PDA

View Full Version : Silly science in a Reuters article



Donnie B.
2002-Apr-11, 09:22 AM
Neutron stars are almost unimaginably dense: a teaspoon of neutron star material weighs a billion tons (1.016 billion tonnes).

Now that's a really accurate teaspoon...

Has anyone at Reuters ever heard of "significant figures"?

GrapesOfWrath
2002-Apr-11, 10:56 AM
Didn't we talk about the "normal" human body temperature before? 98.6 degrees farenheit, right? Converted to celsius, that's 37, exactly.

The average human body temperature was calculated to be 37 degrees celsius to the nearest degree celsius, so you'd expect a range of 36.5 to 37.5. Since degrees celsius are twice the size of degrees farenheit, the range would translate to 97.7 to 99.5, but people expect it to be more like 98.55 to 98.65.

Regardless of whether the 37 degree figure was accurate or not.

Jim
2002-Apr-11, 02:24 PM
Neutron stars are almost unimaginably dense: a teaspoon of neutron star material weighs a billion tons (1.016 billion tonnes).

They're making a conversion from US units to Imperial units. But I think the got it wrong.

1 short ton = 2,000 lbs
1 long ton = 2,240 lbs
1 tonne = 1,000 kg = 2,205 lbs
1 long ton = 1.0161 tonne

But, normally if the measurement is given as simply "tons" it means short tons. So they should probably have said "one billion tons (0.907 billion tonnes)".

It's Mars Polar Lander all over again!

Donnie B.
2002-Apr-11, 06:36 PM
But, normally if the measurement is given as simply "tons" it means short tons. So they should probably have said "one billion tons (0.907 billion tonnes)".

I didn't even think to check their conversion... funny that they got it wrong on more than one axis.

Either way, my point stands: when their source told them a teaspoon of neutronium weighs a billion tons, he didn't mean that your scale would read exactly 1,000,000,000.00 Tons. He meant that it would weigh a whole heck of a lot. Saying a billion tons equals 1.016 (or .907) tonnes is meaningless in this case; both would equal a billion tonnes to the proper number of sig-figs (namely, one).

Or, to put it more succinctly, they took a ballpark figure and turned it into Gospel. Just as GoW's example shows!

Andrew
2002-Apr-12, 07:18 AM
On 2002-04-11 10:24, Jim wrote:

They're making a conversion from US units to Imperial units. But I think the got it wrong.

1 short ton = 2,000 lbs
1 long ton = 2,240 lbs
1 tonne = 1,000 kg = 2,205 lbs
1 long ton = 1.0161 tonne

But, normally if the measurement is given as simply "tons" it means short tons. So they should probably have said "one billion tons (0.907 billion tonnes)".

It's Mars Polar Lander all over again!




They're not wrong.
They're converting British Imperial to metric. An American ton is called a short ton and a British ton is called a long ton. See your own conversion factor for long tons to metric tonnes (1.0161). The author was most likely British, or using British measurements.

<font size=-1>[ This Message was edited by: Andrew on 2002-04-12 03:19 ]</font>

Jim
2002-Apr-12, 01:26 PM
On 2002-04-12 03:18, Andrew wrote:


On 2002-04-11 10:24, Jim wrote:

They're making a conversion from US units to Imperial units. But I think the got it wrong.

1 short ton = 2,000 lbs
1 long ton = 2,240 lbs
1 tonne = 1,000 kg = 2,205 lbs
1 long ton = 1.0161 tonne

But, normally if the measurement is given as simply "tons" it means short tons. So they should probably have said "one billion tons (0.907 billion tonnes)".

It's Mars Polar Lander all over again!




They're not wrong.
They're converting British Imperial to metric. An American ton is called a short ton and a British ton is called a long ton. See your own conversion factor for long tons to metric tonnes (1.0161). The author was most likely British, or using British measurements.


Okay, I can buy this... except that the original article was from US sources, and they (probably) used short tons; which would mean Reuters assumed long tons.

Anyway, Donnie has a point. Converting to 1.016 billion anything is just a bit anal. Reuters would have been better served to say "approximately 1 billion tonnes" than to use a precise conversion of a very large and approximate amount.

Andrew
2002-Apr-12, 01:33 PM
Yeah, they need a primer on accuracy and estimation.