Comments on: Walking in the rain http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html Financial independence, frugality, self-sufficiency, ecology, capitalism, and voluntary simplicity Fri, 21 Nov 2008 21:20:09 +0000 http://wordpress.org/?v=2.6.3 By: Jacob http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-1539 Jacob Wed, 09 Jul 2008 14:51:35 +0000 http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-1539 @Alex K - If you assume that the rain velocity is directly down in the ground frame, it would still be coming in from the front in the moving frame due to aberration. The angle would be atan(v_you/v_rain) and the incident velocity would increase to v=sqrt(v_you^2+v_rain^2). You can consider these as vectors and dot them with your surface normals (just pretend you're a cube). Both are time dependent. Regardless, I grew up in a country with lots of rain. It's better to have your head and shoulders very wet than to have your entire front even slightly wet. When you arrive you take your jacket and hat off. You can probably use one of those wind diagrams showing apparent temperature. Here it's currently 110F. The best strategy on a bicycle is to go fast to get the sweat evaporation as high as possible. @Alex K - If you assume that the rain velocity is directly down in the ground frame, it would still be coming in from the front in the moving frame due to aberration. The angle would be atan(v_you/v_rain) and the incident velocity would increase to v=sqrt(v_you^2+v_rain^2). You can consider these as vectors and dot them with your surface normals (just pretend you’re a cube). Both are time dependent.
Regardless, I grew up in a country with lots of rain. It’s better to have your head and shoulders very wet than to have your entire front even slightly wet. When you arrive you take your jacket and hat off.

You can probably use one of those wind diagrams showing apparent temperature. Here it’s currently 110F. The best strategy on a bicycle is to go fast to get the sweat evaporation as high as possible.

]]> By: Alex K http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-1536 Alex K Wed, 09 Jul 2008 06:00:18 +0000 http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-1536 Hey Jacob I think you are wrong about the theory of walking slow to stay drier. I live in a place where it rains about 3x per year so this is not from experience but mathematically speaking. If we assume a uniform distribution of raindrops in a space, then the number of raindrops crossing a moving vertical plane (representing the front of your body) in a given distance covered is only a function of the raindrop volumetric concentration, not the velocity of the plane. The raindrop velocity (if assumed to be downward) would not contribute to frontal wetness either because it is in a direction parallel to the plane. However, the top surface of your body will be much wetter when walking slowly, since that will be the raindrop volumetric concentraion X body top area X rain drop velocity X time in the rain. I have also thought about another similar dilemma. While riding my motorcycle in cold weather I wonder if it is better to go faster and get home quicker, but with more cold wind on me, or go slower and be in the cold longer but with less wind. I pick faster every time. Hey Jacob I think you are wrong about the theory of walking slow to stay drier. I live in a place where it rains about 3x per year so this is not from experience but mathematically speaking. If we assume a uniform distribution of raindrops in a space, then the number of raindrops crossing a moving vertical plane (representing the front of your body) in a given distance covered is only a function of the raindrop volumetric concentration, not the velocity of the plane. The raindrop velocity (if assumed to be downward) would not contribute to frontal wetness either because it is in a direction parallel to the plane.

However, the top surface of your body will be much wetter when walking slowly, since that will be the raindrop volumetric concentraion X body top area X rain drop velocity X time in the rain.

I have also thought about another similar dilemma. While riding my motorcycle in cold weather I wonder if it is better to go faster and get home quicker, but with more cold wind on me, or go slower and be in the cold longer but with less wind. I pick faster every time.

]]> By: Thrifty Canadian http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-357 Thrifty Canadian Thu, 07 Feb 2008 20:50:28 +0000 http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-357 Let's not talk more than walk but if you could write a post which titles "Winter walking equipment to last 15 years or thousands of miles", it would be really cool. Thanks a lot Jacob. Let’s not talk more than walk but if you could write a post which titles “Winter walking equipment to last 15 years or thousands of miles”, it would be really cool.

Thanks a lot Jacob.

]]> By: Jacob http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-341 Jacob Thu, 07 Feb 2008 02:15:31 +0000 http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-341 This configuration would work down to 0C. For 0F, I've used a turtle neck + wool sweater + zip in fleece vest under the goretex shell. The head would be covered in a balaclava + a neck gaiter with the jacket hood going over that. If the snow/wind is really bad, the eyes can be covered with military netting (like net undershirts). It doesn't fog over like ski goggles. Legs would be long johns, and slacks covered by rain pants. I'd put a thermal sole in my hanwags (medium hiking boots / light mountaineering), then cotton socks covered with thermal socks. Gloves would be finger gloves covered by highly technical waterproof gloves. This is not warm enough to stand or sit in! If I got cold I simply moved faster. If I got too warm, I moved slower. This is obviously not something one should wear while venturing into riskier areas where there are no other humans in sight. In that case I would go with wool. This configuration would work down to 0C. For 0F, I’ve used a turtle neck + wool sweater + zip in fleece vest under the goretex shell. The head would be covered in a balaclava + a neck gaiter with the jacket hood going over that. If the snow/wind is really bad, the eyes can be covered with military netting (like net undershirts). It doesn’t fog over like ski goggles. Legs would be long johns, and slacks covered by rain pants. I’d put a thermal sole in my hanwags (medium hiking boots / light mountaineering), then cotton socks covered with thermal socks. Gloves would be finger gloves covered by highly technical waterproof gloves. This is not warm enough to stand or sit in! If I got cold I simply moved faster. If I got too warm, I moved slower. This is obviously not something one should wear while venturing into riskier areas where there are no other humans in sight. In that case I would go with wool.

]]> By: Thrifty Canadian http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-336 Thrifty Canadian Wed, 06 Feb 2008 17:05:10 +0000 http://earlyretirementextreme.com/2008/01/walking-in-the-rain.html#comment-336 Another good post with details. I'm wondering if you're walking in the minus zone with snow, how would you deal with the cold. Would you use different boots or replace shell with down jacket? Another good post with details. I’m wondering if you’re walking in the minus zone with snow, how would you deal with the cold. Would you use different boots or replace shell with down jacket?

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