- A watt of power multiplied by a second of time has an agreed upon name called joule, but a watt second is also a perfectly valid SI name.
A watt is a joule of energy divided by a second of time, this is a rate, joule per second is also a valid name similar to nautical mile per hour and knot being the same unit.
Multiplication vs division, quantity vs rate, see the relationship? Units may have different names but are equivalent, both the proper name and compound name are acceptable.
A watt hour is 3600 joules, it’s more convenient to use and matches more closely with how electrical energy is typically consumed. Kilowatt hour is again more directly relatable than 3.6 megajoules.
Newton meter and Coulomb volt are other names for the joule. In pure base units it is a kilogram-meter squared per second squared.
- You must still commit the WAL to disk, this is why the WAL exists it writes ahead to the log on durable storage. Its doesn't have to commit the main storage to disk only the WAL which is better since its just an append to end rather than placing correctly in the table storage which is slower.
You must have a single flushed write to disk to be durable, but it doesn't need the second write.
- The acid in lead acid is sulfuric acid and if overcharged vents hydrogen gas, thats why they need a ventilated space typically. Sealed lead acid have safety vents that might pop if enough pressure builds.
They are most certainly not inert, they just have well established safety and charging protocols and are not used in very high quantities together because of their low energy density and cycle life.
LFP batteries which have iron phosphate cathodes are very stable compared to colbalt based batteries that tend to have catastrophic failures due to overcharge causing cathode failure. LFP have higher cycle life and are cheaper and typically whats used for storage and application where the loss in erergy density is not a big deal.
- Yeah so not sure why but Look around coverage is much better in Europe than the US for some reason which seems odd since Apple is US based.
You can see the very poor US coverage here: https://brilliantmaps.com/apple-look-around/
Of course compared to Google Street view there is no comparison on a world wide basis as you can see on the same page.
- In the US is has basically zero coverage outside any major city. Google on the other hand has exentiqive coverage into rural areas, albeit some of it old, at least its there, where it has newer coverage it usually has multiple one at different times allowing one to look back in time as well, very useful.
- I mean in Google Maps you can drag the little man over the map and it has a map layer that highlights all the roads available, so you can easily see where it is and is not. Not randomly picking a point and seeing if indicator is available.
- Hardly anything unless in a major city, no way to easily tell if there is any coverage other than randomly clicking until it shows, also doesn't tell you the date taken.
Google street view has the 2d overlay letting you know where there is coverage, shows the date taken along with previous imagery, and they have coverage nearly everywhere in the US at a least, although some of its pretty old.
Apple Maps does seem to have more up to date satellite / aerial imagery though.
Hard to overstate how valuable all that street view coverage is on the Google side.
- Sorry I was considering a standard container ship voyage at 30 days.
A 9m sphere of 1m thick Aerogel will probably cost above $500k just for the material.
Also lithium hydride itself reacts violently with water, not sure if you want to have a 9m radius 5 million pound sphere of it on a water vessel, this is the "safely" part.
- How can you not realize that’s the point? Monopoly on violence is just that, the definition of the state.
Anarchy is not a stable system, you have no property rights or freedoms without a way to enforce them.
You provide no alternative, a government will form from a power vacuum made up of whoever has the most physical power around you.
- Would love to see any data you have, what kind of storage tank on a ship could keep 680C lithium hydride insulated without significant losses for say a 30 day voyage?
- Unless amelius is stronger than you, or has better weapons, or commands a gang that is bigger than your gang, then you can't stop them.
Its almost like you need some sort of power structure with the monopoly on violence to enforce agreed upon freedoms, they could be called the "government" which enforces "laws".
- Round trip efficiency would be very poor, looks like thermal storage is around 75% efficient for the heat then the heat engine (turbine) maxes out around 45% so maybe round trip 33% efficiency if you lucky.
So that gives you around twice the wh/kg but you must keep the heat energy for the entire voyage which is constantly being lost once the onboard storage is heated up. Not sure what that look like I imagine it would be difficult to keep lithium hydride at 680C very efficiently or safely in an ocean going vessel for any length of time.
- 60 MWh continuous is nonsense because its a unit of energy, 60 MWh per hour is just 60 megawatts, 60 MWh per second however is 216 gigawatts.
- Your math seem to work out, but I don't like the incoherent use if energy units.
60 MWh per what? Per hour? thats just 60 MW continuous POWER or 1440 MWh ENERGY per day.
- Looks like Qualcomm X62
- Your quote lists mobile deployments, their bullet point also says:
>Built for rooftops, remote sites, and vehicle based setups
They are insinuating if you actually read their press release then you would not state it was targeted only at stationary deployments.
Based on the spec sheet 2 out of its 6 antennas are directional, this is probably a 4x4 modem so it must have some way to switch 2 antenna from directional to omni.
- The spec sheet mentions 6 antennas and implies only 2 are directional:
(6) Embedded cellular antennas, including (2) high-gain for downlink: peak 9 dBi, 85°x85°
Typically these modems are 4x4 mimo so it must have some method for switching the 2 directional with 2 of the omnis in it based on which ones is needed.
https://techspecs.ui.com/unifi/integrations/u5g-max-outdoor?...
- Not sure how that makes sense, if the stats change significantly then caches would be evicted during the gathering of statistics.
I believe popular connection poolers and clients attempt to do plan caching through prepared statements and keeping the connection open.
My understanding its not easy to do in PG since connections are process based instead of thread based and the query plans are not serializable between processes, so they cannot be shared between connections.
MSSQL has been doing statement plan caching for at least 20 years and it did stored procedure plan caching before that.
- I wonder if PG will ever implement plan caching like MSSQL so that the speed of the optimizer is less of a concern and it can take more time finding better plans rather than replanning on every execution of the same statement.
The energy unit meter is distance moved, while the force unit meter is the length of the moment arm.
This is confusing even though valid, so the energy unit version is rarely used.
You can exert newton meters of force while using no energy, say by standing on a lug nut wrench allowing gravity to exert the force indefinitely unless the nut breaks loose.