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91
bouldering / Re: The science of condensation
« Last post by WillRobertson on December 03, 2021, 02:23:31 pm »

This can happen for a variety of reasons including, but not limited to:
- Cooling of the rock - typically overnight, and occurs quickest when winds are calm and skies are clear

This seems a misleading way to phrase it. Condensation due to the temperature of the rock is caused by the lag between how fast air temperature changes versus rock temperature.
So whilst a rock is actively "cooling" you will not get condensation because this cooling is the result of the air temperature being lower than the rock temperature. The heat exchange between the rock and air means the air around the rock can carry more water than the surrounding air, so drying takes place as opposed to condensation.
Eventually the surrounding air temp will go up and exceed the rock temp, at which point air around the rock will be cooled by heat exchange and it's capacity to hold moisture will drop, the excess moisture will form condensation on the rock surface, but at this point the rock may be cold but is actively heating up not cooling.

I'm not sure I agree. The rock - similar to grass, road surfaces, and vehicles - will typically cool quicker than the surrounding air - this may differ depending on rock type, structure and exposure, but is generally true. This is why ice can form on surfaces despite the air temperature being above zero Celsius (and hence why cars typically alert of a risk of ice when the air temp falls below 3 C).

And condensation doesn't require the rock temperature being lower than the air temp (dry bulb), but just lower than the dewpoint of the surrounding air. If, as you suggest, it requires "excess moisture" to form condensation then condensation would only form when the air is fully saturated (~100% RH - and hence forming fog or cloud). We see condensation form when this isn't the case so we can rule this out.

Water condensing on rock is the same process as when dew is deposited on surfaces, briefly described here:
https://www.metoffice.gov.uk/weather/learn-about/weather/types-of-weather/temperature/dew
92
shootin' the shit / Re: Coronavirus Covid-19
« Last post by Offwidth on December 03, 2021, 02:17:17 pm »
Well the covid behavioural specialists I know beg to differ with your opinion. Mind you one of them is SAGE and IndieSAGE so I guess you won't trust her. There is clear anecdotal evidence a significant group of the population are being a !ot more careful already... lots of xmas party bookings cancelled in the news... only saw a few people without a mask in the big Sainsbury the day before yesterday, despite mask usage being down to about a half previously (oddly the petrol station there was the opposite but on a tiny sample).

On the subject of Sweden, yes it's the same country that did much worse than Norway but better than the UK. In particular I was angry early on that they tried to form a herd immunity approach pact with the UK and NL. I'm completely happy with my posting history on the subject compared to how things panned out.

My main point was if any lockdown is needed to protect the NHS it simply can't be avoided and any delay, poor messaging or poor compliance will just make restriction requirements worse. I think compliance will be good as I trust the experts I know and there is a significant chance we will get to see who is right.
93
shootin' the shit / Re: Coronavirus Covid-19
« Last post by spidermonkey09 on December 03, 2021, 01:55:24 pm »

Surely the first step is to fully implement the previously announced Plan B: covid pass, masks and advice to work from home. Apart from the advice to work from home, it's no more than is already in place in Wales.

Yeah, I could see that happening, and I'd be ok with it. I don't think it would be enough to satisfy the critics though. I still think, contrary to Offwidth, that workplaces that aren't already doing some form of WFH will need to be legally required to do so this time around. I would be very surprised if my former workplace reverted back to WFH for example, they were back in the office as soon as they could last year.

All the UK evidence is that public compliance with clear advice linked to genuine hospital need  was way better than most of SAGE expected (one of the reasons the March 2020 lockdown was so slow was a worry of lockdown fatigue, subsequently proven wrong). That's why I'm a dove on population compliance: based on that evidence (the biggest hawks tend to be libertarian or some level of covid or vaccination deniers).

That evidence is only of limited relevance given the fact that we now have a vaccine and are close to 2 years on from that first lockdown. An element of fatigue has obviously set in. Holding up evidence of good adherence to the first, game changing, genuinely unique first lockdown and suggesting that adherence is likely to be replicated in subsequent lockdowns seems obviously flawed; the material circumstances are totally different. Adherence was way less in Jan/Feb this year than it was in March 2020; you can see that straightaway through the medium of people going climbing in Jan 21 when they didn't in March 20.

Sweden also showed us that more consistent messaging trusted by the population led to much fewer deaths, less stringent restrictions, lower health system strains and lower lockdown economic costs.

Is this the same Sweden we all (me included) spent much of spring 2020 criticising for their laissez faire approach?

The bottom line is, as you say, we don't have clear data- waiting for it is the only option.



94
bouldering / Re: The science of condensation
« Last post by m.cooke.1421 on December 03, 2021, 01:30:43 pm »
Is a fan always going to improve conditions or are there scenarios where you will be making the rock wetter?
95
abroad / Re: European multipitch
« Last post by oldfella on December 03, 2021, 01:20:39 pm »
I highly recommend Quiros in Asturias (North Spain). You need a car to get there but once you’re there, you can walk to all the crags. Multi pitch sport and lots of grades. I stayed with mates at Casa Quiros. https://rocaverdeclimbing.com/?page_id=678

Amazing rock, not polished. Well equipped.

https://rocaverdeclimbing.com/

Teverga is about 10mins drive and there’s a ton of sport of all grades. Some multi pitch as.


You won’t be disappointed
96
shootin' the shit / Re: Coronavirus Covid-19
« Last post by Nutty on December 03, 2021, 01:17:31 pm »
So out of interest, in terms of what you want to happen based on the data you look at, you'd be in favour of an immediate lockdown, return to furlough etc?

I think its fairly likely that we'll see a wave this winter but I'm unconvinced it is politically possible to lockdown again for numerous reasons, so the more likely outcome is muddling through. Not least because if the variant is as bad as you suggest, we won't be able to stop it spreading anyway, even in a lockdown.
Surely the first step is to fully implement the previously announced Plan B: covid pass, masks and advice to work from home. Apart from the advice to work from home, it's no more than is already in place in Wales.
97
abroad / Re: European multipitch
« Last post by SA Chris on December 03, 2021, 01:15:22 pm »
Sardinia?
98
bouldering / Re: The science of condensation
« Last post by Johnny Brown on December 03, 2021, 01:14:28 pm »
There's also the fact that despite apparently similar ambient conditions, recently dried rock can offer better conditions than long-term dry rock due to the lowering of the surface temperature by evaporation.
99

Maybe it would be possible to train the mindset by signing for a beginner's boxing club and learning how to continue performing a difficult athletic activity requiring co-ordination while getting punched in the face.

Sounds more like training for winter climbing to me.
100
bouldering / Re: The science of condensation
« Last post by Bonjoy on December 03, 2021, 01:12:06 pm »

This can happen for a variety of reasons including, but not limited to:
- Cooling of the rock - typically overnight, and occurs quickest when winds are calm and skies are clear

This seems a misleading way to phrase it. Condensation due to the temperature of the rock is caused by the lag between how fast air temperature changes versus rock temperature.
So whilst a rock is actively "cooling" you will not get condensation because this cooling is the result of the air temperature being lower than the rock temperature. The heat exchange between the rock and air means the air around the rock can carry more water than the surrounding air, so drying takes place as opposed to condensation.
Eventually the surrounding air temp will go up and exceed the rock temp, at which point air around the rock will be cooled by heat exchange and it's capacity to hold moisture will drop, the excess moisture will form condensation on the rock surface, but at this point the rock may be cold but is actively heating up not cooling.
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