DEFINTION:
Den Pressure:
Is the act of Air Pressure creating weight by pressing down on an object. The density of an object determines how much air pressure affects how much force is transferred to the object to create weight. For instance a less dense object would be affected less and in return would weight less.
WRONG !!!
Air is pressing on objects from all directions, not just from above.
Air pressure at higher elevations is lower, so any object will get pressed by air a bit harder from below than from above.
Imagine a block of Lead and a block of wood and a sponge, all of equal size to the eye.
We know that the Lead is heavier than the wood and the wood is heavier than the sponge.
The reason this is the case is because the Lead repels/resists the atmospheric pressure upon it and the ground is the solid in which the Lead pushes against, so we now perceive a push on push effect.
...
We all know that for Cathode Ray Tubes to work, inside must be the highest vacuum achievable.
Cathode Ray Tubes (CRT) are made from glass. Glass maintains that vacuum for long tme.
Glass blocks ALL air around CRT from entering, and some still working CRT are decades old.
Yet, glass is much lighter than lead. And mercury is heavier than lead, gold heavier than mercury,
iridium heavier than gold, and osmium a bit heavier than iridium.
If glass blocks all air, then nothing is left.
How much of that nothing can be blocked by lead more?
And then by gold, and then by osmium?
50% of zero is still zero.
So, letting air in is not the reason why some materials get lighter.
As we saw, glass is letting none.
...
Under the denpressure model, the inflated balloon ought to weigh less than the deflated balloon in step 1 and step 3 due to increased buoyancy.
Under the gravity model, the inflated balloon ought to weigh more than the deflated balloon, as the air inside it is caught and included.
If no change is detected, the experiment is inconclusive. It may simply be the scales weren't sensitive enough to detect the buoyancy or added weight.
...
The difference in weight caused by air inside the balloon is of much less influence, because of atmospheric push.
More air in balloon means bigger balloon. Bigger balloon means more external air displaced and more weight lost because of it.
If we assume compressed air inside balloon is 1.3 kg/m
3 and external is 1.225 kg/m
3,
then the difference is 75 grams per 1000 liters, or 75 milligrams per liter.
I'm not sure cheap commercial scales can detect that.
And I don't recommend wasting money on expensive laboratory scales just for this.
This is why was I talking about Archimedes Principle.