2020-02-22_New_Scientist

26 | New Scientist | 22 February 2020

Editor’s pick

Reasons why we do and

don’t live in a simulation

1 February, p 34

From Andy Howe, Sheffield, UK

In Daniel Cossins’s piece “Do we

make reality?”, philosopher Kelvin

McQueen says consciousness may

not be exclusive to humans or other

complex organisms, but may exist,

in a rudimentary form, in inanimate

objects. How does that differ from

proposing that the wave function

collapse, which produces a “real”

event, occurs whenever quantum

objects interact?

Although ascribing consciousness

exclusively to humans seems

very out of date, ascribing it to

inanimate matter would need

some philosophical and semantic

gymnastics. But if Einstein was

wrong, and reality does depend on

our absurd, pre-Darwinian sense of

superiority – by only existing when

our species is looking – wouldn’t

that constitute sufficient evidence

that we all must be in a simulation?

Simulating only features seen by a

“conscious observer” would save a

vast amount of computing power.

From Carl Zetie,

Raleigh, North Carolina, US

In “Can we create reality?”, Donna

Lu reports the claim by philosopher

Nick Bostrom that if there are any

simulated universes at all they will

vastly outnumber any real ones.

So, he says, we probably live in

a simulated universe.

This argument is fatally

self-contradicting. The universe

that we live in is enormously more

complicated than it needs to be

to simulate intelligent beings like

ourselves. For example, you could

discard the other 100 billion visible

galaxies in our universe without

significantly affecting the

experiment. So simpler universes

should vastly outnumber those as

complex as ours. My conclusion – at

least as logical as Bostrom’s – is that

if we lived in a simulated universe,

it wouldn’t look like this one.

Bostrom is making the same

mistake as many other philosophers

and physicists who propose any

kind of multiverse. Without a

compelling reason to believe from

first principles that we are one of

many universes, we cannot say

anything about the likelihood of

ours being one thing or another.

Technically speaking, we don’t

have a measure for the underlying

population of universes, and so can

say nothing about any distribution.

From John Davenport,

Kenley, Surrey, UK

Lu suggests that if we live in a

simulation it would be switched

off if the overlords realised that we

knew about it. But it is most likely

that the overlords are kids playing

in their bedrooms. Our discovery

would merely add excitement.

The risk arises when they

discover girls, boys or whatever,

at which point they lose interest.

In praise of diverse

and productive forests

Letters, 1 February

From Nick Marshall, Edinburgh, UK

Sandy Henderson, arguing for

meat production, says that this

is the only practical way to farm

much of the north and west of the

UK and Ireland. He omits the

original and best land use for

much of that region: forest.

We shouldn’t plant short-lived

industrial conifer plantations –

though there is a place for these –

but diverse, well-managed forests

producing high-quality logs for

buildings and furniture, as well

as wildlife habitats, which

attract visitors.

In many parts of Europe,

abandonment of hill grazing has

led to restoration of forests by

natural regeneration, which has

cost taxpayers nothing and has

fixed significant amounts of

carbon and expanded wildlife

habitat. We will soon come to

see uncontrolled goat and sheep

grazing for the environmental

disaster that it is, with extreme

examples in Australia, Ethiopia,

Kenya, Greece and Scotland.

From Margaret Pitcher,

Canberra, Australia

In the past, forests were

considered part of the farming

economy. Their resources could

still be used to cut down carbon

pollution in other ways.

If we fed pigs on the dropped

nuts and undergrowth, maybe we

could have occasional pork chops,

as pigs are very good at turning

food waste into crackling.

We should make use

of every scrap of land

1 February, p 15

From Roy Harrison,

Verwood, Dorset, UK

The UK’s Committee on Climate

Change proposes that airlines and

oil companies should pay for a

colossal tree-planting drive. How

much would this reduce the area

of land dedicated to producing

food in the UK?

I wonder whether this is a good

idea in a world that has a growing

population and in which we

expect farmland to be lost because

of rising sea levels.

The report assumes that the

UK will continue to import 47 per

cent of the food it consumes and

export 18 per cent of what it grows.

It does advocate things that we

should do for other reasons,

such as restoring peatlands and

hedgerows. Perhaps we should

make use of every scrap of land.

Perhaps solar panels should be on

the roofs of buildings rather than

occupying cultivable land.

Views You r le t te r s