Given a distance, an allowable time to reach that distance, a payload to send, and an expected exhaust velocity, how would you calculate the time required to convert energy into antimatter fuel and how much antimatter needed to arrive at the destination (starting from the Moon)?
There are a few side calculations, such as the size of the radiator, estimated footprint of the fusion reactor itself, and how much metamaterial is needed. This is to help figure out timelines for a sci-fi novel, so ballpark answers are completely fine.
The calculations yield what appear to be values around the correct order of magnitude. Would be delighted to have insights, comments, and corrections.
This hides memory allocations altogether. As long as the open/close functions are paired up, it gives me confidence that there are no inadvertent memory leaks. Using small functions eases eyeballing the couplings.
For C++, developing a unit test framework based on Catch2 and ASAN that tracks new/delete invocations is rather powerful. You can even set it up to discount false positives from static allocations. When the unit tests exercise the classes, you get memory leak detection for free.
(I don't mind down votes, but at least reply with what you don't like about this approach, and perhaps suggest a newer approach that we can learn from; contribute to the conversation, please.)
> As long as the open/close functions are paired up
Let me stop you right there. I did not downvote you, but I bet that's why others did. If humans were capable of correctly pairing open/close, new/delete, malloc/free, then we could've called C's memory management "good enough" and stopped there. Decades of experience show that humans are completely incapable of doing this at any scale. Small teams can do it for small projects for a small period of time. Large teams on large projects over long eras just can't.
If the advice for avoiding resource errors includes "all the programmer has to remember is...", then forget it. It's not happening. Thus the appeal of GC languages that do this for the programmer, and newer compiled languages like Rust that handle resource cleanup by default unless you deliberately go out of your way to confuse them.
As you add more code between the "open" and the "close", you introduce more opportunities for control flow to accidentally skip the "close" (leak), or call it more than once (double-free). It forces you to use single-return style, which can make some things very awkward to express.
You're basically doing "defer"-style cleanup manually; you may as well just use the real "defer" if your compiler supports it. It's supposed to be official in a future standard, too.
When developing KeenWrite[1], I opted to support only plain TeX. This is because I wanted math typesetting to work for either LaTeX or ConTeXt[2]. To render TeX in the preview panel, I forked NTS[3] into a highly optimized Java version. The lack of cross-platform event-based UI system is what kept me from writing the entire application in Rust (some ten years ago). Has the Rust ecosystem improved with respect to Markdown processing, event-based UIs, and now TeX support?
Sorry for the inconvenience. The email works now. Regarding the article - I use similar ideas to extract colors form artwork images, only difference is I added color prevalence scale for each color and limited it to 10 colors per palette.
My free, open-source, bare-bones, caching-free, dependency-free, authentication- and authorization-free pure PHP raw Git viewer. I developed it because GitList blew out my shared host's drive space and memory (due to a caching bug) and to consolidate my GitHub, BitBucket, and GitLab repos. There's something rewarding about self-hosting and not being beholden to the whims of third parties.
> I truly love GitHub, and I hope they find their way.
I jumped ship as soon as they added MFA. I vibe-coded my own raw Git repository reader to help consolidate my other repos (BitBucket, GitLab), which inevitably started to impose more restrictions (disk space, MFA), as well. It's no GitHub, but works, doesn't cache, and is pure PHP.
The NSF is an independent federal agency that funds roughly a quarter of all basic academic research in the US, laying the groundwork for technologies like the Internet backbone and MRIs. The NSB is its governing body, composed of top scientists who serve staggered six-year terms specifically so no single administration can wipe out the entire board at once. That continuity is designed to insulate scientific priority-setting from political pressure, ensuring American research funding is directed by objective merit rather than political patronage. Dismissing all members simultaneously removes the exact oversight mechanism built to prevent political offices from dictating scientific agendas.
From a political science perspective, this is an institutional move Robert Paxton described in his stages of fascist development. His framework identifies patterns where political actors weaken or bypass independent bodies designed to constrain executive power. In Paxton's fourth stage, the exercising of power, an executive consolidates control by actively dismantling these checks. Centralizing control over scientific governance by firing the board for opposing a budget cut is hollowing out an independent institution; it's a pathway Paxton documented whereby institutional checks are weakened in ways that accumulate over time.
While this is a good step forward, it feels like complaining about the 0.025% of plastic from straws in the ocean while ignoring the 75% of plastic from fishing nets.
I own a 2020 Kona EV. The battery cannot be upgraded. Eventually, I'll have to replace the entire car to get a longer range. BEVs should be mandated to have upgradable batteries and modular interfaces so that the shell can continue to be reused, the batteries (and BMS) upgraded, and old batteries easily recycled.
Useful life of most of the cars is on par with their battery longevity, as long as you have proper thermal management and your usage patterns are not outliers.
Focusing on being able to upgrade battery (and to be clear - upgrade, not replaced/repair) is solving 1% problem.
Cars have basically unlimited useful life because every component (arguably with the exception of the frame) can be repaired. It's surprisingly affordable to rebuild an engine and make it as good as new. I can buy a car made in the 50s today, that's a 70 year old car. And I can keep servicing it and keep it going for another 70 years.
The main enemy of cars is rust, but for that there are cost effective mitigations now. The real reason people ditch cars is always they get tired of the old car and want something more modern, not because the car is at the end of its "useful life".
Batteries are not like that. They actually have a useful life that degrades over time, which makes them non-servicable.
What I would like to see is serviceable batteries, where you can replace individual damaged cells and keep the battery going. Everyone would benefit from that, especially the used EV market, which would help stem the massive depreciation hits EV buyers are facing now.
Given the huge environmental cost involved in manufacturing a car, 20 years seems fair.
I’m still driving a 26-year old Nissan Micra – though it’s now on its last legs: the Irish climate isn’t kind to steel and we’ve had to have the under-carriage re-welded three times in the past five years. :(
EV batteries are expected to offer about 60-70% of capacity at 20 years. I think that's really good compared to general wear and tear of the car.
But let's go back to the original point, about being able to UPGRADE (not repair/replace) battery in the car. 20 years old car is worth like $1k-2k, which is fraction of the cost of the new battery.
While it's cool thing to do for hobbyists, it makes 0 economical sense.
What an old car is worth depends on many factors, but age is not the most important one. The average age of passenger cars on the road in the U.S. is 14 years old -- I think 14.5 years now. I don't think we have data on average appraised value of passenger cars on the road, but I would guess it would be in the range of 10-15K.
Why not ask me my motivations instead of assuming them?
I'm not fine with the range; I bought an EV to stop burning fossil fuels, my 24-year-old RAV4 was on its last leg, and there was a $6K bonus for trade-ins (my RAV4 would have been about $5k in parts).
Because I want to explore the interior of BC, drive across Canada on fewer charges, visit family, go on road trips, etc. Just yesterday I spent 30 minutes trying to charge my Kona. It's a long and boring story, but suffice to say our charging infrastructure here sucks, and is not as simple, quick, or convenient as "tap-to-pay" (with a credit card) at petrol stations.
> Should I be able to eventually replace gas tank with the larger one in my ICE vehicle?
FWIW, that is actually a thing you can do. It is mostly done for SUVs and pickups since the primary use case for the extra range is off-pavement driving and the upgrade is simpler.
Yes, which is why they are replacable, and Hyundai is bound by law to keep making batteries for OP's Kona for a good while even after the production stops.
Unfortunately Hyundai is not required by law to keep making batteries. They are only legally required to provide for warranty support for up to 10 years after a car is made. Usually that means you keep making parts, but I'm not sure how this works with EVs.
But the window is 10 years. After that, you rely on market forces -- if there is a profit to be made from making the part, then it is made. Heavily cars rely on aftermarket parts, but the question of a battery is a bit different.
Again, we need open source cars, with open source designs, so that batteries can be repaired, upgraded, and replaced by an aftermarket. I keep pushing this and hope I'm not being tedious, but people are underestimating the risk to the consumer.
That will probably come when EV marketshare is higher and innovation plateaus. I definitely appreciate the phone thing as someone typing from an iPhone SE. I also think phone batteries degrade faster than cars, right? I think my phone is from 2022 and I’m definitely starting to feel it.
I don't see how that's even remotely comparable. It's not like you can replace the battery in your phone with a larger one. You will be able to buy a new battery for your car, that's already guaranteed in the EU - but it will be the same capacity as what you got.
I don't know why is this even an argument really, like.....in a petrol car, do you expect to be able to fit it with a bigger fuel tank after 10 years? or a more powerful engine? Until very recently even software updates to the infotainment weren't really a thing, if you wanted a newer interface you had to change the entire car(I'm not saying this was a good thing, just that generally the expectation is that the product will work the way it was when you bought it).
> It's not like you can replace the battery in your phone with a larger one.
That was totally a thing for phones in the past. Depending on the model you could get a larger pack that had a bulge on the back of the device to have extra battery time. There was a similar thing with a number of laptops.
I do agree its kind of a questionable thing on something like a car. I imagine packaging concerns would really get in the way of adding a bit extra.
Disagree. I want a replaceable battery in my phone. They can get to extensible memory next. And it's not because you don't care about something that you should remove this freedom from me. And don't tell me that the market will self regulate in the best interests of the consumer or other nonsense like that.
I want replaceable CPU and memory in my phone as well. I demand the government force device manufacturers to use socketed CPUs using standardized sockets and SO-DIMM memory. And it's not because you don't care about something that you should remove this freedom from me.
Fairphones absolutely do not have a socketed CPU and user replaceable memory. Each generation has one mainboard with soldered components, which I don't see listed as a part to replace on their site.
It's not for me at least. Nobody can prove their inner intent to you but most people will know from themselves that their actions are sometimes misunderstood (especially when something worked/came out badly) but that they genuinely mean well
Given a distance, an allowable time to reach that distance, a payload to send, and an expected exhaust velocity, how would you calculate the time required to convert energy into antimatter fuel and how much antimatter needed to arrive at the destination (starting from the Moon)?
There are a few side calculations, such as the size of the radiator, estimated footprint of the fusion reactor itself, and how much metamaterial is needed. This is to help figure out timelines for a sci-fi novel, so ballpark answers are completely fine.
The calculations yield what appear to be values around the correct order of magnitude. Would be delighted to have insights, comments, and corrections.
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