Understanding Size & Energy & Matter

[RichIsnang]

Firstly, I understand that electrons occupy no volume, so aren't they smaller than planck length?

Also, do neutrinos occupy a volume?

[imatfaal]

I think the two statements of mine are very explicit. No idea what "elliptical" is supposed to mean (googling for it I found the explanation "characterized by extreme economy of expression or omission of superfluous elements" - is that what you meant?).

 

I agree that your statements are explicit, short, and to the point.

 

O/T

As you found via google elliptical can be used to describe language that is terse almost to the point of being deliberately unintelligible. Ellipsis is a deliberate omission of words or a phrase - and crucially the sentence does not make sense (grammatically or logically) without the omitted section, it is left to the reader to provide that missing something. [An ellipsis is also the printing term for the three dots that you see to indicate an unfinished sentence or bridge two disparate thoughts.] I would explain in more depth but ...

 

For language to be described as elliptical is rarely complementary; it can either mean deliberately difficult and not easy to understand or jumping from one subject to another, and neither of those alternatives is desirable. Apart from in very special circumstances, often when style is more important than content, being elliptical in speech (especially if the text is intended to inform) is to be avoided.

 

http://www.merriam-webster.com/dictionary/ellipsis

http://www.merriam-webster.com/dictionary/elliptical

[juanrga]

Firstly, I understand that electrons occupy no volume, so aren't they smaller than planck length?

 

Such questions are tricky. An electron in a box of side L can occupy the entire volume of the box according to quantum mechanics. But at the other hand, the electron (at least in the Standard Model of particle physics) has not volume itself. Finally, it is generally agreed (although this is still open to debate) that distances below the Planck length are unphysical.

[Alan McDougall]

Such questions are tricky. An electron in a box of side L can occupy the entire volume of the box according to quantum mechanics. But at the other hand, the electron (at least in the Standard Model of particle physics) has not volume itself. Finally, it is generally agreed (although this is still open to debate) that distances below the Planck length are unphysical.

 

Size is relative is it not? You can only estimate size of something, if you have something other to compare it with.

[juanrga]

Size is relative is it not? You can only estimate size of something, if you have something other to compare it with.

 

First, what has this to do with what I said?

 

Second, we do not estimate sizes; we measure sizes [*]. Size S is a special case of a scientific quantity: S={S}.

 

If measurement of the size of an object gives S, this quantity does not depend on with what you compare it, because comparison with another object must give the same size: S = aA = bB. What varies in the comparison with different objects is the proportionality constant: a or b respectively.

 

[*] Instead "size" is better to say length, height, or some other physical quantity representing size. But I will continue using "size" since this was the original word used by the other poster.

[Alan McDougall]

First, what has this to do with what I said?

 

Second, we do not estimate sizes; we measure sizes [*]. Size S is a special case of a scientific quantity: S={S}.

 

If measurement of the size of an object gives S, this quantity does not depend on with what you compare it, because comparison with another object must give the same size: S = aA = bB. What varies in the comparison with different objects is the proportionality constant: a or b respectively.

 

[*] Instead "size" is better to say length, height, or some other physical quantity representing size. But I will continue using "size" since this was the original word used by the other poster.

 

Length height calculated from some physical thing within or on an object?

[juanrga]

Length height calculated from some physical thing within or on an object?

 

A telephone within a box (or on a table) has length and height.

[alpha2cen]

A telephone within a box (or on a table) has length and height.

 

The one originally has varying shape, and has no fixed shape. Does it have a size?

[Alan McDougall]

Neutrinos are not easily destroyed with matter. So, there will be much neutrinos in the space. Are there any place where neutrinos disappearing in the space?

 

 

What about the BB Singularity did it have size or dimension?

[dapifo]

The neutrino only interacts via the weak force. Neutrons have, in addition, the strong and electromagnetic interactions.

 

 

We could say that the neutrino is the smallest particle known (10^-24 meters)?

 

Such questions are tricky. An electron in a box of side L can occupy the entire volume of the box according to quantum mechanics. But at the other hand, the electron (at least in the Standard Model of particle physics) has not volume itself. Finally, it is generally agreed (although this is still open to debate) that distances below the Planck length are unphysical.

 

 

When we can consider that a particle is physical or unphysical?... what is the difference?

[juanrga]

When we can consider that a particle is physical or unphysical?... what is the difference?

 

All known particles in universe are physical: electrons, photons, protons...

 

An 'unphysical' particle would be particle invented by someone.