[URAIN]

While explaining the E=mc^2, lots of people says matter/mass converts to energy.

Which I read that, while converting matter into its different forms, the missed or not observed matter is equal to energy.

I would like to know more, regarding to this.

For matter converting into energy many people gives the example of radiating materials like uranium ect.

Other than this how we convert huge mass into energy. Like earth ect.......

What needed to convert matter into energy?

[CaptainPanic]

In nuclear fusion / fission, a tiny bit of matter is turned into energy. Quite a lot of energy, in fact.

For example, the sun, reacts hydrogen to helium. And the helium that is formed is a tiny bit lighter than the hydrogen that was needed to make it.

The sun has, according to wikipedia, an overall power of about 3.846×1026 W (I'm guessing this fluctuates a little bit, so 4 significant numbers may be a little bit much). 3.846×10²⁶ W is of course 3.846×10²⁶ J/s.

So, in one second, 3.846×1026 J is created from mass. How much mass?

E = m*c², so m = E/c² = 3.846×10²⁶/299792458²= 4 million ton of mass is gone every second.

That sounds like an awful lot, but according to wikipedia again, the total mass of the sun is 1.9891×10³⁰ kg, so if we would theoretically burn up all the sun (which is not possible, because helium and other elements are made, which also have a weight!) it would take 5×10²⁰ seconds to burn up the sun. That's the same as 1.5×10¹³ years.

If you would turn the entire earth, mass 5.9736×10²⁴, into energy, that would be 5.3×10⁴¹ J of energy. That's 0.1% of a type 1a supernova.
So, yes, there are events in the universe which convert a huge mass into energy. But you don't want to be near it.

[URAIN]

CaptainPanic, on 15 December 2011 - 12:37 PM, said:

In nuclear fusion / fission, a tiny bit of matter is turned into energy. Quite a lot of energy, in fact.

For example, the sun, reacts hydrogen to helium. And the helium that is formed is a tiny bit lighter than the hydrogen that was needed to make it.

The sun has, according to wikipedia, an overall power of about 3.846×1026 W (I'm guessing this fluctuates a little bit, so 4 significant numbers may be a little bit much). 3.846×10²⁶ W is of course 3.846×10²⁶ J/s.

So, in one second, 3.846×1026 J is created from mass. How much mass?

E = m*c², so m = E/c² = 3.846×10²⁶/299792458²= 4 million ton of mass is gone every second.

That sounds like an awful lot, but according to wikipedia again, the total mass of the sun is 1.9891×10³⁰ kg, so if we would theoretically burn up all the sun (which is not possible, because helium and other elements are made, which also have a weight!) it would take 5×10²⁰ seconds to burn up the sun. That's the same as 1.5×10¹³ years.

If you would turn the entire earth, mass 5.9736×10²⁴, into energy, that would be 5.3×10⁴¹ J of energy. That's 0.1% of a type 1a supernova.
So, yes, there are events in the universe which convert a huge mass into energy. But you don't want to be near it.

Thank you.

How the process will go. when we convert Mass to energy.

If we apply square of light speed to any mass, then do mass converts to energy?

[swansont]

URAIN, on 16 December 2011 - 12:57 PM, said:

If we apply square of light speed to any mass, then do mass converts to energy?

It's a mathematical statement, not a physical process.

How do you "apply square of light speed" to a mass?

[JustinW]

Quote

It's a mathematical statement, not a physical process.

How do you "apply square of light speed" to a mass?

I agree. But wouldn't you agree that energy holds mass? And that you can't have mass without energy? I believe the question was, if you could project mass to twice the speed of light, would it turn into a form of energy?

[URAIN]

swansont, on 16 December 2011 - 03:40 PM, said:

It's a mathematical statement, not a physical process.

How do you "apply square of light speed" to a mass?

Quote

How the process will go. when we convert Mass to energy.

If we apply square of light speed to any mass, then do mass converts to energy?

I have also asked how the process go.
How can we convert huge mass into energy?

[JustinW]

I just wonder if it's feasable with any mass.

[IM Egdall]

JustinW, on 16 December 2011 - 07:39 PM, said:

I just wonder if it's feasable with any mass.

E=mc^2 doesn't just apply to nuclear processes like in the core of the Sun or atomic energy (and bombs), it applies to all processes where energy is involved. Say, for example, you have a candle. Then you light the candle and let it burn down. Say you somehow captured all the wax and gases etc. the candle has given off after the candle has burned.

Then you compare the weight of the candle before it burned to the weight of all the stuff captured after it burned (very accurately). You find the stuff from the candle afterwards weighs a tiny bit less than the candle before it was lit.

Where did this missing mass go? It was converted from mass to energy per E=mc^2 -- that is the missing mass was converted to the energy of the light and heat given off by the burning candle.

For other examples, see link: http://www.abc.net.a...ies/3000861.htm

This post has been edited by IM Egdall: 16 December 2011 - 08:11 PM

[michel123456]

JustinW, on 16 December 2011 - 03:50 PM, said:

I agree. But wouldn't you agree that energy holds mass? And that you can't have mass without energy? I believe the question was, if you could project mass to twice the speed of light, would it turn into a form of energy?

It is not twice the speed of light.
It is the speed of light squared.

[URAIN]

IM Egdall, on 16 December 2011 - 08:09 PM, said:

E=mc^2 doesn't just apply to nuclear processes like in the core of the Sun or atomic energy (and bombs), it applies to all processes where energy is involved. Say, for example, you have a candle. Then you light the candle and let it burn down. Say you somehow captured all the wax and gases etc. the candle has given off after the candle has burned.

Then you compare the weight of the candle before it burned to the weight of all the stuff captured after it burned (very accurately). You find the stuff from the candle afterwards weighs a tiny bit less than the candle before it was lit.

Where did this missing mass go? It was converted from mass to energy per E=mc^2 -- that is the missing mass was converted to the energy of the light and heat given off by the burning candle.

For other examples, see link: http://www.abc.net.a...ies/3000861.htm

Thank you 'IM Egdall'. I have searching example like this.

It may converted to heat energy.

As I see this example. I think to convert mass into energy, there must be another energy like heat must exist. Without energy, will we not convert the mass into energy?

Like, if we give a mass a force to move and by fast movement it get converted to energy.

[swansont]

Any exothermic reaction converts mass to energy. To do it completely requires matter/antimatter annihilation.

[URAIN]

Please give examples (particular) relating, energy converting into matter.

[swansont]

URAIN, on 23 December 2011 - 09:53 AM, said:

Please give examples (particular) relating, energy converting into matter.

Examples will depend on if you mean matter in the general sense or matter in the strict sense.

Particle collisions, such as p + p —> 3 protons + antiproton (and many, many other possibilities), where you convert KE into mass and more particles. Some of the possible products are mesons, and some of these have shown a tendency to produce more matter than antimatter as they decay.

[DrRocket]

swansont, on 17 December 2011 - 10:12 AM, said:

Any exothermic reaction converts mass to energy. To do it completely requires matter/antimatter annihilation.

Likewise heat absorption "converts" energy to mass -- heat up a bucket of water and it will weight slightly more than it did when cold.

This very quickly gets into subtleties with what one defines to be either mass or energy. The crux of is that there is no clear cut distinction unless one demands by fiat that mass be rest mass.

[JustinW]

Quote

It is not twice the speed of light.
It is the speed of light squared.

Thanks for the correction michel, I have since learned the errors of my ways. I would hate to implant any misconceptions. I believe I was also corrected by Swansont on the same day for the same thing, if my memory is correct. It must have been a bad day for my brain.

Quote

The crux of is that there is no clear cut distinction unless one demands by fiat that mass be rest mass.

I think this might have answered the question that was bouncing around in my empty skull at the time.

[swansont]

JustinW, on 26 December 2011 - 09:01 PM, said:

I think this might have answered the question that was bouncing around in my empty skull at the time.

One has to be aware that there are different definitions of mass. You have to be careful and not mix the definitions in the same discussion — they are not interchangeable.

[URAIN]

For mass converting into energy, I think we can give example of fat person become slim by making exercise.


If it is correct example, then in my view only movement has converted mass into energy.

[Widdekind]

swansont, on 23 December 2011 - 11:17 AM, said:

Examples will depend on if you mean matter in the general sense or matter in the strict sense.

Particle collisions, such as p + p —> 3 protons + antiproton (and many, many other possibilities), where you convert KE into mass and more particles. Some of the possible products are mesons, and some of these have shown a tendency to produce more matter than antimatter as they decay.

Would you please clarify that ? Are there actually decays, that produce more fermions than anti-fermions ? Or, are we ignoring (anti)neutrinos in such statements ?

[swansont]

Widdekind, on 22 January 2012 - 10:43 PM, said:

Would you please clarify that ? Are there actually decays, that produce more fermions than anti-fermions ? Or, are we ignoring (anti)neutrinos in such statements ?

The asymmetry happens in decays of mesons. IIRC it has been observed with B mesons and Kaons