Has anyone heard of the Hedgehog Concept? What is it? Where can I get more details?

Answer
http://www.wordspy.com/words/hedgehogconcept.asp

Question about sound waves?

“Every year, 100 000 hedgehogs are killed by vehicles on British roads. It has been suggested that if a whistle emitting a sound wave of 5000Hz is attached to the front of a car bumper, that when the hedgehog hears the whistle it will remain at the side of the road.

“The movement of the car forces air into the whistle and creates the sound.

“State and explain what happens to the sound emitted by the whistle as the car moves faster. How may this change be to the hedgehog’s advantage?”

So we’re obviously talking about pitch and loudness of the sound here, meaning frequency and amplitude, respectively.

Can we use v = fλ? What /exactly/ is the relationship between velocity, speed, and wavelength of a wave? As f increases, λ decreases, right? But how does v play into this? And does this only apply for electromagnetic waves, or can it work for sound and water waves, as well?
Thanks. I need to clear up on my relationship concepts.

Answer
You should read the Wikipedia article about the Doppler effect. The article describes in good detail what happens if the observer or the sound source are moving.

In classical physics, which deal with wave propagation in a medium like air the general equation is:

f = (v+v_r)/(v + v_s) * f_0, with

f_0= emitted frequency, f=received frequency, v=wave velocity in air, v_r=receiver velocity relative to air, v_s= source velocity relative to air. If both r and s approach each other f rises.

the receiver (hedgehog) velocity is negligible compared to either the car or the wave velocity, so you can assume it’s zero.

thus you can reduce the equation to:

f = (v)/(v + v_s) * f_0

Beware that this formula is only valid if source and receiver are approaching each other directly.

In Astronomy the doppler effect of electromagnetic waves is also known as red shift or blue shift, which describes the color of stars changing due to the spectral frequency shift towards the long or short wavelength end of the visible spectrum. Blue shift means that a star/light source approaches the observer (or the other way around) and red shift means the light source moves away from the observer (or the observer moves away from the light source). You can use the same formula for calculating red shift or blue shift of electromagnetic waves, if the velocity is much lower than the speed of light. In the case of relativistic velocities you have to use the formulas for relativistic color shifts.

Again, I recommend you read the Wikipedia article. It’s very informative and should be well understandable.

Spiritually speaking I need help! I was just recently attacked by Freudian concepts!?

So I was just looking around on the internet and watched this anime called Neon Genesis Evangelion. Well anyways to make this short, I was attacked with so many Freudian concepts it almost made my head explode. Have any ideas how to calm me down?

Heck the first episode talks about the Hedgehog Dilemma!

I know he just used this specific term, but anything related to Freud was forced down my throat!
Yes.

It was very hard. Very hard!!!
The last episode was the most confusing. Apparently everyone is congratulating Shinji.

Some say they’re congratulating him for getting his thumb out of his butt, but I disagree.

I think it’s a message from the writers to the audience congratulating the us for not slitting ourselves. Through 6 episodes of mind-rapage we did not go insane.
Swallow, when they got to Instrumentality I practically choked! I’m still metaphorically choking and need some water to calm me down.
I said his concepts.

They beat me up!
I love porn as much as the next guy, but slaughtered Palestinians!? That’s a little too freaky for me bud.

Answer
Holy Fuck!
You understood that anime?
Wait till you get to the last episode.
Now THAT was hard to swallow.

how do you make sonic shoes like sonic the hedgehog shoes please help?

i really need help its for an anime convention and i need help heres a model im using now http://fc05.deviantart.com/fs28/f/2008/091/c/7/Sonic_Human_Concept_by_arvalis.jpg the link should work please i need answers fast please

Answer
EASY!

ok …this will take a little work…

first get a good pair of plain white running shoes that look somewhat like sonic’s then take the laces out spray paint the parts except the bottom red then use like a peice of yellow tape over where the straps should be and be creative for the other details

Has anyone heard of the Hedgehog Concept? What is it? Where can I get more details?

Answer
http://www.wordspy.com/words/hedgehogconcept.asp