gns24

> Is it outrageous to think R0 could be 3.5 in NYC but 1.5 somewhere else?

No, not at all. It would be outrageous to think that it doesn't vary by a factor of two IMO.

I don't disagree that wearing masks seems a good idea, I'm just saying 70% reduction in particles doesn't map to a 70% reduction in transmissions. Whether the reduction is 10% or 90%, it's a useful contribution, particularly because in public situations where masks are likely to be recommended (transport, shops) if someone coughs as you're walking past there's no way for contact tracers to know about that link.

A great explanation of a lot of things, but this looks wrong to me: "To put a number on it: surgical masks on the sick person reduce cold & flu viruses in aerosols by 70%. Reducing transmissions by 70% would be as large an impact as a lockdown!"

Reducing the amount of virus in aerosols won't reduce the number of infections by the same amount. If a cough produces ten times the infective dose, then with the mask that's still three times.

Masks are still likely to help (and maybe having a smaller dose will make the disease milder if someone does catch the virus), but it's not possible to make a statement like this about the effect on R.

I'd been wondering why crowded public transport where people are breathing right next to one another hasn't caused massive spreading. This explanation makes a lot of sense - only when we cough or have to speak loudly do we exhale a significant amount of droplets.

It's worth noting that the German study in Gangelt was done because it was considered a hot-spot - this wasn't an attempt to estimate the infection rate across the country. It does however demonstrate that even in places where lots of people have had it, herd immunity still looks a long way off.

It will sync email and other things so that everything is already downloaded when you wake it up. See https://support.apple.com/en-gb/HT204032

Because if you're tested and it's positive you can tell everyone you came into contact that they need to isolate themselves too.

Data? From what I've seen it's a little bit steadier, but not that much.

> Heat lost to the water (maybe half of the energy input to compressed air) could be reclaimed as the pressure is released, with simple heat exchangers.

Heat lost to the water is lost. If you want to try to avoid that you need to save that heat energy after the compression stage.

It's not quite as bad as that, as electricity is a more efficient fuel source for many applications, including heating if you have a heat pump and the cold side isn't a lot colder than your target temperature. For transport it's much more efficient - 1kWh of electricity will get you a few times further than fossil fuels containing 1kWh or energy.

But your point is still valid, we certainly need to more than double grid capacity if we want to rely on electrification to avoid lifestyle changes.

The UK already taxes flights in a similar way. Whilst this does feel like progress, it would be much better to tax the fuel instead of the passengers. Virtually all other fuel is taxed, so it's strange that jet fuel is exempt. The problem with taxing passengers instead of fuel include:

- it doesn't encourage improving the efficiency of planes

- airlines can't fill their planes with really cheap seats, and empty seats seem like a ridiculous waste

- freight isn't taxed

If you tax fuel too much there's a risk that planes will fly in with enough fuel to fly out again, but that could be fixed by legislation or (better) by a standardised fuel tax across a large area.

Yes. This graph from "Sustainable Energy – without the hot air" is a good summary: http://www.withouthotair.com/c20/page_128.shtml

People with also tell you that take-off burns most of the fuel. I think I read that the sweet-spot in terms of miles per unit fuel is about four hours. (Freight seems to go in roughly four-hour hops, I believe partly for that reason).

The greenhouse effect does not require sunlight to work. What matters is how much of the energy radiated from the surface of the earth reaches space and how much is reflected back down. https://en.wikipedia.org/wiki/Greenhouse_effect

This makes no sense to me. The article states that there is one frequency of radiation that will pass through the atmosphere, so the device radiates at that wavelength. But why would it make any difference? The atmosphere might reflect most radiation back to earth, but not back to the point it came from. So it shouldn't matter what frequency the device is radiating - its radiation will be reflected elsewhere, and radiation from elsewhere will be reflected to it.

Yes, I remember listening to the BBC radio ballads with interviews with men who'd worked in mining and heavy industry. These were genuine communities; pretty everyone you socialised with would be people you worked with. And there was a lot of culture - people talked about learning about poetry and being introduced jazz music from older colleagues in a ship yard.

But the thing that really stood out to me was this: men who had worked in the mines were happy with their lot and had lots of positive things to say about their working lives, but when they were asked if they would want their children to work in mines their answer was a definite no.

What dosage did you take?

I don't see how believing it will all work out fine and not worrying is constructive, yet spreading fear (which might actually encourage people to act) is not.

To be honest my rational view is that the situation is hopeless. We haven't even managed to stop global emissions increasing annually yet. That's the second derivative of temperature (even ignoring any feedback loops); the rate at which we're causing temperatures to increase is itself still increasing.

I disagree about special interest groups being the main problem; political will of the population is just as much of an issue. Even in the UK where the majority of people do believe in climate change, successive governments have failed to increase duty on fuel because of a popular outcry every time they attempt to.

I have friends who alternate posts on social media between complaining about a lack of action on climate change and posting photos of their latest intercontinental travel. People are prepared to do quite a lot to look after the planet. What they seem less accepting of is not doing things.

The quote “Natural photosynthesis is not efficient because it has evolved merely to survive so it makes the bare minimum amount of energy needed – around 1-2 per cent of what it could potentially convert and store” makes no sense to me; plants are usually in massive competition for access to light, so in what sense is there no need for it to be more efficient?

Disasters are conceivable with ocean storage too. If a ship's anchor damaged the facility and caused the release of air, the rising air could well sink the ship.

The 'rolling membrane' that they are proposing is described here: https://heindl-energy.com/technical-concept/engineering-chal...

I had never heard of a sun-synchronous orbit before. Intuitively it shouldn't work; if you're orbiting the earth in a plane perpendicular to the sun now, then in three months' time you'd expect to have moved round and the sun to be in that plane.

However, it turns out that the orbital plane can be made to precess by means of interaction with the earth's equatorial bulge: https://en.wikipedia.org/wiki/Sun-synchronous_orbit#Orbital_...

It's worth remembering that this data is for January - April. Solar is going to have a much bigger contribution in the following four months. I don't know about wind patterns in the US, but in Europe the wind also tends to blow less strongly in summer.

Yup. The early MySQL developers spent a lot of time and effort making the install and setup process as fast and smooth as possible; a lot of people stuck with what they could get working first.

Exactly. If we're storing the positional value into 64-bits then there must be some patterns of 64 inserts which don't fit.

The decimal solution is really not bad. You could improve on it by not taking the midpoint between the two values you're inserting between, but rather another point which doesn't require an extra digit, when that's possible, but really that's very likely to be an unnecessary optimisation. So continual insertion on the end might give 0.5, 0.8, 0.9, 0.95, 0.98 0.99, 0.995...

The more you optimise something, the more fragile it gets. So to make something antifragile, you have to make something far from optimal. That book really didn't inspire me like some of his earlier work.

Offshore wind farms around the UK have capacity factors around 40%; the seas are certainly not always windy.

Solar struggles to provide a significant amount of energy in winter. Wind tends to blow or not for a few days or more at a time - meaning you need much more storage than just to carry you from one day to the next as you might in places with consistent solar.

I can't find any good source of UK historical generation data, but from looking at gridwatch the UK patterns tend to be similar to those in Germany, the data for which are available here: https://www.energy-charts.de/power.htm?source=solar-wind&mon...

There's a slight inverse correlation between solar and wind, but not that much.

I'd love to see a lot more renewable capacity installed as soon as possible, but I don't see how we can move away from needing a lot of backup conventional capacity in the near future. This is okay by me; let's halve our emissions and then see what we can do next.

Barnes Wallis developed some interesting designs in the early 50s: http://www.sirbarneswallis.com/Supersonics.htm

French was the Lingua franca of the time and probably the principal language of Henry the Eight's court, so quite possibly not.