FormulaNova said...Ian K said...FormulaNova said...
So, when we burn something, are we adding mass or losing mass?
When we combine something with oxygen, doesn't it get heavier?
I'd say the energy, E, released as heat and radiation, as a mini chemical rather than a nuke mushroom cloud , would lead to a reduction in mass of the combustion products by E/(c^2)
This is my understanding from the popular science novel "E = mc^2" by David Bodanis. My sister gave the book to me years ago but it's still available in departure terminal bookshops. Or you can borrow it. It's a good read.
So, Ian, are you saying that the Earth is getting heavier from all the solar radiation hitting it and being used in photosynthesis?
My understanding of this concept is very limited. I remember in high school, doing the 'burn some wood in a test tube and weigh it before and after' experiment. Surprisingly ours weighed more, and we were the only group in the class to get it right. Ahh, those were the days when science was simple
Wouldn't the extra mass from the oxygen atoms exceed the mass lost from the released of energy? (I will completely ignore the fact that some of it escapes as gas
)
Yeah, I wouldn't mind borrowing that book. If it's 'popular science' I might just be able to keep up!
Yes the products of photosynthesis should be heavier than the raw ingredients.
The mass of the oxygen atoms swamp any relativistic changes in mass. The oxygen has been weighed in with the ingredients as well as the products of the combustion.
The mass changes are very small in everyday reactions so we'd use chemistry methods to follow all the energy exchanges. In the test tube you'd assume the mass didn't change because it would be undetectable with the laboratory scales.
All this wouldn't have much influence on the earth's axis of rotation. But then you know the effect that the butterfly in the Amazon had on the weather in New York.
Let me know when you next pass by the 'gong. I've got the book handy.
. You only get out what you put in. You can't finish with more mass than what was there to begin with. 
