Yaniv

No one in the right mind will heat the balance, but heat convection and conduction and radiation will inevitably heat the balance.

When a balance is heated its readings change, this is why it important to keep it at a constant temperature. In thermogravimetric machines the missing weight predicted by my theory could be interpreted as part of a "noise" and compensated before display. I searched the literature to the best of my ability and could not find this experiment. This is why I posted this thread.

No, I am not waiting for an email from God. I am waiting for an email from an experimentalist with the results of the specified experiment.

Again you send me to look at a different experiment than requested. Can you please find the results of the specified experiment ?

I am not familiar with the machine. Maybe the computer compensate for weight as a function of temperature ? Send me results and I will drop my theory. But don't ask me to drop my theory without the results.

My theory predicts hot and cold objects should fall at the same rate. Google "Magnetic Universe Theory of Science" to check it out. Please do the experiment I propose and don't confuse experiments.

Glaser conclusion is based on the untested assumption that weight does NOT change at increasing temperatures in vacuum. How can he say this when the "control experiment" is missing from the paper ?

Google "Response of Apparent Mass to Thermal Gradients" or go to M Glaser 1990 Metrologia 27.

Glaser paper describes 20 grams metal rod heated by 5 degC lost 100 micrograms. Air convection likely to contribute so lost likely to be even smaller. Modern precision balances measure down to single micrograms (with standard error of a couple of micrograms) and should pick up changes of just a few micrograms. The question now is not how many micrograms to expect. Any measurable change will do. The experiment should be carried out with the highest precision achivable by the experimentalist.

How to eliminate ''noise'' from the experiment ? Set up the apparatus. Place a balance, heat source and a thermometer inside a vacuum chamber and set the electronics for external control. Insulate the balance and use a thermostat to keep balance at a constant temperature as possible to reduce ''noise''. Next, place the metal beside the balance and heat the chamber to a fixed duration to a known temperature. The change in weight you get is your ''noise''. Next, place the metal on the balance and repeat the heating process. Do you get a different reading ? Come on guys, it's not a rocket science.

Metals still have a vapor pressure you will lose atoms faster if you heat the metal, but this will still be a very small effect. A Dmitriev graph shows that when a heated metal is cooled its weight begins to go back to pre-heating weight and Glaser's cooled metals recorded increasing weights so vaporisation is unlikely and could be easily tested. But I don't see how this necessarily measures F=ma. Might a violation be chalked up to a violation of the equivalence principle? If weight changes at increasing temperatures, either the first constant of physics (mass) or the second constant of physics (gravity), or both, are not constants. This is surely more fundamental than the seventh or so constant of physics - speed of light. Earth tides make "fixed position" moot. The heating process should last a few minutes so the position of the moon is likely negligable. Why find so many excuses NOT to do the experiment ?

A good balance in the lab, set on a fixed position, experiences constant gravity. Doing the experiment in the lab is better because your metal is not in motion. Why complicate things. Start with the simplest experiment please.

Weighing a heated metal in VACUUM eliminates air related influences such as bouyancy and heat convection. W=mg is like F=ma. You can not have two constants on one side of the equation and a variable on the other ? If weight changes at different temperatures, then weight is a variable.

You say weight should increase a tiny bit at incresing temperatures. I heard that many times but the experimental results show to the contrary. Maybe your prediction is wrong ?

According to physics weight=mass*gravity. Since mass and gravity are constants weight must be a constant too. I searched the literature and found several papers (Glaser, 1990; Dmitriev, 2003) showing weights of heated metals decrease at increasing temperatures. Glaser says air convection is responsible for weight reduction but Dmitriev weight reduction of a heated thermal insulator cast doubt on Glaser's explanation. Surely not conclusive. I propose an experiment to test this; weigh a heated metal in vacuum. If weight decreases at increasing temperatures in vacuum, as my theory predicts, F=ma is disproved. Interested to do the experiment ?