oanor
Sign up free
Marketplace Pricing Features Sign in

API · /schwarzschild-api

Black Hole Physics API

healthy 4,656 Subscribers

Black-hole general-relativity maths as an API, computed locally and deterministically. The radius endpoint computes the Schwarzschild radius r_s = 2GM/c² — the event horizon of a non-rotating black hole — from a mass given in kilograms or solar masses, together with the photon sphere at 1.5·r_s and the innermost stable circular orbit (ISCO) at 3·r_s; the Sun would have an event horizon about 2.95 km across and the Earth about 9 mm. The time-dilation endpoint computes the gravitational time-dilation factor √(1 − r_s/r) at a distance r from a mass — a clock deep in a gravity well ticks slower than a far-away clock, and at the horizon time appears to stop. The hawking endpoint computes the Hawking temperature T = ħc³/(8πGMk_B), which is higher for smaller black holes, and the evaporation time, which scales as the cube of the mass — a solar-mass black hole would take about 10^67 years to evaporate. Masses are in kilograms or solar masses and distances in metres, using G, c, ħ and the Boltzmann constant. Everything is computed locally and deterministically, so it is instant and private. Ideal for astrophysics, cosmology, science-communication, simulation and education app developers, black-hole and relativity tools, and physics teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is general-relativity black-hole physics; for special relativity (Lorentz factor, E=mc²) use a relativity API.

#black-hole #schwarzschild #general-relativity #hawking #astrophysics #developer-tools
api.oanor.com/schwarzschild-api
Get an API key Try in playground → Contact provider

Machine-readable spec so AI agents can integrate this API.

/api/schwarzschild-api/openapi.json
/api/schwarzschild-api/llms.txt

Discovery: GET /api/index.json lists every API.

API health

healthy
Uptime
100.00%
Server probes · 24h
Avg latency
86 ms
Server probes · 24h
Subscribers
4,656
active
Total calls
20
last 7 days
status Full status page → · 20 probes/24h

Pricing

Pick a tier — billed monthly, cancel anytime.

Free

Free

  • 3,750 calls / month
  • 2 requests / second
  • Hard cap (429 above quota, no overage)
  • 3,750 calls/month
  • 2 req/sec
  • Radius + time dilation + Hawking
  • No credit card
Sign in to subscribe

Starter

€5.00 /month

  • 35,500 calls / month
  • 6 requests / second
  • Hard cap (429 above quota, no overage)
  • 35,500 calls/month
  • 6 req/sec
  • Photon sphere, ISCO, evaporation
  • Email support
Sign in to subscribe

Pro

€14.00 /month

  • 216,500 calls / month
  • 15 requests / second
  • Hard cap (429 above quota, no overage)
  • 216,500 calls/month
  • 15 req/sec
  • Cosmology & simulation pipelines
  • Priority support
Sign in to subscribe

Mega

€44.00 /month

  • 1,305,000 calls / month
  • 40 requests / second
  • Hard cap (429 above quota, no overage)
  • 1,305,000 calls/month
  • 40 req/sec
  • Platform scale
  • Dedicated SLA
Sign in to subscribe

Built by

P
PremiumApi

Related APIs

Other APIs with overlapping tags.

Tidal Forces API

Tidal-physics and gravitational-dominance astrophysics as an API, computed locally and deterministically. The tidal-force endpoint computes the tidal (differential) acceleration that stretches a body, a = 2·G·M·r/d³, from the primary mass, the radius (half-size) of the affected body and the centre-to-centre distance — and the force if a body mass is given; tidal effects fall off as the inverse cube of distance, far faster than gravity's inverse square, which is why they matter only close in. The roche-limit endpoint computes the Roche limit, the distance inside which tidal forces tear a satellite apart, for both rigid bodies, d = R·(2·ρM/ρm)^(1/3), and fluid bodies, d = 2.44·R·(ρM/ρm)^(1/3), from the primary radius and the two densities — Saturn's rings sit inside its Roche limit. The hill-sphere endpoint computes the Hill-sphere radius, r_H ≈ a·(1−e)·(m/3M)^(1/3), the region where a body's own gravity dominates so it can keep moons, from the orbital distance, eccentricity and the two masses. Masses are in kilograms, distances and radii in metres and densities in kg/m³, with G = 6.674×10⁻¹¹. Everything is computed locally and deterministically, so it is instant and private. Ideal for astronomy, astrophysics, planetary-science, simulation and education app developers, ring-system and moon-stability tools, and physics education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is tidal and gravitational-dominance physics; for Newtonian gravity use a gravitation API and for orbital periods an orbital-mechanics API.

api.oanor.com/tidal-api

Star Magnitude & Distance API

Stellar magnitude and distance maths as an API, computed locally and deterministically. The magnitude endpoint works the distance modulus, m − M = 5·log₁₀(d/pc) − 5 — give any two of the apparent magnitude m, the absolute magnitude M and the distance and it returns the third, with the distance in parsecs, light-years and astronomical units (the absolute magnitude is the apparent magnitude a star would have at 10 parsecs). The flux endpoint applies Pogson's relation to turn a magnitude difference into a brightness ratio, F₁/F₂ = 10^(0.4·(m₂ − m₁)), where five magnitudes is exactly a hundredfold change in brightness — from two magnitudes, a magnitude difference or a ratio. The parallax endpoint converts a parallax angle into a distance, d(pc) = 1 ÷ p(arcseconds), and back, the geometric method behind the parsec itself. Everything is computed locally and deterministically, so it is instant and private. Ideal for astronomy-education, planetarium, stargazing and science app developers, observing and astrophysics tools, and STEM teaching. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is stellar magnitude and distance; for orbital mechanics use an orbital API and for great-circle distances on Earth a geo-distance API.

api.oanor.com/starmagnitude-api

Composting API

Composting maths as an API, computed locally and deterministically — the three numbers that decide whether a pile heats up and breaks down or sits there cold and smelly. The cn-ratio endpoint blends a mix to its carbon-to-nitrogen ratio: pass each material by weight with its dry-weight %C and %N as parallel comma-separated lists and it returns the total carbon and nitrogen masses and the blended C:N, with an assessment against the ideal 25–35:1 — ten parts dry leaves (50 %C, 1 %N) with ten parts grass clippings (45 %C, 2.5 %N) comes out at a near-perfect 27:1. The moisture endpoint works out the water to add to reach a target moisture (the pile should be a wrung-out-sponge 50–60 %): from the current mass and moisture it holds the dry matter constant, so 100 kg at 30 % needs about 56 kg of water to reach 55 %, and it flags a too-wet pile that needs drying instead. The mix endpoint gives the brown:green weight ratio to hit a target C:N from two materials' %C and %N — leaves and grass at a target 30:1 want about 1.5 parts browns to 1 part greens. Everything is computed locally and deterministically, so it is instant and private. Ideal for gardening and composting apps, master-composter and allotment tools, regenerative-ag and soil-health sites, and waste-diversion calculators. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 compute endpoints. For material volume use a mulch API; for NPK application rates use a fertilizer API.

api.oanor.com/compost-api

Mahjong Scoring API

Riichi (Japanese) mahjong scoring as an API, computed locally and deterministically and exactly — the points a winning hand pays, straight from the scoring table, not a lookup you have to memorise. The score endpoint turns han and fu into the payment using base = fu × 2^(2 + han): a ron pays base × 4 (a dealer ron × 6) rounded up to the nearest 100, while a tsumo splits base × 2 from the dealer and base × 1 from each non-dealer (a dealer tsumo takes base × 2 from all three) — so a non-dealer 3 han 30 fu ron is 3,900, a 4 han 30 fu is 7,700, and a non-dealer mangan ron is 8,000. The limit endpoint classifies a hand: mangan (5 han, or 3–4 han where the fu pushes the base to 2,000), haneman (6–7), baiman (8–10), sanbaiman (11–12) and yakuman (13+), with the base points behind each. The honba endpoint adds the table bonuses — 300 per honba counter and 1,000 per riichi stick — on top of the won hand. Everything is computed locally and deterministically, so it is instant and exact. Ideal for mahjong apps, online-table and scorekeeper tools, club and tournament software, and learning aids. Pure local computation — no key, no third-party service, instant. Exact scoring-table maths. Live, nothing stored. 3 compute endpoints. Japanese riichi rules; other variants (MCR, Hong Kong) score differently.

api.oanor.com/mahjong-api

Frequently asked questions

Quick answers about pricing, quotas, and integration.

How do I get an API key for Black Hole Physics API?
Sign up for free at oanor.com, generate an API key from the developer dashboard, and call Black Hole Physics API with the x-oanor-key header. No credit card needed for the free tier.
What's the rate limit for Black Hole Physics API?
Free tier allows 1 request per second. Paid plans scale up to 50 requests per second on the Mega tier. Hard limits return HTTP 429 above the quota — no surprise overage charges.
How much does Black Hole Physics API cost?
Black Hole Physics API has a free tier with 100 calls / month. Paid plans start at €5.00 / month with higher quotas and faster rate limits.
Can I cancel my subscription anytime?
Yes. Plans are billed monthly and you can cancel anytime from your billing dashboard. No long-term contracts and no cancellation fee.
Is Black Hole Physics API GDPR-compliant?
All requests to Black Hole Physics API go through our EU-based gateway. Your upstream API key never leaves our server and no personal data is shared with the upstream provider beyond the request you send.

Pick an endpoint from the list on the left to see its details and try it.

Code snippets

Sign up to get an API key, then call any path under your slug.

curl https://api.oanor.com/schwarzschild-api/SOME_PATH \
  -H "x-oanor-key: oanor_test_..."
const res = await fetch("https://api.oanor.com/schwarzschild-api/SOME_PATH", {
  headers: { "x-oanor-key": "oanor_test_..." }
});
const data = await res.json();
$ch = curl_init("https://api.oanor.com/schwarzschild-api/SOME_PATH");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-oanor-key: oanor_test_..."]);
$response = curl_exec($ch);
import requests
r = requests.get(
    "https://api.oanor.com/schwarzschild-api/SOME_PATH",
    headers={"x-oanor-key": "oanor_test_..."},
)
print(r.json())

Ratings

Sign in to rate.

No reviews yet.

Discussion

Ask questions, share usage tips, get answers from the provider and other developers. Public — anyone can read.

Sign in to start a thread or reply.

Sign in

New thread

/ 4000

📌 Pinned 🔒 Locked

·

· ·

/ 4000

🔒 This thread is locked — no new replies.

  • No threads yet — start the discussion.

Support

Private 1:1 support with the provider — billing questions, integration issues, account problems. Only you and the provider team can see these threads.

Sign in to open a support ticket.

Sign in

Open new ticket

Describe what you need help with. The provider team gets an email and replies on the ticket page.

  • No tickets yet for this API.

Subscription active — calls can start immediately.

Send your first request —

Subscription active — copy a snippet and fire off your first call.