Eli5: How is the Sun going to “swell” to the point that it engulfs Mercury Venus and Earth? Where is all of that extra matter coming from? Has this swelling already started?

Question

Eli5: How is the Sun going to “swell” to the point that it engulfs Mercury Venus and Earth? Where is all of that extra matter coming from? Has this swelling already started?

In: 69

Answer 1

Go shake a can of soda really hard. Before you open it, take note of the volume of the contents (the size of the can). Now open the can, and take note of the volume of the contents. Same amount of matter, larger volume because it is no longer constrained and higher pressure was able to equalize outward.