Many promises that never materialized or resulted in mediocre or bad products, from the Mars mission to the Hyperloop, and from Teslas dismal software and often promised, never materializing fully autonomous drive to the Cybertruck. Let's not go into the robot vapourware either...
Hyperloop is the only thing you listed that is accurate, although it was only a whitepaper + competition. It was open for others to pursue.
Tesla easily has the best vehicle software + OTA and has since the S in 2012. It still feels better than most new vehicles.
You can buy a Tesla (including Cybertruck) today that will do 95+% of drives with 0 intervention. It may not be 100% autonomous yet, but there isn't anything obvious limiting the last step.
The robots exist but are still being developed. Within 5 years, it is hard to imagine them not becoming super valuable within factory settings.
If you think Tesla is bad, you should look into GM or Ford.
There have been many accusations about sudden accelleration, but except for the Cybertruck's pedal-cover slide, there has never been a proven case of a Tesla autonomously accellerating into a crash. But these accusations come a lot, because people are always wanting to shift the blame away from themselves and the automaker seems like an easy target.
And yet SpaceX flies the most reliable rocket in history more frequently than anyone in the world has ever flown, takes astronauts to the ISS regularly, and does so for far less then any competition. Tesla changed the automobile from ICE to BEV in a way people wanted to buy and was practical as a replacement for any use, and created a charging standard so successful every US car company is switching to.
>And yet SpaceX flies the most reliable rocket in history more frequently than anyone in the world has ever flown, takes astronauts to the ISS regularly, and does so for far less then any competition
Yeah, after almost half a century, they passed 70s-era Soyuz numbers.
>Tesla changed the automobile from ICE to BEV in a way people wanted to buy and was practical as a replacement for any use
The magic of EV subsidies (for both Tesla and buyers).
>And the Mars missions so far are just delayed.
The magic of that statement is that it can be true at any point in the future!
I've stopped reading anything on blogs on the basis that it's now probably llm spew and life is too short for the signal to noise ratio that implies.
With the exception of things that places like HN seems to consider worth reading, which is why I'm looking through the comments to this and others to find recommendations.
Don't give your code to Microsoft if you don't want them to have your code.
This setting will make no difference to whether your code is fed into their training set. "Oops we accidentally ignored the private flag years ago and didn't realise, we are very sorry, we were trying to not do that".
It's obviously, trivially broken. Stores the index before storing the value, so the other thread reads nonsense whenever the race goes against it.
Also doesn't have fences on the store, has extra branches that shouldn't be there, and is written in really stylistically weird c++.
Maybe an llm that likes a different language more, copying a broken implementation off github? Mostly commenting because the initial replies are "best" and "lol", though I sympathise with one of those.
There's no relationship between the two written variables. Stores to the two are independent and can be reordered. The aq/rel applies to the index, not to the unrelated non-atomic buffer located near the index.
> There's no relationship between the two written variables. Stores to the two are independent and can be reordered. The aq/rel applies to the index, not to the unrelated non-atomic buffer located near the index.
No, this is incorrect. If you think there's no relationship, you don't understand "release" semantics.
This was _really_ surprising to me. What's the point of marking individual stores if it affects everything, not just that address. But yeah, what I can find online agrees that C++ has done this. Thanks!
> A store operation with this memory order performs the release operation: no reads or writes in the current thread can be reordered after this store. All writes in the current thread are visible in other threads that acquire the same atomic variable (see Release-Acquire ordering below) and writes that carry a dependency into the atomic variable become visible in other threads that consume the same atomic (see Release-Consume ordering below).
> write with release semantic cannot be reordered with any other writes, dependent or not.
To quibble a little bit: later program-order writes CAN be reordered before release writes. But earlier program-order writes may not be reordered after release writes.
> Relaxed atomic writes can be reordered in any way.
To quibble a little bit: they can't be reordered with other operations on the same variable.
* we limit data shared to an atomic-writable size and have a sentinel - less mucking around with cached indexes - just spinning on (buffer_[rpos_]!=sentinel) (atomic style with proper sematics, etc..).
* buffer size is compile-time - then mod becomes compile-time (and if a power of 2 - just a bitmask) - and so we can just use a 64-bit uint to just count increments, not position. No branch to wrap the index to 0.
Also, I think there's a chunk of false sharing if the reader is 2 or 3 ahead of the writer - so performance will be best if reader and writer are cachline apart - but will slow down if they are sharing the same cacheline (and buffer_[12] and buffer_[13] very well may if the payload is small). Several solutions to this - disruptor patter or use a cycle from group theory - i.e. buffer[_wpos%9] for example (9 needs to be computed based on cache line size and size of payload).
I've seen these be able to pushed to about clockspeed/3 for uint64 payload writes on modern AMD chips on same CCD.
If you can get a megawatt into the car batteries without setting them on fire, that's game over for petrol cars. And for the other electric vehicles that haven't worked it out yet. Only reason I'm on petrol is unwillingness to wait an hour to recharge the car.
The rest of the infra is fine if that can be done. Array of batteries and/or capacitors at the supply point and draw continuously from the grid.
Most entertainingly run a diesel generator on site if that doesn't work out. Lines up well with basing them at the existing fuel stations, got the diesel supply already sorted out.
Put a bunch of solar near it when you can. Maybe sell back to grid, nice to have the extra capacity available.
All comes down to capital deployment at that point. Do the calculations on how much to charge for slow car charge vs fast charge, fallback to slow with an apology/discount when the infra is struggling etc.
Huge news. Iff the cars don't catch fire when plugged in.
I have as far as I'm aware the cheapest 800v car on sale in the US (Hyundai Ioniq 5) and in the right weather conditions a 20-80% charge is legitimately 10 minutes.
The weather conditions do unfortunately matter. Travelling during the post-Christmas blizzard last year was very much less than ideal. The battery heaters in my car could not keep up with how bitterly cold and windy it was and I had multiple 30-45 minute charging sessions because it wasn't ever warm enough to accept more than ~120kW.
I'm looking forward to traveling with it in the warm season and seeing how things compare.
Now (in China) there are also cars with sodium-ion batteries, instead of lithium-ion batteries.
Sodium-ion batteries have the disadvantage of a worse energy per weight ratio, but they also have an advantage (besides the fact that they will become cheaper when their production will be more mature): they work much better at low temperatures, not losing capacity or charging speed until minus 40 Celsius degrees.
Therefore, they may become preferable in colder climates, where they will not have the problems described by you.
> If you can get a megawatt into the car batteries without setting them on fire, that's game over for petrol cars
Chinese people are complaining about this. In highway service stops, the megawatt charger is too fast, the 20%-95% charging is done before people returns from the toilet. Realistically, the charging speed should take around 10 minutes in average for everyone.
Or there could be some price surges. You are in a really hurry pay some 1.2x price for 3 min megawatt charge, or flat price for a regular 10 min charge.
For me EVs already won when charging got down to 20 minutes.
EVs charge unattended. It takes less of my own time to leave EV plugged in parked next to a place I want to be at, than to go drive to a gas station and stand there holding a smelly nozzle.
Agreed. Right now EVs are almost strictly superior for day to day usage (only real downside is that the higher weight goes through tires faster). But for road trips, combustion vehicles blow them out of the water. If I'm taking a 12 hour road trip, no way am I going to take an EV if that means I will have to spend an extra hour or two charging it.
My wife has an EV and it's genuinely really nice. But until they get the charging experience on par with the speed of filling up a gas tank, we will always have one of our two cars be a combustion car, to give us that extra flexibility for long trips.
Or just eat an extra few minutes of charging time once or twice a year; it's simply not a big deal. Charging at home saves me so much time relative to getting gas that the occasional road trip wait is already overcompensated for. ICE/hybrid only saves you time if you can't charge at home or do lots of road trip type driving.
"Fair" or "insane" ideas on price vary a lot between people. See also "competitive" salary on job posts.
You might think $10 an hour is fair. Or you might think $1000 an hour is fair. If the developers you're trying to contact can't guess where you are on pricing, they'll probably ignore you.
Internet traffic today is estimated to be a few tens of exabytes per day. Even if you assume 100000 Starlink satellites (we're far from that), each satellite would have to handle hundreds of terabytes per day. That's tens of gigabits per second per satellite, assuming traffic is split evenly among them (will never happen in real situations).
Starlink V3 can pump out some seriously impressive speeds and handle thousands of clients. Starlink is both a great leap forward in rocketry and radio technology.
I do still think funny how we are going back to the pre war technology tree for a re-visit
That's not even sufficient to handle the needs of a single large city. The limitation is that even with the much larger constellation they hope to deploy there won't be enough satellites visible at once from any given large metro area.
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