Watch out! I’m a blue whale and I’m about to land on you!

whale

I don’t know why this question popped into my head, but it’s been sitting there for the past week and showing no signs of moving on.

Suppose an enemy of mine threw a friendly blue whale at me. Being a friendly whale, it makes the blue-whale-noise equivalent of “DUCK!” to warn me it’s coming.

How quickly does the whale need to be travelling for its warning to be useful?

Apparently I’m not a maths genius (or, On the Subject of Parcel Sizes)

This article on BBC News caught my eye because it has “maths” in the headline. Yes, I’m that easily pleased.

Somewhere in the middle, it says that myHermes requires the “volumetric area” of a parcel to be less than 225cm. That’s right: the “volumetric area” is neither a volume nor an area but a length. Anyway, the formula for volumetric area of a package with sides $a,b,c$, where $a \leq b \leq c$, is

\[ 2(a+b) + c \]

(Importantly, $a$ and $b$ are always the two shortest sides of the package)

So the constraint is

\[ 2(a+b) + c \leq 225 \]

In the next paragraph is the puzzling statement that the maximum allowable volume for a package is $82.68$ litres, or $82680$ cm3. How did they get that?

I decided to do some calculus of variations, or whatever it’s called.

There’s a new StackExchange site for History of Science and Maths

Just a little note to let you know that there’s a new StackExchange Q&A site for “History of Science and Maths”. Some of the maths questions that have already been asked include:

So if you’ve got a burning question about Maths in the Past, there’s now a place to ask it.

Visit the site: hsm.stackexchange.com

More to be done between universities and industry

I saw the video below, which is Rachel Riley being asked questions about her maths education at a Your Life event, in a tweet by Rob Loe, who quoted a section of one answer around 4:50 where Rachel says: “stop saying proudly that ‘I’m really bad at maths’ because you wouldn’t say ‘I can’t read’, you wouldn’t say ‘I can’t write’ as a proud thing.”

What particularly caught my ear was this section (around 5:30):