The Spacetime Metric

The learning map

What you will learn, and where.

Seventeen units in six parts. Each names what you will be able to do, then the shortest route: watch, read, go deep, study. Start anywhere.

Part I

How to know

The maturity scale, and the government's own reading list.

  1. 01

    The evidence ladder

    How to read a bold physics claim without swallowing it or waving it away.

    You will learn to

    • Place any claim on a five-rung maturity scale, from well-posed idea to textbook fact.
    • Update your confidence the way Bayes' rule says, and tell independent evidence from repetition.
    • Name the next experiment that would move a claim up or down the ladder.
  2. 02

    The reference documents and the institutional record

    Thirty-eight technical documents a defence agency commissioned, and how to read an official record as a document rather than as a verdict.

    You will learn to

    • Say what the thirty-eight reference documents are, who commissioned them and who administered them, and read one as a technical document with a stated scope.
    • Separate what an official record establishes, that a question was funded and studied, from what it does not, and name which of the thirty-eight carry original results.
    • Trace a single claim from a reference document through to the peer-reviewed paper it rests on, and place both on the maturity scale.

Part II

The medium

What the vacuum is, how it is measured, and how it is engineered.

  1. 03

    What the vacuum is

    Empty space is the lowest setting of every field, and the lowest setting is not zero.

    You will learn to

    • Explain why the quantum vacuum carries energy, and how the Casimir force measures it.
    • Say what zero-point energy means, and what the measurements do and do not settle.
    • Follow the vacuum from the old aether to a medium physicists now shape in the laboratory.
  2. 04

    Casimir physics and vacuum-force engineering

    The force between two plates is measured to better than a percent, and it already moves parts on a chip.

    You will learn to

    • Derive and then measure the Casimir force, and say what the two independent 1997 and 1998 measurements settle and what they leave open.
    • Predict how real materials, roughness, temperature and geometry change the force, and use the worldline and scattering methods practitioners use.
    • Design a device that uses the force, an actuator, a self-assembling structure or a torque element, and state its complete force budget.
  3. 06

    The vacuum at cosmic scale

    Dark energy and zero-point energy enter Einstein's equations in the same place, and the gap between them is the research programme.

    You will learn to

    • State the three densities and the size of the gap between them, and say why the gap is the programme rather than an embarrassment.
    • Follow the dark-energy identification through the physical argument rather than the semantic one, and place it on the maturity scale.
    • Name the measurement that would move it: what DESI's next release would have to show, and what a test separating Planck's constant from the fine-structure constant would look like.
  4. 07

    The vacuum as a quantum fluid

    Volovik's programme: particles and gravity as ripples on a cosmic condensate.

    You will learn to

    • Show how curved-spacetime physics genuinely emerges inside superfluids and condensates.
    • Say what analogue Hawking radiation in a laboratory does and does not demonstrate.
    • Name the Lorentz-symmetry tests that decide whether our own vacuum is such a fluid.

Part III

Energy from the vacuum

Devices that break the vacuum's symmetry, and the machines that burn what they make.

  1. 05

    Energy from the vacuum

    Real photons out of nothing was measured in 2011. Standalone power is the milestone three funded labs are building toward.

    You will learn to

    • Explain the dynamical Casimir effect and quantum energy teleportation, and why both obey thermodynamics.
    • Describe how a Casimir-cavity device is built and what its complete energy ledger must show.
    • Name the three funded programmes and the milestone all of them are aiming at.
  2. 08

    Fusion machines: pinches, focus devices and inertial drivers

    Fusion is the first door, and this is the door: every machine that has ever made fusion, and what each one measured.

    You will learn to

    • Tell the confinement families apart by their physics, and say for each one what it confines, for how long, and what its published record is.
    • Read a fusion diagnostic, neutron yield, ion energy or imaging, and say what it establishes and what it does not.
    • Design the direct-conversion stage of an aneutronic machine, and state the energy ledger from wall plug to delivered current.
  3. 09

    Lattice confinement fusion

    NASA Glenn's peer-reviewed fusion in deuterated metals, and the milestones ahead.

    You will learn to

    • Explain how electron screening and the Oppenheimer–Phillips process let fusion run inside a metal.
    • Say what NASA's two Physical Review C papers measured, and how it differs from the 1989 claims.
    • Describe the net-energy milestone and how a calorimeter proves it.

Part IV

Mass, inertia and gravity

If the vacuum makes inertia, the vacuum can change it.

  1. 10

    Inertia and gravity from the vacuum

    What if mass, inertia and gravity are things the vacuum does to matter?

    You will learn to

    • Reconstruct Sakharov's induced gravity and the Haisch–Rueda–Puthoff inertia proposal as published.
    • Use the polarizable-vacuum picture of gravity as a changing refractive index.
    • Separate what is measured from what is a live hypothesis, and name the deciding experiment.
  2. 11

    Gravity control and superconductors

    Frame-dragging is measured. The programmes ask whether coherent matter can make it big enough to use.

    You will learn to

    • State how large gravitomagnetism is, as Gravity Probe B measured it.
    • Compare the Ning Li, Podkletnov, Tajmar and Alzofon programmes and what each measurement found.
    • Name the variable the next run has to control.
  3. 12

    Inertial mass reduction, the Navy patents and transmedium craft

    If inertia is the vacuum's reaction to acceleration, could you lighten a craft, and what do the patents and the sensors actually show?

    You will learn to

    • Read the inertial-mass-reduction and gravitational-wave-generator patents and the operability attestation as documents, and say what each can and cannot show.
    • Trace the conditional chain from a vacuum origin of inertia to a lighter craft, and use the Schwinger limit to size the gap between the first test and the patent's own drive conditions.
    • Follow the bench thruster to its dated orbital flight, and say what each possible result would mean.

Part V

Engineering the metric

You do not move the ship. You engineer the distance.

  1. 13

    The metric, warp drives and wormholes

    The exact idea behind engineering space, and the exact gap between the maths and a machine.

    You will learn to

    • Read a metric as the rulebook for every ruler and clock.
    • Follow the Alcubierre warp bubble and the Morris–Thorne wormhole through Einstein's equations.
    • State why negative energy is the price, how much has been measured, and which bench tests are running now.
  2. 14

    Wormholes, energy conditions and the negative-energy budget

    Every metric-engineering proposal meets the same bill. This is the unit that reads it, line by line.

    You will learn to

    • Write down the energy conditions and say which geometry each one forbids, and why.
    • Apply a quantum inequality to a proposed geometry and get a number for how much negative energy is allowed, over what sampling time, in whose frame.
    • State the negative-energy accounting correctly, below the ambient vacuum level rather than below nothing, and name the laboratory experiments that generate it.
  3. 15

    Scalar waves and the field behind the fields

    Whittaker's real mathematics, the Aharonov–Bohm effect, and the longitudinal fields Maxwell already permits.

    You will learn to

    • Explain why the vector potential is physical: electrons respond to it where the fields are zero.
    • Say where longitudinal fields genuinely exist, and what free-space scalar-wave energy would require.
    • Describe the bench test that would settle the scalar-wave energy proposal.

Part VI

The craft and the ledger

The worked example, and every claim on one map with its next test.

  1. 16

    Plasmoids, charge clusters and the orbs

    Self-organising plasma is real, thriving physics. The orb footage is the worked example, with its tests named in advance.

    You will learn to

    • Explain how plasmoids and ball lightning organise themselves, and what their spectra reveal.
    • Describe Ken Shoulders' exotic vacuum objects and the modern mechanism proposed for them.
    • Test a piece of footage: provenance, optics, and the checks that decide.
  2. 17

    The unified picture

    The convergence thesis: where every claim stands, and the next test for each one.

    You will learn to

    • Draw the energy, medium and actuator stack a metric-engineering craft would need.
    • Place each pillar on the maturity scale and see how the uncertainties compound.
    • Name the single most decisive experiment for each row, and where its result will appear.

Prefer to climb by level?

The same physics is also laid out as 36 courses in 6 levels, from first principles to research preparation.

The six-level course path →