Question about temperature conversion C to F + more
Discussion
This morning on BBC news, it was announced that temperatures had risen by 0.8 Deg C over the past decade.
Link to BBC report
A couple of questions have arisen out of this for me.
The report compares average temperatures over the periods 1961-1990 and 2008-2017.
Firstly, how accurate was our temperature recording (not only the human factor, but the actual devices used) during the period 1960 - 1990?
Secondly, the question about temperature conversion:
0.8 Deg C = 33.44 Deg F - *but* - I found a NASA article from 2011 which also states (coincidentally!!) that temperatures have risen 0.8 Deg C (1.4 Deg F)
Why do they state "1.4 Deg F" when 0.8 Deg C = 33.44 Deg F?
I deliberately didn't put this in the climate change thread as I didn't want it to get lost in the 'noise'
Link to BBC report
A couple of questions have arisen out of this for me.
The report compares average temperatures over the periods 1961-1990 and 2008-2017.
Firstly, how accurate was our temperature recording (not only the human factor, but the actual devices used) during the period 1960 - 1990?
Secondly, the question about temperature conversion:
0.8 Deg C = 33.44 Deg F - *but* - I found a NASA article from 2011 which also states (coincidentally!!) that temperatures have risen 0.8 Deg C (1.4 Deg F)
Why do they state "1.4 Deg F" when 0.8 Deg C = 33.44 Deg F?
NASA article snippet said:
....the average global temperature on Earth has increased by about 0.8° Celsius (1.4° Fahrenheit) since 1880...
I'm confused!I deliberately didn't put this in the climate change thread as I didn't want it to get lost in the 'noise'
TonyRPH said:
Secondly, the question about temperature conversion:
0.8 Deg C = 33.44 Deg F - *but* - I found a NASA article from 2011 which also states (coincidentally!!) that temperatures have risen 0.8 Deg C (1.4 Deg F)
Why do they state "1.4 Deg F" when 0.8 Deg C = 33.44 Deg F?
Because it's the change in temperature they are talking about, not the absolute.0.8 Deg C = 33.44 Deg F - *but* - I found a NASA article from 2011 which also states (coincidentally!!) that temperatures have risen 0.8 Deg C (1.4 Deg F)
Why do they state "1.4 Deg F" when 0.8 Deg C = 33.44 Deg F?
For example: 20 deg C = 68 def F; 20.8 deg C = 69.44 deg F; difference = 0.8 deg C, 1.44 deg F.
Delta (difference) vs absolute value confusion.
Say Tf= Tc*9/5+32
That'll give the absolute value.
You've converted the absolute value 0.8C to F
What they are quoting is a delta
Try the subtraction
e.g 10.8*9/5+32-(10*9/5+32)= 1.44
Offset of 32 cancels out and you're left with the ratio 9/5*delta
Say Tf= Tc*9/5+32
That'll give the absolute value.
You've converted the absolute value 0.8C to F
What they are quoting is a delta
Try the subtraction
e.g 10.8*9/5+32-(10*9/5+32)= 1.44
Offset of 32 cancels out and you're left with the ratio 9/5*delta
jeremyc said:
Because it's the change in temperature they are talking about, not the absolute.
For example: 20 deg C = 68 def F; 20.8 deg C = 69.44 deg F; difference = 0.8 deg C, 1.44 deg F.
Ah, of course (penny drops) - thanks for that.For example: 20 deg C = 68 def F; 20.8 deg C = 69.44 deg F; difference = 0.8 deg C, 1.44 deg F.
Maths remains a weak point for me.
jet_noise said:
Delta (difference) vs absolute value confusion.
Say Tf= Tc*9/5+32
That'll give the absolute value.
You've converted the absolute value 0.8C to F
What they are quoting is a delta
Try the subtraction
e.g 10.8*9/5+32-(10*9/5+32)= 1.44
Offset of 32 cancels out and you're left with the ratio 9/5*delta
Good explanation, thanks.Say Tf= Tc*9/5+32
That'll give the absolute value.
You've converted the absolute value 0.8C to F
What they are quoting is a delta
Try the subtraction
e.g 10.8*9/5+32-(10*9/5+32)= 1.44
Offset of 32 cancels out and you're left with the ratio 9/5*delta
I do wish I had taken more interest in maths at school, as it can be my biggest downfall at times!
Edited by TonyRPH on Friday 2nd November 08:54
Regarding the accuracy of temperature recording - doing so to one decimal pace has been possible for decades.
Physicicists are really really good at measuring stuff. My favourite example is the LIGO (laser inferometer gravitational observatory), which has been used to observe black holes merging. LIGO can detect a change in distance between its mirrors 1/10,000th the width of a proton. This is equivalent to measuring the distance of 4.2 light years to an accuracy smaller than the width of a human hair.
Physicicists are really really good at measuring stuff. My favourite example is the LIGO (laser inferometer gravitational observatory), which has been used to observe black holes merging. LIGO can detect a change in distance between its mirrors 1/10,000th the width of a proton. This is equivalent to measuring the distance of 4.2 light years to an accuracy smaller than the width of a human hair.
Edited by Polite M135 driver on Friday 2nd November 09:09
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