Eli5 The sun converts about 4 million metric tons of its mass into energy every second. Does this mean that it’s mass reduces significantly over the span of, say, ten years?

Question

4 million tons a second is a lot of mass to be lost given enough time. Considering the fact that the sun is over four billion years old, does this mean that the sun was physically bigger when it formed?

What about a couple of hundred years ago? Or a few years ago? Could the suns loss of mass imply that it’s shrinking over time?

In: Physics

Answer 1

What is “significant” when talking about the reducing mass of the sun? On one hand 4 million tons a second seems significant to us, but the sun is really massive.

Over the course of a year it loses 174 trillion tons of mass. But over the next 5 billion years it will lose 0.034% of its total mass. So yes, it is technically becoming less massive over time, but not to any amount significant to its scale.