21

That CAN'T be true! / Re: I don’t understand physics: does anyone understand physics these days?

« on: 29/12/2020 18:45:27 »

I love physics at the Newtonian mechanics end of the scale, but the cutting edge stuff leaves me disillusioned and impatient at the slow progress.

Like you, I love Newtonian physics.  It works, has been tried and tested for over three centuries, both mathematically and in practice. The Apollo missions to the Moon used Newtonian mechanics to calculate their trajectories.

But as you rightly say, the cutting-edge stuff of modern Physics must leave everyone with a feeling of disappointment. It seems like Physicists have lost the plot.

I'm sure they'll get there eventually, I just have difficulty maintaining interest when (at 62) it doesn't look as if it'll happen in my lifetime.

22

That CAN'T be true! / Re: Are electric cars environmental greenwash?

« on: 29/12/2020 13:42:53 »

The root of the problem is status competition.

A consumer society is one in which people compete for status by consuming stuff, and thus the economy, and use of resources grows exponentially as people consume more and more. Marketing men devise ever more manipulative ways making people feel inadequate and inducing them to throw away perfectly good stuff and buy new. This is what the fashion industry does when an elite at the top of society decides to do something different. Conspicuous outrage psychology professor Steven Pinker calls it: demonstrating status by saying "look at me I'm so high status I don't need to conform to society's norms and follow others". The social layer beneath then seeks to acquire status by copying, followed by the next layer down, and the next etc. As this occurs, each layer then has to change again in order to avoid looking like the copycats beneath, and so the process perpetuates indefinitely, consuming resources and creating waste as it goes. In Spent, Geoffrey Miller describes an entertaining example of marketing: luxury car manufacturers advertising in magazines bought by poor people who could never afford to buy one. Why? Because it fuels the jealousy that makes the rich people buy them.

I doubt that, seems more likley the rich seek approval amongst their peers the beggars don’t fit on their radar.

It’s obvious that all levels of society compete with their peers for status. Even the poor will buy consumer goods they don’t need (often on credit from loan sharks) when they can barely afford essentials, simply because they see their friends & family with the latest iPhone or TV or whatever. They don’t want to feel left out, because it’s humiliating, so they will pay for the things that people notice by skimping on something that’s less conspicuous instead.

The problem of course is that status competition is a zero sum game. If the Jones' are only happy when they have a bigger car than the Smiths, and the Smiths are only happy when they have a bigger car than the Jones', then they become locked into an escalating war when no amount of consumption can ever make them both happy at the same time.

Then there's habituation. When you're driving to the car dealer's to pick up your new car, you're full of excitement at how it's going to improve your drive to work, but you've completely forgotten that you once felt exactly the same way about the one you're sitting in, and now can't wait to get rid of.

You often hear talk of 'built-in obsolescence' blamed for waste, but this is naive,

Disagree, products created to be repaired, upgraded, and adapted for other uses,  have a completely different form of production.  And the suggestion that phones that can be repaired,  and upgraded easily would make more waste then what we currently have is rediculas.

I designed radios for a living, you won’t get far lecturing me how they’re manufactured and repaired. Electronic consumer goods are less repairable than they were because they’re integrated, miniaturised, and cheaper to manufacture whilst the skilled labour of a repairman has just gone up and up in price, along with his income.

throw-away products are an inevitable consequence of economic growth (and miniaturisation). Economic growth occurs because automation is used to produce more stuff with the same labour, making everyone richer,

Doesnt make everyone richer makes those that own the machines richer.

So the poor in society still live like mediaeval peasant farmers then, with no electricity, potable water, healthcare, education, transport etc? Yes, of course they do. All but the very poorest enjoy some level of consumer goods too, such as washing machines, fridges, cookers, TVs, and radios. There weren’t many of those around in the Middle Ages.

but one persons income is another's labour charge, so as we all get richer labour becomes more and more unaffordable, and labour-intensive activities become  uneconomical.

Disagree the issue isnt labour costs, it's excessive profits. Increased wages increases disposable income,  prices find there position in a fluctuating market place, the argument you espouse is more a complaint those who seek to pay less make.

These are all arguments about profit.

You’ve just contradicted yourself. First you say there are excessive profits then you say prices find their own level in a competitive market place. Profits or not, as labour gets more expensive, labour intensive activities also get more expensive, that’s why a lot of employment has moved to the far east.

Whilst manufacture is easily automated, because it involves repeating the same steps endlessly, repair isn't,

Which is also an answer to the mass unemployment automation threatens.

This is so obviously untrue it’s absurd, it was the Luddites argument, and history has proved them spectacularly wrong.

(In England) 500 years ago, 58% of the workforce was employed on the land just to grow enough to feed everyone, now it’s 1.2%. Why, because most of the work is now done by mechanisation. Are the other 57% all unemployed? No, of course they aren’t, because they now have jobs producing all the wealth we simply wouldn’t have if they were still needed to feed us. The reason we have wealth like cars, TVs, washing machines, fridges etc. is because automation has freed up spare labour that would otherwise have been needed elsewhere.

because each fault is (relatively) unique. Thus as the economy grows, more and more products become uneconomical repair, who's going to spend £20-30 on skilled labour to mend a kettle when you can buy a new one for £15? (Public services are generally more labour intensive than the private sector too,

The only way you are getting a 15 buck kettle is from sweat shops in Asia, terrible mining conditions, and extreme exploitation.  15 buck kettles shouldnt exist and only exist as an example of  the profit driven insanity this system exists by.

The reason goods are cheaper to manufacture in Asia is that their labour is cheaper, because they are less wealthy, because they are less developed, because they started to industrialise later. If allowed to continue, trade will eventually level out the difference in wealth, and our labour will become more competitive again, but therein lies the problem, the environment can’t sustain the level of economic activity we already have, let alone more. What’s needed is a reduction in consumption by the first world who consume the most.

but people who don't understand this point to the growth of the public sector as evidence of a left-wing takeover when it's actually just another by-product of economic growth.)

As Steven Pinker also points out, waste itself is a status symbol: "Look at me, I can afford to throw away all this perfectly good stuff". I can remember 'money saving expert' Martin Lewis being puzzled that he overheard someone in a queue boasting about spending a fortune on gym membership he never used. No puzzle really, it's an example of conspicuous waste. Buying a Rolex instead of a Timex, buying a Ferrari instead of a Ford, buying gold plated bath taps instead of chrome, all examples of needless consumption in the pursuit of status.

This is consumption by the 1% it's not as wasteful as you suggest simply because it is limited by the numbers engaging in it.

Around 90% of the world’s wealth is consumed by just 10% of the world’s population. That’s us in the first world, we are the problem. With just a 20% reduction in our consumption you could triple the income of the poor without any additional burden on the planet.

What's needed is an alternative to consumption as a means of competing for status.

Disagree we simply need better products,  produced in a better way. Quality not price should drive economic incentives,  and sustainability should be a mark of high quality

And by the time you’ve finished producing these utopian products, there will still be a population competing to consume more and more of them in order to outdo their mates. The problem is that status is measured in relative consumption, but environmental damage is measured in absolute consumption, meanwhile, the ones who already have the most are the ones striving hardest to consume more. If you want to fix a problem you need to identify the cause first.

One final word on status: it really is important, and not the fatuous pursuit that my posts may have made it appear. Professor Michael Marmot has done a lifetime of research into this, and status is one of the biggest determinants of both mortality and morbidity. Low status kills, and before you come back with the obvious retort: yes, poverty kills too, but low status kills as well, quite independently of poverty. It’s a serious problem for society, because as I said above, status competition is a zero sum game.

In this respect, I think that the Scandinavian countries have it nearer to right than the rest of us. They’ve reduced wealth inequality to a much lower level than most, and it appears they are less preoccupied with status, and have lower levels of many of the social ills that plague western societies.

The ethos of the meritocracy has a lot to answer for in my view. On the face of it, it sounds entirely reasonable: “you too can win the race if you just run faster”, but the problem is that that implies that if everyone runs faster they can all win, which is patently absurd. Winning (and status) is a zero sum game, so in a society where everyone runs as fast as they can (or consumes as much as they can), there will still be some who come last, and by the light of the meritocracy, they’re lazy good-for-nothings who deserve their position in society. There have to be winners and losers, but the winners don’t have to win by such a large margin.

23

That CAN'T be true! / Re: I don’t understand physics: does anyone understand physics these days?

« on: 27/12/2020 18:27:26 »

I love physics at the Newtonian mechanics end of the scale, but the cutting edge stuff leaves me disillusioned and impatient at the slow progress.

24

That CAN'T be true! / Re: Are electric cars environmental greenwash?

« on: 27/12/2020 18:18:09 »

The root of the problem is status competition.

A consumer society is one in which people compete for status by consuming stuff, and thus the economy, and use of resources grows exponentially as people consume more and more. Marketing men devise ever more manipulative ways making people feel inadequate and inducing them to throw away perfectly good stuff and buy new. This is what the fashion industry does when an elite at the top of society decides to do something different. Conspicuous outrage psychology professor Steven Pinker calls it: demonstrating status by saying "look at me I'm so high status I don't need to conform to society's norms and follow others". The social layer beneath then seeks to acquire status by copying, followed by the next layer down, and the next etc. As this occurs, each layer then has to change again in order to avoid looking like the copycats beneath, and so the process perpetuates indefinitely, consuming resources and creating waste as it goes. In Spent, Geoffrey Miller describes an entertaining example of marketing: luxury car manufacturers advertising in magazines bought by poor people who could never afford to buy one. Why? Because it fuels the jealousy that makes the rich people buy them.

The problem of course is that status competition is a zero sum game. If the Jones' are only happy when they have a bigger car than the Smiths, and the Smiths are only happy when they have a bigger car than the Jones', then they become locked into an escalating war when no amount of consumption can ever make them both happy at the same time.

Then there's habituation. When you're driving to the car dealer's to pick up your new car, you're full of excitement at how it's going to improve your drive to work, but you've completely forgotten that you once felt exactly the same way about the one you're sitting in, and now can't wait to get rid of.

You often hear talk of 'built-in obsolescence' blamed for waste, but this is naive, throw-away products are an inevitable consequence of economic growth (and miniaturisation). Economic growth occurs because automation is used to produce more stuff with the same labour, making everyone richer, but one persons income is another's labour charge, so as we all get richer labour becomes more and more unaffordable, and labour-intensive activities become  uneconomical. Whilst manufacture is easily automated, because it involves repeating the same steps endlessly, repair isn't, because each fault is (relatively) unique. Thus as the economy grows, more and more products become uneconomical repair, who's going to spend £20-30 on skilled labour to mend a kettle when you can buy a new one for £15? (Public services are generally more labour intensive than the private sector too, but people who don't understand this point to the growth of the public sector as evidence of a left-wing takeover when it's actually just another by-product of economic growth.)

As Steven Pinker also points out, waste itself is a status symbol: "Look at me, I can afford to throw away all this perfectly good stuff". I can remember 'money saving expert' Martin Lewis being puzzled that he overheard someone in a queue boasting about spending a fortune on gym membership he never used. No puzzle really, it's an example of conspicuous waste. Buying a Rolex instead of a Timex, buying a Ferrari instead of a Ford, buying gold plated bath taps instead of chrome, all examples of needless consumption in the pursuit of status.

What's needed is an alternative to consumption as a means of competing for status.

25

Technology / Re: Anyone noticed the variability in Freeview audio?

« on: 22/12/2020 22:49:42 »

Hardly, it would have to be clairvoyant to know which mic the audio was coming from, and keep switching the bandwidth in sync. The cause has to be something that's not common to all the microphones.

26

Technology / Anyone noticed the variability in Freeview audio?

« on: 22/12/2020 21:25:57 »

Has anyone else noticed how the bandwidth of Freeview audio keeps varying from one mic to another?

The recent Panorama documentary on the development of the vaccine would be a case in point, Fergal Walsh would be sat interviewing someone, and whilst the mic of the interviewee was crisp, sharp and sibilant, Walsh's mic was woolly, muffled and lacking in any HF response. By comparison, Walsh's commentary dubbed over the program was clear and sharp.

I'm not just talking about one program, it's a common problem. Two news presenters in a studio for example, one with a clear mic, the other muffled. Absurd, but it makes it look like half the microphones in the BBC are faulty whilst nobody has noticed.

27

Technology / Re: Why do videos of same length and resolution have such contrasting sizes?

« on: 22/12/2020 21:12:16 »

I don't watch TV on the internet, just Freeview. The point here is that you don't miss what you've never had, definition on 625 line UHF was fine when I hadn't seen DTV, but the jittery movement on DTV will never compete with what I was used to on analogue.

28

The Environment / Re: Is it safe to dispose of dog poo down a street drain?

« on: 22/12/2020 20:56:49 »

There are two types of drainage system in use (here in the UK at least), combined and separate. In the latter there are two separate pipes running down the street, one is the foul sewer to carry waste from bath, sink, toilet etc., and the other is the storm drain which carries rainwater runoff from the streets. In a combined system these both share the same pipe.

Sewage and rainwater are clearly very different from the point of view of pollution potential, so they require very different treatment at the sewage works. Rainwater can be discharged into watercourses with relatively little processing compared with sewage, just a bit of filtering to remove debris, which means that there is a huge reduction in the amount of foul water for the main sewage works to handle. The disadvantage is that two pipes are more expensive to install than one.

A combined sewer with only one pipe saves installation cost, but means that the sewage works has to process huge additional quantities of rainwater that was already clean until it was needlessly contaminated by putting it down the same pipe as the sewage. The means that the sewage works has to be capable of handling sudden large surges during a storm, and may be forced to discharge untreated sewage into a river if a big storm overtops the capacity of the plant.

If your street in question has a very old combined sewer there may be little harm, but if it's a separate system, then whatever you throw down the storm drain will go into a river almost untreated, with consequences for the environment.

29

Technology / Re: Why do videos of same length and resolution have such contrasting sizes?

« on: 22/12/2020 15:07:44 »

I really don't understand the current obsession with ever higher definition, when I switch the TV on I'm watching the program, not searching to see if I can spot the hairs on someone's head. I'd willingly sacrifice a considerable amount of resolution in order to get rid of some of the irritating compression artifacts, it particularly annoys me the way moving vehicles leapfrog across the screen in a series of jumps.

30

COVID-19 / Re: Anyone know the details of the new coronavirus variant?

« on: 21/12/2020 17:29:41 »

One of the future hurdles is going to be % vaccine uptake.

The BBC were filming at Danbury surgery in Essex last week. One of the staff said that they were having quite a few people refusing the vaccine, not because of safety worries, or even Bill Gates' microchips, but because it's made by them forriners, and not British.

31

General Science / Re: Frankenstein's Battery

« on: 06/12/2020 17:49:23 »

The test strips on the battery apply quite a heavy load, so that they won't indicate the battery is good when it hasn't sufficient power to operate the heaviest load the manufacturer thinks you may want to use it in. Clocks, on the other hand, use an absolutely minimal amount of power, which is why batteries in them last for years. I save all my AA and AAA cells when they're too flat to run the appliance they were used in, and then use them in the mantlepiece clock. A 'flat' battery will run the clock for many months, particularly if it had previously been used in a heavy load. The test strip is telling you nothing.

Batteries operate more efficiently when they're warm, so it is possible that a slight warming of the room might tip the voltage over the threshold at which the clock starts working. It's unlikely though, if it's been standing for years the self discharge of the battery would have taken the voltage low enough for it not to re-start with a slight temperature increase.

My money says it's almost certainly an intermittent fault, and not a flat battery. The clock stopped working because of the fault, started working spontaneously because that's what intermittent faults do, and then stopped again when you disturbed it.

Intermittent faults can be the bane of an electronics engineer's life, because if the symptoms won't present themselves when you're trying to find the fault, there's a limit to what you can do to root them out. Many intermittent faults boil down to loose/broken/corroded components or connections, in which case heating, cooling, thumping, prodding and vibrating are usually the first resort, not least because they're quick and simple. As well as thermal expansion disturbing a dodgy connection, temperature variation can also affect component parameters, as can supply voltage, but that's less likely in this case.

On a clock, the only external connections you'll find are the battery terminals, if they look ok and aren't corroded, you won't get any further without pulling it apart. That might be easier said than done though, they're not usually designed to be serviced, and might not come apart without breakage. Inside, you're likely to find components that are too small to repair without considerable skill and experience. A cracked chip component for example is likely to be a lost cause, because even if you had the skill to replace it, you won't have any means of establishing its value once it's broken, and without instruments.

32

Question of the Week / Re: QotW - 28.11.19 - Do hairs grow out grey or turn grey?

« on: 12/11/2020 15:36:46 »

My hair grows brown, then turns grey, if I pluck a hair it's easy to see that the root and tip are different colours. It's also conspicuous that I come out of the barbers less grey than I went in.

33

Technology / Re: What happens to unused electricity?

« on: 21/06/2020 17:52:01 »

See: https://www.smh.com.au/business/companies/huge-tesla-battery-in-south-australia-primed-for-big-upgrade-20191119-p53byo.html

What's the environmental impact of that much lithium? You'd need 17 of those to match the power of Dinorwic, and 70 of them to match the energy.

34

Physics, Astronomy & Cosmology / Re: How to convert power into number of molecules per second?

« on: 21/06/2020 17:42:00 »

Yes I can.
It is 0.4 Ohms in each cell whether that cell is in series or parallel.

In which case you'd have to apply the same logic to the voltage and current and say they're not changing either. My comment was in response to the OP who was talking about double voltage with half current, but no change in resistance.

My point- I thought I had laboured it hard enough but, here we go again- is that the cell doesn't know what's happening outside. So each cell has a constant internal resistance.

Yes, I know, but that’s just repeating what I’d already said here:

Snip.JPG (181.46 kB . 1528x617 - viewed 1530 times)

My original point to the OP was that you can't double the voltage in series without doubling the resistance, and you can't double the current in parallel without halving the resistance as he seemed to be arguing.

35

Physics, Astronomy & Cosmology / Re: Does glass absorb extra heat in a microwave,continuing to heat water afterwards?

« on: 21/06/2020 17:14:44 »

One of my Pyrex casseroles gets quite hot in the microwave, you can see from the thin film interference that it's got some sort of coating on it.

36

Physics, Astronomy & Cosmology / Re: Why are passing cars so much more noisy compared to the one you are in ?

« on: 21/06/2020 17:02:33 »

If you drive close to a wall you will hear your own tyre noise reflected, and the lack of tyre noise on fresh snow is remarkable.

Yes. Actually, I think a significant amount of the noise "from" the other car is noise generated by one's own car which is reflected off of the other car. I remember noticing this effect as a child when driving with the windows open: I could tell when we were passing by parked cars, even with my eyes closed.

Snow is very anechoic, too.

37

Physics, Astronomy & Cosmology / Re: How to convert power into number of molecules per second?

« on: 20/06/2020 14:29:19 »

You start by arguing that there isn't any resistance,

Did you miss this bit?

if the load resistor is zero.

No I didn't miss it.

You can't claim the resistance isn't changing when you switch from series to parallel just because it's hidden inside the cells.

38

Technology / Re: What happens to unused electricity?

« on: 19/06/2020 23:43:06 »

When I went round Bradwell in the late 70s they had two clocks on the wall in the control room, one running of the mains, and a battery one adjusted to the Greenwich time signal. They just adjusted the frequency to keep the clocks reading the same time.

39

Technology / Re: What happens to unused electricity?

« on: 19/06/2020 23:38:16 »

Conversely, if a large surge in demand happens- the cliche reason is the end of a popular sport event leading to everyone going and making the - the system has to compensate.
As Evan has pointed out, there are systems that will regulate the voltage and frequency, but that takes some time..
There's another set of automatic controls. Some large scale users of electricity have an agreement with the supplier where, they get their power at a reduced cost in exchange for agreeing to let the grid controllers disconnect them when there's a spike in demand.
An automatic system disconnects them from the grid if the frequency of the mains drops by some set amount.
These users are things like huge refrigerated warehouses. Cutting the power to the cooling plant for a few minutes won't make any real difference to the temperature, but it gives the power suppliers some leeway.
The clever bit is that the mains frequency is a very accurate indicator of the load on the grid, and it's automatically distribute to all users.

There's also pumped storage. Dinorwic empties the turbines with compressed air whilst on standby, and spins the generators at synchronous speed so that when the sluice valves are opened they can go from zero to full power in 16 seconds. It's quite an impressive beastie if you go for the guided tour.

40

Physics, Astronomy & Cosmology / Re: How to convert power into number of molecules per second?

« on: 19/06/2020 00:30:10 »

You would never normally do that with a battery though, the efficiency's only 50%.

Which is the best you can get...

No it isn't. With a series loss only the efficiency is Rl/(Rl+Rs), which is an asymptote to 100% as Rl tends to infinity. With a source that has series and parallel losses (eg a transformer), the load for optimum efficiency is the geometric mean of Rs and Rp (provided that Rs<<Rp).