- When Scott picked the objects up on the Moon, they would have felt, or ‘weighed’ much
lighter than if he picked them up on Earth.
- This is because weight comes from gravity, and it changes depending on where you are.
- changes depending on where you are. If you weigh 100kg on Earth but jump onto a set of
scales on the Moon, they’ll register less than
17kg. This is because weight is actually a measure of how strongly
gravity is pulling you down.
- Mass just recalibrates things to find out what they’d weigh if they were under Earth’s
gravitational force. On the Earth, there’s no need to calibrate anything, and
mass and weight are equal. This is why in casual usage the words are
interchangable, but in physics they are not.
- It converts the weight of an object to what it would have weighed on Earth, so
your mass on the Moon is also 100kg. It does this because it's defined as a
measure of resistance to acceleration.
- From <https://ideas.discover.earth/mass/>
- For instance, gold atoms are more massive than iron atoms, which are more massive
than hydrogen atoms.
- Gold atoms definitely have more protons and neutrons in them than the iron atoms in the
hammer, and the mix of atoms in its wooden handle.
- But this isn't quite where mass comes from.
- The large mass of objects like the Earth and the Sun is
- If someone went into the source code of the universe and switched off mass, then your next
footstep would propel you into space. A few moments later you'd realise that
the sun has been extinguished, the atmosphere is floating away, and the Earth
is hurtling into the darkness of space.
- You'd pretty much ruin the universe.
- But such a fundamental aspect of the universe originates way, way down in the tiniest of
places. Within the atom.
- Mass arises from not just your atoms, or even from the protons and neutrons within
them. It comes from the world inside protons and neutrons, called quantum
- According to the Standard Model,
a proton consists of two up 'quarks' and one down 'quark', and a neutron has
the opposite. Each one also has a great many number of 'gluons' holding them
together (technically, they cause the strong nuclear force that holds the
quarks together). Gluons = the glue that holds everything together.
- It's not even about gold having more protons and neutrons in its atoms than the hammer
does, because //quarks// are massless