How fast is too fast?

It was a dark and stormy night…or something like that.  It is raining, hard.  You got caught out on your bike and just want to get home where it is warm and dry.  Fast.  But how fast is too fast?   Nine times the square root of your tire pressure.    What?

Hydroplaning occurs when you are going fast enough that the tire no longer touches the road surface.  Instead, the tire rides on the top of the water surface and you lose the ability to steer.   If there is standing water on the road surface the approximate speed at which you will hydroplane is calculated by the formula 9 times the square root of the tire pressure.  So if your tires are filled to 36 psi you will hydroplane at 54 M.P.H. (9 x SQRT of 36 = 54).  This equation words for bikes, cars, and airplanes.

So if you are trying to go fast with water on the road you are practically guaranteed to lose control if you exceed our formula speed for hydroplaning.  But beware; oil on the road, a painted surface, etc. can still take you out at much lower speeds.  As always, caution should prevail.

If you have any corrections, bitches or gripes go ahead and fire at us.  We appreciate having you here and welcome the discussion.

Why wearing polarized sunglasses can kill you.

These are essentially polarized sunglasses:

Polarized sunglasses block visible light as it comes in from an angle other than straight in at the eyes.  It is as though you were looking through the slats of a vertical blind.  If you are in a beach chair looking at the ocean or are on a boat trying to catch the big one, you can’t beat polarized lenses.

However, if you are going Mach 5 with your hair on fire sitting on or in a high performance machine you want to see that slick spot as it looms ahead of you.  Polarized glasses would obscure the subtle differences in road conditions and oil or ice spots you would want to adjust for.

On the slopes?  Same rules apply.  That ice patch you need to carve extra for or that line in the bumps you are trying to find are a lot harder to see with polarized lenses.

How about our flyers?  The FAA strongly recommends against use of polarized lenses.  Not only do they obscure digital gages and IPads, they interact with the windscreens to make a rainbow effect on the glass.

Then what is all the rage for polarized lenses?   There are definitely both high quality lenses and crappy lenses out there.  Good marketing years ago moved the majority of the sunglasses towards polarized lenses and the buying public came to believe that it was the superior technology.  Since most of the best lenses happen to be polarized, polarized lenses became the best of what was available to choose from.  Lately, some of the better sunglass manufactures are beginning to recognize the merits of non-polarized lenses and are beginning to offer great lenses in glasses that are not polarized.

Regardless of the lenses you chose, polarized or non-polarized, it would be foolish to not at least choose a lens that offers UVA and UVB protection for the long term safety of your sight.  Of course, if you want a great non-polarized sunglasses option we feel that Ra Vision Gear offers the best sunglasses available.

If you have any corrections, bitches or gripes go ahead and fire at us.  We appreciate having you here and welcome the discussion.

Why airplanes fly, curveballs curve and the shower curtains sucks to your leg.

Welcome to the first post of our musings about the machines that excite us.  We wanted to create a place where we can kick back, crack a beer and tell stories of adventure or geek out about how things work.  The stories may only be mostly true and the technical explanations not perfectly accurate but we will do our best to keep it entertaining and sometimes informative.  We are glad to have you on board for the ride.

This is a pretty basic subject to most of our pilot friends but we thought we would start out with an attempt to explain how airplanes fly.  To do this we need to talk about two principles that are utilized when designing an aircraft.

First, to make a point, inhale deeply and then blow out. You would realize that you pressed your lips together to make a small hole for the air to flow through. You instinctively applied the Venturi Effect, increasing the speed of air by constraining the area though which it flowed. This is the first principle to allow airplanes to fly: Air velocity will increase as it moves through a constriction. To keep things simple think of the wing as your bottom lip with the air accelerating over the top.

The second principle that allows flight is called the Bernoulli principle. This principle says that the air pressure on a surface is lowered as the air velocity is increased over that surface. The faster the air moves over a surface the lower the air pressure on that surface.

So, again imagine the wing as your lower lip with the air velocity over the top of the wing faster than the bottom of the wing. Since the speed of air over the top of the wing is greater than the bottom the pressure is less on the top than the bottom. The pressure is greater on the bottom of the wing compared to the top and the wing is “pushed” upwards and thus is flying.

The same principle works for a curve ball. Since the pitcher puts side spin on the ball, as the ball moves towards home plate, one side of the ball has greater airflow compared to the other side of the ball. This difference in air velocity on each side of the ball causes a higher pressure on one side of the ball and a lower pressure the other side. This difference in pressure causes a “push” which pitchers call a curve. The same principles apply to a “slider” and “sinker” too.

What about that annoying plastic shower curtain that sucks in and sticks to your leg. As the water falls from the shower head to the shower floor the air is accelerated inside the shower. The velocity difference between the inside compared to the outside of the shower causes the pressure difference that moves the curtain inwards, and to stick to your leg.

If you have any corrections, bitches or gripes go ahead and fire at us.  We appreciate having you here and welcome the discussion.