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Comment by Jedd | Hacker News Reader

I really can't tell if this is an expensive and sophisticated troll, or they're genuinely bewildered.

Using a graphic showing several thousand kilometre-wide pool with one edge touching a pole is disingenuous. At that scale, yes, you're going to observe Coriolis effect.

Hurricanes don't form within five degrees of the equator -- that provides a useful data point for the lower end of the scale required to see the effect.

Sydney's 34 degrees south, but the velocity delta at 1 metre distance would be dwarfed by various other environmental factors and starting conditions. (Temperature deltas and wind, especially for the outdoor pool, vortices produced by the elbow close to what looks like a 19mm outlet, texture on the PVC liner, etc.)

Plus of course in any dual-pool-emptying experiment, there's a 25% probability of this result.

I'm miffed that a single experiment gets described as 'this is science, dude!'.

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I'm pretty sure one of them has a PhD in physics, and the other is a rocket scientist (I think for NASA). So, these guys understand science. What they do in their YouTube videos is bring science to the masses-- not always in the most disciplined form. They've interviewed some of the world's leading scientists, have taught Neil deGrasse Tyson a thing or two about hellicopter physics, etc. I think they are doing a lot of good, in the same vein as Bill Nye.

Of course you couldn't take what they did and publish it, but it's good enough to explain a concept to a large group of people (and maybe, sure, on such a small scale it's not possible and was that 25% chance of happening). Don't forget that the videos are for both entertainment and for learning purposes and, while potentially dubious, it is still an experiment and I trust these two guys (both of which have Ph.Ds in some form of physics, I believe) to perform the experiments well. I would absolutely consider what they did popular science.

The video description says: "For the record Destin and I repeated the experiment 3-4 times each in each hemisphere and got the same results every time."

25% for independent yes but not conditional.

Given the result was shown on the video there is a 100% probability it would happen for the attempt shown on the video.

"I'm miffed that a single experiment gets described as 'this is science, dude!'".

A single data point is still a data point and this is still science.

> A single data point is still a data point and this is still science.

Both presenters are enthusiastic and engaging, undeniably. And yes, this is a data point.

But this isn't science.

Partly because they claim they've 'proved it because we eliminated variables' (3'57"), when they clearly haven't.

Partly because one of the basic tenets of science is repeatability. As I noted above, there's a 1 in 4 chance of getting this result if you assume equal probabilities of clockwise / counter-clockwise. That assumption should be the starting point of any experiment around this effect.

Food colouring should have been put in - for some of the repeated experiments at least - before the valve was open, to confirm the water was in fact still motionless. (Or to show that it wasn't.)

Similarly that little match-stick cross on one of the pools - those should have been present on both pools, probably several of them, spread around the surface (though surface motion is not necessarily indicative of sub-surface movements).

I could go on.

It really isn't science. It's pop science, and although I do enjoy the Smarter Every Day guy, I do agree it's kinda disservice to understanding how things work. They should have repeated the experiment; gotten some sensor experts to see if they could quantify the "stillness" of the water, etc.

We've had pop science before (Mr Wizard anyone?), and we're just seeing more of it today. Real science is slow, methodical and doesn't infer causality from one experiment. It says, "Maybe x caused y; let's do some more tests." It's the QA person who says "Happy path works. Let's break it and see if we can inject some Javascript."

Bill Nye is a mechanical engineer/comedian/kids host. Tyson is physicists. They're smart, but they're not experts on everything.

Like I said, I like these guys, but I realize it's not science. It's half entertainment/half makes you think. In these videos it's fun, but in the political arena, _science_ presented this way can be weaponized:

https://www.youtube.com/watch?v=yecefLsE44U

I agree about Bill Nye, that he's more of a science educator than expert about any one specific topic, but Tyson is definitely an expert on astrophysics. He talks about a lot of stuff that he isn't an expert in because he's a popular guy, and for that reason I'm not very fond of his speaking engagements, but it's not fair to say he's not an expert at anything.

"They should have repeated the experiment;"

From the video description:

"For the record Destin and I repeated the experiment 3-4 times each in each hemisphere and got the same results every time."

That wasn't mentioned in the video, so I missed that (I usually avoid clicking 'read more' on youtube descriptions).

'3-4 times' sounds a bit wobbly -- I'm hoping that they meant they repeated it 3 times in one place, 4 in the other.

I'm aware that I'm likely coming across as curmudgeonly.

My other half is a science educator, so I'm also very aware of the problems of getting kids (or even adults) excited about science.

On the other hand, I don't like the pseudo-science cruft the media and our society is full of, and I suspect there's some vague links between misrepresenting what the scientific method actually looks like, and people taking advantage of that growing murkiness.

I'm not questioning the credentials of these guys. Just the validity of this ersatz experiment.

> ... gotten some sensor experts to see if they could quantify the "stillness" of the water, etc.

They did have some archetypal (glasses-wearing) geek do a quick sound bite towards the beginning describing the effect being observed at small scales as 'bunk', but that's all we get from that side of the argument.

Interestingly in the video you can clearly see there's direct sunlight hitting one side of the indoor pool, and parts of the outdoor one. And during the time lapse section of the video, you can see surface debris on the indoor pool swirling around.

If the Coriolis effect worked at this scale, then you'd see consistent circular motion of water in these sized tubs even without emptying.

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