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Okay But How Does GPS Know

@okayfine×Systems Engineer· 1:44

tap anywhere to keep going

Keep going

how did people tell the time before clocks

Telling Time Before Clocks

@thehost
Hold on, you said hours. Their hours were our hours?
Systems Engineer
No, and this is my favourite bad decision in the whole subject. They took daylight — sunrise to sunset — and cut it into twelve…
Chart: twelve daylight hours in Rome. Winter hour 45 minutes, equinox hour 60, summer hour 75.
@thehost× Systems Engineer1:38
why does wifi get worse in one specific room

The One Bad Room

@okayfine
Okay but you just told me I have ninety decibels of room. A wall is not ninety decibels. You've argued yourself out of your own…
Systems Engineer
Fair hit, and I'll cash it out. Ten metres of open air at 2.4 GHz is already about 60 dB of loss — that's just the signal sprea…
Bar chart: typical one-wall signal loss at 2.4 GHz. Drywall 3 dB, wooden door 4 dB, brick 8 dB, concrete 12 dB, foil-backed insulation 25 dB. Note: 3 dB = half the power gone, 10 dB = 90 percent.
@okayfine× Systems Engineer1:25
how does GPS actually know where you are

Explaining GPS to a Dead Man

@nocontext
Your phone knows where it is. Explain how.
Victorian Ghost
Dear soul, I have been dead since 1887 and I was rather hoping you would explain it to me.
@nocontext× Victorian Ghost0:28