Plastic  Orb

Pick the Selection Tool and draw an elliptical selection as shown. Settings below:

Now, Floodfill your current selection with Black-White Gradient

Change layer's Blend Mode to Screen:
( Layers > Properties > Blend Mode = Screen )

Deselect selection by pressing CTRL+D

Add a new Raster layer (Layers>New Raster Layer). Set your Foreground and Stroke Properties to White and Background to Red.

Load your saved selection from Alpha Channel (Selections>Load/Save Selection>Load Selections From Alpha Channel). Floodfill your current selection with Foreground-Background Sunburst Gradient

Apply Spherize filter (Effects>Geometric Effects>Spherize>Strength = 100 )

Change layer's blend mode to Screen (Layers>Properties>Blend Mode = Screen )