Bird in a box

[mosschops2]

No tidel waves, no!!!

Can all the birds in the world fit on the Isle of Wight?

If they all took off, would the world be thrown off it's course??

 

[bonj2]

The bird is warm blooded and gives off heat.

Well, whoop-ti-doo! Someone 4 doors down might have lit a candle in their bedroom, that might heat it up by 0.00000001 deg. C aswell.

The answer to the conundrum is to monitor the weight of the box and bird over a 24 hour period and take the highest weight and subtract that of the box. The bird would have to rest on the floor of the box at some time within the 24 hours and that would give the maximum reading.

Ah, no. Say you haven't got that long. Yours would be one way of doing it, but it relies on a biological principle. I was thinking of a method that doesn't rely on a biological principle.

 

[col]

Iv got a headache

 

[rikki]

I'm surprised that Schrödinger's cat hasn't been allowed into this discussion already.

Since closed boxes always contain an imaginary cat, I cannot imagine a thought experiment where the imaginary box contains an imaginary canary. Well not for very long anyway.

 

[bonj2]

Any ideas? No? Well the answer I was looking for was to attach a pump to a valve on the box, then pump all the air out so the inside of the box was a vacuum. Then the bird wouldn't be able to create a downdraft and fly, and would come to rest on the bottom of the box. It would of course be dead, but at least you'd know it's mass without having to wait 24 hours.
I was thinking of the situation where you're in an underground cave such as the one in indiana jones and the temple of doom, where the spiked walls are closing in, and you only have a bird in a box (with a valve on), and a keypad into which to enter the bird's correct mass. You've probably got about 10 minutes to shout to winnie to go and sneak round the palace above and look for a pump to pass you through the tiny gap.
Come on, sharpen up people - you'd need to know the answer to such things if you're ever going to be able to survive such situations!

 

[mosschops2]

However if you did manage to create a vaccum, there are a couple of things that you appear not to have taken into account.

Firstly, the weight of the air. At 1kg/m3 - and given that this box weights a kilo so is probably a good size - there are a couple of grammes you'll be loosing. (Significant in relation to the 10g of bird anyhow!)

Secondly the bird is likely to start to dry out significantly in a vacuum, as moisture will be extracted to fill the void as it were, caused by the pressure within the presumably ex-bird's cells. This again is likely to have a significant effect on the accuracy of your figures, as mammals are made of what - 60% water?? I remember not!!!

So in summary Mr B, I think that your method is terribly flawed, and think you should come up with a better alternative!

 

[bonj2]

Firstly, the weight of the air. At 1kg/m3 - and given that this box weights a kilo so is probably a good size - there are a couple of grammes you'll be loosing. (Significant in relation to the 10g of bird anyhow!)

yes but you would be able to calculate the weight of the air multiplying its known density by the volume of the box, which you could then subtract.

Secondly the bird is likely to start to dry out significantly in a vacuum, as moisture will be extracted to fill the void as it were, caused by the pressure within the presumably ex-bird's cells. This again is likely to have a significant effect on the accuracy of your figures, as mammals are made of what - 60% water?? I remember not!!!

In an underground cave it's likely to be cold, so most of the water will condense and be incident on the walls or more likely floor, of the box.
Therefore this will be measured by the scales as if it was still in the bird.
Even so, the bird would take quite a while to dry out, by this time you are going to have input the correct mass into the machine.

 

[alecstilleyedye]

I'm surprised that Schrödinger's cat hasn't been allowed into this discussion already.

Since closed boxes always contain an imaginary cat, I cannot imagine a thought experiment where the imaginary box contains an imaginary canary. Well not for very long anyway.

have you ever tried keeping a cat in a cardboard box? they have claws you know…

 

[mosschops2]

In an underground cave it's likely to be cold, so most of the water will condense and be incident on the walls or more likely floor, of the box.

Water can't condense in a vacuum!!

 

[trustysteed]

My "bird" won't get into a box so I can't try!?

can you get into your bird's box?

 

[Mr Phoebus]

Bird in the box? Hope it's not a thrush?

 

[rikki]

I'm surprised that Schrödinger's cat hasn't been allowed into this discussion already.

Since closed boxes always contain an imaginary cat, I cannot imagine a thought experiment where the imaginary box contains an imaginary canary. Well not for very long anyway.

have you ever tried keeping a cat in a cardboard box? they have claws you know…[/QUOTE]

Imaginary cats are different (well obviously)

Schrödinger's cat has never been outside of a box

 

[bonj2]

Killing the bird would be much quicker and simpler Bonj.

But how would you do that, given that the only interface with the inside of the box you've got is a valve and you can't unseal the box. Pumping the air out would kill it.

Water can't condense in a vacuum!!

er... and why would that be?