Cool results and methods, but I'll disagree with one of the article's statements.
In talking about the work done on e. coli, a non spherical cell, it says the methods had to be changed due to "turbulence" attendant to the e. coli's departure from sphericity of the earlier tested yeast cells.
My rough calcs show a Reynolds number in the range of 1e-6. The onset of turbulence happens at Reynolds numbers of ~2300 for pure water. The 1% sugar solution would have a negligibly higher turbulence onset Reynolds number.
I expect the need for different methodology wasn't turbulence, but the difference in drag presented by an elongated e. coli compared to a spherical yeast cell.
atombender · 49m ago
> A typical kitchen scale has a sensitivity of 0.1 grams
As someone who's been looking for a good kitchen scale, your typical kitchen scale is actually precise to then nearest gram at best, and in terms of precision it's probably not very precise at all. 0.1g is rare, and these usually cost more, especially if they're actually reliable.
madcaptenor · 13m ago
I hadn't thought about this, but this is probably why in baking recipes where amounts of flour, sugar, etc. are specified by weight, baking powder and any spices will be specified by volume.
Of course this is all false precision once you start adding eggs.
Metacelsus · 1h ago
Very cool. I wonder how the accuracy of weighing a single cell would compare to counting a huge number of cells (let's say 10^9) and doing a bulk weight measurement. The problem would shift to being able to accurately count cells, and being able to exclude the effects of liquid trapped in between the cells.
franciscop · 45m ago
Some surprising science fact that many people don't know, an animal egg (chicken, birds, etc) is a single cell, so there's a huge variability in the weight of a cell.
btilly · 21m ago
I found this claim unbelievable, but it is mostly true. It isn't quite the whole egg, it is just the yolk. But that's still a very large cell!
It's analogous to the mammalian egg, but a lot bigger. (And IIRC the egg is the largest cell in humans.)
lblume · 1h ago
> Cells are physical objects
This might sound trivial, but in me sparks a much larger point: which kinds of experimental designs and tests might we miss when engaging in a special science? In establishing dedicated methods I think it's highly likely for there to be low-hanging fruits of experimental setups not considered due to prevalence of these very specific frameworks.
shauniel · 1h ago
Asimov really is a breath of fresh air. Love their content
In talking about the work done on e. coli, a non spherical cell, it says the methods had to be changed due to "turbulence" attendant to the e. coli's departure from sphericity of the earlier tested yeast cells.
My rough calcs show a Reynolds number in the range of 1e-6. The onset of turbulence happens at Reynolds numbers of ~2300 for pure water. The 1% sugar solution would have a negligibly higher turbulence onset Reynolds number.
I expect the need for different methodology wasn't turbulence, but the difference in drag presented by an elongated e. coli compared to a spherical yeast cell.
As someone who's been looking for a good kitchen scale, your typical kitchen scale is actually precise to then nearest gram at best, and in terms of precision it's probably not very precise at all. 0.1g is rare, and these usually cost more, especially if they're actually reliable.
Of course this is all false precision once you start adding eggs.
http://cnet.com/home/kitchen-and-household/appliance-science... verifies this.
This might sound trivial, but in me sparks a much larger point: which kinds of experimental designs and tests might we miss when engaging in a special science? In establishing dedicated methods I think it's highly likely for there to be low-hanging fruits of experimental setups not considered due to prevalence of these very specific frameworks.