tomsto

In defence of the black cab, if there is any sort of surge pricing in Uber, the black cab is typically cheaper if you can find one. Apps like Gett solve the ‘not knowing the price upfront’ problem, prebooking and hailing.

I think black cabs are a lot easier if you have lots of luggage, or especially if you have a pram/stroller. Rearward facing seats are safer for kids and cabs seat six comfortably. And the final big advantage: in London, black cabs get to use the bus lanes which can save inordinate amounts of time at rush hour.

I still use Uber all the time but I just thought I would add some balance!

Emphatically so, yes

AS01-adjuvanted shingles (herpes zoster) vaccination is associated with a lower risk of dementia, but the underlying mechanisms are unclear. In propensity-score matched cohort studies with 436,788 individuals, both the AS01-adjuvanted shingles and respiratory syncytial virus (RSV) vaccines, individually or combined, were associated with reduced 18-month risk of dementia. No difference was observed between the two AS01-adjuvanted vaccines, suggesting that the AS01 adjuvant itself plays a direct role in lowering dementia risk.

This is a really interesting idea and the unit economics are great. However when I researched this (or rather Gemini 2.5 Pro researched this) the problem appears that Haber-Bosch produces ammonia, whereas Birkeland-Eyde produces nitrate, which then needs to be converted in nitric acid. Getting from nitric acid to ammonium nitrate (which dominates the fertiliser market) needs ammonia from somewhere, which destroys the economics.

However calcium nitrate, potassium nitrate production via B-E looks really interesting.

Yes. In the UK at least. https://thewaterprofessor.com/blogs/articles/lead-pipes

Hydrocarbons are great for energy density, but gas turbines are brilliant for power density. That's why we need them (and syn fuels)

I may be being dense, and I realise this is a meta analysis, but the abstract doesn’t explain how much fibre one needs to eat to reduce all-cause mortality by the amount they claim?

Thanks. I would still be curious to know how the strength of an artificial magnetic field at a range of say 10 km compares to the order of magnitude of local variations they are talking about in the earth’s magnetic field.

Very interesting, and amazing technology. But… How is it unjammable? Couldn’t you just generate a big magnetic field?

Agree. My mother had a very serious form of cancer (she’s luckily responded well to treatment) but she was overwhelmed by con men promising hope. Adding legitimate research makes this mix less toxic, not more

They lost me at ‘amperage’

This.

I wonder if a big part of the problem is that depression and other mental illnesses are slightly unusual in that they are categorised based on symptoms rather than underlying biology, which are poorly understood. As a diagnosis it’s about as useful as ‘chest pains’

Maybe (I am not a clinical psychiatrist) there are 1, 10, or 100 very different underlying causes which would indicate different treatment if only they were better understood. But nonetheless the existing classification / ontology is established and will be hard to displace.

Disagree. Firstly there aren’t many situations in fluid dynamics where there is a steady constraint on mass flow. Velocity just increases. (The exception is choked flow from a nozzle IIRC)

Now think about what happens when 6000 people/hr leave the station but arrive on 12 trains over the course of the hour, i.e. in surges. Each peak demand will comfortably exceed the flow rate of escalator.

You get a queue; the equivalent in fluid dynamics would be an increase in density upstream of a choked nozzle at Mach 1 but how to turn that into a relevant metric for eg queue length?

Thats also the reason - I suspect - that in many Tube stations two escalators go up and only one goes down.

In the UK, I really like Which. You have to subscribe but the incentives are right, rather than a load of affiliate-driven stuff.

https://which.co.uk/

However what does detract from this point somewhat is that this neglects relative purchasing power. At purchasing power parity, Russia's military spending is actually higher than perhaps people realise.

It’s a fun fact but I’d challenge whether it was the case in Anglo-Saxon education. Do you have a source? The Anglo-Saxons definitely had an early ampersand. I don’t know of any source where they give it a name. It’s still plausible they recited the alphabet in this way.

But the practice of reciting ‘and, per se, and’ is only attested in England and the US in the 19th century as far as I’m aware, and that’s where the corruption came from.

This sounds interesting. You sound like you work in nuclear physics. Please can you explain, or link to an explanation of, divertor (sic?) and strike point materials?

For a symmetric aerofoil, 0 angle of attack is 0 lift. For an asymmetric - there is (some) lift, which comes entirely from the suction side.

https://www.wolframalpha.com/input/?i=NACA+6409+airfoil&assu...

For anyone who’s ever tried building a robotic bird, there is a lot more intricacy to how birds fly than just “pushing air”. A better article might have been, ‘we still don’t understand how certain species of bird fly so efficiently’

I’m not sure I fully agree. Do you not get this trailing edge vortex with an asymmetrical aerofoil at 0 angle of attack? (Just less strongly because less pressure difference between suction and pressure sides)

This is not how it works, no falling or positive angle of attack is required for an asymmetrical aerofoil. Imagine swinging a bucket of water over your head - the force your arm feels is similar to what the top surface of the wing feels.

This is true of a symmetrical aerofoil (e.g. most helicopters) but not for an asymmetrical aerofoil (most fixed wing aircraft). It is true that a slightly positive angle of attack generates more lift than none (because the pressure/lower side starts making a contribution)

Kind of. Actually the real ‘cause’ in my understanding is 1) the curved geometry of the suction (upper) side of the aerofoil and 2) the fact that the flow remains attached to it. Everything else - you can actually approximate the curved surface to a circle and apply equations of circular motion to a parcel of air to satisfy yourself with why the flow is accelerating. And Newton’s 3rd law explains how lift is generated on the wing. In my view there’s no need to use Navier-Stokes to explain how an aerofoil works, if you simplify the geometry to make a special case.

Most of the lift comes from the suction side.

Actually, if you really want to test an explanation, try to apply the same reasoning to explain how a sailing boat can sail upwind (or at least up to about 45 degrees off).

This is how it works in the U.K.

The MHRA decides which drugs are safe and effective and for which diagnoses.

Then NICE decides which of those drugs are available on the public health system (NHS) by evaluating £/quality-adjusted life year. I don’t see why Medicare should be any different.

If it’s not available on the public health system you can still pay for it yourself or via private insurance provided it’s licensed by the MHRA.

You're right, I've done a bit more research into this. The company in question (Ubitricity) are uprating lampposts to 25A single phase at 240V, so 6 kW per post. Even though sodium (and earlier flourescent) lighting never used anything like that much current, I can't find a source to confirm whether or not the lampposts were originally rated at 25A or lower.

On your calculations of how many cars can charge at once, I would keep it simpler and say that a row of parallel parking typical in UK cities, there is one street lamp for every 5 cars. 50 kWh charge overnight, approx 300 km range for every fifth car.

Supposing 100% EV adoption - well, already not everyone drives themselves to work/kids to school in UK cities (where most on-street parking takes place) - but if they do, and have charging at work plus some nearby rapid charging, that should do the trick, assuming a typical commute by road isn't more than 50 km each way. It's certainly in the ballpark.

I don’t know whether on-street parking is as common in the US as it is in Europe, but the solution being quite widely adopted in the UK is to utilise the “leftover” current from when street lighting was converted from sodium to LED to retrofit EV chargers to the lamppost. It works really well up to about 7 kW I think. This is then supplemented with inner city rapid chargers at 22-50 kW.

Not as cheap as charging from the wall but (in London at least) other incentives like free on street parking and no congestion charge more than make up for it.

Interesting tangent, but I believe this is also a slavic surname and is anglicised as Nimitz. And before you know it you have an aircraft carrier called USS Mute.