Frank (Letters, 27 April), your assumptions about the zero-G effect in parabolic flight are incorrect. As soon as the aircraft changes attitude from the upward angle, the passenger will experience reduction in gravity and weighlessness. This can only continue until the point shown in the diagram. Here, unless the plane were to point directly at the ground (inadvisable for this aircraft) the pilot needs to pull up.
RE: Letters, 27 April The zero G section in the article on parabolic flight is correct. Although to begin with the plane is still travelling upwards, it is accelerating downwards in freefall, and this is what causes the feeling of zero G. Likewise, it ends while the plane is still travelling downwards, but has begun to accelerate up again.
I know people are probably wondering, following the recent story on pennies - an Olympic sized swimming pool (50m x 25m x 2m) can fit about ££36.7m in pennies (20.32mm x 1.65mm). So we've lost about two Olympic sized swimming pools of pennies down the back of the sofa.
The research team at QI have (not for the first time) got their facts wrong (Letters, 27 April). You still have to be over 16 to drink alcohol with a meal - the confusion may be that since 2003 accompanied children of any age are allowed in licensed premises.
Rob Stanton, Kenilworth, UK
Headline Iraq reconstruction not working. Does that mean they're reconstructing the war, possibly for Crimewatch, and getting it wrong a second time?
Regarding the Daily Mini-Quiz about Topshop, when I am clothes shopping with my wife I leave her while she tries things on. I use the rule that she takes five minutes in the changing room per item, so in 20 minutes she would try on four items. How Topshop thinks a woman can try on eight items in that time is beyond me!
So shoppers at Kate Moss's new collection at TopShop are restricted to 20 minutes each, what a great idea, could this be adopted by more shops please?
Stoo, Lancashire, UK
So Hugh Grant is A-list now, is he? Are you suggesting he's in the same league as de Niro, or Olivier? What exactly is the criteria for alphabetically listing celebrities? Is it income, quality of output, or merely how often they're mentioned in gossip columns? Perhaps a handy guide...?
Rob, London, UK
Are shops in Oxford Street arranged in alphabetical order?! New Look had a fire, and nearby Muji, M+S and MacDonalds were affected...
Lucy Larwood, London