A tonne of feathers, or a tonne of rocks?

I've only just realised that this old, old chestnut is quite a difficult question.

Any ideas?

__________________
Orion's Arm . The Starlark . Voices: Future Tense . OA Flickr set

Well, I got out my scales, I weighed a ton of rocks and then I weighed a ton of feathers. And you know what? They both weighed one ton. Imagine that!

Was that a ton? or a tonne? or a short ton?

I remember an old thread with this in, and the complexity involves buoyancy, so the answer is the most dense weighs more, probably the rocks I guess.

__________________
Brian's mother: He's not the Messiah. He's a very naughty boy!

It's quite simple really. We are discussing the weight of feathers. So what has feathers? The answer is simple, a duck. So if the rocks weigh as much as a duck, it's a ton.

Or you could just use the metric system. If you're lazy.

not difficult they weigh the same a tonne.

__________________
Great minds discuss ideas,average minds discuss events, small minds discuss people. Admiral Hyman Rickover.USN.

"Make the most of every day like it could be your last and enjoy each others company as this will make good memories for when we pass". chrissy

*A rock is for life not just for throwing*

I think one valid answer may, paradoxically, be the feathers.
Remember that the units for mass and weight are often the same.

__________________
Orion's Arm . The Starlark . Voices: Future Tense . OA Flickr set

wouldn't the 1 tonne mass of feathers have more buoyancy(in air), than the 1 tonne mass of stones, therefore weighing less?

__________________
Brian's mother: He's not the Messiah. He's a very naughty boy!

What weighs more? A 10,000 size chicken (who once had feathers; apparently someone has been going around shaving birds to get a tonne of them for research or something) or a ton (metric) of bricks?

__________________
When the chips are down; put them in a bowl and share them around!

A ton is one hundred runs in cricket and carries a lot more in the record books! so there! ducky!

__________________
clear skies

A tonne (in mass) of rocks on Mars would weigh less.
There are no tonnes of feathers on Mars, or anywhere else in the Solar system. So on average a tonne of rocks would weigh less.
But I don't know what the average weight of rocks in the universe is (note the traditional question asks about weight and rocks, not mass and rock...

__________________
Orion's Arm . The Starlark . Voices: Future Tense . OA Flickr set