes that point a point?

[jnorman]

quarks and electrons are point particles because they have no extension in space. i dont quite understand what you mean by "what makes a point a point"...

[fakts]

I'm sorry for being silly, but I'm not a physicist and I see things as an amount of smaller things, like a house is made out of bricks and bricks are made out of smaller things and so on.
So I'm having difficulties saying this is is the smallest thing and its not made out of anything smaller :confused:
I thought that maybe you can just go forever from small to smaller to smaller and never to smallest.

[jnorman]

again, a point particle has zero volume - you cannot get any smaller than zero volume. there is not, and cannot be, anything smaller than a point particle. point particles are not made of anything smaller. that is why we call them fundamental particles.

[fawk3s]

At some point, theorizing, I think mass becomes energy. Because what I've heard, they are the same thing.
What makes up energy? Thats what you're going to have to ask someone smarter than me.

[fakts]

jnorman,

Thanks alot for taking the time
Just one question, does the same thing apply for the very big? I mean is there an end to the size of the universe or multi-universe as I heard once in some doc?
There is no wall where everything stops, is there? hehe

[jnorman]

oye vey - i dont think there is a limit on big, other than the debate over closed vs open universe. OTOH, if you are talking about the physical size of an object contained within the universe, once any object gets to a certain mass, it will eventually collapse upon itself into a singularity, which once again is a point with no physical size.

[fawk3s]

oye vey - i dont think there is a limit on big, other than the debate over closed vs open universe. OTOH, if you are talking about the physical size of an object contained within the universe, once any object gets to a certain mass, it will eventually collapse upon itself into a singularity, which once again is a point with no physical size.

A star which has collapsed into a neutron star or a black hole has a physical size.
I dont know if this is what you meant though.

[Fuz]

A star which has collapsed into a neutron star or a black hole has a physical size.
I dont know if this is what you meant though.

I think hes talking about where all that matter condenses into a point of zero volume, i.e. the singularity.

[suhagsindur]

I'm sorry for being silly, but I'm not a physicist and I see things as an amount of smaller things, like a house is made out of bricks and bricks are made out of smaller things and so on.
So I'm having difficulties saying this is is the smallest thing and its not made out of anything smaller :confused:
I thought that maybe you can just go forever from small to smaller to smaller and never to smallest.

Plank length puts limit on the smallest dimension which is 1.616×10^-35 Meter. Nothing can be smaller than this. Plank length is 10^20 times smaller than proton diameter.

http://en.wikipedia.org/wiki/Planck_length