Relativity

{
  "asOf": "2026-10-11T08:56:13.797Z",
  "beta": 0.8,
  "contractedLengthM": 60,
  "degraded": false,
  "dilatedTimeS": 16.66666667,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "kineticEnergyJ": 59917011920000000,
  "lengthContractionFactor": 0.6,
  "lorentzFactor": 1.666666667,
  "momentumKgMS": 399723277.3,
  "notChecked": [
    "general relativity: gravity, acceleration and curved space-time are not included",
    "acceleration phases (the twin-paradox turnaround): only constant-speed inertial motion",
    "…1 more"
  ],
  "reasons": [
    "gamma = 1 / sqrt(1 - beta^2); t = gamma t0; L = L0 / gamma; E = gamma m c^2; K = (gamma - 1) m c^2; p = gamma m v.",
    "c = 299792458 m/s exactly (CODATA 2018)."
  ],
  "relativisticKineticMinusClassical": 31156846000000000,
  "restEnergyJ": 89875517870000000,
  "restEnergyMeV": 5.609588604e+29,
  "source": "computed locally",
  "speedMS": 239833966.4,
  "summary": "gamma = 1.666667; 10 s on the moving clock is 16.66667 s for a stationary observer; 100 m at rest measures 60 m along the motion; total energy 149792500000000000 J (kinetic 59917010000000000 J).",
  "timeDifferenceS": 6.666666667,
  "totalEnergyJ": 149792529800000000,
  "totalEnergyMeV": 9.34931434e+29,
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://physics-calc.x402tookit.com/relativity?beta=0.8&properLengthM=100&properTimeS=10&restMassKg=1'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://physics-calc.x402tookit.com/relativity?beta=0.8&properLengthM=100&properTimeS=10&restMassKg=1' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fphysics-calc.x402tookit.com%2Frelativity
const res = await pay("https://physics-calc.x402tookit.com/relativity?beta=0.8&properLengthM=100&properTimeS=10&restMassKg=1");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://physics-calc.x402tookit.com/relativity?beta=0.8&properLengthM=100&properTimeS=10&restMassKg=1")
    print(res.status_code, res.text)