Conversation
![David Watson 🥑](data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" width="96" height="96"><rect fill-opacity="0"/></svg>)
Post your reply
How did that work? It's actually well-known physics called Mach cutoff.
When an aircraft breaks the sound barrier at a sufficiently high altitude, the boom refracts in the atmosphere and curls upward without reaching the
ground. It makes a U-turn before anyone can hear it.
Mach cutoff physics is a theoretical capability on some military supersonic aircraft; now XB-1 has proven it with airliner-ready technology.
Just as a light ray bends as it goes through a glass of water, sound rays bend as they go through media with varying speeds of sound. Speed of sound varies with temperature... and temperature varies with altitude. With colder temperatures aloft, sonic booms bend upward.
This means that sonic booms can make a U-turn in the atmosphere without ever touching the ground. The height of the U varies—with the aircraft speed, with atmospheric temperature gradient, and with winds. So
making this work requires tech not available in Concorde's era...
Boomless Cruise requires engines powerful enough to break the sound barrier at an altitude high enough that the boom has enough altitude to U- turn. And realtime weather and powerful algorithms to predict the
boom propagation precisely.
Boomless Cruise on Overture would not be possible without Symphony engines—which we're designing with enhanced transonic performance, allowing Overture to break the sound barrier at a high enough altitude for Boomless Cruise.
Overture's autopilot will have a "boomless" mode that automatically selects the fastest quiet speed while advising pilots on the fastest on most efficient altitude, based on predictions informed by realtime weather.
Top speed for Boomless Cruise varies with weather and can be as high as Mach 1.3—but will usually be between Mach 1.1 and Mach 1.2. At higher speeds, the geometry doesn't work and a boom will still reach the ground.
Boomless Cruise is not the same thing as "low boom" attempts to dampen sonic boom. Boomless Cruise results in no audible boom; at Mach 1.7, Overture will still make a boom.
So... in honor of Boomless Cruise, we are renaming the company 
Shhh Supersonic. OK, just kidding. But Boomless Cruise is no joke.
Shhh Supersonic. OK, just kidding. But Boomless Cruise is no joke.In addition to the 600+ routes that will benefit from Overture's existing Mach 0.94/Mach 1.7 hybrid speed, Boomless Cruise adds many other practical routes—including U.S. coast to coast flights up to 90 min faster.
Current regulations in the US prohibit supersonic flight over land, even if no audible sonic boom is produced. We look forward to working with regulators to update these regulations to unlock Boomless supersonic flight over land.
This is what happens if smart people take a second look at "settled" facts. Amazing work.
Blake, don’t you mean reflected? Some of the pressure wave passes through the boundary and some reflects off the boundary and doesn’t reach the ground. Like light through an air/water boundary. I’m guessing this is some sort of thermal boundary?
No I mean refracted. There is a continual temperature gradient which means a continual speed of sound gradient. So there’s continual refraction through the gradient. Did I say gradient enough times? 
$SPX is down ~2% again 
Our analyst purchased puts on $SPX live yesterday. SPX rapidly dropped to the area of the largest negative gamma exposure (-50M) at the $5,300 strike.
Want to see data like this? Try our 7-day free trial at: quantdata.us
Ummm. Don't want to burst your bubble, but I think it's called "just fly higher". You're welcome.
Jumping from theoretical government research to successful private demonstration and subsequent commercialization is the dream that built this country.
For anyone not familiar with and what they are doing, while their website does a good job of explaining it I also really recommend this video from they just released on XB-1s first supersonic flight.
thanks Blake, congrats again. can you talk about how this scales? from what i understand, Concorde was pushing Mach 2 at 60k ft cruising, and that still wasn't enough to taper the boom. XB-1 was ~1.1 at 35k ft, does it imply a limit or a consistent tradeoff you'll aim for?
"Babe, can you scoot over?"
"I'm literally on the edge already."
Time to end the single-chair struggles!
For just $109 extra with your Kaiser 3, we'll throw in a whole Novis XL.
That's right - two entire chairs for those late-night gaming sessions.
Finally,Show more
Thanks Blake. I cannot wait to be writing about Overture when it flies.
Can't wait to ride it too
There's a similar phenomenon in oceanography. The depth where temperatures (and salinity) abruptly change is called the thermocline, and it's roughly 100 meters below sea level.
I like how the name of Boom is the antithesis of it, which further reinforces the idea that fate loves irony.
Would the refracted wave affect another aircraft on the far side of the cutoff altitude refraction? There may be an opportunity for a lens effect in the reflection strata that may intensely focus the boom on another aircraft which could lead to turbulence or vibration hazard.
Very cool. So, you made a point of going supersonic at higher altitudes. Did the Concorde fly at, or have to enter at, a lower altitude, meaning the boom reached the ground? And because it flew a bit faster did their boom not reflect back up in time, even at high altitudes?
Amazing! Admire the journey and the perseverance to get here. Hats off to you and the team!
Once you are above mach 1 and the boom is over, what limits your ability to speed up more?
New games alert!
The latest titles from Hacksaw are just around the corner! 
Dive in, grab your daily bits, and get ready to play. Big fun and rewards await! 
Don’t miss out—start playing today! #Hacksaw #Kickr #NewGames #DailyBonus
Time saved benefit of Mach 1.2 over Mach 0.9 is far outweighed by the high cost to fly above Mach 1.
Concorde made its trip at ~Mach 2, shaving off 4-5 hours of the trip each way. Mach 1.2 is just not that much faster than a Mach 0.9 class jet considering the added costs.
If BOOM ever goes public (with that ticker) I can safely say people will be buying on day one.
Impressive thread. If there’s one person who’s gonna figure out aero cavitation it’s you. Space time cavitation is right behind it. Keep going!
Get a whopping 95% off your first 3 months of Market Twists & Turns Pro newsletter!
Unlock premium market analysis 4X/week — insights you can’t afford to miss.
Don’t miss out! Subscribe now & claim your 95% discount. Limited time only.
This summer, joking with a fellow founder at 500 (both our previous startups were in the travel sector), we decided our next one will be "fly faster", finally that is happening! Enough of 12 hours Frankfurt/Rome -> SF, make the world smaller!
That is awesome! The next question everyone will ask, how affordable?
Applies flying slightly above speed of sound and very high altitude. Increased drag, turbulence, and cabin noise, long distance for climb time, much higher fuel burn, small cabin.
All for 30-50% reduction flight time.
Niche market
I was wondering could this be used to numb down the boom of a rocket landing - what would be the smallest angle of the velocity vector vs gravity to get any significant sound refraction?
Congratulations! Can’t wait too see this tech on an actual commercial airliner.
Awesome. Congratulations on the accomplishment. Looking forward to seeing it in the future
I think the deafening explosion of Concord was the big reason it didn't survive. A Boomless cruise will make cities and countries salivate.
Get ready for a full-body VR workout that’s fun, fast, and intuitive — Play PowerBeatsVR (Now on Meta Quest) 
Wait, so my bucket list of flying supersonic remains alive. Following this hard. I cried when there was no more concord. I was to young and didnt have the spare change. Thats changed now and i am here for this. 
So the lesser planes will hear it (the poors) , but mot the earth dwellers!
So cool!
SpongeBob's 25th Anniversary! 
We've partnered up with Nickelodeon's Spongebob Squarepants to bring you the best gaming peripherals in a fun package!
Get it now!
ghostkeyboards.com/spongebob
We've partnered up with Nickelodeon's Spongebob Squarepants to bring you the best gaming peripherals in a fun package! Get it now!
ghostkeyboards.com/spongebob
Incredible! Great work, and well done to the team! The future of flight is now! 
This is actually incredible. The main reason Concorde couldn’t fly over the US is negated with this!
So its like when you shoot an amateur rocket and dont hear the sonic boom even though it has achieved mach 1+?
What is the altitude of the shock wave “U-turn”. I live near Flagstaff AZ at 7k feet. Does this mean a constant background of booms when this becomes operational?
This is something and should be getting unblocked asap. Once regulators update the regulations to unlock Boomless supersonic flight over land flights over the US could be much faster.
Does not work if there is wind that alters the vertical temperature gradient... which is most wind.
Boost, surf, and weave your way through The Art of Flight, an arcade game about flying multiple ships at the same time. With solo, local co-op, and a leaderboard, there are tons of ways to play. Wishlist on Steam today!
I have a question!
What are the general temperature conditions that incentivize this “Boomless Cruise”? Is it operable all throughout the year, at all times of day—or will you need specific weather and atmospheric conditions in order to make it work?
For example,
Show more
Just made a A little side by side comparison with the old Concorde please correct for Boom if I have stated wrong and few upcoming low boom Technology planes.
