Or did they? It seemed to be a signal that they’d reached their goal. Did it surprise them to hear a boom, or had they calculated that there would be one?
Well, it would seem to me that if you understand the physics of what happens to the air when an aircraft approaches the speed of sound, you should be able to correctly surmise that it might be a bit noisy. What with all those sound waves crushing up against each other and all.
Also, they’d heard plenty of bullets and shells crack as they go supersonic.
I don’t think the people inside the airplane hear anything.
Whips have been around for thousands of years.
I’m sure that they must of known that they’re would be a sonic boom, the doppler effect was first discovered in 1845 (and the first test of the doppler effect was on sound waves).
Rockets broke the barrier already…and the whip comment was referring to the crack of the whip…the crack being the whip’s sonic ‘boom’ as it breaks the ‘sound barrier’.
Having flown supersonic, I can confirm this.
Actually, I just wanted to brag.
Actually, I heard that the first time a plane broke the sound barrier, they thought the plane had exploded. As I write this, I think I remember it being a scene in the movie “The Right Stuff”.
Can anyone confirm this?
And theoretically what will happen if/when we exceed the speed of light??
You can’t blink?
A very bright (white?) flash of light. But would we see it, or would it flash be moving to fast for us to see it?
You would know if anyone exceeded the speed of light because Homer Simpson would become Queen of England.
It can’t be done.
SF worldbuilding at
http://www.orionsarm.com/main.html
This is weird because I just watched “The Right Stuff” today. In the film, a test pilot describes the sound barrier as “a farm you can buy in the air”.
Did engineers actually think that supersonic flight was something impossible? I can’t see how the effects of the sound barrier would necessarily make an aircraft’s structure fall apart.
I’m just curious as to how big a deal the sound barrier was.
IIRC, it wasn’t that they’d thought the plane had exploded (pretty obvious it hadn’t , I guess), but that they were concerned beforehand it would be shaken to bits. One of those mid-century collective sighs of relief along the lines of “Ooo. So there’s NOT a chain reaction which would blow up the entire planet. Lucky guess eh, lads?”
That’s how I’ve always heard it, anyway.
The transonic regime is pretty tough on the aircraft. When you start to approach Mach 1, you get a region of supersonic flow in the accelerated flow over the wing, which then sets up a normal shock on the wing. This normal shock tends to fluctuate back and forth, which leads to very high pressure variations on the wing because the pressure is much higher behind the shock than in front (the very definition of the shock). If you don’t accelerate through the transonic regime quickly, this can rattle the airframe pretty badly.
Also, once the whole vehicle is supersonic, you have bow shocks coming from every leading edge (nose, wing leading edge, every expansion of the fuselage). These are the shocks that are interpreted outside the vehicle as the “sonic boom”. Wherever shocks intersect with each other, you get reflections in other directions and wherever they intersect the vehicle you get high pressure on the airframe. If your aircraft was designed to fly moderately well at subsonic speed, these shock may be fairly strong (i.e. the large bow shock from a fat curved leading edge compared to the oblique shock from a thin leading edge). The presence of these shocks in the flow cause the pressure on the vehicle to go way up, and wherever the shocks intersect the vehicle you can get pressure gradients on the vehicle that affect flight characteristic (possibly making it uncontrollable) and stress the airframe (possibly relieving you of those pesky, shock-inducing wings).
Here’s an interview with Chuck Yeager that includes discussion of what pilots knew before breaking the sound barrier, and a more detailed one specifically on the famous flight itself.
micco - yes as a plane approaches the speed of sound the stress is incredible on an aircraft. WW2 fighter pilots noted this when they were in power dives and approached the speed of sound.
I have read that, when landing, the Space Shuttle produces 2 “sonic booms”. Anyone know why ?
The “booms” are shockwaves generated by the vehicle. I believe in the case of the shuttle that the two most noticable shocks are the ones from the nose and tail structure, and the fact that these are separated by the length of the vehicle means there is a time gap between them when they sweep past a stationary listener on the ground.
In fact, the space shuttle produces a number of discernable shocks from the nose, wingtips, tail, and every bump along the fuselage. Every other supersonic vehicle does too. It’s the fact that the shuttle shocks are very strong and that they are separated by a larger gap than on most other supersonic vehicles is what makes it possible for a person to hear them as two distinct booms. The nose and tail shocks from a fighter jet passing overhead are so close that I don’t think you can tell they are two distinct waves.
Micco you are a perfect example of why I love these boards: I get to read an explanation of something I already know about and come away with an insight or two for having it explained so nicely. Bravo.