ok...
cancelled out some more possible options (see below), and am now left with these:
- gravity-plant-upside down-thing
- egg-buoyancy-density-water-add-salt-vinegar-etc
- effect-heat-on-rubber
which one?!!!!!!!!!
ok: this is the conversation leading up to me cancelling out the option for observing-heartrate-boy-girl one:
me: i don't really think it'll work
mum: yeah, but you dont have to do your own age group, you can do sasa's (my sister,5) and nana's (my boy cousin, 7?) age group.
me: but little kids arent good for experiment. they never have a resting heartrate!!!!
mum: well, thats true!
me: well, i could do old, people, like you...
mum *offended*
mum: that's it, im not taking part.

lovely. i now have no candidates for that experiment. thank you shirley zhao for suggesting i make a brochure for guys to volunteer- but i would sound super desperate :(