Viewing profile — bernulli

Maybe ;-) I do know that this course is still offered widely across the US, but maybe not within CS, and maybe not as a mandatory course. But, bottom line: if you're interested, it…

Sounds like a vanilla numerical math course?

It really is a tragedy of the commons with a changing demographic, where DINK are more prevalent that, say, 50 years ago, where most tried to contribute to raising the next generat…

But you still benefit even from the mere _existence_ of human beings younger than you are (e.g. service, manufacturing, research, medical, etc.). If you think you don't, think abou…

There's a simple word for people with that attitude: freeloader. It's pretty easy to understand: > I can not image the extra amount of work that get places on people that do not ha…

Just a few words from the other side of the table: I have the highest respect for students sitting there who juggle college, family, sometimes job, after having worked for a while …

Nitnitpick: and we know it isn’t and the corrosive propellants will contaminate surfaces: https://apps.dtic.mil/dtic/tr/fulltext/u2/a588174.pdf

Absolutely! I’m sure they analyzed for that, but backflow to the opposite direction of the nozzle is quite unintuitive but normal in rarefied flow, with propellant deposition next …

Thank you! I don’t think I understand the resolution then, could you explain a bit more? Say, I request data along a 100km line, every 10m. Do I get the same numbers if it’s in the…

Hi meteo-jeff, this looks really cool! I have two questions: 1) How does the spatial resolution come into this? Is it constant data all across the 2kmx2km (?) parcel with an abrupt…

Hi Otras, a few things to wrap this up for me, and thank you for your civil answer to a not so civil comment. 1st: I should have made this a 'yes and' rather than a 'no but' commen…

Not in the countries you refer to, and not in gliders in many European countries. Not 'everywhere' then.

That we can calculate the distance to a lightning to great accuracy (my example in the very first sentence) by accounting for a finite speed of sound only and assuming an infinite …

> The noise is always pointing behind the aircraft or any moving object due to lag. I don't know what a pointing noise is. > Light also encodes the direction to an objects past loc…

You're the one bringing up the finite speed of light that has zero relevance to the problem at hand.

Seems to cut either way.

The title is "How far behind a plane is its noise?" It's not. It's ahead of the aircraft.

> " These statements exhibit a fundamental misunderstanding of the phenomenon. It's not that the sound outpaces the aircraft. It's that light from the aircraft (reflected or transm…

It's just completely unrelated to why the aircraft passes you before you hear it.

Thank you.

For all practical purposes it's really completely unrelated to the speed of light. Nothing would change in the argument if light travelled instantaneously. Sure, the numbers would …

Because an aircraft does not make a sudden noise? At least where I'm from aircraft don't sound like discrete booms. I'm not sure I understand your question. > But when the aircraft…

> "Of course you hear the siren or crazy man or anything, before it passes you if the component of the velocity vector pointing to you is slower than the speed of sound." So, only …

Thanks for chiming in! My point is that your one instant in time is completely arbitrary. You do not know where the position is, and you do not know when the sound was emanated . I…

Well yeah, if the plane is faster than its sound (and flying towards you), the plane will reach you earlier than the sound does. The plane does not get attenuated by flying farther…