Submitted by 1r0ut3 t3_yzaa76 in technology
i_have_chosen_a_name t1_iwyz6bf wrote
Reply to comment by FIicker7 in The leap second’s time is up: world votes to stop pausing clocks by 1r0ut3
> Won't this mess up GPS over time?
No cause GPS clocks (the atom clocks inside the satellites) are already separated from UTC, they have never adjusted for leap seconds. Neither does galileo, only glonass adjusts for leap seconds.
>Don't most countries base their time on GPS signals?
GPS is primarily a global position system, not primarily time system even though to work it require sending time to the receivers. Countries have their own agencies in charge of time and those run their own atomic clocks, modern countries don't just copy over the time of the gps satellites. Sure there are tons of devices that use gps signals to sync their clocks with but such signals can also just be ground signals.
>So after a few years GPS and their terrestrial clocks will be out of synch, messing up bank transfers...
WTF does GPS have to do with bank transfers? Do you even know what GPS is?
>I guess they will change their minds, when things start to break...
Why would anything break? Universal coordinated time and astronomical time will drift out of sync by one minute over a 100 years. But if all computer systems keep in sync with astronomical time and never care about leap seconds anymore why would they break? Who care if a weather website that calculates the sunset gets it wrong by one minute a 100 years from now?
dopazz t1_iwz13ni wrote
>GPS is a global position system, not a time system.
Oversimplified: GPS calculates position using precise timestamps transmitted from the satellites. It's completely based around time. The satellites have atomic clocks in them to maintain accuracy.
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>Do you even know what GPS is?
Do you?
i_have_chosen_a_name t1_iwz4gmi wrote
yeah but it's not the only way for a device to get a signal to help sync it's clock.
dopazz t1_iwz6crk wrote
You mean an alternative signal like WWVB in Colorado USA / MSF in Cumbria UK? There are signal deadzones all over; if you can see the sky you can receive the GPS signal.
Regardless, your initial post seemed to lack understanding of how GPS works. Time is the crux.
[deleted] t1_iwz7rmc wrote
[deleted]
ric2b t1_ix33n6a wrote
>Oversimplified: GPS calculates position using precise timestamps transmitted from the satellites. It's completely based around time.
Yes, but it has 0 need for leap second adjustments, it's the relative timestamps between the satellites that matters, not their absolute values. (T1 + 18) - (T2 + 18) is still T1 - T2.
Way to miss the point just to act superior.
dopazz t1_ix3dm2n wrote
>Do you even know what GPS is?
Way to misinterpret which person was acting superior.
Sulpfiction t1_iwz34ck wrote
Plot twist: YOU don’t know what GPS is.
FIicker7 t1_iwyz9s1 wrote
i_have_chosen_a_name t1_iwyzv7a wrote
How does a ATM in a underground mall receive a GPS signal?
FIicker7 t1_iwyzwto wrote
They have antennas.
Edit: Most ATMs work off cell towers. Cell Towers depend on GPS.
fatdonuthole t1_iwz13ai wrote
Lots of industries decode time from GPS signals to remain in sync with each other. https://www.gps.gov/applications/timing/
ric2b t1_ix33u1g wrote
And none of those industries need GPS to have leap second adjustments. Because it never had them.
jorge1209 t1_ix5le7o wrote
There is a distinction between needing a way to synchronize, and needing accurate timekeeping.
GPS needs accuracy. The satellites are moving many kilometers per second and so to know where they are (and this where you are) you need to know the exact time a signal was sent, and then that pulse is synchronized across the globe.
It is a rather unique application. Lots of other applications need a global source to synchronize but are less sensitive to errors in that source.
For example you need to sync power across a large network to avoid blowing out transformers, but you have a rather wide acceptable variation in the frequency with which you can synchronize that network. For instance the Texas network ran at 59.4Hz during the 2021 blackouts without failing.
bkoly t1_iwz45y1 wrote
Jesus how does this have so many upvotes
golyadkin t1_iwz7vuo wrote
It actually is also a time system. The precision time signals from GPS are used in situations where it's important to have standardized time across geographically dispersed equipment. It's used in telecommunications, power distribution, financial networks, seismic monitoring and a lot of industrial processes ad the default.
ric2b t1_ix33yhz wrote
>used in situations where it's important to have standardized time across geographically dispersed equipment.
NTP also works fine.
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