That animation shows a relative emitter to wave speed of roughly 60%...

Yes, and if a Harley could reach a reasonable percentage of the speed of sound in air you would have a point. Let me guess, you also worry about time dilation while flying in a jet?

True, the Doppler effect ‘diminishes’ the sound of an approaching vehicle at speed. However, to really get out ahead of the wave, you need some high mach numbers. It’s rare to see a Harley moving over mach 0.15 and I’ve never personally seen one exceed 0.2.

What you are describing has nothing to do with the doppler effect. You hear them better behind them because the exhaust points backward. It’s the same reason you hear a trumpet better when its bell is pointed at you than when it’s pointed away.

People only hear Harleys after they have passed because the tailpipe - from which said noise emerges - points backwards. This has nothing to do with the Doppler effect and everything to do with the direction of sound emission. In fact, your illustration uses an omnidirectional point source, rather than a highly…

That’s an object going near the speed of sound. At normal speeds the doppler effect isn’t going to prevent people in front from hearing things.

Edit: I think it has more to do with the fact that the exhausts are facing backwards, so most of the sound is directed backwards. If you bend those so that they’re facing…

Here’s a crazy idea: what if the radiator also functions as a coolant-to-fuel heat exchanger? If the fuel needs to be evaporated before combustion, wouldn’t that be easier if it were heated first?

“The bean counters told me we literally could not afford to buy seven dollars worth of moon rocks, much less seventy million. Bought ‘em anyway. Ground ‘em up, mixed em into a gel. And guess what? Ground up moon rocks are pure poison! I am deathly ill…”

It really is as simple as this.

I just literally never answer a number that isn’t one I recognize. If it’s important they’ll leave a message.

And negatory on the cost of this mo-chine there, Red Ryder.
You might say I went right up to the factory and picked it up, it’s cheaper that way.

If they pulled the lifters off the valves, I can see it working. It’s just a plug to close off the hole. An SBC will run on 7.

Guernsey has a bunch of WWII bunkers, they’d probably do ok. (Guernsey along with the other Channel Islands were invaded by the Germans in WWII, which might be why this car was buried)

MO-PEDS, MO-PROBLEMS am I right??

Or, simply: Kylo Ren lied to her.

It is the responsibility of the original owner to remove all logos from the vehicle prior to sale/disposal.

Can we stop saying stuff like this disregards the laws of physics? THE REASON THIS WORKS IS BECAUSE OF AN IN DEPTH UNDERSTANDING OF THE LAWS OF PHYSICS!

Gun control is simple, hold the gun steady with two hands in a defensive stance against an attacker wishing to harm others.

Good job Opportunity! (via XKCD)

He became The Joker after he was rejected by a girl. Because he’s a NICE GUY!