Any evidence of humans
would quickly disappear
Scientists of the future will have
difficulties finding evidence of us,
as most of our remains would quickly
be destroyed. If we disappeared, cities
would be unrecognisable after 10 years.
YEAR 1:
Asphalt would
crack, tunnels
would be flooded,
and nuclear
reactors would
melt down.YEAR 100,000:
The CO 2 level of
the atmosphere and
global temperatures
would have been
restored as if we
had never existed.YEAR 10,000:
The last buildings
would disappear,
and ecosystems
would achieve a
new balance
without us.YEAR 1000:
Buildings and
metal vessels
would have
corroded.
Chemical pollution
would no longer
exist in nature.YEAR 100:
Roofs and walls
would collapse
along with
bridges; forest
would completely
cover all cities.YEAR 10:
Trees and plants
would slowly take
over cities, rising
ground water would
create new lakes and
streams, and build-
ings would crumble.HUMAN BODY A squint is defined
as eyes that have difficulties when
coordinating their motions, so they
may look in separate directions.
Squinting is often due to the nerves
that control eye motion being
damaged. The injury can occur during
birth, when the skull is compressed
on its way out via the pelvic floor, or if
the baby is delivered by forceps. But it
can also occur if the vision of the eyes
is so different that the eyes look in
different directions. Squint-eyedness
can make it difficult to judge distance,
and can even cause blindness of one
eye if the brain shuts the eye down to
clear the field of vision.270 decibels! With the specific aim of producing the loudest
possible sound, Stanford University scientists in 2019
bombarded tiny water jets with an X-ray laser. The result
was perfect sets of over- and underpressure: a wave-train.Underwater X-ray laser
SATURN V
204 DECIBELS
3 History's most
powerful rocket
carried man
to the moon.
At its launch,
Saturn V
produced some
of the loudest
ever noises.DRAGSTER
160 DECIBELS
4 Dragsters are cars
that accelerate
very fast. This
requires powerful
engines which
make so much
noise that they
could present a
health hazard.CANNON
155 DECIBELS
5 Hearing protectors
are compulsory
when warships
test their
cannons. In the
future, cannons
will be able to
send grenades
1500+km away.MEGATON BOMB
210 DECIBELS
2 In air, the volume limit
is normally 182
decibels, but a one
megatonne (Mt)
explosion can
cause overpressure
in the sound waves,
and is therefore able
to break this limit.TOP 5 · Which machine is the world’s noisiest?
1
What causes a squint
in someone’s eyes?
AN
DERS (^) B
OTH
MA
NN
/ILL
UST
RER
ET (^) V
IDE
NSK
AB
BBC
(^) & (^) S
HU
TTE
RST
OCK
SLA
C (^) N
ATI
ON
AL (^) A
CCE
LER
ATO
R (^) L
ABO
RAT
ORY
Eye turns inwards
(Esotropia)
Eye turns outwards
(Exotropia)
Eye turns upwards
(Hypertropia)
Eye turns
downwards
(Hypotropia)
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Editor: Esben Schouboe