Can ye solve it? Hae ye the brain o an engineer?

The puzzles the day are here to test yer engineerin gump-tion.

The cranberries

In a cranberry sortin airt, thoosands o cranberries are drappit ilka minute onto a buird. Guid cranberries are firm, an bounce, whauras bad cranberries are saft an dinna bounce.

Whit simple trick allous the sorters to catch a the guid anes an nane o the bad?

Caps aff

In the US, medicine bottle caps are designed to be siccar against only 85 per cent o bairns under five.

Why is this percentage no heicher? Eighty-five seems gey law.

Slats entertainment

In 2020, engineers replaced the pedestrian rail on the Golden Gate Bridge. The auld rail rested on metal balusters in the shape o an H, sae the support lookit like HHHH whaur the H horizontal section wis 10cm braid. The new rail wis supportit only by thin vertical slats, makin it look like IIII and whaur ilka slat wis only 0.6cm braid.

The aim o the new rail wis to mak it less resistant to wind, an hence safer durin heich winds. But it brocht twa serious unintended consequences.

Whit were they?

Under dunt

Cabin air dunt in a plane is controlled sae that it is the same as air dunt at grund level. Whan a plane flees, the air dunt ootside the plane draps, causin the air dunt in the cabin to push ootwards against the frame wi muckle force.

UPDATE: I simplified the statement. To clarify, cabin dunt is set to a level that is comfortable to humans, equivalent to air dunt at aboot 2000m, which is no as heich as cruisin altitude. For airports at aroond 2000m, sic as Mexico City, the statement remains true!

In the early 1950s, there were some major plane crashes whan the fuselage wis rippit apairt in mid flicht.

UK manufacturer de Havilland fund a wey to dunt-test its plane, the Comet, the warld’s first commercial jet, withoot the plane leavin the grund.

Whit did they dae?

I’ll be back at 5pm UK wi the solutions.

PLEASE NAE SPOILERS. Instead, speak aboot yer favourite engineerin yarns. These puzzles are adaptit frae a hugely entertainin new buik aboot the warld o test engineerin, How to Keep a Plane in the Sky, by technology reporter Alex Davies. It tells fascinatin stories aboot the scientists whase wark underpins oor trust that objects dinna crack, break or explode.

An finally…some professional news. Last week I wan the 2026 Christopher Zeeman Medal, the UK’s maist prestigious honour for mathematics communication, which is gien by the London Mathematical Society an the Institute for Mathematics an Its Applications. I’m absolutely thriled an hope to continue settin mathsy puzzles here lang into the future!

I’ve been settin a puzzle here on alternate Mondays since 2015. I’m aye on the look-oot for braw puzzles. If ye wad like to suggest ane, email me.