You can't conduct commerce on a bike. Anti-car policies are also closely coupled with inflated housing prices, since they effectively reduce the available housing supply by requiring employees to commute from within public transit distance of their job.
I'd highly recommend reading Confessions of a Recovering Engineer before debating my communication of it. There's a lot more depth to the arguments than the one-sentence summary a novice (me) can give :)
Namely, Strong Towns isn't anti-car! In fact, they explicitly arguing _against_ removing cars from city centers in most cases, for reasons related to those that you mention. If I remember correctly, many towns tried to do this in the 70's or something, and most of them failed; cars are still required in most cases.
That being said, _requiring_ cars and _allowing_ them are very different things. Being anti-bulldozing city blocks to put in 6-lane highways isn't anti-car, it's pro people!
Again, highly recommend engaging with the source material rather than taking my word for it. I've been consuming and parroting (sometimes badly) their content for months - they have been thinking about these questions for literally decades!
> That being said, _requiring_ cars and _allowing_ them are very different things. Being anti-bulldozing city blocks to put in 6-lane highways isn't anti-car, it's pro people!
That's a semantic argument that doesn't address the real problems that skimping on commuter infrastructure can cause. San Francisco and Seattle have both achieved some of the highest housing prices in the nation thanks to chronic underinvestment in highway infrastructure.
No thank you: I don't care for content that's searching for evidence to support a preconcieved position. There is too much dogma and not enough pragmatism in this space.
I already get enough of their content on HN to recognize dogma when I see it. Quite frankly, it's a circlejerk where everyone else is wrong unless they follow the ST-scene's ideologically-founded prescriptions, and if you post evidence to the contrary you'll often get shouted down.
Anti car policies need to be paired with pro sustainability and livable city policies. You can’t do just one or the other, both need to happen close to simultaneously. We need to strongly discourage car use and encourage sustainable transportation while strongly safeguarding it for those who truly need it, rather than those who just want it.
You can conduct many types of commerce, maybe most types of commerce by bike. You can’t do things like say transporting more than two sofas, or large scale building materials, but if the goal is to reduce car usage as much as possible you’d be surprised how much you can do with a good cargo bike.
With an electric bike most people could easily do a 15km commute within 40 minutes especially where provided safe cycling infrastructure. And with no need to store and transport all of these cars despite them only being used for two hours a day you can use all of that space to build more housing.
People who want to live outside of population centres and thus feel the need to own a car but need to commute into population centres can instead commute to large scale park and ride for public transit. Maybe they can also charge their cars there too, maybe even for free with ownership of a transit pass.
And the best part about strongly discouraging car ownership and usage while strongly encouraging sustainable transport is that it frees up space on the road for busses, emergency services, cyclists, pedestrians, and those who need vehicles for transporting goods or for accessibility reasons.
Finally, consider that housing prices in areas with sustainable transport options might be higher because people want to live where they can safely walk and cycle surrounded by trees and plants. Make that possible for anybody who wants it and we’ll have a cheaper house prices, healthier populations, less climate change, safer societies, and just generally a nicer time.
They are being downvoted because 1) California being shitty should have no effect on whether Texas is shitty or not and because 2) even IF California is shittier than Texas (an opinion rather than fact), that doesn't make it any better than the other 48 states that aren't regularly in the news for shitty electrical infrastructure that fails regularly.
Since the Aug. 2020 blackout the state has added 2 GW of battery storage for solar and wind, as well as delayed closure of a natural gas plant. There's another 2 GW of battery storage planned for this year. If California had the extra 2 GW of storage in 2020, the blackout would have been averted.
4GW gives California 100 wh per capita. Doesn't seem like much but if they keep adding that much a year. What if they have ten times as much. That would be something.
Wikipedia seems to contradict your claim. Am I missing something here?
>The Texas Interconnection is maintained as a separate grid for political, rather than technical reasons,[1] but can also draw some power from other grids using DC ties.
That's DC power not AC needed to power homes, and even then only 2 minor junction points.
The power plants and substations are still needed to act as a giant DC-to-AC inverter. So if the plants are offline then the grid is effectively down, as it was in the Feb 2021 blizzard.
Does maintaining a system for political reasons remove the technical drawbacks?
We’re mostly engineers on this board, have you never had to build a substandard system to meet the political needs of a higher up and then watched it blow up in their face as reality doesn’t care about political needs?
Those interconnections are basically small scale arbitrage connections setup to take advantage of the difference in spot prices. They aren't close to the scale needed to make a dent in a power shortage.
This is true in theory, but in practice it makes little difference.
When California has increased demand, so do all the states it's connected to. Hence the rolling blackouts a couple years ago and more are expected for this summer.
Most blackouts in California are not driven by electricity shortages but rather by hot and strong wind events that lead electric utilities to shut off certain transmission lines in rural areas to avoid sparking wildfires. This distinction probably doesn't matter much to those who have their power cut but it is important to actually fixing the root cause.
There was a particularly nasty heat wave in the western US in 2020 that did lead to load shedding due to a shortage of electricity. That was the first time California had load shedding since 2011 IIRC, and it did not repeat in 2021.
> Hence the rolling blackouts the last few years and more are expected for this summer.
California has had two days with rolling blackouts since 2001, August 14-15 of 2020.
It has had public safety power shutoffs in some areas since 2019 to prevent fire risk during dry, high-wind conditions, but those are a different issue than rolling blackouts and unrelated to energy generating capacity.
california is also an ISO and still does load shedding. oh and Tres Amigas stil isn't done, like over 10 years later, mostly bc federal regulation held it up.
I don't know much about the power consumption and efficiency of vertical farm lighting and heating; can you share any references about them?
One thing that does occur to me is that artificial lighting wouldn't be limited by the passage of the sun, so crop growth could potentially continue 24 hours a day.
The original comment suggested putting the farm below apartment buildings ("below grade" means underground).
It's extremely costly to provide sufficient light to grown plants, as photosynthesis isn't terribly efficient. Natural sunlight is significantly stronger than what people tend to expect.
Not only that, but you would need to move massive amounts of air to keep the plants happy, plus the humidity from being underground and all the water they need. Beyond that, you need to go quite a bit underground to feed a sufficient number of people, which isn't always feasible depending on the type of soil and water table, etc
Final note, most plants do better not getting 24 hours of light. They can only grow just so fast and need to photosynthesize just so much.
That's a lot of work (meaning higher prices for people who need to eat) for very little gain.
Below ground has trade offs, it's easier to use gravity flow designs but you lose all natural sunlight. Most of the time rain catchment systems on roof top vertical farms or free standing green houses are easier to design. There are already a bunch of vertical farms in commercial operation. The Netherlands in particular is leading the science here but in the US a number of farms exist. Vertical farming uses around 90% less water and solar/wind/hydro power for LED's is extremely doable. You are wholly incorrect about the amount of work required and amount of resources. It does take smart design to work however.
Where I live, people already struggle with eliminating excess moisture from their basements. Putting growing plants there requires a significant upgrade to air ventilation and dehumidification, as it is the perfect breeding ground for mold.
As for LED grow lights, you typically use about 30-40 watts / square foot. That's a not insignificant added cost compared to growing above ground.
The added challenges to growing underground simply make it irrational.
Yeah, I'd agree with the underground part. Above ground vertical greenhouse's are absolutely viable but I'm not sure underground would make any sense. LED grow lights I'm using on Tower or aeroponics (Plants grown in towers with a gravy mist based irrigation and feeding) are much less than 30-40 watts / square foot, around 10-20 depending on the time of year but that's above ground in a greenhouse situation with Sun light help.
jaegerpicker is really uncooperative, even with numbers that should be easy to debunk he is struggling and trying to change the topic to stop you from thinking critically.
"It turns out it would take about 4.5 acres of solar cells for every one acre of plant growth space" well that implies that the 100x efficiency factor has actually been met for lettuce but jaegerpicker didn't seem too keen on telling you. The obvious problem though is that solar panels are only 20% efficient hence roughly 5 acres of solar per 1 acre of vertical farming grow space.
Wrong question to ask, PPFD's is the correct measure. It's not a direct energy comparison. Photosynthesis is a chemical reaction of Chlorophyll reacting to certain but not all light wavelength's (Red and Blue being the major ones) plus the distance from the light source. The amount of watts the the sun generates is NOT what grows plants. LED's can produce the same light wavelength's but much closer and with no obstructions. The question isn't about LED's power generation, it's how much power does it take for an LED to cover an area. Obviously a LED can't compare to pure Solar efficiency on a watt by watt basis but it doesn't need to.
That's actually a good question, I have no experience with underground systems. Most are free standing greenhouses (about 10x more efficient (water and yield) that traditional farming per square foot). Electric is only a major cost for the pumping of water, LED light coverage is very cheap and we don't need to compete with the power of the sun.
Vertical farming is far less resource intensive, using LEDS powered by solar or wind and gravity flow designs. I posted this in another comment but here is very brief video talking about it. https://www.youtube.com/watch?v=5clOYWsNhhk
I have other resources should you wish and I ton of personal experience. I have 3 Hydroponic systems (1 off the shelf, 2 custom designed by me) and 2 Aquaponics systems. The custom ones took 3 months to recoup the costs of materials vs the cost of produce, though the liquid fertilizer is a cost and input that I don't love. I've switched most of my effort to Aquaponics (Aquaculture - raising fish, which provides a natural fertilizer), I have 1 microsetup growing herbs and microgreens that has been running for 1 year. Only inputs are water and fish food, I clean it 1 once every 3 months since the plants act as a natural filter to clean the water.
This is completely misinformed, there are tons of vertical Hydroponic and aquaponic farms already in production that are thriving at much lower resource costs. Solar panels powering LED's and gravity flow water make a massive difference. For example:
US farmland occupies 895 million acres (3.6M km^2) [1]. Average solar irradiance on most US farmland is about 200 W/m^2 [2]. By being generous and assuming vertical farming is 100x more efficient than natural photosynthesis, the energy requirements come out to 7.2 terawatts of generating capacity. In contrast, the US currently has 1.1 terawatts of generating capacity. [3] Vertical farming isn't just uneconomical: it's completely absurd.
Thanks for doing the numbers, it’s interesting that in 50 years people are predicting annual TW installs of global solar capacity. So maybe a technology for the future if storage and distribution gets solved.
Except none of that matters, Solar Irradiance has very little to do with actual photosynthesis. You are measuring Watt's as a pure energy source, that's useless in this case. Photosynthetic photon flux density (PPFD's) are what's important, that's the amount of light wavelengths that the plant needs to absorb to power photosynthesis. Here is a definition from another source, I'll post the link at the bottom:
PPFD is a measure of photosynthetic active radiation, PAR for short. PAR is not a measure of anything itself but is more of a description. PAR light is all the visible wavelengths of light which cause photosynthesis, found within the 400-700 nanometer range. PPFD is a ‘spot’ measurement that tells you how many photons from the PAR range hit a specific area of your canopy over time. It is expressed as micro moles per square meter per second (μmol/m2/s). For this reason, PPFD is the most accurate measure of light power. First, unlike other measures, it considers the entire spectrum of light that plants see. PPFD also takes into account the amount of light that will actually reach the plant instead of focusing only on the point of origin. A light source can be very bright and powerful, but if it is too away from the plant, or obstructed in some way, the plant won’t be getting all the light it needs for photosynthesis. PPFD controls for this kind of inaccuracy.
With LED's you can place the plants much closer to the light source and control the color spectrum along with the obstructions 24/7. It allows you to grow indoors at an extremely efficient rate. Your formula has almost nothing to do with indoor farming.
Quick summary: PPFD measures the amount of light wavelengths that the plant captures that kicks off the chemical reaction of Chlorophyll. Red and Blue lights are the vast majority of wavelengths that interact with Chlorophyll. That's a major reason why the solar irradiance measure of pure Wattage is irrelevant.
>Except none of that matters, Solar Irradiance has very little to do with actual photosynthesis. You are measuring Watt's as a pure energy source, that's useless in this case
>That's a major reason why the solar irradiance measure of pure Wattage is irrelevant
You are quite literally missing the tree for the forest. Parent assumes that photosynthesis is 1% efficient with sunlight so he added the 100 factor to estimate how much energy plants would need if photosynthesis was 100% efficient and you could skip photosynthesis just feed plants energy straight from the power grid and on top of that he is assuming you can turn 100% of solar radiance into electricity.
If we assume 20% efficient solar panels your growing lights need to be 500 times more effective or power efficient than sunlight.
You should have based your argument on arguing that the vast majority of acres that the parent used are e.g. suitable for solar panels but not for farming plants and hence the number of acres is unfairly bloated. But all I see is excuses in trying to tell people how your growing lights are going to be 500 times more efficient when we know that isn't going to happen.
Are you able to achieve a 10000x efficiency improvement vs natural photosynthesis by using those technologies? If not, the idea is still completely unfeasible.
IT'S COMPLETELY IRRELEVENT, the efficiency at generating electricity is not what powers photosynthesis. It's a chemical reaction to light wavelengths (ie the absorbing of Red and Blue light) that powers it. More watt's doesn't equal more growth, it equals more heat which allows longer growing seasons. LED's and Sunlight have EXACTLY the same level of photosynthesis, none of the math you did matters at all. For LED's you need to calculate coverage of the area not pure power. If you produce Red or Blue wavelength's that's all that matters, the Sun does that and a hell of a lot more but we don't need the power of the sun or even a tiny faction of it's power for photosynthesis, we need to heat and cool and creat weather which effect plant growth but Watt's is irrelevant.
>For LED's you need to calculate coverage of the area not pure power
He already abstracted over that by using efficiency.
>none of the math you did matters at all.
One would have expected an increase in coverage to increase efficiency by 10 vs sunlight which would have require explaining another factor 10 which could have been explained by e.g. saying that converting useless wavelengths into useful wavelengths increased efficiency by 10.
You're arguing that the things you have said do not increase efficiency. That is even more damning than a ridiculous efficiency gain.
WHAT MATH?!?!? Electricity doesn't have any thing to do with it except in very tiny amounts. You need light coverage not heat wattage! There is no math to do! Photosynthesis doesn't work like that. It's a chemical reaction to light wavelengths. I posted numerous papers detailing this. The unit of measure is PPFD Photosynthesis Photon Flux Density, that's the coverage of the number of light wavelengths the plant can absorb. LED's provide plenty of PPFD's, exactly the same as the Sun. So all you need is the correct amount to cover your growing space with a minimum amount.
I think the events of this week should put an end to this line of argument, which claims that protecting gun rights will have a positive halo effect on all other human rights.
Why are we assuming this wouldn't have happened either way? It seems to me that the repeal of Roe v. Wade is the only precedent necessary. Given that abortion is illegal in Arkansas, the tracking of women seeking abortions is far less legally grey than the tracking of gun owners.
The premise of lawfare is that you enact laws and legal precedents primarily with intent of undermining your opponent, rather than to benefit anyone in particular. The American right just realized that they can do this too.
Please elaborate. From what I've seen, the right has done this a long time, be it dumbing down education, defunding social services, advocating for war to benefit their lobbyist friends, or restricting access to nature's bounty.
Punishment is in the eye of the beholder: the left and right don't care about the same issues, and that's the principle that makes it possible to hurt your opponent through lawfare without hurting yourself. Eliminating federal protections for abortions annoys the left without hurting the right. Conversely, banning religious services during covid while promoting protest gatherings bothered the right, but not the left. You wouldn't be able to list the lawfare issues that bothered the right, because that's the point. Lawfare is only lawfare to your opponent, not to yourself.
If you choose to ignore the example I just gave, that's on you, but luckily I can provide additional examples from the last few years:
- bans on legal ownership of certain types of firearms while simultaneously weakening firearms penalties for the primary types of gun violence: gang and drug crimes
- using lawsuits and legal harassment to shut down right leaning personalities, businesses, and institutions
- selective prosecution by activist DAs, depending on political alignment
Shall I list more? And, again, these are supposed to be things that you feel are justified, but the right does not, because that's the purpose of lawfare.
> Eliminating federal protections for abortions annoys the left without hurting the right
I have to assume you mean emotionally, not physically. Conservatives have women in their lives who will suffer and die from legal interference in the process of pregnancy and childbirth also.
Oh no! Now that the right has "just realized this", they might try to overturn the American Care Act primarily with intent of undermining their opponent, rather than to benefit anyone in particular.
You know, somehow I just have a hard time getting behind the most numerically murderous ideology in the history of the planet. Communist periodicals have just as much business being on HN as their nazi counterparts: none.
Don't be so dismissive: it's a legitimate concern. These are the same western governments that are already trying to clamp down on internet content they don't like: e.g. pornography, encryption, etc.
Uses coordinate-based neural networks to model the scene volumetrically. However, in the case of this paper does not use an MLP to represent the scene. Instead, proposes to directly learn a voxel grid representation.
Yes, and then polygonal models (and other things) are built from those.
For anyone who wants a more technical dive into the photogrammetry pipeline, here's a video I made for a company called Mapware for NVIDIA GTC 21: https://youtu.be/ktDVWzshR4w?t=331
Some techniques for downsampling point clouds use voxelgrid representations but in general you're mapping pixel data from varied images to each other in space and producing points from that to try and capture surface geometry.
But it does? Agisoft will first estimate depth maps and then project them into a voxel volume for extracting the high-resolution mesh. Debug logging even lists the voxel grid dimensions.
regular photogrammetry usually means searching for common features in a bunch of photos.
if you find the same feature in 3 photos you can triangulate its location in 3d space.
the output of this process is a point cloud which you can then process into a triangle mesh.
(google structure from motion).
this OTH is differentiable voxel rendering. so basically optimizing the colors of a bunch of cubes to make it look the pictures.
using backpropagation just like you would do it for neural networks.
