When discussing the weather, I am more comfortable discussing the temperature in degrees Celsius (also known by the older name of Centigrade) than in degrees Fahrenheit. As I know that in Britain, many people prefer to use Fahrenheit, I always specify a temprature in both.

Converting from one scale to the other used to be something taught in science classes at school but I meet so many people these days who are igorant of the method for doing it or who have forgotten it. So here is a quick reminder:

If we let F be the temperature in degrees Fahrenheit and C the temperature in degrees Celsius, then we can convert from Celsius to Fahrentheit thus:

Conversion formula: F = ⁹⁄₅C + 32

For example, the boiling point of water is 100°C. In Fahrenheir, therefore, it is:

F = ⁹⁄₅ * 100 + 32 = 180 + 32 = 212°F

At the sort of temperatures we meet in out daily lives, the number of degrees in Fahrenheit is always different from the number of degrees in Celsius. Is it possible, though, for the two ever to be the same or, in other words, is there a temperature at which the number of degrees Fahrenheit is the same as the number of degrees Celsius?

The answer is yes but this poses another question: how do we work out what temperature that is? It’s quite simple, actually, if we use the above formula and a little elementary algebra.

If, as before, we let F = the temperature in Farenheit and C = the temperature in Celsius, then we are looking for a temperature at which:

(1) C = F

Substituting the right-hand side of the conversion formula for F we have:

(2) C = ⁹⁄₅C + 32

Multiply both sides by 5:

(3) 5C = 9C + 160

Subtract 9C from both sides:

(4) -4C = 160

Divide both sides by -4:

(5) C = -40

Therefore both Fahrenheit and Centigrade coincide at a temperature of -40°.

I bet you always wanted to know that! 🙂 Well, now you do know but better still, you know how to prove it!

I am having an at-home day today. This is because Tigger used up her daily outing to go shopping and as I do not care to go out alone, I am staying indoors.

On returning from her shopping trip, Tigger brought a treat with her: coffee and croissants! The croissants came from Marks & Spencer and the coffee came from old friends of ours.

Jusaka

Yes, Jusaka, the juice and coffee bar at the Angel crossroads that I have mentioned in several of my posts and was closed until now, has reopened for takeaway only.

This means that on our daily walks, we now have a choice as to where to go for our coffee, depending on which route we take.

I hope that the small income they receive from their takeaway service will enable them to survive the lockdown and recover when it ends.

It is another fine spring day with sunshine and warmth – according to the weather forecast, the temperature was 21°C (70°F) but Tigger reckoned it was warmer than that. Perhaps because of this, there were a lot of people about, some of them congregating in all defiance of the distancing rules.

Traffic on Pentonville Road

As you can see from this view of Pentonville Road, there was plenty of traffic about too.

Round the corner (well, round two corner, actually) in Chadwell Street, this sight met our eyes.

Queueing for the butcher’s

People were queueing for the butcher’s shop on the corner and they at least were observing the two-metre rule in well behaved fashion.

Rainbow and clouds in the window

In Rainbows and Easter greetings, I mentioned that on many windows, children living within have pasted examples of their art, often with a rainbow or two. We saw this example as we walked this afternoon. I like to see these creations by young artists not too shy to display their works. Who knows how many will later go on to be artists of renown? It’s just a pity that circumstances don’t permit us to ring the doorbell and compliment the young artists.

Our path of course led inevitably to Myddelton’s where we bought our usual coffees. We have promised ourselves that, having made their acquaintance and become “regulars”, if only for coffee, we will continue to call in from time to time when the crisis is over. In normal times, they have chairs and tables outside and it will be pleasant to take our coffee that way, instead of grabbing it in takeaway cups and rushing home before it cools.

Cat sunbathing on the windowsill
Photo by Tigger

By convention, Tigger buys the coffee and I carry it home. This means that my hands are not free to take photos on the way back. Any photos from the return journey, then, are likely to be by Tigger, as indeed is this one of a cat sunning itself on a first-floor windowsill.

I wonder what domestic animals make of the strange new behaviour of their human companions? Like us, no doubt, each reacts according to its own character but probably also reflects something of the emotional state of its people. They cannnot explain to us how they feel just as we cannot explain to them why we are behaving in this anomalous way.

QR (short for “Quick Response”) codes were invented in 1994 by Masahiro Hara of the Japanese firm Denso Wave. Designed for a specific purpose, the QR code quickly “escaped” from the company where it was born and is now found in many different situations worldwide.

A QR code is essentially a machine-readable label that contains information. Once the reader has accepted and decoded it, the information can be used for a variety of purposes from displaying bus or train times to making payments in shops and restaurants.

The QR code has enjoyed an upsurge in popularity now that most smartphones can read the code and then perform the action they prescribe. For a fuller account of the history and use of QR codes, see this Wikipedia article.

Useful as they are, QR codes can also pose a threat. As they are not readable by humans, the human observer has no way of knowing what the code does. This opens the possibility of criminals posting malicious QR codes, for example to damage or infect your phone, to steal personal data or make illicit payments. One should always exercise caution about which QR codes one allows one’s device to read.

Just for fun, here is a QR code that is safe to use.

All it does is convey the URL of this blog. That might be useful if you wish to read the blog on your mobile phone or tablet!

If you have an iPhone, all you need do is point the camera at the code and then touch on the notice that appears at the top of the screen bearing the phrase ‘Open “home.blog” in Safari’. You can then view the blog or add the URL to your Bookmark file or the Reading List.

If you have an Android phone, then things are unfortunately not so simple. The usual advice is to download an app capable of reading QR codes but this article suggests a way to read them without a special app. As I have never owned an Android phone, I cannot comment further on that.

What strange uses have you found QR codes being made to serve or have you perhaps used them yourself to perform unusual purposes?

The sunny warm weather continues and I am beginning to believe that spring really is here and that it is not just one of those occasional “heat waves” that, along with “cold snaps”, are so characteristic of our beloved British climate. If you want me to put a number on it, the temperature stood at 23°C (73°F) when we ventured out.

As has become our custom, we were heading for Myddelton’s for our coffee treat but, to lengthen the walk a little, we took a roundabout route. This took us via Myddelton Square – yes, again (I said our walks were apt to become repetitive) – where Tigger took this panorama showing two sides of the square and the central garden.

Panorama of Myddelton Square
Photo by Tigger

Perhaps because we were later than usual, there were more people about in the streets and we even spotted someone picking berries through the railings of the reservoir. Happily, we were able to keep our distance by the now familiar avoidance tactics.

On the way home, we spotted a couple of mounted police officers, the first we have seen for quite a while. Tigger managed to get a quick snap of them.

Mounted police officers
Photo by Tigger

Public attitudes to the police have changed somewhat during the lockdown. Many people now wave to officers passing in police cars or on horses as they do to passing ambulance crews. Whether this new friendliness will survive a return to normality remains to be seen.

In fact, a lot remains to be seen. Suggestions are being made that the pattern of our daily life will have to change, at least for some time to come if not permanently. That might be no bad thing if it means that the sense of working together in a crisis, appreciation of the NHS and ambulance crews, and the friendliness that has come from the feeling of all being in the same boat were to continue. After all, even when the disease itself is beaten, we will have enormous problems to overcome of which dealing with a shattered economy and facing up to climate change are only the two most obvious.

I would like to believe this and I hope I will not be disappointed.