Do you believe; and why?

[hollodero]

(05-09-2019, 03:43 PM)Dill Wrote: The activity you describe (photon release, sunburning, etc.) is still comprised of sub atomic particles in various states. 

Let me put it this way.  If you could put the universe in giant plastic bag from which nothing could escape and then place it on a giant bathroom scale and weigh it at 1 pm.  It would be the same weight if you weighed it at  2 pm, no matter how much mass has been converted to energy or reconverted back to mass in the intervening hour.   Possibly.

Well, the photons carry the energy away that is gained by the mass deficit of the resulting core in the fusion process. I see no reason to believe this energy is bound to turn into mass again. Hence, I do not think your assessment is entirely true. (It obviously isn't true regarding the annihilation of electron and positron. Those masses are just gone, e.g. converted into energy)

Now sure, since mass equals a lot of energy (two times the speed of light factors into it, after all), these are tiny fluctuations that don't matter much on a big scale. But I disagree, your system doesn't have to have the exact same weight at all times. Same overall energy, ok, that law stands. But there's no such law regarding conservation of mass.