If that situation was real and was going-on in an apartment above me.... I would go to the party store and buy a dozen tanks of Helium , drill a very small hole in my ceiling (their floor), and fill their apartment full of that gas until the noise stopped or I heard two heavy thuds on the floor.

http://www.partycity.com/category/balloons/helium+tanks.do

I recently got into astronomy so I installed a skylight...the people who live above me are furious

That poor floor, scraping, dropping, rolling, etc. Hope they that apartment is not rental, poor owner.

#1: helium is not going to work. It's pretty safe to breath and since it's lighter than air, it's just going to escape too quickly.

What you need is CO, CO_2, HCN or C_4H_8Cl_2S.

#4 I guess you failed science class if you think breathing Helium is safe. It is the most popular gas to use for suicde because it is odorless and you do not feel oxygen deprived or panicked while breathing it.....you just go to "sleep".
The helium will not escape unless the doors or windows are left open and it will fill the living space from the top down.
Just listen for the two thuds.

Love thy neighbor 101

This is either pure BS or these people are major Aholes.

I live in my apartment above my parents and I don't allow my small children to play since my parents always complain about the noise coming from above (they don't have understanding for children!!)

I've lived in 2 basement apartments where the noises were like that (one of them fairly recently)! From 7:00 am to 11:00 pm it sounded like a 747 flying through a thunderstorm while being pelted with golfball-sized hail. It inspired me to start my own website ( currently under construction) aptly named basementapartmentsfromhell.com where people can let others know about their horror stories, and the addresses from which they came. Places like Craigslist and Kijiji allow the landlord to tell everyone about how "great" the place is, I believe it's time to let people have their say as to how horrible the place is. The landlords will however, be allowed their chance to have a rebuttal.

#10 "The landlords will however, be allowed their chance to have a rebuttal." Or maybe just double your rent?

#11 This is after you have moved out. Only a moron would do it while they are still living there. It's to warn other people about the place. Forewarned is forearmed. I'm already posting on Kijiji and Craigslist telling people to avoid my previous landlord like the plague. They are advertising every day, and I advertise right after with my warning so that it appears first, before their ad. They lure you in with lies, and then do a complete 180 as soon as you've paid.

hahahahaha