Is your canoe's wake angle greater or lesser when you travel faster or slower, in a heavier canoe or a lighter canoe, in deeper water or shallower water, in salt or fresh water, if your canoe is made of wood or vibranium/adamantium?
In 1887, the famous British physicist, mathematician, engineer and amateur sailor, Lord Kelvin (1824-1907), computed mathematically that the wake angle for all surface vessels is always 19.47° no matter whether it is an ocean liner, a Rushton canoe or a duck, and no matter the speed. The following diagram illustrates the "Kelvin wake angle":
However, in 2013, two physicists examining satellite photos of wakes argued that the constant Kelvin wake angle might actually narrow for a certain class of Froude numbers, and published their research in the Physical Review Letters. That prompted other physicists and mathematicians at M.I.T. and elsewhere to criticize the Kelvin critics and to suggest they were being fooled by the photos.
This 2021 article reviews the controversy and seems to support the 19.47° Kelvin wake angle except, perhaps, when there are shear flows in different layers of water.
Anyone who figures this all out . . . wake me.
In 1887, the famous British physicist, mathematician, engineer and amateur sailor, Lord Kelvin (1824-1907), computed mathematically that the wake angle for all surface vessels is always 19.47° no matter whether it is an ocean liner, a Rushton canoe or a duck, and no matter the speed. The following diagram illustrates the "Kelvin wake angle":
However, in 2013, two physicists examining satellite photos of wakes argued that the constant Kelvin wake angle might actually narrow for a certain class of Froude numbers, and published their research in the Physical Review Letters. That prompted other physicists and mathematicians at M.I.T. and elsewhere to criticize the Kelvin critics and to suggest they were being fooled by the photos.
This 2021 article reviews the controversy and seems to support the 19.47° Kelvin wake angle except, perhaps, when there are shear flows in different layers of water.
Anyone who figures this all out . . . wake me.