One sticking point I reach in certain discussions on this site is trying to pin down exactly what constitutes a fact in science. Let’s try a simple one as a test case.

The temperature is 68° Fahrenheit.

Is this measurement a fact, or a conclusion based on a tall tower of theories? I’ll bet that you forebode where I’m going with this.

First, let’s get legal and precise: The air temperature in the shade in my garden at the location of my thermometer at precisely this moment (as defined by some reading at GMT-6 on the radio-synchronized clock on my wall) is 68°F (292.0K). We cannot conclude (absent other information) what the temperature is elsewhere in the neighborhood, or the rate and direction of the change of temperature from this single reading.

Next, considered as an experiment: The incident radiant heat from reflecting sources is minimal, estimated as an error of increase of less than 0.1°F. The relative humidity and breeze are constant enough to ensure that the thermometer is dry, therefore evaporative cooling can be ignored. The temperature is safely too high for quantum effects, yet far too low for relativistic effects to be measurable. The instrument is viewed at eye level normal to its plane at teh reading height, reducing parallax effects to negligible.

Next, how well is this thermometer calibrated? Um. Well, it has numbers and marks. But those indicate only about one degree of precision, without indicating any accuracy in particular. It is not a laboratory …