Star Stuff

Stimpunks × More Realms · Zine No. 71

Nothing Is Pushing

on escape velocity as a coasting number, the places inside a well that cost nothing to sit in, and a telescope built so that it cannot brake

for everyone who has been told to want it more

L★S

Love You Down To Your Star Stuff
open edition · print freely

The shape mass makes

The well is not a defect

A gravity well is not damage done to space. It is what mass is, described from the outside — the potential energy of every position near a body, drawn as a curve.

Outside a sphere of mass M, the gravitational potential at distance r is Φ = −GM/r. Inside it, the curve flattens into a bowl and bottoms out at the centre. Plot it and you get the shape everyone recognises: steep sides, a rounded floor, and a long shallow approach to nothing at all.

Nothing in that curve is a fault. The same well that makes leaving expensive is the thing that holds an atmosphere down, keeps an ocean from boiling off into vacuum, and gives a moon somewhere to be. You cannot have the holding without the depth. They are one property, seen from two directions.

A well is the price of having a place. The depth is the belonging, measured in joules.

So the first thing to say about being at the bottom of one is that it is not evidence of anything having gone wrong. It is a position. Positions have costs attached, and the costs are arithmetic.

Figure 1 · the depth and the holding are one feature

Three things, not one

What “stuck” is a description of

In orbital mechanics, nothing is stuck. A body is at a position, with an energy, in a field. Change any of the three and the verdict changes with it — and two of the three are not the body.

This zine grew out of one of Helen Edgar's constellations. In My Monotropic Galaxy she names twenty parts of her Autistic self after real objects in the sky, and the fourteenth is Gravity Well:

Gravity Well represents my monotropic looping and ruminating mind. Thoughts that circle and return, that find their way back to the same point regardless of how many times I try to leave them. It represents Autistic inertia and a feeling of being stuck.Helen Edgar, My Monotropic Galaxy, constellation 14

She is not describing a failure, and she says so elsewhere in plain words: it is the same mechanism whether what you are held by is bad or good. Writing about looping thoughts on Autistic Realms, she notes that focusing attention on something positive “can be a wonderful, JOYFUL experience” — and that it is hard to shift attention tunnels when consumed by looping thoughts, “whether they are positive or negative.”

That is the difference-not-deficit move made already, in her own voice, before any physics arrives. The depth is not the problem. The depth is the reason anything stays.

What the physics can add is narrower and more useful: an account of what it would actually take to move — and the answer is nothing like the one we are usually handed.

11,186 metres per second

The coasting number

Escape velocity from Earth's surface is about 11.186 km/s. That figure is quoted constantly and almost always misread, because the definition carries a condition that gets dropped in transit.

Escape velocity is defined for a ballistic trajectory. It is the speed at which a body's kinetic energy equals the depth of the well at that radius — assuming no other force acts on it afterwards. It is the number you need if you are going to be thrown, and then coast.

It is not the speed required to leave. It is the speed required to leave without help, from exactly where you are standing.

Two consequences follow immediately, and both are unglamorous arithmetic rather than interpretation.

First, the number is local. v_esc = √(2GM/r) — it falls off as the square root of one over distance. At twice Earth's radius it is 7.9 km/s. At four times, 5.6. The requirement is not a property of the body you are leaving; it is a property of where in the well you are asking from.

Second, it says nothing at all about anything under thrust. A craft with an engine running is not on a ballistic trajectory, so the figure simply does not apply to it. That is not a loophole. It is the scope of the definition.

Figure 2 · a requirement, not a property

Dawn, at Vesta, 2012

Two ways out, and neither is out-muscling gravity

The picture most people carry — a sustained heave against a force that never lets up — is not how anything leaves anything. There are two documented exits and that is not either of them.

The first is the burst. One correctly-sized, correctly-timed input of energy, after which the well no longer decides the outcome. The engine burns for minutes; the coasting lasts for years. The effort is not distributed across the journey. It is concentrated, and then it is over.

The second is the spiral, and it never makes the jump at all. On 5 September 2012, NASA's Dawn spacecraft left the asteroid Vesta — not by reaching 11-kilometre-per-second speeds from the floor, but by climbing gently outward on ion thrust until the requirement had fallen far enough to meet it.

Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions.Marc Rayman, Dawn chief engineer and mission director, NASA JPL, September 2012

JPL's own description is that the spacecraft “spiral[led] away as gently as it arrived.” Its thrusters are about twelve inches across and produce less push than a conventional engine — but they can run for months.

Being exact about this, because it is the kind of claim that gets improved in retelling: Dawn did eventually exceed the local escape speed. The point is not that it dodged physics. The point is that it never had to make the jump from the bottom, because it changed where it was asking from first. The bar is a function of position, and position is negotiable.

Figure 3 · gently, for four months

Where the energy comes from

The engine is not the spacecraft's willpower

Every exit above needs an input of energy. Not one of them generates it internally. The impulse comes from a burn; the burn comes from propellant; the propellant was loaded by somebody else, on the ground, in advance.

The largest first-hand study of Autistic inertia arrives at the same structure from the other side. Kristen Buckle, Kathy Leadbitter, Ellen Poliakoff and Emma Gowen worked with 32 Autistic adults across six focus groups — four in person at Autscape in 2019, two online in 2020. Their participants describe inertia not as a difficulty with starting but as one tendency to remain in whatever state you are in: starting, stopping and switching are the same problem wearing three faces.

And what they report as working is not resolve.

The only thing that helps me…is just to have a stuck buddy that I text.“Elizabeth,” in Buckle, Leadbitter, Poliakoff & Gowen (2021)

Prompting by another person was the most consistently effective support in the study. So was somebody simply working nearby — not interacting, just present. Impersonal strategies — alarms, reminders, lists — rarely substituted for a human being.

The title of the paper is a participant's own phrase: “No Way Out Except From External Intervention.” That is not a confession of inadequacy. It is a correct statement about where energy enters a system, and it is the same statement a flight director makes about a spacecraft without hearing anything shameful in it.

We are told the burst is a thing we should be able to produce from inside. Nothing produces a burst from inside. Not one thing in the sky.

Five points

There are places to sit inside a well

Leaving is one question. Staying is a different one, and the answer is stranger and much better.

Where two bodies orbit a shared centre — a star and a planet, a planet and a moon — there are five positions at which a third, much smaller body can keep station with them. They are the Lagrange points, and they are not a trick of framing: they are solutions to the equations of motion.

They do not all behave the same way, and the split is the whole point.

L1, L2 and L3 lie on the line through the two bodies. They are saddle points — unstable. Nudge something sitting there and it drifts away, slowly, and does not come back on its own.

L4 and L5 sit sixty degrees ahead of and behind the smaller body, each forming an equilateral triangle with the other two. Under the right conditions they are genuinely stable. A body placed there is not balancing. It is not holding on. Nudge it and the Coriolis effect curls it into a small orbit around the point and it stays.

Nothing at L4 is expending anything. It is not coping. It is simply somewhere that works.

About a hundred thousand Jupiter Trojans larger than a kilometre are sitting at Jupiter's L4 and L5 right now. They have been there since they were captured, during the upheaval of the giant planets' early migration.

Figure 4 · two of the five are somewhere to live

Toulouse, 1843

The stability belongs to the system, not to the rock

Here is the fact this whole zine was built to arrive at, and it is a hundred and eighty years old.

Whether L4 and L5 are stable has nothing to do with what is sitting there. It depends on one number: the mass ratio of the two big bodies. Write μ for the smaller body's share of the total mass. The triangular points are linearly stable when

μ < μ_G = (1 − √(23/27)) / 2 = 0.0385208965…the smaller root of 27μ(1−μ) = 1 — equivalently, the larger body must be about 24.96 times the smaller

Above that value they are unstable and nothing can rest there. Below it they are stable and anything can.

The same rock. The same rock exactly. Put it at Jupiter's L4 and it stays for the age of the solar system. Put it at the L4 of a pair whose ratio is too even and it wanders off. Nothing about the rock changed — not its composition, not its mass, not its effort. What changed was the system it was asked to sit in.

The criterion is usually called Routh's, after his 1875 paper. It should be called Gascheau's: Gabriel Gascheau, a professor at Toulouse, published it in Paris in 1843 — more than thirty years earlier — and Bruno Sicardy says so plainly, that it “should actually be called Gascheau's value in view of the precedence of his work.”

We are in no position to leave that uncorrected. A piece about how the environment decides the outcome should not misattribute the theorem that proves it.

Figure 5 · one number decides it, and it is not about the occupant

Every three weeks

Even the unstable places are cheap

Suppose you are not at a stable point. Suppose the place you need to be is one of the unstable ones. It is still not a fight.

The James Webb Space Telescope orbits the second Lagrange point of the Sun–Earth system. L2 is one of the unstable three. Jeremy Petersen, writing the mission's station-keeping strategy, puts it without softening: “The dynamical region about the SEMB L2 point is inherently unstable.”

So how much does it cost to hold an inherently unstable position for twenty years?

Orbit around L2 is maintained through regular station-keeping burns, which are scheduled every three weeks…with typical durations of tens of seconds.Rigby et al. (2023), The Science Performance of JWST as Characterized in Commissioning

Tens of seconds. Every three weeks. To hold a position that would otherwise be lost.

And then the sentence that ought to be printed on something and hung up:

During commissioning, three station-keeping burns were skipped because the computed correction was negligibly small.Rigby et al. (2023), §2.1

The maintenance schedule for an unstable place includes doing nothing, because sometimes nothing is what it needs. Not endurance. Not vigilance. A short nudge, occasionally, and a documented willingness to skip it.

Webb launched with propellant for ten and a half years and now expects more than twenty — partly because the launch was accurate, and partly because holding the position turned out to be that cheap.

Figure 6 · what it costs to hold an unstable place

A design that assumes undershoot

Webb cannot brake

One more fact about that telescope, and it is the reason this zine exists in the shape it does.

Webb's instruments have to stay near forty kelvin, which means nothing warm can sit on the cold side of the sunshield. Thrusters are warm. So there are none facing the Sun. Petersen states the consequence directly:

Thermal requirements also prevent the placement of thrusters on the instrument side of the observatory; consequently, no direct observatory-to-Sun vector maneuver directions are allowed.Petersen (2019), AAS 19-806

Webb can push away from the Sun. It can never push back toward it. If it drifts past L2 on the far side, there is no manoeuvre that brings it home. The mission ends.

So every burn is deliberately thrown short. The insertion was aimed to fall slightly under, not over. Each station-keeping nudge is sized to leave the observatory still on the near side of the point, needing another small push later, forever.

The whole approach is engineered around the certainty that it will arrive not-quite-there — because arriving short is recoverable and arriving past is not.

Nobody in that flight dynamics team regards this as the telescope's failing. It is a constraint, it was known in advance, and the entire trajectory was designed around it — at a cost, in propellant and in planning, that the mission simply paid.

We ask people to run the other configuration. Aim past, and brake if it is too much. For a great many of us that thruster is not fitted, and the answer is not to demand it, and not to call its absence a deficiency. It is to throw short on purpose, and to plan for the nudge.

Figure 7 · the constraint was designed around, not argued with

What this does not say

A piece about inertia is one bad sentence away from becoming the thing it is arguing against. So, plainly:

Not:“reach escape velocity” as a slogan. The phrase has been fully absorbed by hustle culture, where it means push harder for longer. The physics says the exact opposite: the number is small, the burn is brief, the requirement drops as you rise, and the energy is supplied by something that is not you. Every part of the motivational reading is inverted.

Not:that the burst is available on request. Buckle and colleagues' participants describe “a literal paralysis,” hours passing while unable to move, self-care and medical needs going unmet. Knowing that an engine would fix it does not conjure an engine. A well-understood mechanism is not the same as an accessible one, and a zine that blurred those would be doing harm with a citation attached.

Not:“you're not stuck, you're just orbiting.” Helen Edgar's own words for it are looping, Autistic inertia, a feeling of being stuck — and she describes elsewhere how debilitating it is when the loop is a bad one. A reframe that files the distress away as a misunderstanding is not an accommodation. Nothing here revises anyone's account of their own life.

Not:that gravity is the villain. The well is also the reason there is an atmosphere, an ocean, a moon, a home. Depth of attachment and cost of departure are one quantity. You do not get to keep the holding and delete the price.

Not:a claim that Lagrange points make inertia fine. They make one specific and checkable claim: that the cost of remaining somewhere is a property of the system, not of the occupant. That is an argument about who owes whom an adjustment. It is not a consolation, and it does not require anyone to feel better about anything.

Not:a diagnosis, a protocol, or advice. We are not clinicians and this is not a plan. If you want a practical piece on the loops specifically, Sonny Hallett's Loops of Concern was written for that job by someone who lives it, and it is better at it than we would be.

Not:a proof. A rhyme, not a proof. Gascheau's value establishes nothing whatsoever about a nervous system. What the orbital mechanics supplies is one honest shape — a cost that turns out to be a fact about the arrangement rather than about the thing being arranged — and that shape then happens to fit what 32 Autistic adults said about their own lives. Their testimony is the evidence. The physics is only how we noticed what shape it had.

L★S

The bar is a function of where you are. Somebody else loaded the propellant. Nothing pushes itself out.

FG 12 My Monotropic Galaxy — Helen Edgar's Gravity Well, constellation fourteen

No. 45 The Cloud Phase — the other constellation that grew into a zine

No. 59 The Rest You Keep — rest is not a reward paid out after work

No. 68 Proportioned to the Groove — the narrow channel as a fit, not a shortage

No. 71 Nothing Is Pushing — the cost of staying belongs to the place ← you are here

Reflection

What have you been calling laziness that was a question about where you were standing?

Who is your stuck buddy — and do they know that is what they are?

Which of the places you hold cost you something daily, and which cost you nothing at all?

Where in your life is the correction small enough that it could honestly be skipped?

What have you been aiming past, when you could have aimed short on purpose?

Sources

Escape velocity. v_esc = √(2GM/r), about 11.186 km/s at Earth's surface. The load-bearing point is the definition's own scope: escape velocity is specified for a ballistic trajectory, with no propulsion acting after the initial impulse, which is why it says nothing about a craft under thrust. The derived values on spread four (7.91 km/s at two Earth radii, 5.59 at four, 3.73 at nine) are computed here from the inverse-square-root relation rather than quoted.

Dawn at Vesta. NASA JPL, “NASA's Dawn Prepares for Trek Toward Dwarf Planet” — for the departure on 5 September 2012 PDT, for “spiral away as gently as it arrived,” and for Marc Rayman's “Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions.” Rayman was Dawn's chief engineer and mission director. Stated on the spread rather than buried here: Dawn did cross the local escape threshold in the end. The claim is that it never had to make that jump from the floor, not that it escaped without ever meeting the condition.

Lagrange point stability, and a precedence correction. Bruno Sicardy, “Stability of the triangular Lagrange points beyond Gascheau's value,” Celestial Mechanics and Dynamical Astronomy 107, 2010 (DOI 10.1007/s10569-010-9259-5) — read at the paper, which is where μ_G = (1 − √(23/27))/2 = 0.0385208965…, the smaller root of 27μ(1−μ) = 1, comes from. Sicardy's own words: the value “should actually be called Gascheau's value in view of the precedence of his work.” Gabriel Gascheau (b. 1798), professor at Toulouse, published in Paris in 1843; Routh's more general treatment came in 1875, and Sicardy notes it as “more than thirty years” later. The standard textbook treatment is Murray & Dermott, Solar System Dynamics (1999). Open: we have not read Gascheau 1843 itself, only Sicardy's account of it, and this line says so.

The Trojans. William F. Bottke, Raphael Marschall, David Nesvorný & David Vokrouhlický, “Origin and Evolution of Jupiter's Trojan Asteroids,” prepared for Space Science Reviews (2023) — for the projection of ~10⁵ Trojans with D > 1 km, and for the capture picture: they were scattered inward during the giant planets' migration rather than forming where they now sit. That detail is deliberately kept — the stable place was not where they started, and they did not choose it either. There is also a real asymmetry between the two swarms (L4 holds more than L5) which remains unexplained; we mention it nowhere in the body because we could not do it justice in a line.

JWST. Jeremy Petersen, “L2 Station Keeping Maneuver Strategy for the James Webb Space Telescope,” AAS 19-806 (2019) — PDF read directly, for “The dynamical region about the SEMB L2 point is inherently unstable,” for the 21-day cadence, and for the sunshield constraint quoted on spread ten. Jane Rigby et al., “The Science Performance of JWST as Characterized in Commissioning” (2023) — PDF read directly, §2.1 and §2.2, for burns “scheduled every three weeks…with typical durations of tens of seconds,” for “three station-keeping burns were skipped because the computed correction was negligibly small,” and for propellant now expected to last “more than 20 years” against a pre-launch requirement of 10.5. One number we went looking for and then refused to print: an annual station-keeping budget of about 2.4 m/s is widely quoted and we could not source it primarily, so the spread makes its case from burn duration and cadence instead. The argument did not need it.

Autistic inertia. Kristen L. Buckle, Kathy Leadbitter, Ellen Poliakoff & Emma Gowen, “‘No Way Out Except From External Intervention’: First-Hand Accounts of Autistic Inertia,” Frontiers in Psychology 12:631596 (2021), DOI 10.3389/fpsyg.2021.631596 — open access, read at the paper. 32 Autistic adults; four in-person focus groups at Autscape in July 2019 and two online text groups in May 2020; reflexive thematic analysis; the lead author is Autistic and experiences significant initiation difficulties. Source of the starting/stopping/switching finding, of the primacy of prompting by another person over impersonal strategies, of “Elizabeth's” stuck buddy, and of “a literal paralysis” on spread eleven. Participant names in the paper are pseudonyms and are quoted as such.

Monotropism is Dinah Murray, Mike Lesser & Wenn Lawson (2005). Sonny Hallett's Loops of Concern (2021, revised 2025) is named on spread eleven and is his. A deliberate abstention: Helen Edgar's constellation says “ruminating,” and we have not reached for the clinical rumination literature, which is a depression construct with a different history. Hallett writes loops of concern precisely to avoid that import, and following him and Helen rather than the clinical vocabulary is a choice, made once, on purpose.

Credits

The naming and the frame are Helen Edgar's, from My Monotropic Galaxy, where Gravity Well is constellation fourteen and carries the line a burst, not a constant push. The astronomy and the argument are ours. This is the second time one of her twenty constellations has grown into a zine — The Cloud Phase (No. 45) came out of Emergence Point — and it follows that precedent deliberately, including the part where the zine takes a name of its own rather than reusing hers. Her constellation's colour, violet, is this zine's accent.

Proposed by Ryan Boren, whose brief already contained the two moves the piece is built on: that leaving a well is one correctly-timed burst rather than constant force, and that a Lagrange point is “a real, stable place to sit without being ‘stuck’ in the pejorative sense.” Two things the research then changed. The brief said escape velocity does not require constant force, which is right; reading the definition properly showed something better, that the requirement falls with altitude, so the bar itself is negotiable and Dawn's spiral is the demonstration. And Buckle et al. moved the burst from an internal resource to an external one — which turned spread six from a physics analogy into an accommodation claim, and is the reason the piece ends where it does.

What this deliberately does not re-argue

Proportioned to the Groove (No. 68) owns the narrow attention channel as a fit rather than a shortage, and this piece stays off that ground: it is about the cost of moving and of staying, not about the shape of the channel. The Rest You Keep (No. 59) owns rest, burnout, and the ledger that was never there — spread nine is adjacent to it and stops short on purpose. The Cloud Phase (No. 45) owns arriving in one's own time.

A rhyme, not a proof. No result in celestial mechanics establishes anything about a nervous system, and nothing here is offered as a cause. What the orbital mechanics supplies is one honest shape — a cost that turns out to be a fact about the arrangement rather than about the thing arranged — and that shape then fits, exactly, what 32 Autistic adults said about their own lives. The testimony is the argument. The physics is how we noticed what shape it was. Nothing pushes itself out of anywhere. Somebody loads the propellant, or nobody goes.