What would happen if the internet went down?

Card payments, bank transfers and point-of-sale systems are the fastest visible failure, because they authorise over networks and few retailers can operate offline for long. Logistics fails next: freight booking, port scheduling, warehouse management and just-in-time manufacturing all coordinate over networks, and the inventory buffers that once absorbed such disruptions have been deliberately minimised for decades. Utilities are more resilient than people assume, because power and water control systems generally run on private networks and are designed for isolated operation, though remote monitoring and repair coordination would degrade. Emergency services would fall back to radio, which still exists precisely for this. National-scale shutdowns provide real data: deliberate government internet blackouts have repeatedly cost the affected economies substantial fractions of daily output, and the disruption compounds with duration rather than stabilising.

What happens, in order

How confident this is

This is a reasoned extrapolation rather than an observation. The mechanism is understood, but the scale of the consequences depends on assumptions that could reasonably be argued differently.

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 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 money stopped existing? Trade would collapse to what barter can support, and something money-like would be reinvented within weeks.
• 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.