Based on their work on the X-59, I wonder if they just want to collect sensor data on its sonic boom characteristics, and feed that into a model for sonic booms.
They don’t need to be able to build something in order to be able to learn something from that thing in operation.
What’s interesting about supersonic flight is that there’s been some developments on making supersonic flight more fuel efficient.
The F-22’s big strategic advantage is that it can supercruise at Mach 1.5, without afterburners, and although the details are not publicly known, the publicly known facts suggest that it’s about 3x as fuel efficient as the other fighters in the US arsenal.
If they can get supersonic flight to be more fuel efficient, and avoid sonic booms (an active area of research for NASA’s X-59 project), and we develop manufacturing capacity for huge amounts of synthetic sustainable aviation fuel from CO2 and water and green energy, then maybe we’ll be at a place where supersonic commercial flights can be both economically feasible AND environmentally responsible. Probably not in my lifetime, but still something I expect to happen in the next century or so.
Sometimes the cost of processing itself is non-trivial.
Fermented sauces, for example, tend to be much more expensive than just the raw ingredients, because the process itself is complex (and requires significant labor and/or equipment to keep safe for human consumption).
In order to make some of these plant based meat substitutes, the complex processes need to basically move enough volume to be able to take advantage of economies of scale. So we’ll probably get there eventually, at least once these plant protein products become mainstream enough.
not because of its price tag
I get what you mean, and agree, but want to point out that at least in a sense, it is because of the price tag: the cost to the environment and to others, in the form of water use, land use, carbon and methane emissions, etc. Internalizing those external costs would make beef cost more money at the point of sale.
To be clear, the price of diesel on the sign is “out.” Which I guess could be considered ∞ per gallon. Or per liter. Whether talking euros or dollars.
The US national average for diesel just hit $6/gallon (€1.40/liter).
There are many different formulas for deriving digits of pi, and the history of mathematics has a bunch of people trying to brute force inefficient formulas for pi out to a few digits, as they develop more efficient methods.
Archimedes drew a circle and put some polygons around the inner and outer limits to determine that it was somewhere between 22/7 and 223/71, accurate to within 2 digits. That general polygon method was used by Ptolemy to calculate out to 3 digits, and used by Chinese mathematician Zu Chongzhi to estimate pi at 355/113, accurate to 7 digits.
The polygon method was very tedious, requiring many, many calculations in order to advance just a few digits.
The Liebniz formula was a breakthrough (discovered by Indian mathematician Madhava of Sangamagrama), because discovering that pi/4 was equal to the infinite series 1 - 1/3 + 1/5 - 1/7 . . . meant that someone could calculate some number of digits accurately, and then continue the calculation in a way that reports what is known so far, and can continue down the line towards a more precise result. Still, by itself, it was a very slowly converging algorithm, requiring 5 billion terms just to get to 10 digits of accuracy. Mathematicians got to using other tricks (that, if I’m being honest, I don’t understand) to make it faster.
Then Ramanujan discovered series that were rapidly converging (including the one in this meme) where although calculating each term might require a lot of calculations, it would spit out 8 digits for each term you fed it. It became the preferred method for calculating digits of pi, and when computers were developed, they were able to make use of that computational efficiency. It still remains the basis for how a computer will calculate a few million digits of pi.
There are 3 elements that are required for high yield on crops: nitrogen, potassium, and phosphorous.
Nitrogen (in molecules usable by plants) was traditionally the bottleneck, the limiting factor, until the development of the Haber Bosch process, which allows plentiful atmospheric nitrogen to be combined with hydrogen and energy to make ammonia.
Creating green hydrogen (by cracking H2O/water into hydrogen and oxygen molecules using electrolysis) allows for the process to generate ammonia without contributing carbon to the atmosphere. That means it doesn’t actually need plants or any biological feedstock for the process. Nitrogen can be fixed into the soil without plants (or fossil fuels), so that part isn’t going to be the limiting factor.
I’d be much more concerned about the sources of mined potassium/potash and phosphorus/phosphates.
“Eating salami increases your cancer risk by 25%!” When it went from 0.3% to 0.375% over your lifetime or something.
Eating 50g of cured meats every day raises the risk from about 5% to about 6% chance of getting certain gastrointestinal/colorectal cancers, compared to someone who never eats cured meats. A couple different ways to state this:
But it’s not negligible. And the causal connection is pretty strongly proven.
The costs associated with nuclear are so overwhelmingly everything other than fuel that selling fuel isn’t going to be a big business, nowhere near the global markets for fossil fuels in actual dollars, even if the market one day approaches the same amount of useful energy in joules or kWh.
Some military tanks are going hybrid, too, despite not really being able to move very far on the electric battery. It’s still worth it for idling and running the on-board systems without actually running the fossil-fuel-burning engine, though, and is potentially a stepping stone towards greater improvements in the electric drivetrain for quieter and more energy efficient movement.
And if not why are we even investing in this because those short hop flights frankly need to be eliminated for trains anyway.
Well, islands and other geographical features still exist in some places to provide geographical and geological barriers to train connections between certain city pairs.
If humans can hang glide I don’t see why we couldn’t use those aerodynamic principles to try to glide a car hooked up to glider wings. It’s a real engineering challenge, but I feel like it would be possible to get some distance in a scenario where a car uses its wheels to go fast, drives off a cliff, deploys some kind of glider wings (or drive with the glider wings timed out to where the car gets to the cliff edge right at the point where the wings plus updraft provide enough lift) to get the vehicle to glide a substantial distance.
Seems horribly dangerous but not impossible.
It’s hapening already if you look at birth rates.
That’s why I’m skeptical of degrowth actually doing something to effectively reduce consumption. Because some individuals consume 3, maybe 4 orders of magnitude more resources (and the accompanying pollution or ecological destruction, however you want to measure it), I’ve always believed that reducing population runs a significant risk that the remaining smaller population will use far more resources than the previous larger population.
You see it in rich countries. We have low birth rates and high consumption rates, and our consumption grows exponentially even as our population does not. We run a serious risk of being very destructive childless retirees, and consumption and pollution and emissions and ecological impact need to still be worked on, even if we do shrink the population.
They’re omitting the fact, that a lot of the biomass we’re eating comes from farming. Those plants that collect carbon dioxide from the atmosphere use a lot of synthetic fertilizers to grow, which itself uses A LOT of fossil energy to be produced.
The CO2 emissions per calorie of food varies almost 3 whole orders of magnitude between different food types:
https://ourworldindata.org/grapher/ghg-kcal-poore
At the same time, our CO2 exhalation is about the same per calorie of food, regardless of source. So it’s more fair to describe our baseline biological needs and bodily functions separately from our economic consumption of the products we prefer to consume (food or otherwise).
So I still think the focus on the raw calorie count of our consumption (and the accompanying CO2 exhalation) obscures, rather than explains, how our food consumption contributes to climate change.
With mirrors, the maximum power is whatever sunlight hits the area of the mirror. Which for these satellites is 324 square meters. With solar irradiance at 1361 W/m^2 , that’s only 440 kW of energy, probably spread over a very large area, and not all of the spectrum useful for whatever you might want to use it for.
It’s an unbelievably stupid idea, but that also swings the other way in that it would be highly ineffective for any nefarious purpose, and will probably run out of money before it scales up to where each annoying satellite really does damage to visibility in the nigh sky or anything like that.
Exactly. Cutting out all net resource consumption is really difficult, but almost all of the difficulty tends to come in the second half. The first half is worth doing.
Somewhat counterintuitively, switching from a 15 mpg vehicle to a 20 mpg vehicle (and driving the same number of miles) represents a greater reduction in fuel consumption compared to switching from 20 mpg to 30 mpg. Side note, this is also why we probably should’ve always been talking about fuel consumption per unit distance rather than distance per unit fuel, but it’s hard to change the conventions around this.
So there are a ton of examples of products that use far more or less energy than alternatives, or simple changes in time of day that can make a huge difference in fossil fuel demand.
You should read the article. The concern is metal oxides, specifically aluminum and titanium.
I’m referring to the overall style that uses vague introductions that effectively pad out what should be a short summary with an unnecessarily wordy general-to-specific funnel:
found that its composition was relatively rare and could change what we know about the dinosaurs’ last days.
could offer more insights into the extinction of the dinosaurs.
Through their analysis, the team was able to narrow down the meteorite’s composition.
The article style also self interrupts with citations to sources, but doesn’t actually synthesize multiple sources in any given sentence:
Chondrites are an abundant type of stony meteorite and get their name from chondrules, the nearly spherical particles in the meteorite, according to the Buseck Center for Meteorite Studies. Far less abundant, however, are carbonaceous chondrites. Carbonaceous chondrites are separated into further categories based on their composition, according to Britannica.
The other “according to” phrases in the article are similarly awkwardly constructed, like an undergrad student or an LLM being instructed to be careful to include their sources. And when one of the sources is Britannica, that style looks especially unnecessary.
The overall big picture organizational scheme doesn’t flow logically, either. If I were the editor I would’ve told the author to go in order: punchy intro, background about the meteor, what was believed before, what the study changed in our understanding, what it means to the science.
As it stands now, the intro drags because it’s intentionally vague instead of actually summarizing. The content I would consider to be background happens at the end, describing the meteorite that likely killed the dinosaurs and the approximate size and the location/size of the crater, all things we already knew before this “summarized” study. Then, when it describes the study itself, it’s a mess. It doesn’t define “Oranans-class” or “Ornans-class” and doesn’t explain whether those are the same thing but spelled differently (either because of a typo or a difference in convention). The description of what a carbonaceous chondrite is, how it relates to chondrites, and how those relate to CO or Oranans/Ornans class carbonaceous chondrites, is not clearly stated or presented in a way that is easy to understand.
The article also doesn’t explain how it changes the science. It vaguely alludes to an alternative sulfur-based explanation that might be weakened by these findings, but doesn’t actually explain how.
The article is poorly written. I can’t tell if it’s AI or a bad writer, but the end result is not good.
Why does this article read like an AI generated article designed to increase the length of a summary of text it didn’t understand? Either way, this is bad writing that basically fails to explain the important parts, and then spends way too much time repeating itself.
Yeah, the Concorde was interesting in that its design was optimized for cruising, so that taxiing, takeoff, and reaching cruise altitude/speed took a gargantuan amount of fuel compared to other aircraft and even to its own cruising efficiency.
I can see why someone could look at that and assume that they could do better with modern design principles, including the knowledge that planes need way more passenger seats to improve the per passenger efficiency.
Then again, the company that took the most concrete steps towards developing a supersonic engine pivoted to creating gas turbines for AI data centers (but was just dropped by its major customer on that, so who knows what they do next).