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.
Just think about it in terms of the number of people and number of days per year where they need to raise the indoor temperature by a certain amount, compared to the number of people and days needing to lower the temperature.
If you’re looking at a place where it’s 95°F during the day and 85°F at night, and you like to set the temperature to 75°F, you’re only cooling it 10-20°F by time of day.
But if you’re looking at a place where it’s 35°F during the day and 15°F at night, and you want to heat things up to 65°F, you’ve gotta change the temperature by 30-50°F throughout the day.
Even when you’re comparing absurdly hot weather to absurdly cold weather, you’re still comparing something like 110°F to 0°F. You’re still looking at a 70°F swing versus a 35°F swing towards comfort.
Throw in the fact that combustion of fuels (fossil fuels like heating oil or natural gas, or other fuels like wood in a fireplace) is usually only about 1/3 or 1/4 as energy efficient than the equivalent temperature change by heat pump, and you can see how much more energy intensive the typical indoor heating setup is compared to the typical indoor cooling setup.
Some of it is obscured by the fact that fossil fuels are much cheaper per unit energy than electricity from the grid, so that heating bills aren’t as expensive in the same ratio, but in terms of actual energy used, it’s a big difference.
where @sparkyshocks@lemmy.zip spent what was probably a lot of time crafting a thoughtful and intuitive explanation for all the actual, tangible reasons why in all their nuance
Only 5 minutes to write the comment, but 20 years obsessing over this shit so that it’s ready to go when people ask.
There are a few different reasons why.
There is high speed rail called Brightline in Florida between Miami and Orlando, with the longest segment operating at 125 mph (200 km/h), and some of the more populous segments operating at 110 mph/180 km/h or 80 mph/130 km/h. It tries to manage those tradeoffs on all new track dedicated to it. But the company is struggling to make money.
There’s a whole saga in California in that the proposed high speed rail project is decades behind and still bogged down, and has examples of all of these problems. The route it takes to connect the two largest cities on the coast (Los Angeles and San Francisco) goes through the inland central valley, to service a bunch of other cities in between. Bizarrely, phase 1 of the project will only serve the relatively low density, low population cities in the Central Valley, without connecting either San Francisco or Los Angeles. Some segments are to share rail usage with lower speed trains, complicating scheduling and risking delays. The environmental debates have slowed things down, as well.
Watch what happens in Texas with its proposed high speed line (bogged down in political infighting), Florida (see above, already built and operational, but facing serious financial concerns about its ability to continue), and California (see above).
I think we’ll eventually see some projects push through, especially if jet fuel gets more expensive than electrical grid power. But for now, America is uniquely hostile to passenger rail, and increasing high speed offerings isn’t necessarily going to induce enough demand for these projects to become economically competitive with other forms of intercity transportation.
Even in the U.S., we use a lot more energy heating homes than cooling homes. Around 43% of our total in-home energy usage is on heating, and about 8% is on cooling.
Heat waves don’t cause nearly as big of a strain on our grid as winter storms, because AC doesn’t consume as much energy as even our efficient heat pumps in the winter.
That’s because a heat pump that can lower the temperature by 10°-15°C is really all you need in the hottest part of the summer, whereas in the winter raising the temperature 25°C isn’t uncommon.
I was flabbergasted the first time I realized just how far north Europe is, compared to North America.
Paris is at 48° 51’ N, significantly further north than Toronto (43° N), Montreal (45° N). London is at 51°N 30’, which is further north than Vancouver (49° N), and just slightly further north than Calgary (51°N).
Even southern European cities like Ibiza (39° N) are at comparable latitudes to northern American cities like Philadelphia (40°N) or even New York (41°N).
If Europe starts seeing climate comparable to similar latitudes in North America, that would represent a huge change from the recorded history.
That’s not true. There is plenty of profit to be made with selling stuff that helps reduce energy use, selling energy that uses less fossil fuel (or produces less CO2), undercutting competition with more efficient methods, etc.
The tech world talks a big game about disruption and making billions or even trillions from it. You don’t think there are people who want to make trillions disrupting fossil energy companies?
The University of York compared panels capable of 1.5 kW and found that vertically mounted bifacial panels generally outperformed tilt mounted monofacial panels, by between 14-27% on a monthly basis, at least when surrounded by gravel, in the climate/altitude of that particular location.
The reason given is that vertically mounted systems capture a lot more indirect reflected sunlight from the surroundings, across a wider range of conditions.
The biggest US market SUVs are huge, yes, but the SUV market as a whole is skewed heavily towards small SUV “crossovers,” basically as a replacement for sedans that are disappearing (probably due to a complex set of fuel efficiency regulations that perversely incentivize making bigger vehicles to get away with less fuel efficiency).
Our most popular models are the Toyota RAV4, Honda CR-V, Chevy Equinox, Tesla Model Y, and Chevy Trax. 4 out of the 5 are smaller and lighter than, say, a BMW X3, and the Model Y (which is also a somewhat popular model in Europe) is about the same size as the BMW. So if X3s and Model Ys are representative of the typical SUV in Europe, then the most popular American SUVs are smaller.
Even driving up next to our most popular sedan, the Toyota Camry, shows that these crossover SUVs aren’t actually longer or even taller at the highest point, just tend to be taller in the back to have a rear tailgate instead of a separate trunk compartment.
Yeah, one of the issues I’ve read about happening for concrete failures was that some construction crews are under enormous pressure to salvage concrete that had been mixed too early, or delayed in pouring, or whatever, and where the concrete pouring characteristics cause issues (or crews add unauthorized water or things to slow down curing and then alter the characteristics of the poured concrete without the engineers’ awareness).
It’s wildly counterintuitive to those of us who don’t work in the space.
Yeah, the most prominent examples:
Motorola spun off its cell phone division (despite being the company that invented the cell phone and the clamshell cell phone) and sold it to Google, who sold it to Lenovo. So Motorola phones, under the Motorola Mobility name, don’t have anything to do with the radio and electronic equipment company that is currently known as Motorola Solutions.
Volvo spun off its car division and sold it to Ford, who sold it to Geely, and kept the truck business. So Volvo trucks are made by a different company under different ownership from Volvo cars.
River sand is the right amount of jaggedness to where it can pour and settle into the right density in cement to have the right strength in the finished concrete. Ocean/beach sand works, too, but needs to be rinsed with fresh water, and is usually pretty valuable where it is (for beach resorts and what not).
They’re testing for how to use different types of sand (desert sand, manufactured sand, recycled sand) and testing the pouring characteristics and resulting concrete strength, so that they can make reasonable decisions on when it’s worth using substitutes.
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.