Am 24.02.2015 um 17:31 schrieb clipka:
> Am 19.02.2015 um 09:25 schrieb scott:
>>> I'm building a bubble around my spaceship to protect from "drag" at
>>> interstellar velocities. This site says that for subsonic craft a
>>> parabola is a better shape for the nose. However, an ogive is better at
>>> supersonic speeds.
>>>
>>> http://www.aerospaceweb.org/question/aerodynamics/q0151.shtml
>>>
>>> Which applies in outer space? Or, should I not use either and use a
>>> teardrop shape instead?
>>
>> What is the speed of sound in space... I don't think any "supersonic"
>> designs are necessary.
>
> In an ideal gas, the speed of sound is proportional to the square root
> of the pressure... until relativistic effects kick in, I guess.

In numbers: Speed of sound in hydrogen and helium is roughly 10^3 m/s at 
atmospheric pressure. With the pressure in outer space being lower by a 
factor of about 10^14, according to Newtonian mechanics the speed of 
sound in this medium would be about 10^7 times higher, i.e. 10^10 m/s - 
exceeding the speed of light by about 1.5 magnitudes.

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