I think the answer we want now is a non-mathematical one. It gets tiresome how most of the "answers" are just too afraid( or maybe naive?) to just say "we don't know" why the speed of light is the constant of proportionality in the mass-energy conversion equation.
You can answer the "how" very well which is what the mathematical derivation is, and which is what most people are answering in this thread but you see that none of those answers start with "Because..." but rather just keep on spitting out more math. And what we want is an explanation for why c^2 is there and what it means.
We don't know what it means, we haven't answered that question and we don't know how to answer it. It's similar to how pi keeps coming up in a lot of equations and we struggle to understand why.
No one has answered your question. There is no answer really to your question. At least, not to the level that you are asking. Why is c^2 in that equation? What does it mean? We don't know. It's a deeper level of understanding that we haven't achieved.
Another similar question would be why does pi come up in everything? There's a lot of physics where pi comes up and we don't know why.
If YC research is a success, would you consider establishing a website onto which researchers can publish the data and the analysis they did to reach their conclusions?
Often I see people say what they used to take the data and then the end result of the analysis, but never do I see any details whatsoever about the specific techniques or steps they took to transform the raw data into what ends up being published.
It's a very frustrating thing for me and I don't see a mainstream or more easily accessible way for me to post my raw data + analysis other than making a blog for myself, which I have no easy way of promoting in a paper.
I think it would be great to be the ones that set the tone for transparency and it would be a fantastic way of teaching others how to analyze data, or how to catch errors in someone's analysis.
Right now there's a huge wall of obscurity in that we have to take the author's word for it. I know many things cannot be reproduced in experimental science, but the analysis of the data should be. I can't see a reason why people would not want to share their data in academia since most people are funded by DOE, NSF, NIH and DOD and hence by the taxpayer. I think it would be great for pedagogical purposes, it would encourage best practices and it would help us be honest.