BBC Knowledge Asia Edition

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It wouldn’t be easy. The Permian

period, just before the dinosaurs

appeared, ran from about 300 to 250

million years ago. The drifting continental

plates had clumped all the land together

into one supercontinent called Pangaea.

The huge size and limited coastline made

the interior of Pangaea a hot desert, while

the south was frozen under ice caps.

The north was only slightly better, with a

hot climate and huge seasonal variations

from wet to dry. Flowering plants had only

just started to appear and almost all the

food crops we eat today hadn’t evolved

yet. We would be restricted to pine nuts

and a few edible tubers. Most of our diet

would probably consist of insects, but 90

per cent of all insects at the start of the

Permian were varieties of cockroach, so

that’s hardly an attractive prospect.

More importantly, we would still need

to worry about being eaten ourselves.

Just because the dinosaurs hadn’t

appeared yet, it doesn’t mean there

weren’t large carnivores. Dimetrodon and

other large crocodile-type animals were

the top predators. Our intelligence and

cooperation would help against these

threats, but we would have to manage

with primitive weaponry. The plant matter

laid down in the Carboniferous period

wouldn’t turn into coal for another 100

million years yet, so we would have to

make do with peat and pine wood for fuel,

which would make it difficult to get a fire

hot enough to melt iron with. LV

Could a modern human survive on

pre-dinosaur Earth?

Time travelling humans could

come face-to-face with the

predatory Dimetrodon...

better hone those sprinting skills

At a microscopic level, paper is actually
quite rough. A metal knife makes a clean
straight cut, but paper acts like a saw blade
and does a lot more damage to cells and
nerve endings. Paper also leaves behind tiny
fibres and chemical residues, which irritate
the wound even more. LV

Why are paper cuts so

painful?

On a website’s login page, CAPTCHAs
are those obscure-looking characters we use
to verify that we are human users and not
bots. The characters are often distorted with
the letters or numbers running into each
other. Optical character recognition software
struggles to pick out the individual forms,
especially when their shape and size vary
from one CAPTCHA to the next. GM

Why can’t computers

complete CAPTCHAs?

Common CAPTCHAs have only been around since 1997