mockingbirdnest · Nov 21, 2021 · Nov 22, 2021 · Nov 22, 2021 · Nov 23, 2021
diff --git a/astronomy/epoch.hpp b/astronomy/epoch.hpp
@@ -1,12 +1,7 @@
 
 #pragma once
 
-#include "base/macros.hpp"
-#include <limits>
-
 #include "geometry/named_quantities.hpp"
-#include "quantities/quantities.hpp"
-#include "quantities/si.hpp"
 
 // |geometry::Instant| represents instants of Terrestrial Time (TT).  The
 // utilities in this file provide its standard epoch and two ways of specifying
@@ -17,9 +12,6 @@ namespace astronomy {
 namespace internal_epoch {
 
 using geometry::Instant;
-using quantities::Infinity;
-using quantities::Time;
-using quantities::si::Second;
 
 // |J2000| represents to the standard epoch J2000.0.
 // According to Resolution B1 (On the Use of Julian Dates) of the XXIIIrd IAU
@@ -31,13 +23,8 @@ using quantities::si::Second;
 // "2000-01-01T11:58:55,816"_UTC
 constexpr Instant J2000;
 
-CONSTEXPR_INFINITY Instant InfinitePast = J2000 - Infinity<Time>;
-CONSTEXPR_INFINITY Instant InfiniteFuture = J2000 + Infinity<Time>;
-
 }  // namespace internal_epoch
 
-using internal_epoch::InfiniteFuture;
-using internal_epoch::InfinitePast;
 using internal_epoch::J2000;
 
 }  // namespace astronomy

diff --git a/benchmarks/apsides.cpp b/benchmarks/apsides.cpp
@@ -27,11 +27,11 @@ namespace principia {
 
 using astronomy::GCRS;
 using astronomy::ICRS;
-using astronomy::InfiniteFuture;
 using astronomy::ITRS;
 using astronomy::StandardProduct3;
 using base::dynamic_cast_not_null;
 using base::not_null;
+using geometry::InfiniteFuture;
 using geometry::Position;
 using geometry::Vector;
 using integrators::EmbeddedExplicitRungeKuttaNyströmIntegrator;

diff --git a/benchmarks/discrete_trajectory.cpp b/benchmarks/discrete_trajectory.cpp
@@ -20,14 +20,14 @@
 namespace principia {
 namespace physics {
 
-using astronomy::InfiniteFuture;
 using base::make_not_null_unique;
 using base::not_null;
 using geometry::Barycentre;
 using geometry::Displacement;
 using geometry::Frame;
 using geometry::Handedness;
 using geometry::Inertial;
+using geometry::InfiniteFuture;
 using geometry::Instant;
 using geometry::Velocity;
 using ksp_plugin::World;

diff --git a/geometry/instant_output_test.cpp b/geometry/instant_output_test.cpp
@@ -10,12 +10,12 @@
 namespace principia {
 namespace geometry {
 
-using astronomy::InfiniteFuture;
-using astronomy::InfinitePast;
 using astronomy::J2000;
 using astronomy::operator""_TT;
 using astronomy::operator""_UT1;
 using astronomy::operator""_UTC;
+using geometry::InfiniteFuture;
+using geometry::InfinitePast;
 using quantities::Time;
 using quantities::si::Second;
 using ::testing::Eq;

diff --git a/geometry/named_quantities.hpp b/geometry/named_quantities.hpp
@@ -1,8 +1,10 @@
 
 #pragma once
 
+#include <limits>
 #include <type_traits>
 
+#include "base/macros.hpp"
 #include "geometry/affine_map.hpp"
 #include "geometry/grassmann.hpp"
 #include "geometry/point.hpp"
@@ -12,27 +14,40 @@
 
 namespace principia {
 namespace geometry {
+namespace internal_named_quantities {
+
+using quantities::AngularFrequency;
+using quantities::Infinity;
+using quantities::Length;
+using quantities::MomentOfInertia;
+using quantities::Speed;
+using quantities::Time;
+
+using Instant = Point<Time>;
+
+CONSTEXPR_INFINITY Instant InfinitePast = Instant() - Infinity<Time>;
+CONSTEXPR_INFINITY Instant InfiniteFuture = Instant() + Infinity<Time>;
 
-using Instant = Point<quantities::Time>;
 template<typename Frame>
-using Displacement = Vector<quantities::Length, Frame>;
+using Displacement = Vector<Length, Frame>;
+
 template<typename Frame>
 using Position = Point<Displacement<Frame>>;
+
 template<typename Frame>
-using Velocity = Vector<quantities::Speed, Frame>;
+using Velocity = Vector<Speed, Frame>;
 
 template<typename Frame>
-using AngularVelocity = Bivector<quantities::AngularFrequency, Frame>;
+using AngularVelocity = Bivector<AngularFrequency, Frame>;
 
 // An arbitrary rigid transformation.  Simultaneous positions between two frames
 // are always related by such a transformation.
 template<typename FromFrame, typename ToFrame>
 using RigidTransformation =
-    AffineMap<FromFrame, ToFrame, quantities::Length, OrthogonalMap>;
+    AffineMap<FromFrame, ToFrame, Length, OrthogonalMap>;
 
 template<typename Frame>
-using InertiaTensor =
-    SymmetricBilinearForm<quantities::MomentOfInertia, Frame, Bivector>;
+using InertiaTensor = SymmetricBilinearForm<MomentOfInertia, Frame, Bivector>;
 
 // IEEE 754:2008 nextUp and nextDown for Instants.
 // We would like to avoid the terms “up” and “down” when referring to the
@@ -43,10 +58,25 @@ using InertiaTensor =
 constexpr Instant JustAfter(Instant const t) { return NextUp(t); }
 constexpr Instant JustBefore(Instant const t) { return NextDown(t); }
 
+}  // namespace internal_named_quantities
+
+using internal_named_quantities::AngularVelocity;
+using internal_named_quantities::Displacement;
+using internal_named_quantities::InertiaTensor;
+using internal_named_quantities::InfiniteFuture;
+using internal_named_quantities::InfinitePast;
+using internal_named_quantities::Instant;
+using internal_named_quantities::JustAfter;
+using internal_named_quantities::JustBefore;
+using internal_named_quantities::Position;
+using internal_named_quantities::RigidTransformation;
+using internal_named_quantities::Velocity;
+
 namespace internal_point {
 // We must declare this in the internal namespace where Point is defined so that
 // it is found by ADL.
 std::ostream& operator<<(std::ostream& os, const Instant& t);
 }  // namespace internal_point
+
 }  // namespace geometry
 }  // namespace principia
diff --git a/ksp_plugin/vessel.cpp b/ksp_plugin/vessel.cpp
@@ -8,8 +8,8 @@
 #include <string>
 #include <vector>
 
-#include "astronomy/epoch.hpp"
 #include "base/map_util.hpp"
+#include "geometry/named_quantities.hpp"
 #include "ksp_plugin/integrators.hpp"
 #include "ksp_plugin/pile_up.hpp"
 #include "quantities/si.hpp"
@@ -19,14 +19,14 @@ namespace principia {
 namespace ksp_plugin {
 namespace internal_vessel {
 
-using astronomy::InfiniteFuture;
-using astronomy::InfinitePast;
 using base::Contains;
 using base::FindOrDie;
 using base::jthread;
 using base::make_not_null_unique;
 using base::MakeStoppableThread;
 using geometry::BarycentreCalculator;
+using geometry::InfiniteFuture;
+using geometry::InfinitePast;
 using geometry::Position;
 using quantities::IsFinite;
 using quantities::Length;

diff --git a/ksp_plugin_test/planetarium_test.cpp b/ksp_plugin_test/planetarium_test.cpp
@@ -33,8 +33,6 @@
 namespace principia {
 namespace ksp_plugin {
 
-using astronomy::InfinitePast;
-using astronomy::InfiniteFuture;
 using base::not_null;
 using base::make_not_null_unique;
 using base::ParseFromBytes;
@@ -45,6 +43,8 @@ using geometry::DeduceSignReversingOrientation;
 using geometry::Displacement;
 using geometry::Frame;
 using geometry::Handedness;
+using geometry::InfinitePast;
+using geometry::InfiniteFuture;
 using geometry::Instant;
 using geometry::LinearMap;
 using geometry::OrthogonalMap;

diff --git a/ksp_plugin_test/vessel_test.cpp b/ksp_plugin_test/vessel_test.cpp
@@ -6,7 +6,6 @@
 #include <vector>
 
 #include "absl/status/status.h"
-#include "astronomy/epoch.hpp"
 #include "base/not_null.hpp"
 #include "geometry/barycentre_calculator.hpp"
 #include "geometry/named_quantities.hpp"
@@ -38,6 +37,7 @@ using base::make_not_null_unique;
 using geometry::Barycentre;
 using geometry::Displacement;
 using geometry::InertiaTensor;
+using geometry::InfiniteFuture;
 using geometry::Instant;
 using geometry::Position;
 using geometry::R3x3Matrix;
@@ -166,7 +166,7 @@ TEST_F(VesselTest, PrepareHistory) {
   EXPECT_CALL(ephemeris_, t_max())
       .WillRepeatedly(Return(t0_ + 2 * Second));
   EXPECT_CALL(ephemeris_,
-              FlowWithAdaptiveStep(_, _, astronomy::InfiniteFuture, _, _))
+              FlowWithAdaptiveStep(_, _, InfiniteFuture, _, _))
       .Times(AnyNumber());
   EXPECT_CALL(ephemeris_,
               FlowWithAdaptiveStep(_, _, t0_ + 2 * Second, _, _))
@@ -190,7 +190,7 @@ TEST_F(VesselTest, AdvanceTime) {
   EXPECT_CALL(ephemeris_, t_max())
       .WillRepeatedly(Return(t0_ + 2 * Second));
   EXPECT_CALL(ephemeris_,
-              FlowWithAdaptiveStep(_, _, astronomy::InfiniteFuture, _, _))
+              FlowWithAdaptiveStep(_, _, InfiniteFuture, _, _))
       .Times(AnyNumber());
   EXPECT_CALL(ephemeris_,
               FlowWithAdaptiveStep(_, _, t0_ + 2 * Second, _, _))
@@ -267,7 +267,7 @@ TEST_F(VesselTest, Prediction) {
   // these points.
   EXPECT_CALL(
       ephemeris_,
-      FlowWithAdaptiveStep(_, _, astronomy::InfiniteFuture, _, _))
+      FlowWithAdaptiveStep(_, _, InfiniteFuture, _, _))
       .WillRepeatedly(Return(absl::OkStatus()));
 
   vessel_.PrepareHistory(t0_,
@@ -322,7 +322,7 @@ TEST_F(VesselTest, PredictBeyondTheInfinite) {
       /*t1=*/t0_ + 5.5 * Second,
       /*t2=*/t0_ + FlightPlan::max_ephemeris_steps_per_frame * Second);
   EXPECT_CALL(ephemeris_,
-              FlowWithAdaptiveStep(_, _, astronomy::InfiniteFuture, _, _))
+              FlowWithAdaptiveStep(_, _, InfiniteFuture, _, _))
       .WillOnce(DoAll(
           AppendPointsToDiscreteTrajectory(&expected_vessel_prediction2),
           Return(absl::OkStatus())))
@@ -358,7 +358,7 @@ TEST_F(VesselTest, FlightPlan) {
   EXPECT_CALL(ephemeris_, t_max())
       .WillRepeatedly(Return(t0_ + 2 * Second));
   EXPECT_CALL(ephemeris_,
-              FlowWithAdaptiveStep(_, _, astronomy::InfiniteFuture, _, _))
+              FlowWithAdaptiveStep(_, _, InfiniteFuture, _, _))
       .Times(AnyNumber());
   EXPECT_CALL(ephemeris_,
               FlowWithAdaptiveStep(_, _, t0_ + 2 * Second, _, _))
@@ -392,7 +392,7 @@ TEST_F(VesselTest, SerializationSuccess) {
   EXPECT_CALL(ephemeris_, t_max())
       .WillRepeatedly(Return(t0_ + 2 * Second));
   EXPECT_CALL(ephemeris_,
-              FlowWithAdaptiveStep(_, _, astronomy::InfiniteFuture, _, _))
+              FlowWithAdaptiveStep(_, _, InfiniteFuture, _, _))
       .Times(AnyNumber());
   EXPECT_CALL(ephemeris_,
               FlowWithAdaptiveStep(_, _, t0_ + 2 * Second, _, _))

diff --git a/physics/checkpointer_body.hpp b/physics/checkpointer_body.hpp
@@ -8,15 +8,15 @@
 #include <vector>
 #include <utility>
 
-#include "astronomy/epoch.hpp"
 #include "base/status_utilities.hpp"
+#include "geometry/named_quantities.hpp"
 
 namespace principia {
 namespace physics {
 namespace internal_checkpointer {
 
-using astronomy::InfiniteFuture;
-using astronomy::InfinitePast;
+using geometry::InfiniteFuture;
+using geometry::InfinitePast;
 
 template<typename Message>
 Checkpointer<Message>::Checkpointer(Writer writer, Reader reader)

diff --git a/physics/checkpointer_test.cpp b/physics/checkpointer_test.cpp
@@ -1,16 +1,16 @@
 #include "physics/checkpointer.hpp"
 
-#include "astronomy/epoch.hpp"
 #include "base/status_utilities.hpp"
+#include "geometry/named_quantities.hpp"
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "testing_utilities/matchers.hpp"
 
 namespace principia {
 namespace physics {
 
-using astronomy::InfinitePast;
 using base::not_null;
+using geometry::InfinitePast;
 using geometry::Instant;
 using quantities::si::Second;
 using testing_utilities::StatusIs;

diff --git a/physics/continuous_trajectory_body.hpp b/physics/continuous_trajectory_body.hpp
@@ -10,9 +10,9 @@
 #include <utility>
 #include <vector>
 
-#include "astronomy/epoch.hpp"
 #include "base/status_utilities.hpp"
 #include "geometry/interval.hpp"
+#include "geometry/named_quantities.hpp"
 #include "glog/stl_logging.h"
 #include "numerics/newhall.hpp"
 #include "numerics/ulp_distance.hpp"
@@ -23,9 +23,10 @@ namespace principia {
 namespace physics {
 namespace internal_continuous_trajectory {
 
-using astronomy::InfiniteFuture;
 using base::dynamic_cast_not_null;
 using base::make_not_null_unique;
+using geometry::InfiniteFuture;
+using geometry::InfinitePast;
 using geometry::Interval;
 using numerics::EstrinEvaluator;
 using numerics::PoissonSeries;
@@ -622,7 +623,7 @@ Instant ContinuousTrajectory<Frame>::t_min_locked() const {
   lock_.AssertReaderHeld();
 #endif
   if (polynomials_.empty()) {
-    return astronomy::InfiniteFuture;
+    return InfiniteFuture;
   }
   return *first_time_;
 }
@@ -633,7 +634,7 @@ Instant ContinuousTrajectory<Frame>::t_max_locked() const {
   lock_.AssertReaderHeld();
 #endif
   if (polynomials_.empty()) {
-    return astronomy::InfinitePast;
+    return InfinitePast;
   }
   return polynomials_.crbegin()->t_max;
 }

diff --git a/physics/discrete_trajectory_body.hpp b/physics/discrete_trajectory_body.hpp
@@ -8,18 +8,18 @@
 #include "absl/container/flat_hash_map.h"
 #include "absl/container/flat_hash_set.h"
 #include "absl/strings/str_cat.h"
-#include "astronomy/epoch.hpp"
 #include "base/status_utilities.hpp"
+#include "geometry/named_quantities.hpp"
 #include "quantities/quantities.hpp"
 
 namespace principia {
 namespace physics {
 namespace internal_discrete_trajectory {
 
-using astronomy::InfiniteFuture;
-using astronomy::InfinitePast;
 using base::make_not_null_unique;
 using base::uninitialized;
+using geometry::InfiniteFuture;
+using geometry::InfinitePast;
 using quantities::Length;
 
 template<typename Frame>

diff --git a/physics/discrete_trajectory_iterator_body.hpp b/physics/discrete_trajectory_iterator_body.hpp
@@ -9,7 +9,7 @@ namespace principia {
 namespace physics {
 namespace internal_discrete_trajectory_iterator {
 
-using astronomy::InfiniteFuture;
+using geometry::InfiniteFuture;
 using geometry::Instant;
 
 template<typename Frame>