Month: July 2017

South Pacific – You’ve Got to Be Taught

6:01 pm

An evening pause: This clip includes the scene that leads up to the song, and helps explain its dramatic context.

To be honest, this has never been one of my favorite Rodgers & Hammerstein songs. The musical, South Pacific, is magnificent, and has been featured before as an evening pause, but this song to me always seemed a bit preachy. It was written in the 1950s, however, and thus for its time was, as was the musical, important components of the civil rights movement that ended the bigoted discrimination against blacks in the United States.

I should add that as a child who loved this musical when I first heard and saw it in the early 1960s, I never understood what Nellie’s problem was. Why did it matter that the kids’ mother had been Polynesian?

Hat tip Edward Thelen.

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Will Dawn head to another asteroid?

4:31 pm

NASA is still reviewing the proposal by the Dawn science team that they send the spacecraft to another asteroid in its last years before its fuel runs out.

The spacecraft has continued operations despite problems with its reaction wheels, used for attitude control. After suffering the loss of two of its four reaction wheels earlier in the mission, a third wheel malfunctioned in April. The spacecraft went into safe mode briefly, but controllers resumed operations with hydrazine thrusters taking over for the failed wheel. That failure will eventually lead to the end of the mission when the spacecraft runs out of hydrazine. “It does reduce our lifetime because we have to use hydrazine at a faster rate,” Raymond said at the SBAG meeting in June.

That lifetime, she said, is dependent on the spacecraft’s orbital altitude. Dawn has spiraled out to a higher orbit during its extended mission, which reduces the amount of hydrazine needed for attitude control. “The lifetime is now highly dependent on orbital altitude because we need to use the jets to fight the gravity gradient torques,” she said. In its current high orbit, Raymond said that Dawn had sufficient hydrazine, as well as xenon propellant used for the ion engine, to operate at least through the end of 2018.

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Five satellite Air Force contract up for bid

4:26 pm

Capitalism in space: The Air Force has announced that it will be soliciting bids from SpaceX and ULA for a 5-satellite launch contract.

Claire Leon, director of the Launch Enterprise Directorate at the Air Force’s Space and Missile Systems Center, told reporters that grouping launches together was an effort to streamline and speed the acquisition process at a time when the national security sector is demanding ever-increasing access to space. “By doing five at once, it makes our acquisition more efficient and it allows the contractors to put in one proposal,” she said.

This grouping however might make it impossible for SpaceX to win the contract, as the company’s Falcon 9 rocket might not be capable of launching all five satellites, and its Falcon Heavy has not yet flown the three times necessary before the Air Force will consider using it.

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Fastest stars in Milky Way escaped from Large Magellanic Cloud?

9:01 am

Astronomers have proposed that the fastest stars in Milky Way actually escaped from the Large Magellanic Cloud (LMC), the largest nearby satellite dwarf galaxy.

The LMC is the largest and fastest of the dozens of dwarf galaxies in orbit around the Milky Way. It only has 10% of the mass of the Milky Way, and so the fastest runaways born in this dwarf galaxy can easily escape its gravity. The LMC flies around the Milky Way at 400 kilometres per second and, like a bullet fired from a moving train, the speed of these runaway stars is the velocity they were ejected at plus the velocity of the LMC. This is fast enough for them to be the hypervelocity stars. “These stars have just jumped from an express train – no wonder they’re fast,” said co-author Rob Izzard, a Rutherford fellow at the Institute of Astronomy. “This also explains their position in the sky, because the fastest runaways are ejected along the orbit of the LMC towards the constellations of Leo and Sextans.”

Their calculations predict how many hypervelocity stars should be detectable and where in the sky they should be. If right, the data from Gaia, soon to be released, should prove them right or wrong.

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Qatar blockade threatens worldwide helium supply

8:54 am

The recent blockade imposed against Qatar by other Middle East countries, supposedly because of its support of terrorism, threatens the world’s supply of helium.

Qatar is the world’s largest exporter of helium and its second-largest producer, accounting for 25% of global demand (see ‘Helium supplies’). So the blockade will inevitably cause shortfalls over the next few months, says Phil Kornbluth, a consultant based in Bridgewater, New Jersey, who specializes in the helium industry.

Countries likely to be most affected are those closest to Qatar. But Asian countries such as India, China, Japan, Taiwan and Singapore are also at risk. “But none of us are immune,” adds William Halperin, a researcher in low-temperature physics at Northwestern University in Evanston, Illinois.

The U.S. is the world’s largest producer of helium, producing about twice as much as Qatar. That production is for our local markets, while Qatar exports it worldwide.

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1776 – Hatching an Egg

6:01 pm

An evening pause: I posted this last year for the Fourth of July. It is worth watching again, and again, and again. From the 1976 movie version of the 1972 musical, 1776. As I said last year, not only did the musical capture the essence of the men who made independency happen, it is also a rollicking and entertaining work of art.

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A look at the war for independence

4:00 pm

For the Fourth of July. Link here. Key quote:

O’Donnell urged listeners to contemplate the incredible nation forged from Washington’s courage and humanity, mixed with the wisdom and intellect of the other Founding Fathers. He agreed with Marlow that it was amazing how much the Founders got right from the beginning. “They got it right in terms of how power is used and abused,” O’Donnell said, noting that modern Americans might be surprised how controversial the Bill of Rights was at the time. “Just putting power back to the people, it’s an incredible thing.”

“They were also paranoid, rightfully so, of a central government that would encroach upon the rights of citizens,” he continued. “These were citizen-soldiers. They didn’t want to have a situation where there was potential tyranny.”

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“People were different, not only from Swedes, but from each other.”

3:00 pm

For the Fourth of July. Link here. Key quote:

I’m not sure if I can fully convey the cultural shock of going from Sweden to Dallas in the 1990s, or if it is even wise to try. Because how can I describe what it is to taste your very first doughnut or go to Toys R Us at that age [9 years old] and see row after row of wonderfully girly Barbie dolls? I came from the country of meh to the nation of yeah. And it was nothing short of magnificent.

I was lucky enough to spend my summers there, in the heart of Texas, and with every visit I gained a growing awareness of the differences between your country and mine. America was loud. It was uncomfortable and alive. People were different, not only from Swedes, but from each other. [emphasis in original]

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A close look at the first paragraph of the Declaration of Independence

11:30 am

For the Fourth of July: Link here. The author discusses it phrase by phrase, placing the words in their historical context so there will be no confusion. For anyone who is intellectually honest, however, I think the meaning is quite clear.

We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, — That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.

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“It took two wars to make me an American.”

10:21 am

For the Fourth of July. Link here. Key quote:

My parents were born in the north, and when an international summit divided the country into communist North Vietnam and non-communist South Vietnam in 1954, their families were among a million who left all they owned to flee south away from Ho Chi Minh’s troops — troops whom my dad once had idolized as nationalist boy and girl scouts. Scouts honor no more. Escaping to America in ’75 was the second time my parents sacrificed the past to save their future. Second. Anything but communism.

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New data suggests Sun undergoing fundamental changes

8:40 am

The uncertainty of science: New data, when compared with similar data collected over decades, suggests the Sun’s solar cycle is undergoing some fundamental changes.

In work just published in the Monthly Notices of the Royal Astronomical Society, the team shows that the interior of the Sun has changed in recent years, and that these changes persist in the current cycle. In combination with theoretical models, the observations suggest that the magnetic field distribution in the outer layers may have become a bit thinner. Other seismic data shows that the rotation rate of the Sun has also undergone some changes in the way the Sun rotates at different latitudes.

“Again, this is not how it used to be and the rotation rate has slowed a bit at latitudes around about 60 degrees. We are not quite sure what the consequences of this will be but it’s clear that we are in unusual times. However, we are beginning to detect some features belonging to the next cycle and we can suggest that the next minimum will be in about two years,” says Elsworth.

First, they don’t know what will happen because of these changes. Second, their data confirms that the solar minimum will occur in about two years, which would make this cycle only 9 years long, one of the shortest but also one of the weakest that has been observed, two things that previously had never gone together.

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Becoming American

8:15 am

For the Fourth of July. Link here. Key quote:

The process of being an American goes on, though. As almost everyone here should be aware, being an American – not just fitting in the culture, and because that’s regional it means I’ll need to learn to talk and walk again if I move across the country again – is an ongoing process, an ongoing fight between liberty and totalitarian impulses which exist in every society and possibly in every human. And it is a struggle to free yourself from the inherited nonsense that has plagued other societies too: ideas of class and inherited rank or ability.

It is our solemn duty, no matter how many of our compatriots fail at it, to live up to our amazing luck in being citizens of the greatest nation on Earth, one founded on the belief that individuals can be self-governing and are the bosses of their own government.

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World View test balloon flight cut short due to leak

9:10 pm

The first test flight of World View’s Stratollite balloon, planned for 4 days, was ended after only 17 hours because of a leak in the balloon.

Though the mission was the longest yet for the balloon, and though they managed to test the attitude control, communications, and solar power systems, they need to find out why the balloon did not hold pressure as expected before they can begin flying missions lasting from months to even a year.

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North Korea test fires another ballistic missile

7:01 pm

North Korea today launched another test missile into nearby waters, this time landing in Japanese waters.

Update: North Korea now claims this was an ICBM that could have reached Alaska, and some of the experts quoted appear to agree.

It was estimated to have reached an altitude that “greatly exceeded” 2,500 kilometres, Japan said, prompting arms control specialist Jeffrey Lewis to respond on Twitter: “That’s it. It’s an ICBM. An ICBM that can hit Anchorage not San Francisco, but still.”

David Wright, of the Union of Concerned Scientists, wrote on the organisation’s allthingsnuclear blog that the available figures implied the missile “could reach a maximum range of roughly 6,700 km on a standard trajectory. … That range would not be enough to reach the lower 48 states or the large islands of Hawaii, but would allow it to reach all of Alaska.”

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Sunspot update for June 2017

11:47 am

Today NOAA posted its monthly update of the solar cycle, covering sunspot activity for June. As I have done every month since 2010, the graph is posted below, with annotations.

June 2017 Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

Sunspot activity in June was almost exactly the same as in May, and thus continued the overall downward trend that is below the 2007 low prediction and that suggests that this very weak solar maximum will end much earlier than predicted, and will make it an unprecedented short but weak cycle. The Sun is once again blank today for the first time in about two weeks, repeating the pattern we have seen for several months where, because one hemisphere of the Sun is blank while the other hemisphere has some sunspots, the rise and fall of the sunspot counts tracks the 27-day solar rotation almost precisely.

There continues to be evidence that the Sun is undergoing significant changes this solar cycle, all of which are pointing to the possibility that a grand minimum is coming, with no sunspots for decades. And as I have said now monthly for six years, past grand minimums have consistently occurred at the same time the Earth’s climate has cooled. The scientific link remains unclear, but if we should undergo a grand minimum in the coming decades, we will finally have the opportunity to find out what that link is.

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The soft craters of Epimetheus

9:24 am

The soft craters of Epimetheus

Cool image time! The image on the right, reduced in resolution to show here, is the highest resolution image that Cassini has taken of the Saturn moon Epimetheus, taken from only 9,300 miles away on February 21, 2017.

Epimetheus (70 miles or 113 kilometers across) is too small for its gravity to hold onto an atmosphere. It is also too small to be geologically active. There is therefore no way to erase the scars from meteor impacts, except for the generation of new impact craters on top of old ones.

Below is the inset at full resolution, showing several craters, with ponds of dust on their floor. Overall, the surface of this tiny moon looks soft. The craters are all shallow, as if any impact merely plunged into a blob of ice cream. Any ejecta from those impacts eventually rained back down, and then settled slowly in the moon’s low points, forming those ponds of dust.

close-up of soft craters

In many ways this image is very revealing, as it shows what the early accretion process of any planetary body will look like. Nor is this unique. Earlier images taken of the asteroid Eros by the NEAR probe saw many of these same features, as have images of Saturn’s other small moons. In the early stages, new material gets absorbed easily because it finds it easy to bore into the body of the newly formed and not very dense planetary body. There isn’t much ejecta, and what there is doesn’t fly that far away so that it can settle back down on the surface and add to the new body’s total mass.

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Long March 5 failure occurred at satellite separation

8:57 am

This story notes that the failure of the Long March 5 launch occurred 30 minutes after launch, when the second stage and the satellite were due to separate.

The link also includes footage of the launch through first stage separation and ignition of second stage engines.

It appears therefore that the failure was not in the Long March 5 rocket itself. When satellite separation occurs the second stage has completed its work, so the rocket apparently did its job getting the satellite into orbit. What happened next however remains unknown.

Based on this information it would appear that this failure might not delay later launches of the Long March 5 that much.

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Reba McEntire -You can’t get a man with a gun

6:01 pm

An evening pause: From the Broadway musical Annie Get Your Gun. In January 2001, McEntire, a well known country singer, made her Broadway debut in the 2000 revival of the musical that was opened originally with Bernedette Peters in the role. McEntire was an instant sensation, performing the role on Broadway for eighteen months. In many ways this role made her, as it showed she could do far more than sing, and was in fact a very skilled comedic actor.

This clip, shot by an audience member, does a remarkable job of capturing part of one of those performances.

Hat tip Diane Zimmerman.

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