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Walking in a straight line

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pagetheoracle
1104641.  Mon Dec 08, 2014 9:11 am Reply with quote

Has anyone checked if it is always to the right the spiral starts? Could it be different for left handed, bias people? Is it to do with one leg being shorter than the other?

 
14-11-2014
1104661.  Mon Dec 08, 2014 10:28 am Reply with quote

pagetheoracle wrote:
Has anyone checked if it is always to the right the spiral starts? Could it be different for left handed, bias people? Is it to do with one leg being shorter than the other?


Yes (no, not always to the right), no, no (https://www.youtube.com/watch?v=yzpUKET1Ki0#t=21m15s).

 
suze
1104673.  Mon Dec 08, 2014 12:01 pm Reply with quote

See also a thread beginning at post 886983.

It's not the case that the spiral is always clockwise, but it usually is - and this is true whether the person walking be right handed or left handed.

One question which I asked there which we didn't resolve. The research which discovered that the spiral is usually clockwise was conducted in Kansas. Had the research been conducted in Australia, would it have produced the opposite result?

 
14-11-2014
1104675.  Mon Dec 08, 2014 12:58 pm Reply with quote

suze wrote:
It's not the case that the spiral is always clockwise, but it usually is - and this is true whether the person walking be right handed or left handed.


The least likely result is a draw, but what's usual in San Francisco and why would that be true? The Mythbusters video:

Adam walking: countercw (GPS data @ 5:00)
Jamie walking: cw (GPS data @ 5:39)
Adam swimming: countercw (no GPS data, evidence @ 13:09)
Jamie swimming: countercw (GPS data @ 14:08)
Adam driving, first attempt: countercw (finally 2 out of 3, GPS data @ 23:38)
Jamie driving, first attempt: countercw (finally 2 out of 3, GPS data @ 23:41)
Adam walking blindfolded: countercw (GPS data @ 34:16)
Adam and Jamie, helping eachother: countercw (GPS data @ 37:26)

Countercw is a clear winner, excluding second and third attempts and educated ways to avoid the problem. It doesn't support the claim that it's usually clockwise. Countercw wins, 7 out of 8 first attempts. But perhaps the Mythbusters aren't usual.

 
ellylles
1104736.  Tue Dec 09, 2014 4:46 am Reply with quote

surely it would make more sense for it to be related to left- or right- footedness rather than handedness? (except in examples like swimming and driving where the legs are used less).

handedness and footedness are not necessarily on the same side - whilst most right-handers are also right-footers, apparently most left-handers are not left-footers. this means that the overall majority of people must be right-footed which would explain why spirals are usually clockwise - the minority of counterclockwise spirals could relate to the minority of left-footers.

I can't put my hands on my reference material at the moment, but I remember covering this for a childrens TV science series a few years back!

 
14-11-2014
1104756.  Tue Dec 09, 2014 7:33 am Reply with quote

ellylles wrote:
surely it would make more sense for it to be related to left- or right- footedness rather than handedness? (except in examples like swimming and driving where the legs are used less).


What about the direction of the wind/rain, sounds, or the position of the sun?

The results of driving were 2 to 1, twice, but that may have to do with compensating, so I only used their first attempt, which was countercw. The crash, not the first move.

Most questions can actually be answered by trying this at/near home, but make sure that a health and safety officer is watching you.

I wouldn't use blindfolded straight line field walking for charity, offering more than a refund when somebody reaches the destination within a minute, because cheating is easy (vibrating phones, or sounds the supervisor cannot hear or recognize, and so on).

 
14-11-2014
1108471.  Thu Jan 01, 2015 4:57 am Reply with quote

suze wrote:
The research which discovered that the spiral is usually clockwise was conducted in Kansas. Had the research been conducted in Australia, would it have produced the opposite result?

Apparently it wouldn't. GI:

mentalfloss.com wrote:
File under "News to Me": you know that old story about how northern hemisphere toilets flush counter-clockwise, and southern hemisphere toilets (and buckets, drains, and such) flush clockwise, due to the Coriolis effect? It's bogus! Today I learned that while the Coriolis effect is significant for hurricanes, it's not strong enough to make toilets flush in different directions at different points on the Earth. The real cause of "backwards"-flushing toilets is just that the water jets point in the opposite direction. Mind blown. (Mind blown even more because this was the inciting event on a Simpsons episode, and everybody knows cartoons are never wrong.)

http://www.ems.psu.edu/~fraser/Bad/BadCoriolis.html
No punner wrote:
Why do teachers claim that a draining sink reflects the rotation of the Earth?

A trip to the school washroom (let alone the ones at home) will reveal drainage in both directions.

Sigh... I donít know why teachers do claim this. I can but assume that those who do so just never feel any need to wash their hands --- or their minds.


it works on large scales. But on small scales (like in your toilet, sink, or bucket), the rotation of the Earth itself is much weaker than other forces -- like the force of water jets in a toilet, or the force of water hitting slopes in a sink.

 
suze
1108502.  Thu Jan 01, 2015 8:25 am Reply with quote

Thanks for that, 14-11. The way it was taught when I was about nine was that it was bathtubs which emptied "backwards" in the Southern Hemisphere. And do you know, I think I may have believed that ever since!

Someone then asked what happened to the water in the bathtub if it happened to be positioned exactly on the Equator. I'm not sure that the teacher had an answer for that, but the answer is now clear - the bathtub would drain the same way it always does.

Incidentally, the link in my post upthread is wrong - it should be post 866983.

 

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