Rest energy of a sample of pure matter

In summary, the concept of "pure matter" is not possible as all matter is composed of quarks, which cannot be infinitely compressed. The density of a neutron star can be used as an estimate for the rest energy of one cubic meter of matter, which is approximately 3.6 x 10^34 J. Some alternative theories, such as the gravastar, propose even denser forms of matter.
  • #1
jaketodd
Gold Member
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I am wondering what the rest energy (mc^2) is of 1 cubic meter of pure matter (no empty space).

Thanks,

Jake
 
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  • #2
Pure matter? There is no such thing.
You need choose a density of some amount or tell us the mass of the matter.
 
  • #3
Drakkith said:
Pure matter? There is no such thing.
You need choose a density of some amount or tell us the mass of the matter.

I know there's no such thing. Well I was thinking a neutron star would be pure matter, but I'm unsure of that, so I'm asking: Theoretically, how much rest energy would one cubic meter of pure matter have?

Thanks,

Jake
 
  • #4
jaketodd said:
I know there's no such thing. Well I was thinking a neutron star would be pure matter, but I'm unsure of that, so I'm asking: Theoretically, how much rest energy would one cubic meter of pure matter have?

Thanks,

Jake

There is no such thing as "pure matter", not even theoretically. You're taking a few science terms and using them incorrectly.
 
  • #5
Let me put it this way. Matter is composed of quarks, which form into protons and neutrons, and of electrons. Compress matter enough, such as in a neutron star, and you get a superdense material known as neutronium. Compress it even more and the end result is what appears to be a singularity, a region of space where matter is compressed into infinite density. It is unknown whether singularities actually exist or if they are simply artifacts of an incomplete theory. "Pure matter" seems to me to be the infinitely compressed type, which cannot occupy a set volume of space, as it is compressed infinitely small.
 
  • #6
It should be simple enough to determine the density of neutronium, calculate the mass of a cubic metre of it, then apply E=mc2.

Mass of a cubic metre of neutronium, which is similar to the density of atomic nuclei:
http://en.wikipedia.org/wiki/Neutron_star
and an energy calculator:
http://www.1728.org/einstein.htm

[ EDIT ] you could skip down 2 posts where Pengy does it for you.
 
Last edited:
  • #7
Drakkith said:
Let me put it this way. Matter is composed of quarks, which form into protons and neutrons, and of electrons. Compress matter enough, such as in a neutron star, and you get a superdense material known as neutronium. Compress it even more and the end result is what appears to be a singularity, a region of space where matter is compressed into infinite density. It is unknown whether singularities actually exist or if they are simply artifacts of an incomplete theory. "Pure matter" seems to me to be the infinitely compressed type, which cannot occupy a set volume of space, as it is compressed infinitely small.

If quarks are the most fundamental units of matter, then it seems all you would need to do is fill a cubic meter with them, with no empty space. This would be more dense than neutronium, as that is formed of neutrons, which are, in turn, formed of quarks. If space is quantized, which I, personally, believe it must be, then you can't form a singularity because that would have more than one quantum's worth of matter occupying the same quantum. I know there is a class of matter that can occupy the same space as other matter within that class, but let's leave that out for now.
 
  • #8
Let's just decide we're using a neutron star's density of roughly [itex]4.0 \times 10^{17} kg/m^3[/itex]. So one cubic meter would have the rest energy of [itex]4.0 \times 10^{17} kg/m^3 \times 9.00 \times 10^{16} m^2/s^2 = 3.6 \times 10^{34} J[/itex]. There you go.
 
  • #9
Pengwuino said:
Let's just decide we're using a neutron star's density of roughly [itex]4.0 \times 10^{17} kg/m^3[/itex]. So one cubic meter would have the rest energy of [itex]4.0 \times 10^{17} kg/m^3 \times 9.00 \times 10^{16} m^2/s^2 = 3.6 \times 10^{34} J[/itex]. There you go.

I knew that, but thanks. BTW, is a Pengquino the speed of a neutrino in Antarctica?

Jake
 
  • #10
jaketodd said:
I knew that, but thanks.
Then why did you ask the question?
 
  • #11
DaleSpam said:
Then why did you ask the question?

I asked the question because I thought there might be a more-dense solution, and from the discussion, it seems the answer is quarks.
 
  • #12
A Bose-Einstein condensate is effectively a collection of atoms that have formed into a single atom so this is matter with no gaps between its constituent particles. In an alternative model of the black hole called the gravastar, the outer shell is made of a very dense Bose-Einstein condensate type material which is possibly the densest material theorized to exist. In the classic interpretation of black holes there is no upper limit to the density of matter that is compressed to a singularity at the centre.
 

What is the concept of rest energy?

Rest energy refers to the amount of energy that an object possesses even when it is not in motion. It is a fundamental concept in physics and is closely related to the famous equation E=mc², which states that energy (E) is equal to the mass (m) of an object multiplied by the speed of light (c) squared.

How is rest energy related to mass?

Rest energy and mass are equivalent and can be converted into each other. This is known as the mass-energy equivalence principle, which was first proposed by Albert Einstein. This means that even a small amount of mass can contain a significant amount of energy.

What is the formula for calculating rest energy?

The formula for calculating rest energy is E=mc², where E is the rest energy in joules, m is the mass in kilograms, and c is the speed of light in meters per second. This formula is also known as the mass-energy equivalence equation and is used to calculate the amount of energy released in nuclear reactions.

How does the rest energy of matter affect its stability?

The rest energy of matter is a crucial factor in determining the stability of an object. In nuclear physics, it is used to calculate the binding energy of an atomic nucleus, which is the amount of energy required to break it apart. A higher rest energy can make a nucleus more stable, while a lower rest energy can make it more unstable.

Can rest energy be observed or measured directly?

No, rest energy cannot be observed or measured directly. It is a theoretical concept that helps us understand the relationship between mass and energy. However, the effects of rest energy can be observed and measured in various physical phenomena, such as nuclear reactions and radioactive decay.

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