[donh]

In 1979 Baylor, Lamb and Yau were able to use rods from toads placed into electrodes to show directly that they respond to single photons.

I assume this means you acknowledge that if I handed you a quanta counter, you'd have not the foggiest notion when to click it to indicate a quanta impinged on your rods.

[AndrewC]

You can infer what you like. I presented evidence that we can directly "measure" quanta.

One can dig up a bone. It is a bone or fossil that is direct. It may weigh 50 KG. It may be "white". Those are direct "measurements". Saying that it is the ancestor of your poodle is not a direct measurement. However you wish to characterize your sensations is of no interest to me. However, normally people consider evidence of the senses as direct. It may be erroneous, but it is nonetheless direct.