Subrahmanyan Chandrasekhar: A study in fortitude and rigor
1 day ago in The Curious Wavefunction
Sounds from a left speaker trace Huygens' motion, with tones changing with rotational speed and the tilt of the parachute. There are also clicks that clock the rotational counter, as well as sounds for the probe's heat shield hitting Titan's atmosphere, parachute deployments, heat shield release, jettison of the DISR cover and touch-down.
Sounds from a right speaker go with DISR activity. There's a continuous tone that represents the strength of Huygens' signal to Cassini. Then there are 13 different chimes - one for each of DISR's 13 different science parts - that keep time with flashing-white-dot exposure counters.
One estimate was that over 240,000 meteors fell during that period, so many meteors in the sky at a time that many people were woken from their beds and stared at the sky in panic, believing the sky to be on fire. Many feared that it was the end of the world and dreaded what they would see at daybreak.Update: I should clarify that when I refer to debris left by Temple-Tuttle I am referring to debris left by Temple-Tuttle's previous close passages to the sun which may have occurred long ago. For example the most recent close passage of Temple-Tuttle to the sun was 1998, but most of the meteorites seen in this shower were left by debris trails originating from passages in 1466 and 1533. And finally here is a cool meteor detector that works by detecting reflected radio waves from the ionized trails created by particles of rock entering the upper atmosphere.
Out of the night that covers me,
Black as the Pit from pole to pole,
I thank whatever gods may be
For my unconquerable soul.
In the fell clutch of circumstance
I have not winced nor cried aloud.
Under the bludgeonings of chance
My head is bloody, but unbowed.
Beyond this place of wrath and tears
Looms but the Horror of the shade,
And yet the menace of the years
Finds and shall find me unafraid.
It matters not how strait the gate,
How charged with punishments the scroll
I am the master of my fate:
I am the captain of my soul.
There are times and places where formal punctuation, grammar, or style are not called for and I think those times include numerical responses and singing.
- If your topic makes little use of numbers, "you may spell out numbers written one or two words" (Gibaldi 98). Otherwise, use arabic numerals.
- If your writing contains the recurrent use of numeric statistical or scientific data, use numerals for those numbers but write out other numbers in the text if you can do so in one or two words.
- Do not mix numbers that are spelled out with symbols, write out the term for the symbols as well. For example, write: 45%, or forty-five percent; $20 or twenty dollars.
ATSC’s promotional material claims that its device can find guns, ammunition, drugs, truffles, human bodies and even contraband ivory at distances up to a kilometer, underground, through walls, underwater or even from airplanes three miles high. The device works on “electrostatic magnetic ion attraction,” ATSC says.I am incensed by this electrostatic magnetic ion attraction device's outrageously unrealistic claims. I would go into the physics of magnetic ions, but if you have ever used an Ouija board you understand already. The real forces at work here are sociological, variable reinforcement conditioning is a powerful way to shape behavior; it is the reason that baseball players have absurd rituals before games and why even apparently logical people have illogical superstitions. In this case if the device doesn't work it is explained as user error and when it does work it is the life saver. In reality Iraqi soldiers are simply relying on their intuition to perceive threats. Studies show the device performs no better than random chance. People are dieing and we can do better. Let's get the word out about this situation. The people profiting from this need to get what is coming to them. I have a feeling there will be blood before the dust settles. More from the article:
Despite major bombings that have rattled the nation, and fears of rising violence as American troops withdraw, Iraq’s security forces have been relying on a device to detect bombs and weapons that the United States military and technical experts say is useless.Read on...
The sensor device, known as the ADE 651, from $16,500 to $60,000 each. Iraq has bought more than 1,500 of the devices.
The small hand-held wand, with a telescopic antenna on a swivel, is being used at hundreds of checkpoints in Iraq. But the device works “on the same principle as a Ouija board” — the power of suggestion — said a retired United States Air Force officer, Lt. Col. Hal Bidlack, who described the wand as nothing more than an explosives divining rod.
Still, the Iraqi government has purchased more than 1,500 of the devices, known as the ADE 651, at costs from $16,500 to $60,000 each. Nearly every police checkpoint, and many Iraqi military checkpoints, have one of the devices, which are now normally used in place of physical inspections of vehicles.
With violence dropping in the past two years, Prime Minister Nuri Kamal al-Maliki has taken down blast walls along dozens of streets, and he contends that Iraqis will safeguard the nation as American troops leave.
But the recent bombings of government buildings here have underscored how precarious Iraq remains, especially with the coming parliamentary elections and the violence expected to accompany them.
The suicide bombers who managed to get two tons of explosives into downtown Baghdad on Oct. 25, killing 155 people and destroying three ministries, had to pass at least one checkpoint where the ADE 651 is typically deployed, judging from surveillance videos released by Baghdad’s provincial governor. The American military does not use the devices. “I don’t believe there’s a magic wand that can detect explosives,” said Maj. Gen. Richard J. Rowe Jr., who oversees Iraqi police training for the American military. “If there was, we would all be using it. I have no confidence that these work.”
The Iraqis, however, believe passionately in them. “Whether it’s magic or scientific, what I care about is it detects bombs,” said Maj. Gen. Jehad al-Jabiri, head of the Ministry of the Interior’s General Directorate for Combating Explosives.
Dale Murray, head of the National Explosive Engineering Sciences Security Center at Sandia Labs, which does testing for the Department of Defense, said the center had “tested several devices in this category, and none have ever performed better than random chance.”