What would happen if money stopped existing?

Money solves a specific problem: barter requires a double coincidence of wants, where each party has exactly what the other needs at the same moment, and that requirement scales terribly as an economy specialises. Remove money and complex production stops almost immediately, because a bakery cannot pay a hundred suppliers in bread. Credit is the deeper layer and would go with it, taking pensions, insurance, mortgages and wages, all of which are promises denominated in money rather than piles of it. What historical and observed cases suggest is that the vacuum does not persist: prisoners have used cigarettes, post-war populations used cigarettes and coffee, and prison and refugee economies reliably reinvent a unit of account within a short period. Anthropologically, the barter-preceded-money story is itself contested, with credit and obligation appearing to come first in many societies. This is marked speculative because the outcome depends entirely on what people would do next.

How confident this is

This is speculation. The scenario is far enough outside anything observed that the answer depends heavily on which assumptions you start from — treat it as a thought experiment, not a prediction.

Everyday systems

• What would happen if everyone on Earth jumped at the same time? Essentially nothing. All of humanity together is about one ten-trillionth of Earth's mass.
• What would happen if the internet went down? Payments fail first, then logistics — most physical supply chains now depend on network connectivity rather than the other way round.
• What would happen if all the power went out worldwide? Water supply is the first life-critical failure — most tap water is pumped, and pumping stops when the grid does.
• How much space would it take for everyone on Earth to stand in one place? About 2,000 square kilometres — smaller than Luxembourg, and less than twice the area of Los Angeles.
• What would happen if GPS stopped working? Timing, not navigation, is the real dependency — mobile networks, power grids and financial systems all use GPS clocks.
• What would happen if all the satellites stopped working? Weather forecasting would lose most of its accuracy beyond a day or two, along with navigation, timing and most long-range communications.
• What would happen if all refrigeration stopped? Food waste would rise enormously and the vaccine cold chain would fail — refrigeration is a public health system, not a convenience.
• What would happen if the water supply stopped? Three days for drinking, but sanitation fails first — waterborne disease is what historically kills people in a water outage.
• What would happen if all digital data was lost? Ownership would be the deepest problem — land registries, bank balances and medical records exist almost entirely as data.