Why are records always "SMASHED!!!"

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Originally Posted by ian

bloody physicists 46.1 +/- 0.05 is the same as 46.2 +/- 0.05.
reminds me of the joke told by [pure] mathematicians "I know there's an answer to 2 + 3 =, I just don't know what it is!"

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It depends what you means by "2"

a) Some physicists will say that a number expressed as 2 (ie no decimal) usually means 2 +/- 1 in the last digit, so 3 = 3 +/-1 so the answer to 2 + 3 = somewhere between 3 and 7?

b) Mathematicians are more likely to say that numbers expressed as "2" and "3" represent integers so they are 2 +/- 0 and 3+/- 0 so the answer is 5 +/- 0

In case a) where no decimal is shown, the uncertainty is technically in the last non zero digit so a number like "100" is 100 +/- 100 if you want to show indicate that you mean 100 +/-1 you should show the input numbers as 100. ie specifically include the decimal point.

I spent many hours in international science and tech panels discussing this and related concepts. It sounds like crap but it is essential for international scientific and engineering communication and even in trade of things like precious metals. A friend of mine was working for an international LPG trading company and he saved the company millions by potentially by showing how important it was to know exactly what the numbers meant. (Specifically he worked on reducing the uncertainty of the Universal gas constant)

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Originally Posted by BobL

It depends what you means by "2"

a) Some physicists will say that a number expressed as 2 (ie no decimal) usually means 2 +/- 1 in the last digit, so 3 = 3 +/-1 so the answer to 2 + 3 = somewhere between 3 and 7?

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that's what I meant by "bloody physicists", their answer to 2 + 3 is 5 +/- 2.

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b) Mathematicians are more likely to say that numbers expressed as "2" and "3" represent integers so they are 2 +/- 0 and 3+/- 0 so the answer is 5 +/- 0

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I did qualify it by referring to PURE mathematicians. It's those APPLIED buggers who contend that 2 + 3 = 5

the joke can be extended to accountants who when asked what's 2 + 3, respond "what ever number you need".

BTW, if you ask an engineer, what's 2 + 3, the answer is 9 -- after applying the appropriate "safety factors"





But I'd be more interested in a response to my other post about comparing "converted" temperature measurements from 80 years ago with actual measurements made today.

To me, broken means able to be fixed. Smashed means irreparably damaged. Point one of a degree is nothing. I grew up in the far west of NSW and spent most of my childhood wandering the middle of Australia. As kids we thought nothing of forty degrees. It was dry heat.
Now humidity, that's the game breaker.

can I just say it was bloody hot

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Originally Posted by ian

But I'd be more interested in a response to my other post about comparing "converted" temperature measurements from 80 years ago with actual measurements made today.

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There would have been no problem with conversion from F to C as the conversion factor has not changed since that time.
It turns out that accurate temperature measurements were being done more than 100 years ago provided the exact same thing was being measured ie the boiling point of distilled water at the same atmospheric pressure.

However, reliable atmospheric temperature measurements require the use of a shelter called a Stephenson screen which date from the late 1880's but one does not always know how widespread in use or how well maintained they were even as late as the 1950's . If such a screen was not being used or the screen was in a poor state of repair then chances are the temperatures would have been unreliable and were almost always measured too high. Reports of record high temperatures around the middle and turn of the 19th century are therefore generally considered highly suspect. Climate change deniers often trawl out the 1896 record temperatures as evidence that it was hotter back then than today. They also claim that these have been expunged from the record by climate changers.

See FactCheck: was the 1896 heatwave wiped from the record? for the fact check on that one.

Official BOM weather stations are also occasionally moved which make comparisons tricky.

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I did qualify it by referring to PURE mathematicians. It's those APPLIED buggers who contend that 2 + 3 = 5

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My experience is that 5 would be the answer given by pure maths people as they don't usually consider uncertainty. Applied mathematicians are more likely to look at tolerances etc.

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Originally Posted by ian

But I'd be more interested in a response to my other post about comparing "converted" temperature measurements from 80 years ago with actual measurements made today.

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There would have been no problem with conversion from F to C as the conversion factor has not changed since that time.
It turns out that accurate temperature measurements were being done more than 100 years ago provided the exact same thing was being measured ie the boiling point of distilled water at the same atmospheric pressure.

However, reliable atmospheric temperature measurements require the use of a shelter called a Stephenson screen which date from the late 1880's but one does not always know how widespread in use or how well maintained they were even as late as the 1950's . If such a screen was not being used or the screen was in a poor state of repair then chances are the temperatures would have been unreliable and were almost always measured too high. Reports of record high temperatures around the middle and turn of the 19th century are therefore generally considered highly suspect. Climate change deniers often trawl out the 1896 record temperatures as evidence that it was hotter back then than today. They also claim that these have been expunged from the record by climate changers.

See FactCheck: was the 1896 heatwave wiped from the record? for the fact check on that one.

Official BOM weather stations are also occasionally moved which make comparisons tricky.

Easy to read technical report on the BOM weather station with a large section on history and background here
http://cawcr.gov.au/technical-reports/CTR_049.pdf

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I did qualify it by referring to PURE mathematicians. It's those APPLIED buggers who contend that 2 + 3 = 5

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My experience is that 5 would be the answer given by pure maths people as they don't usually consider uncertainty. Applied mathematicians are more likely to look at tolerances etc.

For your various interests :D
https://www.woodworkforums.com/f43/ka...smashed-225827

Let's bring in the cricket "heros". Or footy heros. Or such. Other much abused words or terms. :((

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Originally Posted by BobL

There would have been no problem with conversion from F to C as the conversion factor has not changed since that time.
It turns out that accurate temperature measurements were being done more than 100 years ago provided the exact same thing was being measured ie the boiling point of distilled water at the same atmospheric pressure.

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I know the conversion factor has remained at 1.8 since 1804(?) when the French academy established the centigrade scale.

But Bob you have missed the core point.

Back in 1939, civil temperature was measured in degrees Fahrenheit, if you convert 46.1 Celsius to Fahrenheit you get 114.98 -- but you would need to show me a year's worth of records before I believed you that back in 1939 daily temperatures were measured to a precision of 1/100th of a degree. So until you do I suggest that the old record was 115 degrees Fahrenheit. Back in 1939, it's possible that the "official" Adelaide thermometer had a precision of 0.5 degrees, but I suspect that back then the precision was most likely 1 degree. Remember we are talking civil temperatures, not fancy and expensive laboratory instruments which are periodically re-calibrated.

So the new Adelaide "record" of 46.2 Celsius just happens to be 115.16 Fahrenheit which if it had occurred in 1939 would most probably have been written as 115 degrees F.

So the "new record maximum" is most probably just a second instance of the previous maximum temperature. Not a new record at all.

There is an old joke about numbers but I'll post it in jokes.

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Originally Posted by BobL

My experience is that 5 would be the answer given by pure maths people as they don't usually consider uncertainty. Applied mathematicians are more likely to look at tolerances etc.

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It's a joke Bob.

Physicist: 2 + 3 is really 2 +/- 0.5 plus 3 +/-0.5 = 5 +/-1

Engineer: 2 + 3, well you have to account for the various factors of safety, 2 + 3 becomes 2 x (DL SF of 1.5) + 3 x (LL SF of 2) = 2 x 1.5 + 3 x 2 = 3 + 6 = 9

Applied mathematician: 2 + 3 = 5

Pure Mathematician: (one who deals in the abstract), ponders a moment or two, and then says "2 + 3 I know there is an answer, but I'm not sure what it is."

Accountant: "you ask me what is 2 + 3, it can be any answer you want."

Well, having just been exposed to"The Good Place", I now know that "smash" means sexual intercourse to generations younger than me, so that temperature record is well and truly forked :)

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Originally Posted by ian

I know the conversion factor has remained at 1.8 since 1804(?) when the French academy established the centigrade scale.

But Bob you have missed the core point.

Back in 1939, civil temperature was measured in degrees Fahrenheit, if you convert 46.1 Celsius to Fahrenheit you get 114.98 -- but you would need to show me a year's worth of records before I believed you that back in 1939 daily temperatures were measured to a precision of 1/100th of a degree. So until you do I suggest that the old record was 115 degrees Fahrenheit. Back in 1939, it's possible that the "official" Adelaide thermometer had a precision of 0.5 degrees, but I suspect that back then the precision was most likely 1 degree. Remember we are talking civil temperatures, not fancy and expensive laboratory instruments which are periodically re-calibrated.

So the new Adelaide "record" of 46.2 Celsius just happens to be 115.16 Fahrenheit which if it had occurred in 1939 would most probably have been written as 115 degrees F.

So the "new record maximum" is most probably just a second instance of the previous maximum temperature. Not a new record at all.

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I don't know how widespread they were in use but even back as the early 1900's there were many mercury thermometers that could measure to 0.1ºC. We had some of these at Uni that were standard first year undergraduate thermometers from the old Perth Technical College (TAFE) from ~ 1910. I would assume the official Adelaide BOM thermometer in 1939 would have then been at least as good at these if not better.

Mercury in glass thermometers go back to Newton and were refined by Fahrenheit in the early 1700's. During the 1700's and 1800's thermometry became a highly developed science (would have been the equivalent of subatomic physics today) and had many many people working in the field as every half amateur naturalist had a least one and many had several. A serious naturalist would travel with a leather case with a set of these probably lined in purple velvet to cover different temp ranges and to take averages and cater for breakage.

Given that glass blowing was well developed, high resolution was not that difficult to achieve ie draw long columns of glass tubing attach to a mercury bulb and calibrate against the boiling and freezing point of pure water. To get 0.1ºC resolution the tubing is made finer/ longer. 1m long master calibrator thermometers only needed to have lines 1mm apart to achieve 0.1ºC. Then using magnifiers 1/2 and 1/4 and even 1/5mm etching marks could be made. Several of these masters were used to calibrate shorter but still high res working thermometers with limited temperature ranges which made them easier to transport in purple velvet lined leather cases..

Mercury in glass thermomemeters are still considered to be one of the most accurate ways of measuring temperature and were only phased out of the NIST reference temperature measurement program about 30 years ago.

So actual thermometer used back then is unlikely to be at fault issue - it's the location, how the measurement was done, and who was the nut behind the wheel.

I am reminded of a Temp-Time graph of water supposedly coming up to the boil from room temp submitted in an experimental report by a grade 11 chemistry student back in 1978. The graph showed a quick rise in temp to about 35ºC and then it did not change much after that. Instead of placing the bulb in the water the student had been holding the thermometer bulb between his fingers and had the other end in heating water. I think that student ended up doing engineering at Uni.

Ok, just to drag this back on topic, and away from how many beans make 5, and the History of the Thermometer (as interesting as it is), it's 29° at my desk right now which smashed yesterday's record of nearly 29°. However, yesterday was not the record. That would have been last week when it was 32.

(this is a fun thread - let's not bog it down)

Under the front verandah roof of our little piece of rural Australia the thermometer is saying its 35°. The back verandah says its 31°. Whether the 2 thermometers are trying to out do each other is an unknown. I do know one thing......its flamin' hot and its going get even hotter......so with the prevailing weather conditions,at hand, we have the Evaporitive Cooler set at 24°, so now its up to me to.......settle in my recliner and reread an old novel from my high school days.
I went out to the shed earlier for 10 minutes and that was enough to convince me to stay indoors