WAGS 25.11.2020: Bubbles in the Rain

 

Bubbles in the Rain

   You have all seen this, but perhaps never questioned why the bubbles form from some rain drops and not from others!  I have noticed that more often than not, the bubbles form on asphalt, such as used in roads and playgrounds. Not so much on flat concrete.  Sometimes on mud and low grass.  My grandfather, who was a bit of a savant used to say, "bubbles in the puddles it will rain all day".  But then where he lived, in England, it used to rain all day quite a lot.  

          Now I researched this and came up with some probable reasons from apparently learned professors:

        Bubbles consist of a gas trapped by a liquid, where the liquid has a surface tension high enough to encapsulate the gas. This gives bubbles three ingredients: the liquid, the gas, and surface tension.

The first ingredient, the liquid, is obviously the rainwater.

The second ingredient, the gas, is (also obviously) air. But what isn't obvious is how the gas becomes entrained in the liquid. Asphalt is porous, meaning the microstructure of asphalt consists of lots and lots of tiny random tubes through the solid material. Thanks to the capillary effect, water is sucked into those tiny tubes, and gas is forced out. This gas being forced out of the porous asphalt material and through the liquid on the surface creates bubbles.

Surface tension is the third ingredient, and controls the bubbles' shape, size, and strength. Surface tension can be enhanced by surfactants (big molecules which, when added to a liquid, agglomerate and increase the surface tension). The surface of a road accumulates lots of surfactants - mostly, oil. Oil consists of many long-chain hydrocarbons, which are perfect surfactants (most detergents are actually long-chain hydrocarbons that are polarized at one end). Surfactants tend to agglomerate (that's why, if you pour a little oil on top of water, it will tend to clump together as it spreads out over the surface of the water). Having oil act as a surfactant increases the surface tension of the rain water on the surface of the road, and makes any bubbles formed in the water stronger. That explains the large bubbles you saw.

Well I can't argue with that. But within a year another learned professor weighed in with:

     The high-level concept here may be correct. Unfortunately, there are at least three factual problems: (1) surfactants decrease surface tension; related, (2) surface tension must be low in order for bubbles to form; and (3) oils themselves are not surfactants; only the fatty acids derived from them are. There may still be surfactant residues on roadways, but they are definitely not oils. 

I am definitely with my grandfather here. Bubbles form, rain all day - and if it doesn't you are lucky or unlucky depending on whether you live in Manchester, most parts of Scotland or on the other hand, the Algarve fast approaching desertification.

    This is by the by, the witty link here is that WAGS Bubbles do NOT form in the rain. At least the Lagos Bubble decided against early on, and I did see a note that the Silves Bubble would reconsider postponing until the Thursday, and for one week only, become the TAGS. The Salir Bubble may well have ventured out, Terry not in the least being a fair weather walker, but I have yet to hear.

      My aspirations of last week of a padding-free blog have to be set aside yet again. 

 

The day finished much better than it started. View from my terrace looking west.

From Henry's square

   However, a WAGS motto is "If you can't walk the walk - Eat the meat!!"  So Myriam and I decided to try for  a nourishing lunch after a quick sortie during a temporary dry spell.

We ended up at Até Qu'Enfim, which was quite appropriate and went for the (expensive?) €10,50 Lunch of the Day which included a drink, main, dessert and coffee.

No conversation over lunch! Myriam had bochechas de porco with rice, and I went for Coelho Caçador........

................piping hot with great chips.

Desserts were tarte de natas, which we didn't really deserve as we had not walked, but wolfed them down anyway. Myriam's could only manage half of her pig's cheeks so did a takeaway for dinner the next day!

Little else to relate. On the way back we passed a pair of engineers who had set up an office in the middle of a traffic island! Myriam took this pic.

As is usual they had a policeman (beside the photographer and chatting - where else?) watching to take care of any traffic issues arising!

And that was our activity. Nothing coming in from the other half of the Lagos Bubble, who no doubt took Sasha out for their routine daily walk. I have just heard that the Salir Bubble found other ways to occupy themselves with domestic trivia, so stayed safely indoors.

And now some Info Padding. UK Gov contacted me personally to advise me how to Bubble Up. Maybe they had wind of our Bubble activities here in the WAGS! I will add a couple of paragraphs which contain the main precautions just in case you are not interested enough to read the whole document whose link is below:-

GovUK Guidance

Making a support bubble with another household

How you can safely expand the group of people you have close contact with during the coronavirus (COVID-19) pandemic.

What a support bubble is

A support bubble is a close support network between a household with only one adult or a household with one adult and one or more people who were under the age of 18 on 12 June 2020 in the home (known as a single-adult household) and one other household of any size.

This is called making a ‘support bubble’.

Once you’re in a support bubble, you can think of yourself as being in a single household with people from the other household. It means you can have close contact with that household as if they were members of your own household.

Once you make a support bubble, you cannot change who is in your bubble.

Continue to follow social distancing guidance with people outside of your household or support bubble. This is critical to keeping you, your family and friends as safe as possible.

Do not change your support bubble

From 14 September, if you form or continue in a support bubble, you cannot then change your support bubble. It does not have to be the same support bubble you may have been in previously.

And there it is. Words of wisdom from Boris's Government.  Didn't we used to call that 'Swinging?' Will it work in a democratic,'Free' Society? Well our own Bubble system here is a shining example, so lets stick to it and stay safe.

The full Gov.uk guidance can be seen HERE

And now over to the Silves Bubble for Rod´s battle ground SitRep (Military shorthand for Situation Report)

Patiently awaiting the arrival of the famed French photographer who, true to form, treated them (and us) to an innovative Starter pic.

An egotist? Moi?

I suppose it served me,  us,  right ......postponing the walk from Wednesday to Thursday  because of inclement weather was pathetic enough but in the event we got our just desserts twofold.First, it never rained at all, in these parts anyway, on the Wednesday and then  we had several  showers on the Thursday when it was supposed to have been dry,  Secondly our dear Leader failed to remember that Thursdays  are still designated hunting  days....  to the detriment not only of sadly decreasing wildlife but nearly also of somewhat decreasing WAGS as well.

A depleted band of 4 Silves Bubble WAGS; Hazel, Maria, Yves and the undersigned....but minus John who had temporarily joined the Walking Wounded ... set off once again from the Casa de Pasto Parreirinha heading beyond Cafe Oriq. The track up from their carpark is now alluringly marked by a high-viz sign "Le Salao". 

This proved to be a very simple timber building in the grounds of an otherwise undistinguished house. Whilst it could have been used for any number of dubious purposes, closer inspection disappointingly indicated it was  merely a Hairdressing Salon!

A bit steep

For a while thereafter there was little else of  note as we headed past the big electrical sub-station towards the lake not visited for about 15 years.  We should have been amply forewarned by the sound of distant gunfire.  But on we went past an extremely expensive and high post and wire fence under construction but obviously designed to keep out even the most determined WAG  and presumably to be reinforced by a vast stack of steel sheets loaded on a large timber tractor.

There´s the timber tractor

By now the sound of gunfire was getting ominously close as we followed a footpath down a narrow valley.

As we emerged from the valley we were suddenly faced by the entire 1st Battalion of the Portimao Light Infantry engaged in full scale exercises. At that moment they were spread over the entire opposite hillside  and through billowing gunsmoke we could see they were being directed by the General(4 star) of the Algarve Division comfortably seated on  a shooting stick beneath an imposing golf umbrella with a fearsome blunderbuss across  his knees, screaming orders at his errant troops. We approached him cautiously to seek his authority to follow the main track one way or the other.  This was peremptorily refused and, barking that we were trespassing in a Military Reserve, he ordered us to retreat the way we had come.  Further pleas obviously being futile, we retired ... fortunately without loss.(We regret not being able to bring you any photographs of the 4 star General due to strict military censorship.)

We returned more or less via the same outward route, a possible extension being rejected owing to time pressure to claim our reserved table where John was patiently waiting. 

Perhaps it was as well he was not with us since, had we returned with him in his wounded state, we might well have been accused of initiating an Algarve extension of The War of Jenkins Ear. After all the Portuguese cast a blind eye to the Spaniards lopping it off!  

 Just in case, he was seated in a quiet corner, partially hidden behind an empty Sagres bottle, disguised by a distinctly unfashionable (for WAGS anyway since it seems they are not included in the Tilley range!)  corblimey flatcap pulled down over the bandaged auricular area. Let us hope for a full recovery of the reattached ear by next week. 

Rod.

"Distinctly unfashionable " indeed ! I will have you know that my distinguished titfer is by Loden-Steiner, hat makers in Austria since 1888 and sold in Edinburgh by Ede & Ravenscroft (established 1689 - purveyors of headgear and other perquisites to the Duke of Rothesay, a.k.a. HRH The Prince of Wales.

The Expeditionary Force on their return to base.

Distance: 7.17 kms, over 3hrs 6 minutes at an overall speed of 2.31 kph, but with a very creditable 230 metres total ascent. 

Lunch was substantial for some but Rod, as before, was not greatly impressed by the lack of tostas nor by the quality of the bifana despite the added garnish of a sardine.

But others enjoyed  a very filling shepherd´s pie.............

Chips..........

and sardines served with a soggy bread compote.........

which was much tastier than it looks.

Let´s at this point revert to that photo of Jenkin´s Ear which was taken by that renowned French photographer

and sent with the caption "Why so glum, Vincent?"

Not so much glum as puzzled, in fact. Puzzled by the fact that all the reports of Vincent Van Goch´s ear-cutting episode state that he cut off his left ear, but when you look at the picture

it looks as if it was his right ear that took the hit. But, of course, it´s a self-portrait of him looking into a mirror.

Time for a bit of music, I think.

And the final word on Johnkin's Ear, after seeing the comparisons with Vincent, I thought back to that comedy genius of yesteryear, Bob Newhart, and his conversation with Sir Walter Raleigh on tobacco among other New World discoveries. The classic line is at about 2 minutea 18 seconds into the vid. Enjoy.

"Don't tell me Walt ..........."