Sideswipe: April 27: The hot tub

More blue-collar innovation: the hot tub.

Wow, teacher, you're the bomb

A reader writes: "One of the outstanding memories I have of a school lesson from 40 years ago was our physics master, Mr Harris, trying to display Newton's Third Law of Motion - 'that every action has an equal and opposite reaction'. He placed a sturdy metal rubbish bin on top of a set of bathroom scales and inserted into it a quantity of gunpowder and a detonator that he had made himself. He placed a large book covering the top of the bin and a blackboard duster on top of the book - the theory being to ignite the gunpowder, blowing the book and duster upwards (the action) whilst registering the downward (reaction) pressure on the scales. Mr Harris mustn't have followed his gunpowder formula very well or just misjudged the amount required, because when he set off his charge, the duster was blown through the roof of the lab and the legs of the desk underneath his display collapsed. Nobody was injured, but the smoke that filled the lab forced everyone to evacuate the building. Mr Harris was affectionately known as "Bomber' Harris for the remainder of my schooldays."

Big Tobacco feels the burn

When social media backfire: the human face of British American Tobacco New Zealand has set up an official Twitter account and is being asked some tough questions ...

1."Do you consider that the thriving marijuana industry poses a threat to cigarettes?"

2. "WHEW! Huf. Huf. I have to go and catch my breath with one of your delicious products. Gasp. Huf. BRB. Cough."

3. "I quit smoking cos my kids cried that I'd die (like my dad did). How can I smoke without them finding out?"

3.Is [British American Tobacco NZ] planning to offer @johnkeypm TWO convention centres if the Government relaxes tobacco law?

4."So, your product is natural, organic and low-fat. You recommend it as a health supplement?"

5. "Do men at tobacco companies have beards - or can they look at themselves in the mirror long enough to shave?"

6."Is it true that the John Key cycleway will be paved with tar coughed up from smokers' lungs?"

(No answers to these questions from British American Tobacco NZ except to say the Twitter account has not been set up to "promote smoking or BATNZ's products" but "to communicate BATNZ's views on tobacco-related policy issues.")