“On the nose, we expect to see temperatures of around 3,600F (1,980C). On the Mach 7 flight, they were closer to 2,000F (1,090C). Temperatures will be nearly twice as hot,” said Joel Sitz.
Nice going. I sure hope he’s not a scientist involved with this project. Dumbass.
I propose a the Mangetout standard of temperature measurement; using the centigrade scale, but zeroed on the melting point of Titanium; under this scheme it will be appropriate to say:
“On the nose, we expect to see temperatures of around -1440M. On the Mach 7 flight, they were closer to -2330M. Temperatures were nearly twice as cold last time around”
Tungsten, not Titanium. Dammit.
Seems he’s the project manager. Let’s hope he doesn’t actually do anything other than play with Gantt charts.
Well. he’s not so far off beam.
1980ºC = 2253K.
1090ºC = 1363K.
I don’t think it’s that much of a stretch to say 2253 is “nearly twice as much” as 1363.
What is moronic, of course, is when people say that, say, 100ºF is “twice as hot” as 50ºF…
Given he quoted the Fahrenheit figure first, I would assume that’s what he was reasoning in. Otherwise why not give the figure in Kelvins then Celsius? Even giving him the benefit of the doubt, he’s not explaining things clearly, which is bad whether he’s scientist, project manager or PR.
There was a similar bit in The Core, when one of the crew had to go outside the ship to fix something. The temperature was about 9000 degrees and their suits were only rated for “half that”.
I swear, that one major technical flaw just ruined the whole movie for me!
Bryan, why is that a flaw?
Assuming they are talking about degrees Fahrenheit:
9000F = 5255K
4500F = 2755K
Still pretty damn close to twice as hot, wouldn’t you say?
Once you’re talking thousands of degrees, the shift in zero points from absolute zero is really negligible.
Because he works for NASA and he was speaking to the American press, so if he quoted the temperatures in Kelvins, then Centigrade, the American public would have been all utterly clueless.
I’m with Colophon. Once you get up around 2000 Centigrade, you’re in the realm of Really Flippin’ Hot, where, in casual speech, you can blur the distinctions between Centigrade and Kelvins (it’s only 300 degrees difference, after all.)
I’ve never seen The Core, but the screenwriter hung out on another messageboard I frequented; according to him, they had tons of fun massacring the science, in good old-fashioned '50s pulp SF style. Trying to watch it with your hard-SF hat on will make your head explode, I think.
Daniel
Fight my ignorance, please.
459 below zero Fahrenheit is absolute zero. The only meaningful way to measure “half as hot,” “twice as hot” is their distance, on any scale, from absolute zero.
Working in Fahrenheit degrees from absolute zero is the Rankine scale. So 50ºF is 509ºR. “Twice as hot” as 50ºF is 1018ºR, or 559ºF. Or, taken the other way, 100ºF is 559ºR. Half as hot as that is 279.5ºR, or -179.5ºF.
Maybe he was reffering to a “wind chill” type of measurement. You know, 3,600F feels twice as hot as 2,000F when applied to the skin. 
I think it’s better understood this way.
If you say something is “twice as hot”, you are saying that something contains twice as much heat. However, at 0F or 0C there isn’t “zero heat”. The only temperature at which there is “zero heat” is at absolute zero.
Therefore, when it’s 30C, it’s actually absolute zero + 273 + 30 degrees. Similarly, when it’s 60C, it’s actually absolute zero + 273 + 60 degrees. Therefore, it is not “twice as hot”.
An analogy would be to have 2 barrels of water, each with 100L in them. You then call it “zero level”. You add 1L to one barrel and 2L to the other. Obviously, one does not have twice as much water as the other.
And I think he made a booboo. I mean, sure, it’s only a difference of 400C, but that’s almost a 20% error.
Maybe it’s because I’m an astronomer, when you’re making a statement like like “nearly twice as hot” (emphasis mine), a 20% error doesn’t sound like a mistake, to me; he was just speaking in round numbers. Contrary to the standard fictional devices, scientists don’t quote everything out to the Nth decimal place.
And notice that the numbers he gives in Farhenheit are only given to two significant figures, i.e. ± 10%. (I’d assume that the conversions to Centigrade were done by someone else as the article was being written, and they kept too many sig figs!)
Definition of an astronomer:
Someone who’s happy to get the order of magnitude of the exponent right.
Well, the joke was that this one flaw ruined…
…meh, never mind.
From a measurement theory angle, all measurements belong to a scale type, and the operations permissible on each vary. So meaningful statments will vary according to the scale
Fahrenheit and Celsius belong to the interval scale, which:
preserves order (allowing us to rank and make comaprisons such as >,=, <)
captures information about the size of interval between classes (allowing us to add and subtract) So for example, drop in temperature, from 20 degrees C to eighteen is a drop of two degrees, as is a drop from 10 degrees C to 8 degrees C
In order to make meaningful statements about the ratios, the measurement needs to be of the ratio scale (e.g. Kelvin) which in addition to the above
captures information regarding the size of the ratios
has a zero element (as previous posters have stated)
the measurement mapping must start at zero and increase at equal intervals
This allows us to same one piece of string is three times as long as another, for example.
So the guy in question was making statements which are only meaningful for the ration scale but applying them to measurements in the interval scale.
He should have given the temperature in Kelvins in order to make the statement, then the temperatures could then have been given as Fahrenheit in order to allow people to get a handle on just how very, very hot it gets.
Yup, that’d be us! Its a bonus when your calculations predict your observations exactly. As mine just have.
Bloody suspicious, I’d say!
