Hey man good to see you again! :)👍 I have one question. Believing Einstein, massive particles moving faster get also heavier. After watching your video I wonder: Do objects become heavier when they get hotter?
Hello, Nice to hear from you! :) So, for the question above, i think it depends on the heated object, if it loses some matter (for example through evaporation); then it would get lighter. If no mass is lost (which should be true for most solids like metals); Then i don't think heating it makes it heavier. As you correctly pointed out, Einstein's E=mc^2 makes a big difference when the speed is close to that of light; However, electrons in a heated object drift very slowly (~ 0.0001 m/s, but differs with materials), so they can't gain any observable mass to make the object heavier. This answer was my initial thought when i read this question, I will update it if i have a better idea.