Doesn't convection also require movement of the fluid? Under gravity convection works by changes in density when the fluid is heated (e.g. hot air rises). This

Doesn't convection also require movement of the fluid? Under gravity convection works by changes in density when the fluid is heated (e.g. hot air rises). This movement of the fluid provides an extra component beyond regular conduction. The movement of the fluid transfers heat away. In low g environments, convection due to density changes doesn't happen (hot air does not rise) which means heat pools around bodies at rest. Edit: after reading the article a bit, i see that you were quoting a section that ends with "...(conduction and convection) cannot occur without matter." Which does make the distinction the author was making a little more less useful. However lack of convection is an issue inside the space station where fans must be installed to keep air from pooling around heat sources like lights and human bodies.