U.S. Air Force places overpowering jet armada near Iran

The U.S. Air Force is quietly assembling the world’s most powerful air-to-air fighting team at bases near Iran. Stealthy F-22 Raptors on their first front-line deployment have joined a potent mix of active-duty and Air National Guard F-15 Eagles, including some fitted with the latest advanced radars. The Raptor-Eagle team has been honing special tactics for clearing the air of Iranian fighters in the event of war.

The highly-experienced Massachusetts Guardsmen, who typically have several years more experience than their active-duty counterparts, would be ready “should Iran test the 104th,” said wing commander Col. Robert Brooks.

…it’s the methods above that the U.S. dogfighting armada would likely use to wipe out the antiquated but determined Iranian air force if the unthinkable occurred and fighting broke out. The warplanes are in place. The pilots are ready. Hopefully they won’t be needed.

via Wired – Danger Room

 

F-15 Eagle at Mountain Home Air Force Base

 

// Photo – Bundeswehr-Fotos Wir.Dienen.Deutschland.

Jet travels more than 13,000 mph (Mach 20) thanks to sleek aerodynamic systems

It’s amazing that this Hypersonic jet was able to travel more than 13,000 mph with heats of over 3,500 degrees.

During flight it experienced shockwaves, 100 times more powerful than expected, which caused it to spin. It then righted itself and flew for twice as long before technicians finally aborted the mission.

The full story:

In August the Pentagon’s research arm, known as DARPA, carried out a test flight of an experimental aircraft capable of traveling at 20 times the speed of sound.

The arrowhead-shaped unmanned aircraft, dubbed Falcon Hypersonic Technology Vehicle 2, blasted off from Vandenberg Air Force Base, northwest of Santa Barbara, into the upper reaches of the Earth’s atmosphere…then glided above the Pacific at 20 times the speed of sound, or Mach 20.

The plan was for the Falcon to speed westward for about 30 minutes before plunging into the ocean near Kwajalein Atoll, about 4,000 miles from Vandenberg.

But it was ended about nine minutes into flight for unknown reasons. The launch had received worldwide attention and much fanfare, but officials didn’t provide much information on why the launch failed.

via LA Times

 

Then last week, DARPA said in a statement:

The flight successfully demonstrated stable aerodynamically-controlled flight at speeds up to Mach 20 for nearly three minutes. Approximately nine minutes into the test flight, the vehicle experienced a series of shocks culminating in an anomaly, which prompted the autonomous flight safety system to use the vehicle’s aerodynamic systems to make a controlled descent and splashdown into the ocean.

“The initial shockwave disturbances experienced during second flight, from which the vehicle was able to recover and continue controlled flight, exceeded by more than 100 times what the vehicle was designed to withstand,” said DARPA Acting Director, Kaigham J. Gabriel. “That’s a major validation that we’re advancing our understanding of aerodynamic control for hypersonic flight.”

…larger than anticipated portions of the vehicle’s skin peeled from the aerostructure. The resulting gaps created strong, impulsive shock waves around the vehicle as it travelled nearly 13,000 miles per hour, causing the vehicle to roll abruptly. Based on knowledge gained from the first flight in 2010 and incorporated into the second flight, the vehicle’s aerodynamic stability allowed it to right itself successfully after several shockwave-induced rolls. Eventually, however, the severity of the continued disturbances finally exceeded the vehicle’s ability to recover.

via DARPA

Hypersonic Technology Vehicle (HTV-2)

 

How close does an object have to be to earth to be pulled by gravity?

Pulled from Quora, here is one of the best, and most popular, answers to a question. Written by Mark Eichenlaub, a graduate student in physics.

How close does an object have to be to earth to be pulled by gravity?

This question doesn’t have a direct answer because, for lack of a less-direct way of saying it, that’s not the way it works. If there were no atmosphere, you could have the ISS be just above the surface of the Earth, high enough only to clear the mountains. On the other hand, you could have something as far out as the moon, and if it weren’t going fast enough and in the right direction, it would still fall back down. The ISS doesn’t stay up because of how high it is, but because of a combination of that and how fast it’s going.

One of the most difficult things to learn about physics is the concept of force. A force in a given direction does not make things go straight in that direction. Instead, it influences the motion to be a bit more in the direction of the force than it was before.

For example, if you roll a bowling ball straight down a lane, then run up beside it and kick it towards the gutter, you apply a force towards the gutter, but the ball doesn’t go straight into the gutter. Instead it keeps going down the lane, but picks up a little bit of diagonal motion as well.

Now we can talk about an very early thought experiment in physics. Imagine you’re standing at the edge of a cliff 100m tall. If you drop a rock off, it will fall straight down. If you throw the rock out horizontally, it will fall down, but it will keep moving out horizontally as it does so, and falls at an angle. (The angle isn’t constant – the shape is a curve called a parabola, but that’s relatively unimportant here.)

The the force is straight down, but that force doesn’t stop the rock from moving horizontally. If you throw the rock horizontally harder, it goes further, and falls at a shallower angle. The force on it is the same, but the original velocity was much bigger and so the deflection is less.

Now imagine throwing the rock so hard it travels one kilometer horizontally before it hits the ground. If you do that, something slightly new happens. The rock still falls, but it has to fall more than just 100m before it hits the ground. The reason is that the Earth is curved, and so as the rock traveled out that kilometer, the Earth was actually curving away underneath of it. In one kilometer, it turns out the Earth curves away by about 10 centimeters – a small difference, but a real one.

As you throw the rock even harder than that, the curving away of the Earth underneath becomes more significant. If you could throw the rock 10 kilometers, the Earth would now curve away by 10 meters, and for a 100 km throw the Earth curves away by an entire kilometer. Now the stone has to fall a very long way down compared to the 100m cliff it was dropped from. Continue reading How close does an object have to be to earth to be pulled by gravity?

“Trust, but verify” – the code of nuclear treaties

English – “trust but verify”

Russian – “doveryai, no proveryai”

The phrase was used by U.S. President Ronald Reagan at a press conference with Soviet General Secretary Mikhail Gorbachev during the of the signing the INF Treaty at the White House in 1987.

After Reagan used the phrase, Mikhail Gorbachev responded: “You repeat that at every meeting,” to which Reagan answered “I like it.” (thx to Darin McClure)

Why the treaty was important:

The Intermediate-Range Nuclear Forces Treaty was unique when negotiated and remains so. It was designed as a global ban on all U.S. and Soviet missiles having a range of 500-5500 kilometers and, for the first time in U.S. treaty history, contained verification measures that permitted the presence of U.S. inspectors on Soviet soil, and vice versa. The fact that inspectors could for the first time enter sensitive U.S. and Soviet missile facilities was a breakthrough and harbinger of the end of the Cold War.

The treaty not only eliminated an entire class of nuclear missiles but also “brought about a new standard of openness.”

by Rose Gottemoeller

 

Brought up as my local nuclear power plant faces a growing tide of questions about a nuclear leak. The authorities and corporations involved are providing limited information and asking us to trust them.

Sure, we can trust, but we want to verify.

Star Wars Identities – trailer – a character-driven adventure into Darth Vader

What forces shape you?

 

Get to know the characters of Star Wars™ on a whole new level.

Stunning costumes, models, and artwork from the films. A complete interactive immersion into the world of Star Wars.

Pick up your Lightsaber, your adventure awaits.
 

Also, view the poster art for the exhibit.