54 | New Scientist | 10 August 2019
Schrödinger’s scissors
I was once looking for nail scissors
but couldn’t see them. My wife
then entered the room and
immediately saw the scissors
in plain view, exactly where I had
been looking. Why couldn’t I see
them until she found them?Stephen Mitroff, professor
of cognitive neuroscience
George Washington University,
Washington DC
There is no single answer to this
question. A visual search can fail
for any number of reasons. If the
person had a different picture
in their mind of the item while
searching, that could interfere
with finding it. For example, they
might be thinking of an older or
different version of an object.
Other items that were recently
looked at but weren’t the desired
object can also interfere with
finding an item. Stress can affect
performance, and just being tired
can also make searches hard.Janet Mackenzie
Thurso, Highland, UK
Once when I was looking
frantically for something,
my daughter came in and said:
“Don’t look for, mum, look at”.
I did this, and it worked. Maybe
this is what happened with your
reader. He was looking for, his
wife came in and looked at.Future fossils
If, some day, our civilisation fries
itself out of existence, will new
reservoirs of fossil fuels eventually
accumulate, and could they power
some future industrial revolution?Tony Power
Sydney, New South Wales, Australia
Coal is the remains of plants,
collected long ago in slowly
sinking basins. The northern
hemisphere coal deposits built
up in the Carboniferous period,
between about 360 and 300
million years ago. In the southern
hemisphere, coal was mostly
deposited in the Permian (some300 to 250 million years ago).
Around 290 million years ago,
several species of fungi evolved
that could digest the main
components of wood: cellulose,
lignin and hemicellulose. One
theory suggests that fossil fuels
formed before these fungi evolved,
but afterwards, plant material
rotted and was returned to the
carbon cycle.
Deposits known as brown coal
formed more recently, but they
are relatively uncommon and low
quality. So if the fungus theory is
correct, unless the fungi get fried
before the trees, not much coal
will form in the future.Jeff Dickens
Strachan, Aberdeenshire, UK
Assuming we don’t completely
sterilise the planet in frying ourcivilisation, the answer is almost
certainly yes. All it takes is time
and the continued tectonic
development of the planet.
Plate tectonics continuously
pushes and pulls Earth’s crust
in different directions. If a basin
forms, it could be filled by
sediment eroded off uplifted
areas. To form a fossil fuel
accumulation, certain conditions
are required. Swampy delta
regions are good for coal. For
oil and gas, there needs to be
a substantial influx of organic
material. Marine microorganisms
do nicely; the process will thenwork even if we trash the rest
of the biosphere.
The present day Black Sea is a
good example, where a deep water
basin has become anoxic. This
lack of oxygen has resulted in
the preservation of the organic
material falling into the basin.
On top of that, we need suitable
temperatures and pressures,
and a geological event that
results in the surrounding rocks
forming effective traps for the
petroleum fluids.
This process can happen
surprisingly quickly, geologically
speaking. A lot of the action
described above is ongoing, and
has only recently generated some
oil and gas fields, in basins like the
Gulf of Mexico and the Caspian
Sea. You could get your first new
accumulations in as little as a
couple of million years.
Finally, there are some schools
of thought that postulate an
abiogenic origin for some fossil
fuel accumulations. In other
words that natural gas develops
from methane deep in the mantle,
for example, without the input of
living organisms. So you might
not even need the biosphere,
although you might expect
the resulting volumes would
be much lower.Douglas Thompson
Whitford, Flintshire, UK
Of course new reservoirs of
hydrocarbons will accumulate
after humanity has shuffled off
its mortal coil. Whether they
power a future industrial
revolution is another matter
and could depend on whether
a future intelligent community
had access to information about
the disastrous way we exploited
our own reserves. ❚This week’s new questions
Lightning bulb A summer storm woke me around 2 am.
I heard a sizzling sound before lightning struck about
100 metres away. Then I saw a 1.5-volt solar-powered outside
light glowing like a 50-watt bulb. It faded after a few minutes.
What caused the sizzling sound and made the light glow so
brightly? Douglas Fairchild, Two Harbors, Minnesota, USBattery power Why has there never been an international
standard requiring manufacturers to display the capacity of
alkaline batteries? All we have to go on is words such as “super
power” or “long life” on the packaging. I want a number!
Stephen Brown, Girona, SpainTime and tide What is the smallest body of water that is
influenced by the moon’s gravitational pull? Hilary Perry,
Dinas Powys, Vale of Glamorgan, UKWant to send us a question or answer?
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ALEXEYS/GETTYWhy does a lightning strike
make the air sizzle and light
bulbs glow?