Assertion: telescope's lense | /r/CapableOf | distort under their own weight
Facets:
Source sentences:
text: In addition, the largest refractor ever built has a diameter of only 40 in (102 cm): lenses of a larger diameter will tend to distort under their own weight and give a poor image.
text: In addition, lenses in telescopes can only be supported around the outside, so large lenses can sag and distort under their own weight.