Regrettably the USA persists in using it, all of it. The BBC write-up of the new launcher for the next Moon missions expressed the thrust of the solid fuel boosters in lbs.
The worlwide scientific community is beholden, in my view, to working in metric, a system designed, beyond the simple units introduced by Napoleon, for science.
But the BBC has lapped up the melange of units dished out by NASA’s press office. The main rocket is ‘65m [212 ft]’ . The two boosters produce ‘8.8 million pounds [39.1 Meganewtons] of thrust’.
I’d say that the lb is not suitable in any circumstance to describe a very large weight. And it is a measurement of weight, not ‘thrust’. Used in this way it assumes that the rocket does not move but could support 8.8 million 1lb bags of sugar 1cm off the ground.
The newton is the unit to describe the power of these engines, being a unit of acceleration. And acceleration is the name of the game in launching a mass out of the Earth’s gravitation field.
I believe Wall St still uses fractions to describe prices “US$ rose 7/32 of a cent later dropping 3/16” Dumb. They have a decimal currency!
Force, in fact which is why it is useful for measuring engine output, acceleration does not have a fundamental SI unit being expressed in terms of distance and time (metres per second squared - m/s2 or ms-2).
The nice thing about SI units is that they combine properly, Newton’s 2nd law states
So, force, mass and acceleration are linked by the equation F = ma - so 1 newton is the force which will cause a 1kg mass to accelerate at 1m/s2 - it’s almost always much messier to do such calculations in the imperial system.
By the way - assuming acceleration due to gravity of ≈ 10m/s2 and the average weight of an apple being ≈ 100g then 1 newton is the downwards force exerted by an average apple lying on a table
It really doesn’t bother me having metric and imperial - and keeps the mind active doing the mental arithmetic between them. Some things I think in one, others in the other. My weight is in stones, but the dog is in Kilogrammes… some recipes are in ounces others in grams…
Yes, I do, but not really! I still have old UK imperial spanners all mixed up with French metric spanners and it’s so annoying when nothing fits! Can never find a screwdriver that fits…hopeless! Sometimes can’t find any screwdrivers so buy another one. What happens then is that several old screwdrivers will inevitably turn up…!
Same problem, at least in my household, with ball point pens. When I need one - where is it? Buy a new pack from the supermarket and then they begin reappearing. Maybe moving the armchair to one side reveals one! Ball point pens and screwdrivers!
I’li have a think about a possible formula - something to occupy the mind.
I have both, too. It’s many years since I needed an Imperial spanner or socket - I think my Bedford CF camper van in 1975 was probably the last time. But I can’t find it in myself to get rid of the Imperial stuff just in case the right metric went missing and an Imperial would do… 13mm - 1/2" are pretty much the same and a very common nut/bolt size.
On the apron on the far side of a peage on the m/way to Valencia I was waved down by guy with a flat on his caravan. He had no tools at all. No jack, wheel wrench - nothing.
Standard procedure - start by slacking off nuts on flat. As I was in my self-build camper van - and self-builds are never completed - I had a mass of tools with me. A 19mm socket and tommy bar - nuts slacked off. Scissor jack - this caravan was so heavy the jack started to fold up!
That was me done, then, except I went thru’ the Imperial side of the socket set and found one that would do for 19mm and gave it to the guy- Jane Jones will tell us what size, as she likes to “keep the mind active doing the mental arithmetic between them”.
Fortunately the next vehicle along was an HGV. But I suspect that the caravan hd no spare. And judging by the state of the car [packed with people inc small children] and the 'van, no tax or insurance, either. A tasty snack for the Guardia Civil.
Actually there can be good reasons for working in both.
During a couple of decades as an artist printmaker who made large (33"x44") screenprints, choice of unit for the dimensions of internal elements would depend on how much I wanted to sub-divide something - multiples of three can be a bugger in metric and not all imperial yard sticks have tenths of an inch.
Today, if doing DIY I find it easier to work in feet and inches than trying to remember large numbers in centimetres, but the latter’s essential if something needs Briconautes (great word, not least because my DIY’s often a voyage into the unknown) cutting to size.
When I moved to S Africa in '97, I couldn’t figure out why sheet materials were sold in unwieldy numbers of centimetres, but then realised that twenty years after the country went metric, plasterboard was still ‘eight by four’.
for us, it’s academic now but looking back, it was 13 years ago yesterday 14 December 2007 that we disembarked from the ferry at Calais about 4am (it was bloody cold and I it was here that I learnt what verglas meant!).
Took best part of the day to get to the cottage we were renting in the Auvergne.
Happy days and never looked back
I’ve received an email from ‘pref-sve-sejour@charente-maritime.gouv.fr’ confirming an appointment to finalise my registration for residency…at the Charente Maritime Prefecture.
However, my suspicious mind sees that La Rochelle in the email is spelt La Rochellle (3 l’s). I’m always on the lookout for spoof emails! The French don’t do that, do they? Make spelling mistakes, in an official email?
See attachment. I’ve blocked out the reference number they’ve given me.
Is this a spoof email? Should I ring up the prefecture to confirm?
Is the reference number the same as your original email confirmation one? A phone call can’t do any harm.
I don’t know what a scammer could gain from this, apart from knowing you won’t be in your house at the given time.
We went to the same Prefecture but our email didn’t include a ref number and La Rochelle was spelt correctly.
As Mark says, cant see there’s anything to be gained from a scam but got to be worth giving them a call.
The reference number for the ATTESTATION D’ENREGISTREMENT, which I received when I made the initial application online, is different to the reference number on the email.
Could be just a nuisance spam, but I’ll check it out with the prefecture. Thanks both.
Certainly cheaper than the one where the tea-leaves send authentic tickets to a big show in The West End that you ‘won’ in some competition or prize draw that you can’t recall having …
Somewhat difficult to see how it would work as a scam.
Are you able to get whatever email client you use to display all the headers for the email - if so send me them in a DM and I’ll see if I can spot anything.
As it stands .gouv.fr is the official French government domain - it’s going to be impossible to get a subdomain of that for nefarious purposes.
