Stories tagged estimating

May
14
2010

Leaky pipe: I tried counting each particle myself, but didn't get very far.
Leaky pipe: I tried counting each particle myself, but didn't get very far.Courtesy BP
National Public Radio reported this morning about several methods being used to guess how much oil, methane, and other stuff is leaking out of the BP well at the bottom of the Gulf of Mexico.

It's interesting to see how various members of the scientific, government, and business community go about trying to guess the real size of the oil spill. NPR worked with a scientist to estimate the size of the leak by literally watching the video from the subs working on the well, and using a computer to estimate the amount of fluid gushing out over time--a technique called PIV. They got a scary big number. The Coast Guard (and BP) have been looking at satellite images of the oil slick. They look at the size of the slick and come up with an esitmate, based on what they know about how oil disperses in water. BP likes this number because it's not super big. Another group did some estimates based purely on the size of the pipe from which the oil is leaking. This number was also big, but there seems to be some scuttlebutt about the actual size of the pipe.

So what does big"" even mean? We mortals have a hard time understanding the scope of numbers after they start to get lots of zeros on them. So we contextualize these numbers. Everyone seems enamored with using the Exxon Valdez disaster as base unit for oil-spill-disasterdyness. Less than Valdez, bad, but good. Bigger than Valdez, bad. A factor of ten worse than Valdez, whoa-momma...we should really...[insert action here].

This story is a great reminder to think critically about the way we think about science in the news.

The oil spill is now X big.

Wait, how did they even come up with that number?

The oil spill has now surpassed a slightly arbitrary point in the past or record.

Um, yes, and.... Is there's a specific number past which this spill will dictate a different action? I'm totally fascinated with all these stories about the scope of the spill, but I do sort of wonder how far beyond, "really freakin' bad" we need to quantify the oil spill. What do you think?