are we heavier outside? outside as opposed to indoors?

[soserious]

stupid question?

not really:
air apparently weighs 1.25 kilos a square metre, indioors this column of air pushing down on us is obviouskly shorter- but once outside this can be many kilometres high? therefor are we heavier outside?

i also feel heavier outside.
ss

[Spike]

Obviously not.

But you will weigh less if you put your scales on the carpet instead of a hard floor - go try it then expain how the hell that works.

[Bobo]

The air pressure is the same indoors as it is outdoors, unless Your house is 100% cealed and pressurized. If there is a difference, it's so small You definately can't feel it.

[Godma]

Dunno.

However, I do know that you're a quite a bit taller when you wake up in the morning than when you go to bed at night.

[soserious]

i thought itd be the same weight- i just wanted to hear HOW .
yes, i wondered if the pressure cancelled it out. but what about true pressuriised places? submarines, aeroplanes. (before normal pressurisation).

yeah whats with the carpet thing?

[soserious]

Dunno.

However, I do know that you're a quite a bit taller when you wake up in the morning than when you go to bed at night.

yeah, like an ich sometimes. i actually measured my height this morning and im shorter than i was before a couple years ago :x a good 3/5th of an inch shorter. wth is that? lack of calcium?

[Bobo]

This is actually quite interesting question. The air pressure effect on weight is there, but it's so small we will never feel it. Air pressure is the same outdoors and indoors because it's gas and therefore the fact that how much air is above us doesn't add weight to our shoulders, it only makes the air density higher the more air there is above us -> more air molecules per volume unit. Our relative mass is the same no matter how high we are, but the air pressure does change. The air's density depends on its temperature, its pressure and how much water vapor is in the air. It's easier to move in high altitudes, but not because we'd weight less, but because of less air resistance. Basically, SS, You definately can't feel any difference between indoors and outdoors.

[Bobo]

yeah, like an ich sometimes. i actually measured my height this morning and im shorter than i was before a couple years ago :x a good 3/5th of an inch shorter. wth is that? lack of calcium?
The soft tissue between Your spinal vertebra and joints has sort of collapsed, the size of Your bones doesn't change.

[Spike]

You're taller in the morning because during the day the gristly bits in your backbone compress and expand back out when you're in bed ( or not in your case :lol: )

I'm pretty sure air pressure is all around so you'd weigh the same even if you were in a vacuum.

Did you try the carpet test? Works even better if you put the scales on your bed or sofa.

[Bobo]

That carpet-thingy is interesting... must be something to do with friction. Bobo's theory: the carpet gives up some, and You lower as much... then the point where the carpet gives enough resistance goes past and it sort of pushes You back upwards, only to actually elevate You back it would need more force. This is difficult to explain, but what the scale shows is Your mass + the "spongy-force" of the carpet. Kinda the same effect as in "stationary friction" (don't know the word) where getting an object to move demands more power than moving it further when it actually moves... Damn this is difficult to explain.

[Spike]

Close with the "spongy force", but no banana.

[Bobo]

:x C'mon, it was worth a banana! :D

[Spike]

It was a nice try, but the banana is the top prize, you get a grape for effort. :lol:

[Spike]

BTW, I had it the wrong way round - you weigh less on the carpet and even less balancing on a mattress.

[Bobo]

Damn. :x *chews the grape with tears in his eyes*

[Bobo]

BTW, I had it the wrong way round - you weigh less on the carpet and even less balancing on a mattress.
That makes more sense. The carpet's "spongy force" eats up a part of Your weight. Banana?

[Spike]

OK, but it'll be an unripe one for the poor scientific explanation.

[soserious]

ok ok, but i was shorter this morning AFTER sleeping then i was 2 years ago also After sleeping.

i seen this guy shrink like a foot in height (hes backbone disuintegrated) after abusing steroids .

[Bobo]

:mrgreen Too late for good scientific explanations, it's 1:37am here. Will You mail the banana to me?

[Dong_Johnson]

unstable, uneven carpet surface reduces the pressure read in by the scales, presuming it was designed for a rigid and uniform floor. Depends on the scales though, some show more depending on their calibration/operation.

As far as i know weight is mostly caused by gravity (to do with size, mass etc or earth) not air pressure but i could be wrong on that one

[soserious]

yeah, we know.
i was asking if the column of air directly over you had any affect on your weight* since 1 metre square of air is aparentkly 1.25 kilos- thats fairly significant. in the same way the bottom of the sea has great crushing pressure.
i was watching a programme on helicopter dynamics or something- cool apatches.

[Spike]

Weight is really kilograms/force which is mass x gravity - that's all , no mention of pressure.

So if you're 98kg your mass is 10kg (9.8 metres per second x 10kg). The 98kg should really be 98kgf (or Newtons) but we call it kilograms.

[Bobo]

yeah, we know.
i was asking if the column of air directly over you had any affect on your weight*
No, it should be some sort of solid matter, gas can't pile up weight that way because the molecules float free there. They should be connected so that their weight could pile up on each other. No gas can build weight that (column) way.

[Spike]

Er what?

It's only a matter of temperature whether something is gas, liquid, solid, plasma, etc.

The column of air extending above you all the way to space weighs 14psi or 1kg.sq.cm.

Pressure is equal all around you so it makes no difference to your weight

[Spike]

since 1 metre square of air is aparentkly 1.25 kilos

Do you mean one cubic metre?

Air pressure in square metres is 10 tonnes/sq.m

[soserious]

yes i meant cubic metre3- not square.2

[wern]

The weight readout on the scales is determined by the pressure you exert on the scales. When placed on a hard surface, the scales absorb most if not all of the force of your weight. If you put the scales on a carpet, the carpet absorbs some of the force, so because the scales now absorb less of the total force of your weight, the readout is lower. A matress absorbs even more.

[Bobo]

Er what?
What I meant was, gas can't build weight on Your shoulders because it isn't in its solid form -> molecules aren't forming "crystals" or other forms, the molecules float free. For example water: You can dive 5 meters under water and won't get killed by the water on top of You, it only adds more pressure. But, if there would be a 5 meters high column of ice on top of You, You'd definately die under its weight. On liquid form the molecules can move quite freely but in ice form they're not moving at all -> they form crystals -> the mass of each molecule pile up because they're all attached to each other. It's the same with gas, only the molecules are even further away from each other than in liquid form.

[soserious]

interesting, but what about the gas o star nurseries?
aside fromm the obvious immense heat that gas is so vast it can collapsev in on itself. so therefore there must be a breaking point, therefore there must be some effect of gas even if its undetectable no?

[Bobo]

Dense gas clouds form liquid/solid particles... the same happens with any gas in high pressure. More and more gas gathers to one spot/area until it's a star with amazing pressures and heat... something like that in a nutshell.

[soserious]

yes but is that gas when its in high enough volume?
or is that gas BECAUSE and only bacuase its in high enough volume?
wth? how did i spell that??

[Bobo]

Something is "gas" when the molecules can move freely in it and the density of molecules / volume unit is low enough. When the molecules are near enough each other but can still move (=don't form crystals or other solid patterns), it's in liquid form. A gas can turn into its liquid form by pressure and/or temperature (like water... below 100 celsius it's liquid, and over 100 celsius it's gas unless high pressure forces it to liquid form. Below zero: crystal form = ice).