Question

"A cloud of gas and dust in space, called nebula, began to rotate and condensed into a flattened disk. Gravitational force pulled the gas and dust closer together. This resulted in the nuclear fusion of gases and dust to create the sun and planets at the outer flattened portion of the disk." What is the flaw in the student's explanation?

Answer 1

Nuclear fusion is a process that happens after the Sun is formed. The gas must be pulled together first then only after internal combustion due to the high pressures of gravity acting inward, only then as the sun/star burns its fuel does it use a nuclear fusion process. The planets where the lefts overs that didn't make it into the sun formation and the sun pushed out extra gas that was left over after it formed. The disk became flattened because the whole thing was spinning and that is the conservation of angular momentum.

Answer 2

Thanks

Answer 3

I would have said a major flaw is "began to rotate." There is no way a nebula can begin to rotate -- there is nothing to cause it to do so, no force acting on it. The nebula will certainly begin to rotate faster as it collapses, just like a skater rotates faster when she pulls her arms in, because of conservation of angular moment, but it has to be rotating to begin with.

Answer 4

Thank you also i will try and use both answers in a way.