Buckets of sand.
 

Here is an easy and fun thought experiment.

Place these in order of total mass (least to greatest) for a level bucket.

Bucket 1: Dry Sand packed down.
Bucket 2: Moist/wet Sand packed down.
Bucket 3: Dry Sand packed down then wetted.

There are 6 possible orders, so we can't use voting buttons :no:

Post your vote (1,2,3 1,3,2 2,1,3 etc). Wait to post reasons behind until 0100 CET Thursday morning (0000 GMT) (~48 hours from now).

total mass (least to greatest)
1,2,3

I've noticed that no one else has voted. I am now unsure if you meant us to vote openly (not PM). If I have blundered, please accept my sincere apology.

only_human, you did fine. The instruction was [b]"Post your vote ..."[/b]

It's just that you've posted the obviously correct answer, and no one else feels a need to "me too".

... except, of course, unless the correct answer is: 1,3,2 :smile:

I'll go for 1,3,2.

This puzzle reminds me of the old story:

A professor stood before his philosophy class and had some items in front of him. When the class began, wordlessly, he picked up a very large and empty mayonnaise jar and proceeded to fill it with golf balls. He then asked the students if the jar was full. They agreed that it was.
So the professor then picked up a box of pebbles and poured them into the jar. He shook the jar lightly. The pebbles rolled into the open areas between the golf balls. He then asked the students again if the jar was full. They agreed it was.
The professor next picked up a box of sand and poured it into the jar. Of course, the sand filled up the remaining space. He asked once more if the jar was full. The students responded with an unanimous 'yes'.

Now, said the professor, "I want you to recognize that this jar represents your life. The golf balls are the important things - your family, your children, your health, your friends, your favourite passions - things that if everything else were lost, and only they remained, your life would still be full. The pebbles are the other things that matter like your job, your house, your car. The sand is everything else - the small stuff."

"If you put the sand into the jar first," he continued, "there is no room for the pebbles or the golf balls. The same goes for life. If you spend all your time and energy on the small stuff, you will never have room for the things that are important to you. Pay attention to the things that are critical to your happiness. Play with your children. Take your partner out to dinner. Go out with friends. There will always be time to clean the house and fix the washing. Take care of the golf balls first, the things that really matter. Set your priorities. The rest is just sand."

One of the students walked up to the front, produced two cans of beer and poured the entire contents into the jar, effectively filling the space between the sand particles. The professor asked what he was doing.

"Professor," he replied "I just wanted to show that no matter how full your life may seem, there's always room for a couple of beers." :grin:

So far, no right answer......:ernst:

2,1,3

nm

Michael has the right answer. If he wishes to post the reason behind it, well. On the other hand if he does not.... I will in about a day.

the reason I edited my post is because I had the order wrong, and it was the same as Michael's, and until explanations were allowed, I didn't think I was adding anything .. anyway, my reasoning was as follows:

sand is denser than water, that's why the ocean is water on top and sand on the bottom.

bucket 2 is the lightest, because the water takes up space that the heavier sand could be in

bucket 1 is heavier than 2 because it's all heavier sand

bucket 3 is the heaviest because of the "room for 2 beers" approach. The dry sand is already packed everywhere it's going to be, so adding water won't displace anything, but will add mass

I was thinking that wet sand behaves strangely when stepped upon. I remember reading somewhere that it expands. You can see in footsteps by the shoreline that something funny is going on.