Scientific Myths

Actually water in the southern hemisphere does spin down the drain in the opposite direction of the northern hemisphere. Lookup the Coriolis effect.

Agreed : The claims are taken from their editorial introducing the issue. As a critical reader you are sure to enjoy what they have to say about biomass replacing gasoline. Parse the Myth and response titles carefully.

Editorial license- revoked.

milo

I've read about Coriolis acceleration effect even in textbooks and being both lazy and naive blindly relied on that printed out statement until decided to perform experiment. I had found no evidence that water spins at the same direction for different cases for my location I've got both (Northern semisphere). I suppose it depends upon of a particular geometrical shape of sink or where had been directed initial jolt.

Case where Coriolis effect is [hopefully] working is the steepness of opposite river's banks.

Btw I'm curious which should be water's spinning direction on an equator? :).

regards

caramba

Water in a sink moves too quickly (and not far enough) to be affected by the Coriolis force.

May be it is not affected by the C force . But your argument is wrong since the C force is proportional to velocity and rotation. So that for constant rotation the higher the speed the bigger the force.

Sorry but what you wrote is not physically correct.

While your reasoning about rotational moments is correct and sinks and tubs geometry and prior flow have a great deal of influence over rotation rate these are normally random influences.

Every flow system begins from a standing start. The bias the favors Coriolis arises from the uneven distribution of mass asymmetrically below the sink or tube. Since it is a bias in the curvature of space time imposed on a pseudo random population of molecular velocities that gives rise to the bias in initial rotation centripetal forces are not a factor at all except in sustaining and strengthening the vortex once it has chosen its direction of rotation.

Experimental studies rather than theoretical computations have shown a strong bias in terms of preferential rotation in each hemisphere. It is really only strong in mid-latitudes, nuetral at the equator and should be,(I don't know if its been tested weak at the poles.)

I read the article you listed and while I applaud the remediation efforts at Oak Ridge I have seen the data and considered bidding on some of the work and I would be surprised if anyone knowledgable considers the work complete. I would call it 0 for 3 for your initial efforts at myth busting. Fortunately for all of us, radioactive contamination is a short lived problem. ;-)

"Pseudo random?"

Does this mean some of the molecules move about randomly and others do not? Or does it mean that they all move about randomly for a set number of movements and then everything starts over?

You just gave me an idea for a product no self-respecting federally-funded Coriolis laboratory should be without: The KrisDel™ Mighty-Morphin' PseudoRandom Molecular Movement Simulator: Construct an N-bit shift register and XNOR the last two bits. Feed this into the first stage and clock at Your Favorite Frequency. Each state represents a unique configuration of molecules. Sequence repeats after 2ⁿ-1 shifts. Scale as necessary.

Thanks, Dude!

There's nothing "pseuodo random" about molecular movement. It's 100% virgin random.

--

...Coriolis arises from the uneven distribution of mass asymmetrically below the sink or tube (sic). Since it is a bias imposed on a ..."

Sweet Jesus, son, don't you ever inhale?

LOL

Mr brown-ian will be really pissed...

milo

Hell yeah! I mean, what's the point in straining your eyes looking for hours at bits of crud floating around under a microscope when you can simulate the whole shootin' match on a supercomputer? Jeeeze! I mean, why build anything in hardware?!?

I'm with you here Bhankiii.

I would add in a word the Coriolis force effect could be noticed for relatively large scaled and long lasted Natural processes. Rivers' banks as I said before. For home conditions it's a dice game.

By the way as we're aware ours Sun system is rotating as well along with ours Galaxy.

"Coriolis force effect could be noticed for relatively large scaled and long lasted Natural processes. Rivers' banks..."

The curvature of river banks is more heavily affected by rocks or logs forcing a change in the direction of the current. Erosion on the outside of the curve then makes it self perpetuating until finally the bend becomes so extreme that during a flood the river will cut the neck, isolating the curved section and forming a billabong or oxbow lake or whatever it is called locally.

I doubt that coriolis effect has any significant influence on the process.

I said "could be" not "should be". I've read of that "fact" as well. I had no means to check it by myself. Maybe you're right.

Caramba, I'm trying to figure out your avatar. Correct me if I get this wrong:

You're using chopsticks to perform a frontal lobotomy on that fish, right?

<Just kidding!>

yes please - look it up.

This is a myth. Water moves too quickly to be affected by Coriolis forces. It is, however, responsible for the formation of hurricanes, which can't form within a few degrees on the equator due to the weakness of the forces, and which rotate anti-clockwise in the north, and clockwise in the south.

Can someone please sell me a toilet with the water jets pointed the other direction?

Maybe this is a big conspiracy, started by the toilet manufacturers to justify the design and sale of hemisphere 'regionalized' toilets!

Very interesting.

I was wondering always why that kind of mythes classified as scientific? Rather pseudo-scientific. Here's an obvious contradiction.

regards,

caramba.

Re: Direction water spins in N & S hemispheres.

I had a fluid mechanics lecturer who actually tested this out.

With care, the effect could be noticed, but the slightest movement of the water near the perimeter of the container was amplified by conservation of angular momentum so that the coriolis force was completely overwhelmed at the drain hole.

The effect is seen in the spin of hurricanes (N hemisphere) and cyclones (S hemisphere).

If one crosses the equator does the storm die out quicker?

Low activity and low oxygen increase the likelihood of yawning and everyone in the vicinity experiences these conditions simultaneously, so, yawning is contagious, sort of, keep up the good work, though, so far your O for 2.

So does anyone else see http://www.ornl.gov/info/ornlreview/v41_3_08/article06.shtml as being hyprocritical.

they claim that it is a myth that ethanol is replacing food crops, then they use an argument based on a theoretical method for extracting sugars from cellulose, then admit that they haven't figured out how to do it yet, and it might take 10 years.

see .. http://www.monbiot.com/archives/2007/11/06/an-agricultural-crime-against-humanity/ for the other side of the coin.

Myth : don't think so ...

Hi stoney,

"They claim that it is a myth that ethanol is replacing food crops, then they use an argument based on a theoretical method for extracting sugars from cellulose, then admit that they haven't figured out how to do it yet, and it might take 10 years".

I agree.

If it takes the researchers 10 years to crack the process required for turning cellulosic materials into ethanol, you can be sure it will take an extra 10 years before the commercialization will be on a large enough scale to make a difference.

Until then, much of the ethanol produced will be from food crops.

Of course in the case of sugar cane it can be argued that most of this goes into coke which may not be recognized as a food.

We can turn anything putrescible into a mixture of CH4 and CO2 by use of standard sewage treatment technology. With the right catalysts and process, this can then be turned into oil.

Why don't we turn our sewage into oil and make pollution work for us?

The fact that their website ends in '.gov' pretty much explains it, IMHO.

We used to play a game in boring classes where several of us would start to "fake yawn." Within 5 minutes a lot of other people would be yawning reflexively. One girl who knew what we were doing would ask us to stop because she couldn't stop herself.

It's also true that people will react to a cough by coughing themselves.

As others have pointed out the coriolus effect is reversed in the southern hemisphere and if there are no other effects involved the water will spin down the drain in the opposite direction just as cyclones south of the equator spin CCW.

Just looking at the ORNL "myths" I don't think I'll be subscribing any time soon. For example, the ethanol vs. food "myth:" Nobody said anything about celluloistic ethanol vs. food. The controversy has been with government subsidies that shift corn from food to ethanol production. There's no myth there.

Your tax dollars at work. The ORNL folks should find something useful to do; but I suppose "government efficiency" is at work here.

OK, off the soap box. Sorry!

I'm sure the contagion of a yawn is psychological. Your yawn will suggest the idea to anyone who sees it. If you are in a boring environment, the yawn will spread.

If you are in a brilliant, interesting lecture (if such things exist), your yawn will not transmit.

Think I might apply for a government research grant to pursue this one. Might even get a "golden fleece" award!

I've got 4 kids and when they're very young they are immune to the yawn although they can be known to provoke an outbreak. I used to try to lul them to sleep by yawning and talking as if I was half asleep...a really good fake yawn and I could make myself yawn again for real!

...all this while the little one stares me down, completely unaffected. This might be the infant equivalent of a brilliant, interesting lecture...daddy trying to his hardest to be unstimulating and boring.

Their immunity wears off eventually once they find out I am quite boring (a.k.a. not a huge fan of barbies)

Have you experimented with laughing? Something says me it would be more contagious :).

depends on how drunk the test subjects are, of course....

seriously, laughing isn't that contageous. Strange but true.

Maybe you're right,i.e. how drank or if you wish how young. It seems kids are more influenced to laughter. In a world of adults we're living only few of us (actors) can make natural "fake laughing".

Stand outside at a busy marketplace sometime and look straight up. Intently do this until a number of people become interested. When they ask (and they will), earnestly tell them, "Do you see it?" and point. When they ask, "What is it?" (and they will), say, "I don't know, but I've never seen anything like it!"

After awhile enough people will gather, looking for whatever-it-is. At that point quietly leave.

Works best on a partly-cloudy day. The uncertainty of whether or not the 'thing' has passed behind a cloud makes them look harder.

I pulled this at a Whataburger and the crowd looked for at least twenty minutes after I left. I discretely watched them as I enjoyed my burger and fries in the air-conditioned comfort of my car. LOL

Ah, the myth of scientific competency within a government agency! I think we're all familiar to some extent with that one...

The electronic and/or acoustic rodent & insect repellers are an example.

http://www.youtube.com/watch?v=TRrx2DWjWEo

http://www.youtube.com/watch?v=YM5lSBLNV_s&feature=related

any counter examples?

The discussion of coriolis forces brought to mind one of the great myths perpetuated in many physics classes - that the British fleet mistakenly used a northern hemisphere coriolis correction during the battle near the Falkland Islands during WWI and were thus unable to hit the German ships. Naval archives, common sense, artillery spotting practices, and the actual battle results all show this to have been most unlikely, yet it continues to be taught.