99 Fun Facts About Gravity

How long would a drop through a frictionless tunnel bored right through Earth take to reach the far side?

About 42 minutes is the textbook answer for a uniform-density Earth, the same as half the orbital period of a low satellite. A realistic density profile trims the trip to about 38 minutes.

Gravity on the Moon, where Apollo astronauts bounded along in their suits, is roughly what fraction of Earth's?

About one-sixth is right: lunar gravity is 1.62 m/s², 16.6% of Earth's. With no air to get in the way, the hammer and feather David Scott dropped on Apollo 15 sank to the dust side by side.

Crew on the International Space Station, where gravity is still 90% of surface strength, float because they are in what?

Free fall is the whole trick: station and crew are falling toward Earth together, but moving sideways at 28,000 km/h so they keep missing it. Calling the condition weightlessness is fine; calling it the absence of gravity is not.

On most coastlines, how many high tides does the Moon's pull raise in the course of a single day?

Two high tides a day is the norm because the Moon raises one bulge on the side facing it and another on the far side, and Earth turns through both. A few places, such as parts of the Gulf of Mexico, get only one.

Which Canadian bay, a funnel-shaped basin that resonates with the tide, has the highest tidal range on Earth?

Bay of Fundy tides can rise and fall by as much as 16 metres, against a typical ocean range of about one metre, enough to push the rivers that drain into it backwards twice a day.

Which planet, with 318 times Earth's mass, has the strongest surface gravity of any planet in the Solar System?

Jupiter's pull at the cloud tops is still less than three times Earth's despite 318 times the mass, because all that bulk is spread through a globe eleven times as wide.

Ignoring air resistance, how fast must a rocket leave Earth's surface to coast away without ever falling back?

About 11 km/s, 11.2 km/s to be exact, is Earth's escape velocity, roughly 40,000 km/h or 33 times the speed of sound. The Moon's is just 2.4 km/s, which is why Apollo could leave it on a single small engine.

Gravitational waves, ripples in spacetime first directly detected in 2015, cross the universe how fast?

The speed of light is exactly how fast gravitational waves move: GW170817's ripples and its gamma-ray flash arrived within two seconds of each other after more than 100 million years in transit, a dead heat that confirmed it.

Why does the Moon always show Earth the same face, leaving its far side unseen until a probe flew past in 1959?

Tidal locking means the Moon spins exactly once per orbit, so the same hemisphere always faces us. Earth's tides braked its rotation into step billions of years ago, and the Moon is slowly doing the same to Earth.

What nickname did NASA's reduced-gravity aircraft earn from the parabolic arcs that leave passengers briefly weightless?

Vomit Comet was the passengers' own name for it, since each flight strings together dozens of plunges and many riders are sick; Project Mercury astronauts trained aboard one in 1959.

A belly-down skydiver stops speeding up once air drag balances gravity, settling at a terminal speed of roughly what?

About 200 km/h, or 55 metres a second, is where drag on a spread-eagled body matches its weight; tucking into a head-first dive cuts the drag and pushes the limit past 300 km/h.

Because Earth bulges at the equator, which Ecuadorian volcano's summit is the farthest point from the planet's centre?

Chimborazo's summit is about 2 km farther from Earth's centre than Everest's, even though it stands nearly 2,600 m lower above sea level, which makes it the peak that reaches farthest into space.

Which Greek philosopher's Physics claimed bodies fall at speeds proportional to their weight, a view Galileo demolished?

Aristotle held that a stone ten times heavier falls ten times faster. Galileo noted that tying a small stone to a heavy one should then both slow it and hurry it along.

Instead of dropping weights from a tower, Galileo mostly studied falling bodies by rolling balls down what?

Inclined planes slowed the motion enough for Galileo to time it with water clocks, and showed that distance grows with the square of the time. The tower drop, if it happened at all, was over too fast to measure.

The extra-high spring tides arrive twice a month when the Sun and Moon line up, at which pair of lunar phases?

New and full moon put Sun, Moon and Earth in a line called syzygy, so the Sun's tidal pull reinforces the Moon's; the name has nothing to do with the season. At the quarter moons the two pulls partly cancel, giving weak neap tides.

Laser pulses bounced off reflectors left by Apollo crews show the Moon receding from Earth by how much each year?

About 3.8 cm a year is the Moon's retreat, paid for by tidal friction that is also slowing Earth's spin. Run the clock back and the Moon once loomed far larger in the sky, with tides to match.

If you could stand at the very centre of the Earth, the net pull of gravity on you would be what?

Exactly zero is the answer: with equal mass pulling from every direction, the forces cancel at the centre. You would still be crushed, not by gravity but by the pressure of everything above.

Compared with an identical clock on a mountaintop, a clock at sea level, deeper in Earth's gravity well, runs how?

Slightly slower is right: the closer a clock sits to a mass, the slower it ticks, an effect atomic clocks picked up in 2010 across a height difference of just 33 cm. Your head is ageing faster than your feet.

How strong is gravity at Saturn's fast-spinning equator, given the planet's 95 Earth masses?

Slightly less than Earth's, 8.96 m/s² against our 9.8, because Saturn's mass is spread through a huge, low-density globe and its spin flings the equator outward; at the poles the pull is about a third higher.

Gravity on Mars, a planet with 11% of Earth's mass, comes to what percentage of Earth's surface gravity?

About 38%, 3.72 m/s², is the Martian figure, so a person could jump well over twice as high there as on Earth.

In which German city did Einstein present the final field equations of general relativity to the Academy of Sciences in November 1915?

Berlin heard the theory in four weekly lectures that November, and Einstein was still correcting his equations between them: only the last, on the 25th, had them right.

Tidal friction from the Moon is braking Earth's rotation and lengthening the day by roughly how much per century?

About 2 milliseconds a century adds up, which is partly why leap seconds exist: they keep atomic time in step with the slowing planet.

General relativity's first success explained a stubborn leftover drift in Mercury's perihelion of how much per century?

About 43 arcseconds a century, a hundredth of a degree, was the gap Newton's laws could not close, and Einstein's equations matched it with nothing added, ending a half-century hunt for an unseen planet.

Which hypothetical planet did Urbain Le Verrier propose between Mercury and the Sun to explain Mercury's stray orbit?

Vulcan was hunted by astronomers for half a century; it never existed, and general relativity accounted for the orbit instead. Le Verrier had earned the benefit of the doubt by predicting Neptune the same way.

Eddington's 1919 eclipse party went to Príncipe; a second team measured starlight bending from Sobral, in which country?

Brazil's Sobral team got its sharp plates from a small backup telescope, and they backed Einstein's prediction over Newton's; the main telescope's blurred plates, nearer Newton's figure, were set aside.

The 2017 neutron-star merger seen in gravitational waves and light forged up to 13 Earth masses of which metal?

Gold by the planet-load: a single collision may make between 3 and 13 Earth masses of it, so some of the gold in a wedding ring may well be neutron-star shrapnel.

LIGO's twin L-shaped detectors in Louisiana and Washington measure length changes across mirrors spaced how far apart?

4 kilometres of vacuum pipe in each arm lets LIGO sense a stretch of less than a ten-thousandth of a proton's width, among the tiniest measurements ever made.

Virgo, Europe's gravitational-wave detector and LIGO's partner, sits outside which Italian city, Galileo's birthplace?

Pisa is a short drive from Virgo's site at Cascina, and the detector's data helped narrow the 2017 neutron-star merger to a patch of sky small enough for telescopes to find its galaxy.

What is the nickname of the first confirmed gravitational lens, a distant object found in 1979 to appear more than once?

The Twin Quasar is one object split in two by the gravity of a galaxy in front of it, and light along one path arrives about 14 months after the other.

The Bullet Cluster, where lensing maps show mass sitting apart from the hot gas, is prized as evidence for what?

Dark matter is the simplest reading: when two galaxy clusters collided, the lensing mass sailed on with the galaxies while the hot gas, most of the ordinary matter, lagged behind.

The James Webb Space Telescope orbits which Lagrange point, 1.5 million km from Earth on the side away from the Sun?

L2 keeps the Sun, Earth and Moon all on one side of the telescope, so a single sunshield can shade its mirrors from all three; any pair of orbiting bodies has five such points.

Gravity Probe B, launched in 2004 with ultra-precise gyroscopes, tested the geodetic effect and what other prediction?

Frame-dragging is spacetime being swirled around by Earth's rotation, and the probe's gyroscopes tilted by the predicted whisker of 39 milliarcseconds a year.

What name is given to the hypothetical massless, spin-2 particle that would carry gravity in a quantum theory?

Graviton is the name, though none has ever been detected, and catching one may be beyond any realistic machine: a detector as massive as a giant planet, parked beside a neutron star, would register about one a decade.

What do geodesists call the lumpy surface the oceans would settle into under gravity and rotation alone, with no winds?

The geoid dips about 100 m below the reference ellipsoid south of India, the deepest 'gravity hole' on the planet, and sea level faithfully follows it.

Which twin satellites, nicknamed Tom and Jerry, mapped Earth's gravity by tracking the 220 km gap between them?

GRACE watched Greenland and Antarctica lose ice by weighing them from orbit: as meltwater drained away the pull below weakened, and the distance between the two satellites shifted in step.

NASA's GRAIL mission mapped lunar gravity in 2012 with twin probes named by Montana fourth-graders as what?

Ebb and Flow were the winning entries from a Bozeman elementary school, and the probes went on to chart the Moon's buried mass concentrations, the 'mascons' that tug satellites off course.

The Pound–Rebka experiment measured gravitational redshift over a 22.5-metre tower at which American university?

Harvard's Jefferson Laboratory tower was enough: gamma rays climbing it lost a sliver of their energy, just as Einstein predicted, and only the newly discovered Mössbauer effect made so small a shift measurable.

Irwin Shapiro's 'fourth test' of relativity predicted that what, bounced off a planet past the Sun, would return late?

Radar signals skimming the Sun take measurably longer, because spacetime near a mass is effectively stretched, and the same delay in pulsar timing now lets astronomers weigh neutron stars.

Surface gravity on a neutron star, which packs a star's mass into a city-sized ball, is roughly how many times Earth's?

About 200 billion g is typical, so an object dropped from just one metre up would hit the surface at well over 1,000 km/s.

Which unit of acceleration used in precision gravimetry, equal to 1 cm/s², honours an Italian scientist?

The gal honours Galileo and is tiny: Earth's surface pull is about 981 gals, and field gravimeters hunting ore bodies or magma chambers resolve changes of a few microgals.

On which moon of Saturn would thick air and weak gravity let a person strap on wings and fly by flapping?

Titan's gravity is 14% of Earth's while its surface air is about four times denser than ours, so muscle-powered flight would be easy; NASA's Dragonfly rotorcraft is built to exploit the same physics.

Surface gravity is lowest anywhere on Earth, at 9.764 m/s², atop which Andean peak, the highest mountain in Peru?

Nevado Huascarán combines altitude with a near-equatorial latitude, the two things that weaken the pull, against 9.834 m/s² at the surface of the Arctic Ocean. The spread across the whole planet is only about 0.7%.

Because orbital gravity is weaker and the satellites move fast, GPS clocks drift from ground time by how much a day?

About 38 microseconds a day sounds trivial, but left uncorrected it would push GPS fixes off by roughly 10 km within a day; the weaker gravity alone makes the clocks gain 45 microseconds, and their speed claws back 7.

At which giant radio telescope did Hulse and Taylor find the pulsar pair whose shrinking orbit betrayed gravitational waves?

Arecibo's 305-metre dish found the pair in 1974, and their orbit has shrunk ever since exactly as Einstein's theory predicts for a system radiating gravitational waves, which won the 1993 Nobel.

In 2023, CERN's ALPHA experiment dropped antihydrogen atoms and found that antimatter falls which way under gravity?

Down, like ordinary matter, was the verdict, ruling out the science-fiction hope of antigravity from antimatter; it came 21 years after the first cold antihydrogen was made.

Galileo reportedly noticed a swinging cathedral lamp kept the same rhythm however wide it swung, timing it against what?

His own pulse is the timer in the story his pupil Viviani told, and the insight led both to pendulum clocks and to pendulums as the first precise gravity meters.

At 'magnetic hills' like New Brunswick's, where parked cars seem to roll uphill, what is actually at work?

An optical illusion is all it is: the surrounding landscape hides the true horizon, so a slight downhill slope reads as uphill and gravity does exactly what it always does.

Mariner 10 reached Mercury in 1974 via the first planet-to-planet gravity assist, bending its path around which world?

Venus bent Mariner 10's path inward and dropped its perihelion to Mercury's orbit, a slingshot trick Voyager later used to tour the outer planets for free.

Gravity at the Sun's visible surface, which is 109 times wider than Earth's, comes to roughly how many g?

About 28 g, 274 m/s², is the solar surface figure; the Sun's 333,000 Earth masses are offset by a radius so large that the pull at the surface is tamed.

Isaac Newton began working out gravity at his family farm after which disease shut Cambridge University in 1665?

Bubonic plague, in the Great Plague of 1665–66, closed the university as a precaution just after Newton took his degree. His private studies in those years have been called the most productive any scientist ever had.

On the Moon in 1971, David Scott dropped a hammer and which light object to show gravity treats them alike?

A feather from a falcon hit the dust at the same moment as the hammer, because the Moon has almost no air to hold it back. The crew's lunar module was called Falcon too.

Which animal's 11 kg heart generates about double human blood pressure to keep blood reaching its brain against gravity?

Giraffe hearts must drive blood all the way up the neck, while thick, tight skin on the lower legs stops it pooling at the bottom. Valves in the neck veins guard the brain when the head drops to drink.

If a black hole with the Sun's exact mass took the Sun's place, what becomes of Earth's yearly orbit?

It stays unchanged, because from far away a black hole pulls exactly like any other body of equal mass. The popular picture of a cosmic vacuum cleaner only applies very close in.

Which sport did Alan Shepard play on the Moon in 1971, swinging one-handed in a stiff suit under weak gravity?

Golf reached the Moon when Shepard fixed a six-iron head to the handle of a sample scoop and hit two balls. Thick gloves forced him to swing with one hand.

Which British physicist floated weightless in 2007 aboard a modified Boeing 727 flying steep arcs off the Florida coast?

Stephen Hawking, a wheelchair user since the late 1960s, flew with Zero-G Corp to experience weightlessness for himself. The jet creates it by tracing the same arc a thrown ball would follow.

Gravity is drawing the Milky Way toward a possible merger, billions of years from now, with which neighbouring galaxy?

Andromeda, the nearest major galaxy to our own, may meet the Milky Way in about 4.5 billion years. Simulations published in 2025 put the odds of a head-on crash at only about half.

Which planet was found in 1846 after astronomers calculated where an unseen world must be tugging on Uranus?

Neptune turned up within a degree of the spot Urbain Le Verrier had predicted, a planet found on paper before it was seen. John Couch Adams had reached a similar answer independently.

What happens to an astronaut's height during the first month of weightlessness aboard an orbiting space station?

An astronaut's height grows by a few centimetres, up to 3% in NASA's figures, because the spine stretches once nothing is pressing it down. Bones pay for the holiday, though, thinning by about 1% a month.

What name do astronomers give the boundary around a black hole beyond which nothing, not even light, can return?

Event horizon is the term for that point of no return. The idea dates to 1784, when John Michell proposed that gravity near a massive enough body could stop even light escaping.

Which English discoverer of hydrogen first measured gravity's pull between lead spheres in a laboratory, in 1798?

Henry Cavendish used a torsion balance devised by John Michell, in which the faint attraction of lead spheres twisted a wire. His result came out as the density of the Earth, which amounted to weighing the planet.

Which astronomer paid to publish Newton's 1687 masterwork on gravity and later predicted a famous comet's return?

Edmond Halley saw the importance of Newton's work, arranged its publication and covered the cost himself. He never saw his comet come back in 1758 as he had forecast.

Whose three laws of planetary motion became one of the foundations for Newton's theory of universal gravitation?

Johannes Kepler described how the planets move without a full theory of why. Newton then showed that an attraction fading with the square of distance produces exactly those paths.

In which three-volume book, written in Latin, did Isaac Newton set out his law of universal gravitation?

Principia, in full Philosophiæ Naturalis Principia Mathematica, was licensed for printing by the diarist Samuel Pepys, then president of the Royal Society. It also contains the three laws of motion.

Which rival of Newton, known for a law of springs, said he had given Newton the inverse-square rule of gravity?

Robert Hooke said the notion of gravity weakening with the square of distance was his. Newton granted that others had grasped the rule, but denied that Hooke had told him anything new.

In Newton's cannonball thought experiment, a shot fired from a mountaintop at exactly the right speed would do what?

It would keep circling the planet and come back to the mountain it left, always falling but never landing. Newton used the picture to argue that gravity also steers the worlds of the Solar System.

Vera Rubin found the outer stars of spiral galaxies moving too fast for their visible mass, key evidence for what?

Dark matter is the usual explanation, since extra unseen mass would supply the missing gravity. The speeds Rubin measured stayed flat far from each galaxy's middle instead of dropping away.

Which Nobel-winning gravitational-wave physicist was the scientific consultant on Christopher Nolan's film Interstellar?

Kip Thorne wrote The Science of Interstellar in 2014 to explain the film's physics, three years before he shared the Nobel Prize in Physics with Rainer Weiss and Barry Barish.

What is the supermassive black hole, about four million times the Sun's mass, at the heart of the Milky Way called?

Sagittarius A* is so heavy and so compact that only a black hole fits, a finding that won Reinhard Genzel and Andrea Ghez a share of the 2020 Nobel Prize in Physics.

What do astrophysicists call the stretching of anything falling toward a black hole into a long, thin strand?

Spaghettification happens because gravity there pulls far harder on the near end of a falling body than on the far end. Close to a black hole the stretch becomes so strong that no object can resist it.

Which idea, set out by Einstein in 1907, says standing in a gravity field matches accelerating in a rocket?

The equivalence principle holds that the same physical laws are seen under gravity and under steady acceleration, so the two cannot be told apart from inside. Einstein built his later theory of gravity on it.

Which NASA probe, launched in 1977, used a chain of gravity assists to become the only one to visit either ice giant?

Voyager 2 exploited a periodic alignment of the outer planets in the late 1970s, letting each world's gravity fling it on to the next. A single probe could then tour all four giants.

Tidal heating inside which small moon of Saturn drives more than 100 geysers that spray water from its south pole?

Enceladus is held in a slightly stretched orbit by a resonance with the moon Dione, so Saturn's pull flexes and warms its interior. The jets throw about 200 kg of material into space every second.

Inside which distance from a planet do tides pull a loosely bound moon apart, the zone where almost all rings lie?

The Roche limit is where a planet's tidal pull beats the gravity holding a moon together. Material inside it spreads out into rings, while material outside tends to clump into moons.

In 1672 Jean Richer learned that gravity is weaker near the equator when which instrument ran slow in French Guiana?

A pendulum clock he took to Cayenne lost two and a half minutes a day, the first sign that gravity varies from place to place. Newton reasoned that Cayenne must lie farther from the Earth's middle than Paris.

Tiny calcium carbonate grains called otoliths let humans sense gravity and tilt from inside which part of the body?

The inner ear holds the grains in two small chambers, where they shift as the head tilts or speeds up. Every vertebrate, from fish to birds, carries a version of the same sensor.

Which plant response, documented by Charles Darwin, sends roots downward and stems upward?

Geotropism relies on dense starch-filled grains that settle to the low side of special cells, telling the plant which way is down. Roots then grow with the pull and stems against it.

Near NASA's Johnson Space Center in Houston, astronauts rehearse weightless spacewalks for hours inside what?

A large indoor pool, the Neutral Buoyancy Laboratory, holds full-scale mock-ups of space station modules, and trainees wear suits adjusted so that they neither sink nor rise. An earlier tank was too small for station-sized hardware.

Designs for long space voyages would spare crews the harm of weightlessness by creating artificial gravity how?

Spinning the craft presses everything aboard toward the outer wall, which then serves as a floor. A rotating centrifuge does exactly that for the crew of Discovery in the film 2001: A Space Odyssey.

Water held high behind a hydroelectric dam stores which form of energy until gravity pulls it down to the turbines?

Potential energy is what anything gains by being lifted against gravity. Pumped-storage plants bank spare electricity by pumping water back up to a higher lake, ready to fall again.

Which crippled 1970 mission looped around the Moon, letting lunar gravity bend its path back toward Earth?

Apollo 13 lost an oxygen tank on the way out, so its crew powered up the lunar module as a lifeboat and swung behind the Moon instead of landing. All three astronauts came home safely.

Einstein–Rosen bridge is the formal name for which hypothetical tunnel linking distant points in spacetime?

A wormhole of this kind was first spotted in the equations of general relativity by Ludwig Flamm in 1916. Einstein and Nathan Rosen rediscovered it and published in 1935, and their names stuck.

A balloon rubbed on hair clings to a wall, beating the whole Earth's gravity, thanks to which far stronger force?

Electromagnetism dominates at the scale of atoms, where gravity is the weakest of the four fundamental interactions. A few stray charges on the balloon are enough to out-pull an entire planet.

Which theorised shell of icy bodies, up to 3.2 light-years out, marks the edge of the Sun's gravitational hold?

The Oort cloud is so loosely bound to the Sun that passing stars and the pull of the Milky Way itself can nudge its icy bodies. Some of them then drop inward as comets.

The James Webb Space Telescope circles which gravitational balance point, about 1.5 million km beyond Earth's orbit?

L2 lets the telescope go round the Sun in step with the Earth, so a single sunshield can block the Sun, Earth and Moon at once. It arrived there in January 2022.

Which European lander bounced twice in a comet's feeble gravity in 2014 after its anchoring harpoons failed to fire?

Philae went on to make the first soft landing on a comet nucleus, although a thruster meant to pin it down did not fire either. It came to rest in an awkward spot after its second bounce.

What name is given to the month's smallest tidal ranges, when the Sun's pull works at right angles to the Moon's?

Neap tides arrive around the Moon's first and third quarters, when the Sun's tidal force partly cancels the Moon's. The gap between high and low water is then at its smallest.

Which doomed moon creeps about 2 cm closer to the world it circles each year and should be torn apart by tides?

Phobos already circles closer to its planet than any other known moon, and tides are dragging it lower. In 30 to 50 million years it should break up into a ring around Mars.

What do astronomers call the shared centre of mass two bodies orbit, which for Earth and Moon lies inside the Earth?

The barycentre of the Earth–Moon pair sits about 4,671 km from the middle of the Earth, roughly three-quarters of the way to the surface. Both worlds swing around that point.

What term describes a world massive enough for its own gravity to pull it into a nearly round shape?

Hydrostatic equilibrium is one of the three tests in the 2006 definition of a planet. Mercury is not strictly in that state, yet the definition names it as a planet all the same.

What word names a straight-line arrangement of three celestial bodies, as happens at every solar and lunar eclipse?

Syzygy also covers transits and occultations, when one body passes directly in front of another. The term applies to any three or more bodies lined up in one gravitational system.

Which hidden region, lying behind the Milky Way's plane, was inferred from the unexpected drift of galaxies toward it?

The Great Attractor sits in the Zone of Avoidance, where our own galaxy's disc blocks the view in visible light. Farther structures such as the Shapley Supercluster are now known to add to the pull.

By tradition, the apple that set Isaac Newton thinking about gravity was which green cooking variety?

Flower of Kent trees grown now are mostly said to descend from those at Woolsthorpe Manor, Newton's family home. The National Fruit Collection lists one of its specimens as Isaac Newton's Tree.

Which Canadian body of water sits at the centre of a gravity anomaly partly left by the vanished Laurentide ice sheet?

Hudson Bay lies on crust that is slowly adjusting to the loss of the ice, which explains roughly a quarter to a half of the anomaly. Slow convection in the mantle below is thought to supply the rest.

Which science-fiction author's 1945 article popularised the orbit where a satellite hovers over one spot on Earth?

Arthur C. Clarke set out the idea in Wireless World magazine as a way to relay radio around the globe. The geostationary orbit is sometimes called the Clarke orbit, and Syncom 3 became the first satellite to use it in 1964.

Which American physicist popularised the term "black hole" after using it in a 1967 talk at a NASA institute?

John Wheeler took up the phrase after a listener at one of his lectures tired of hearing him say gravitationally completely collapsed object. It had already been used earlier that decade.

Which German physicist found the first exact solution to Einstein's gravity equations while serving in World War I?

Karl Schwarzschild solved the case of a single round, non-rotating mass in the same year the theory appeared, and died the next. The size of a simple black hole is given by the radius that bears his name.

Which dense patches under the Moon's surface, found in 1968 by tracking Lunar Orbiter probes, tug satellites off course?

Mascons, short for mass concentrations, make the Moon the lumpiest major body known for gravity. Their small tugs build up until a low satellite's path is bent enough to hit the surface.

With no gravity-driven convection to stretch it upward, a candle flame aboard a space station takes which shape?

A sphere is what a flame settles into once hot gas no longer rises, and it burns bluer and more efficiently as well. NASA experiments confirmed gravity's indirect hand in shaping flames in 2000.

Because Earth spins and bulges, a person would weigh about 0.5% more standing where than at the equator?

At the poles a person stands closer to the planet's middle and loses nothing to its spin. Sea-level gravity climbs from about 9.780 m/s² on the equator to about 9.832 m/s² there.