Brief Summary of Light Weight Proppants, page-196

Part of the reason I don't like to put people on ignore.
But in all walks of life statements made without a factual basis are always dismissed quickly.
My scientific training has taught me to quickly evaluate claims, and if the facts don't add up or simply are not there then move on to other claims.
Anti-vaxxers are the classic example. No amount of evidence will shift their stance, they will continue to pull out the Wakefield paper. Quite laughable really.