Act 03
Your memory is leaking right now.
Not as a metaphor. The machine you are reading this on stores its working memory as electrical charge in tiny capacitors, and that charge drains away within milliseconds. It survives only because something rewrites all of it, constantly, forever.
One bit, one capacitor, one leak
A DRAM cell is about as simple as storage gets: a capacitor that is either charged or not, and a transistor to reach it. Charged is a one. Empty is a zero. The D stands for dynamic, and the dynamic part is the problem, because no capacitor holds charge indefinitely. It bleeds away through the transistor, through the dielectric, through anything that will take it.
Left alone, a row of DRAM loses its contents in a fraction of a second. Which means the only thing standing between you and total amnesia is a circuit that reads every row and immediately writes it back, unchanged, over and over, for as long as the power is on. The JEDEC standard requires every row to be refreshed within 64 milliseconds. Your RAM is not holding your data. It is continuously reminding itself.
Brightness is charge. The green row is being rewritten.
Slowed by orders of magnitude. Real DRAM does every row inside 64ms.
Stop the reminding and watch
Turn the refresh off on the block above and it fades to nothing. That is the honest picture, just slowed down enormously so a human can watch it happen. This costs real power, incidentally: a meaningful slice of the energy your machine spends on memory goes on refresh cycles that store no new information whatsoever. You are paying, all day, to keep saying the same thing to yourself.
The decay is not perfectly uniform either. Some cells leak faster than others, and the rate rises with temperature, which is why a hot machine has to refresh more aggressively.
The gap that leaks secrets
Decay is fast on human timescales but not instant, and that gap is exploitable. Cool the modules and the charge persists for seconds or longer, long enough to cut power, move the memory to another machine and read out what was in it: encryption keys, passwords, anything the running system was holding. That is the cold boot attack, and it works because forgetting takes time.
Which is a strange inversion of everything else on this site. Usually decay is the failure. Here, memory not decaying fast enough is the vulnerability.