Total Posts:8|Showing Posts:1-8
Jump to topic:

Question About Gravity

Cobalt
Posts: 991
Add as Friend
Challenge to a Debate
Send a Message
7/3/2016 1:15:56 AM
Posted: 5 months ago
I've been watching a great interview about the guys from LIGO who detected a gravitational wave at the beginning of this year and again 2 weeks ago.

This all got me thinking about the following questions:

Things with mass have gravity, in that they cause a stretching of spacetime.

The conservation of mass says that, in an isolated system, the amount of mass remains constant despite any internal interactions.

Does this mean that mass stays as mass, or can some be converted to energy, or that mass and energy are considered the same thing.

My real question: Can mass be converted into energy? Or is it more accurate to say that the energy inside of a particular mass (like gasoline) just changes form (when burned), and that the actual mass that formed the gasoline is still there?
dee-em
Posts: 6,469
Add as Friend
Challenge to a Debate
Send a Message
7/3/2016 2:07:31 AM
Posted: 5 months ago
At 7/3/2016 1:15:56 AM, Cobalt wrote:
I've been watching a great interview about the guys from LIGO who detected a gravitational wave at the beginning of this year and again 2 weeks ago.

This all got me thinking about the following questions:

Things with mass have gravity, in that they cause a stretching of spacetime.

The conservation of mass says that, in an isolated system, the amount of mass remains constant despite any internal interactions.

Does this mean that mass stays as mass, or can some be converted to energy, or that mass and energy are considered the same thing.

Energy and mass can be considered equivalent.

My real question: Can mass be converted into energy?

E = mc^2

Or is it more accurate to say that the energy inside of a particular mass (like gasoline) just changes form (when burned), and that the actual mass that formed the gasoline is still there?

Your example is a chemical reaction where there is no loss of mass. All that is happening is that stored energy from the Sun which was used by plants to form chemical bonds (which was in turn transformed into oil in the ground under pressure and heat) is now being released again when those bonds are broken. Ultimately coal and gasolene energy is recycled solar energy.

You have to look to the Sun to see mass being converted to energy. That is what the fusion of hydrogen into helium is producing, a tiny loss of mass translating into a huge release of energy via E = mc^2.
Cobalt
Posts: 991
Add as Friend
Challenge to a Debate
Send a Message
7/3/2016 2:16:27 AM
Posted: 5 months ago
At 7/3/2016 2:07:31 AM, dee-em wrote:

Thanks. That leads into my next question:

You say mass can be converted into energy. Let's say we have some device that lets us do this perfectly -- so that we can convert 1 unit of mass into 1 unit of energy.

Say we have a box in which there is 1 unit of mass and it emits a gravitational force equal to what we'll call 1F.

After converting that mass into energy, does the box still emit a gravitational force of 1F. Ie, does the portion of the mass that gets converted to energy still emit a gravitational force? Does energy have a gravitational force?
dee-em
Posts: 6,469
Add as Friend
Challenge to a Debate
Send a Message
7/3/2016 2:40:11 AM
Posted: 5 months ago
At 7/3/2016 2:16:27 AM, Cobalt wrote:
At 7/3/2016 2:07:31 AM, dee-em wrote:

Thanks. That leads into my next question:

You say mass can be converted into energy. Let's say we have some device that lets us do this perfectly -- so that we can convert 1 unit of mass into 1 unit of energy.

Say we have a box in which there is 1 unit of mass and it emits a gravitational force equal to what we'll call 1F.

After converting that mass into energy, does the box still emit a gravitational force of 1F. Ie, does the portion of the mass that gets converted to energy still emit a gravitational force? Does energy have a gravitational force?

Yes, that is my understanding. You have to realize though that in practical terms it is hard to confine energy in this way. Mass can congregate in small volumes of space to produce a measurable gravitational effect (warping of space-time). The equivalent amount of energy is almost impossible to confine in this manner.
Cobalt
Posts: 991
Add as Friend
Challenge to a Debate
Send a Message
7/3/2016 2:43:29 AM
Posted: 5 months ago
At 7/3/2016 2:40:11 AM, dee-em wrote:

Yes, that is my understanding. You have to realize though that in practical terms it is hard to confine energy in this way. Mass can congregate in small volumes of space to produce a measurable gravitational effect (warping of space-time). The equivalent amount of energy is almost impossible to confine in this manner.

I can understand that. I was mainly thinking about Alcubierre's (Warp) Drive. It's a physically sound idea, provided we had some "antigravity" particles. It seemed that, if energy did not exert the force of gravity, then turning matter into energy could in some way simulate the effect of "antigravity" particles.

But alas, if energy also emits a gravitational force, then this wouldn't work. Thanks for your help!
keithprosser
Posts: 1,975
Add as Friend
Challenge to a Debate
Send a Message
7/3/2016 4:06:20 AM
Posted: 5 months ago
I thnk the most familiar example of energy producing gravity is that objects get heavier as they are accelerated, their kinetic energy manifesting itself as extra mass and we all agree mass has gravity.

The number are that all the energy released by the bomb that destroyed Hiroshima would extert less gravitational force than that of a mass of 0.7 grams, which is a heck of a lot of energy to produce a tiny bit of gravity. The mass of the entire earth only produces a force of about 10 Newtons so the amount of acceleration you'd get using the gravitational pull of a 0.7 g lump of matter would shame a snail with asthma.
lannan13
Posts: 23,062
Add as Friend
Challenge to a Debate
Send a Message
7/3/2016 4:24:34 AM
Posted: 5 months ago
At 7/3/2016 1:15:56 AM, Cobalt wrote:
I've been watching a great interview about the guys from LIGO who detected a gravitational wave at the beginning of this year and again 2 weeks ago.

This all got me thinking about the following questions:

Things with mass have gravity, in that they cause a stretching of spacetime.

The conservation of mass says that, in an isolated system, the amount of mass remains constant despite any internal interactions.

Does this mean that mass stays as mass, or can some be converted to energy, or that mass and energy are considered the same thing.

My real question: Can mass be converted into energy? Or is it more accurate to say that the energy inside of a particular mass (like gasoline) just changes form (when burned), and that the actual mass that formed the gasoline is still there?

Doesn't this happen after the Plank's Constant (Absolute Max Temp) where matter escentially turns into plasma?
-~-~-~-~-~-~-~-Lannan13'S SIGNATURE-~-~-~-~-~-~-~-

If the sky's the limit then why do we have footprints on the Moon? I'm shooting my aspirations for the stars.

"If you are going through hell, keep going." "Sir Winston Churchill

"No one can make you feel inferior without your consent." "Eleanor Roosevelt

Topics I want to debate. (http://tinyurl.com...)
-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~-~
bamiller43
Posts: 200
Add as Friend
Challenge to a Debate
Send a Message
7/5/2016 3:38:29 PM
Posted: 5 months ago
At 7/3/2016 1:15:56 AM, Cobalt wrote:
I've been watching a great interview about the guys from LIGO who detected a gravitational wave at the beginning of this year and again 2 weeks ago.

This all got me thinking about the following questions:

Things with mass have gravity, in that they cause a stretching of spacetime.
Correct.

The conservation of mass says that, in an isolated system, the amount of mass remains constant despite any internal interactions.
correct, except replace mass with matter.

Does this mean that mass stays as mass, or can some be converted to energy, or that mass and energy are considered the same thing.
Matter can be converted to energy, and vice versa. If i am not mistaken, we achieved the former with the atom bomb.

My real question: Can mass be converted into energy? Or is it more accurate to say that the energy inside of a particular mass (like gasoline) just changes form (when burned), and that the actual mass that formed the gasoline is still there?

Burning gasoline only releases potential (stored) energy. This is a chemical reaction, and therefore no matter is lost.

This is my best explanation of the relation of matter and energy. In essence, matter is a form of energy that when passed through the higgs field, is given mass by higgs-boson particles and becomes matter. Other forms of energy (light, sound) avoid the field and remain as energy. If i am wrong about any of this, please let me know.