# How does energy (from fusion reactions still inside the sun) still have gravitational attraction?

While the conversion of mass matter† to energy in the Sun's core now represents a loss of mass proper matter, it turns out that that energy (trapped in the Sun and slowly diffusing towards the surface) will have the same gravitational attraction as the matter it came from until it actually escapes the Sun!

Now I expect that when mass is converted to energy, it has become an electromagnetic wave that can propagate through matter or empty space.

My question is: How does energy (from fusion reactions still inside the sun) still have gravitational attraction?

• Energy and mass are both equivalent . E=m c**2. – planetmaker Feb 29 at 10:15
• Thanks - does that imply that energy has gravitational attraction? – hawkeye Feb 29 at 10:19
• yes, exactly that – planetmaker Feb 29 at 11:42
• +1 @hawkeye this is definitely a good question and while I am sure the answer is correct I can't explain why, so it deserves a much better answer than I can write! – uhoh Feb 29 at 13:47
• "it has become an electromagnetic wave that can propagate through matter or empty space." This isn't really true, as you note in your quote. The electromagnetic wave is very much trapped by all the Sun's matter. It takes a long time for the photons to work their way through all the mass in the sun, bouncing around for a long time before making it into space. – userLTK Feb 29 at 14:09