The Mach. 3 value is rather arbitrary, but it is used because gas flows with a Mach number below that value demonstrate changes in density with respect to the change in pressure of less than 5 %.

In the 1970s, the term generally came to refer to speeds of Mach 5 ( 5 times the speed of sound ) and above.

The Phoenix has several guidance modes and achieves its longest range by using mid-course updates from the F-14A / B AWG-9 radar ( APG-71 radar in the F-14D ) as it climbs to cruise between and at close to Mach 5.

Avro proposed that Blue Steel would evolve over time, subsequent versions increasing speed ( to Mach 4. 5 ) and range.

On launch the rocket engine's first chamber developing thrust would power the missile along a predetermined course to the target at around Mach 1. 5.

The engine was intended to switch from jet propulsion to pure rocket propulsion at 26 – 32 km high, by which time the craft would be travelling at Mach 5 to 7.

Mach received a major boost in visibility when the Open Software Foundation ( OSF ) announced they would be hosting future versions of OSF / 1 on Mach 2. 5, and were investigating Mach 3 as well.

Mach 2. 5 was also selected for the NeXTSTEP system and a number of commercial multiprocessor vendors.

The CD also contained videos for " Lump ," " Peaches ," " Mach 5 ," and " Dune Buggy.

For example, from the equation, with an of 0. 7, a rocket flying at Mach 0. 85 ( which most aircraft cruise at ) with an exhaust velocity of Mach 10, would have a predicted overall energy efficiency of 5. 9 %, whereas a conventional, modern, air-breathing jet engine achieves closer to 35 % efficiency.

* While at lower speeds, air-breathing engines are very efficient, the efficiency ( Isp ) and thrust levels of air-breathing jet engines drop considerably at high speed ( above Mach 5 – 10 depending on the engine ) and begin to approach that of rocket engines or worse.

On the other hand LACE-like precooled airbreathing designs such as the Skylon spaceplane ( and ATREX ) which transition to rocket thrust at rather lower speeds ( Mach 5. 5 ) do seem to give, on paper at least, an improved orbital mass fraction over pure rockets ( even multistage rockets ) sufficiently to hold out the possibility of full reusability with better payload fraction.

A rocket sled holds the land-based speed record for a vehicle, at Mach 8. 5.

The vehicle that achieved Mach 8. 5

A world speed record of Mach 8. 5 ( 6, 416 mph / 10, 325 km / h ) was achieved by a four-stage rocket sled at Holloman Air Force Base on, 2003.

" Former NASA sonic boom expert Dom Maglieri studied the 15-year old sonic boom data from the California Institute of Technology and has deemed that the data showed " something at 90, 000 ft ( c. 27. 4 km ), Mach 4 to Mach 5. 2 ".

Simulation of hypersonic speed ( Mach 5 )

Since the 1970s, the term has generally been assumed to refer to speeds of Mach 5 and above.

Mach argued, beginning in the 1880s with The Science of Mechanics ( 1883 ), that the mind had a fundamental structure, and that subjective experience was based on the interplay of parts of the mind.

By 2000, most large-scale ( Mach-like ) efforts had ended, although OpenStep used an adapted Mach kernel called XNU, which is now used in the OS known as Darwin, which is the open source part of Mac OS X .. As of 2012, the Mach-based GNU Hurd is also functional and its inclusion in testing versions of Arch Linux and Debian in progress.

A small team had built Mach and ported it to a number of platforms, including complex multiprocessor systems which were causing serious problems for older-style kernels.

Many attempts were made to improve the performance of Mach and Mach-like microkernels, but by the mid-1990s much of the early intense interest had died.

Under Mach this wasn't possible because the kernel had no real idea what the operating system consisted of.

Likewise Mach caused problems when memory had been moved by the operating system, another task that only really makes sense if the system has more than one address space.

A team led by Avie Tevanian, who had joined the company after working as one of the Mach kernel engineers at Carnegie Mellon University, was to develop the NeXTSTEP operating system.

The supersonic wind tunnel at Peenemünde's " Aerodynamic Institute " eventually had nozzles for speeds up to the record speed of Mach 4. 4 ( in 1942 or 1943 ), as well as an innovative dessiccant system to reduce the condensation clouding caused by the use of liquid oxygen, in 1940.

The French had a nominally Mach 2 Dassault Mirage IIIV fitted with no less than 8 lift engines that flew ( and crashed ), but did not have enough space for fuel or payload for combat missions.

The French in competition with the P. 1154 had developed a version of the Dassault Mirage III capable of attaining Mach 1.

By the end of the war, Germany had at least three different supersonic wind tunnels, with one capable of Mach 4. 4 ( heated ) airflows.

Mach had a direct influence on the Vienna Circle philosophers and the school of logical positivism in general.

FLASK, in turn, was based on DTOS, a Mach-derived Distributed Trusted Operating System, as well as Trusted Mach, a research project from Trusted Information Systems that had an influence on the design and implementation of DTOS.

They also had experience in microkernel design as a side-effect of their Mach based Workplace OS efforts.

On October 1, 1913, he married Margarete Georgen with whom he had three sons, Heinz Günter ( born Aug 2nd 1914 to 2004 ) and Kurt ( born 17th September 1918 to 1984 ), Ronald Mach Dornaldt Guderian ( born 15th May 1919 to 1995 ).

After early appointments at Rostock and Kiel, in 1922 Schlick assumed the chair of Naturphilosophie at the University of Vienna which had previously been held by Ludwig Boltzmann and Ernst Mach.

Saunders composed the track with Vince Lawrence in order to replace a record which had been stolen from Saunders ' collection, the " On & On " bootleg disco megamix by Mach.

It had quickly focused on computer networking, operating systems ( Mach ), and robotics.

Concorde had a lift / drag ratio of around 7 at Mach 2, whereas a 747 is around 17 at about mach 0. 85.

Higher speeds up to Mach 3 had been considered and found to be possible, but it appeared that a practical upper limit was Mach 2. 2, above this speed the duralumin used for most aircraft construction would start to go soft due to the heat of friction, and some new material would have to be used instead.

By 1958, the Type 198 had evolved into an eight-engined shoulder-wing delta of around 150 seats and a Mach 2 speed.

In 1959, they received an additional £ 350, 000 study contract to continue work on the design, and by the end of the year the 198 had evolved into a 136-seat aircraft cruising at Mach 1. 8.

Vos Savant was born Marilyn Mach in St. Louis, Missouri, to Joseph Mach and Marina vos Savant, who had immigrated to the United States from Germany and Italy respectively.