PC Gamer - UK (2021-12)

worse,”Beachumreflects.“Butitwasreallybad,andif

anything,Ithinkitshouldhavebeenthereverse.Itshould

have been that everything around you speeds up.”

The aforesaid black hole distorts light believably – it

recreatesthedeflectionofphotonsbygravitational

lensing,thoughasVerHoefacknowledges,“It’ssuper

fudged–[an actual photon] would follow a curved path

and ours just go: boink!” But there’s no time dilation, and

as with the sun and planets, the object’s gravity is

carefully contained. “A black hole the size of Brittle

Hollow should have a distortion radius larger than our

real-world solar system.”

It’s easy to forget amid talk of refraction and dilation

that what motivates all these projects is a sense of

wonder – not just at the operations of gravity, but at the

mingled elegance and eccentricity of the models

describing it. “You have simple formulas and equations

that give you this approximation of the universe,”

enthusesFalanghe.AmongGiantArmy’sgoalsis

teachingplayerstoembracetheimperfectionsofsimsat

large–from videogames to the supercomputer-powered,

yet no less flawed models used by NASA.

As Dixon concludes, “What a cool way to be able to

learn about the amazing reality that we find ourselves in,

and that the universe is weirder than anyone ever

imagined.” It remains difficult to conceive of a gravity sim

wholly based around Einstein’s theories, but if the above

projects are any indication, it’s only a matter of time

before somebody takes the plunge.

relativisticeffectsintheformofalientimetravel

experiments,connectedtoaminiatureblackholethat

lurksbeneaththecrustofoneunfortunateplanet.During

thegame’salpha,Mobiusalsoaddedanislandareathat

turnedtimedilationintoaperformanceissue.“Whenyou

got close to this antenna, I just made the framerate

BothKerbalandUniverseSandbox 2

arecheckedfrom

exploringEinsteinbecausethey’reborn

ofgenresthatare

steepedinconceptsfromNewton.Thanks

story, toitssci-fi

OuterWildsisabletoforgealittlefurther.

Ithintsat

HEARTOFDARKNESS

“Ifyoudeletedthesun,

itwouldtakeacertain

timeforittodisappearoff amountof

yourscreen.”

witnesstheeffects

ofgravityonlight.

somewhatinterferewith Thiswould

theusualrunning

ofagodsim.

vantagepoint

withinthe

universe,so

asto,forexample,

playerto

actually

berelative

tothings

• to occupy a

problem is that simulating general relativity requires the

to our sun to experience time dilation from its mass. The

elusive behaviour of Mercury, which orbits close enough

fundamentallygroundedin‘classical’Newtonian

physics,theircreatorshaveallflirtedwiththemore

recent,andtransformativetheoriesofgravity

introducedbyAlbertEinstein.Tocrudelysummarise

theirdifferences,Newton’sphysicsholdsthatspaceis

fullofmassesandforcesactontheminlineartime.

AccordingtoEinstein,however,spaceandtimeare

actuallyasingle,fluctuatingentity–a ‘spacetime’ which

is woven together and distorted by mass, and this

distortion is what we call gravity.

Einstein’s theory dictates that planets and stars don’t

just reel in other masses, but ‘dilate’ time nearby relative

to the passage of time for an observer further afield. This

obliges a fascinating, but not very

intuitive rethinking of the act of

falling. “The idea is that it’s not a

force pulling you down, it’s the future

leading you towards the ground,”

Falanghe explains. “Spacetime bends,

so that when your straight-line

trajectory turns towards the ground

it’s not just space that bends but time.

The future bends your trajectory.”

As fascinated as he is by this

prospect, Falanghe decided early on

not to apply Einsteinian physics to

Kerbal Space Program, partly because

theramificationsare negligible at solar system scale, and

partly because time dilation is tricky to portray in a

management game where solid scheduling is key. “In

Kerbal, we have the orbit map that shows your trajectory,

and you can plan manoeuvres and see how your trajectory

would intersect with another celestial body, turn around

and things like that. But if you said, ‘Oh, by the way, your

ship clock will desynchronise with your home clock by

like, 0.2 seconds, by the time you get here,’ that’s much

harder to communicate to the player.”

Giant Army has thought more earnestly about

introducing relativistic effects. As Nesvold and Dixon

point out, these can be observed ‘close at hand’ in the

DISTANT REL ATIVES

While Outer Wilds, Kerbal and Universe Sandbox 2

are

inherent to simulations.”

it’s become inaccurate, which is [a problem]

what’s happened is you sped up time so much that

gonnafly away from the sun,’” says Dixon. “No, no, no,

“Some users thought, ‘Oh, in the future, everything’s

interval too much, and whole star systems may disappear.

Gravity

FEATURE

SPACE AND

TIME ARE

ACTUALLY A

SINGLE,

FLUCTUATING ENTITY