Tuesday, January 27, 2015

In Memoriam

High Flight

(Pilot Officer Gillespie Magee, No. 412 Squadron RCAF, KIA 12/11/1941)

Oh! I have slipped the surly bonds of earth
And danced the skies on laughter-silvered wings;
Sunward I've climbed, and joined the tumbling mirth
Of sun-split clouds - and done a hundred things
You have not dreamed of - wheeled and soared and swung
High in the sunlit silence. Hov'ring there
I've chased the shouting wind along, and flung
My eager craft through footless halls of air.
Up, up the long delirious, burning blue,
I've topped the windswept heights with easy grace
Where never lark, or even eagle flew -
And, while with silent lifting mind I've trod
The high untresspassed sanctity of space,
Put out my hand and touched the face of God.

In respectful memory of:

Virgil I. "Gus" GrissomEdward H. White IIRoger ChaffeeApollo 1, 1/27/1967

Vladimir KomarovSoyuz 1, 4/23/1967

Major Michael J. Adams, USAF: X-15 Flight #191, 11/15/1967

Georgi DobrovolskyVladislav VolkovViktor PatsayevSoyuz 11/Salyut 1, 6/30/1971

Dick ScobeeMichael SmithEllison OnizukaJudy ResnikRon McNairChrista McAuliffeGregory JarvisChallenger, 1/28/1986

Rick HusbandWilliam McCoolDave BrownKalpana ChawlaMichael AndersonLaurel ClarkIlan RamonColumbia, 2/1/2003

Michael Alsbury, VSS Enterprise Flight PF04, 10/31/2014

Requiem aeternam donum est, Domine, et lux perpetua luceat eis.

Saturday, January 17, 2015

Stopping The Earth

The short answer: It can't be done. Not no way, not no how. But first, some background...

I saw this item on Andrew Sullivan's site, a link to an article by Aatish Bhatia about what would happen if the Earth were to somehow stop orbiting around the Sun. Well, the obvious answer is that if it stopped orbiting, it's fall into the Sun. What Bhatia tells us, though, is specifically what would happen, on a day-to-day basis, during the sixty-four and a half days it'd take to get there.

I had no beef with that ... except for one sentence, early on in the article:

"What would happen to us if a giant space finger were to gently stop the Earth in its orbit?"

It didn't hit me right away. It set off a kind of slow-burn ... I don't want to call it annoyance, it doesn't rise to that level, but there's no other word that quite describes the sensation. Something was just not right with that sentence.



Before I reacted any further, I needed figures. What was Earth's mass, and its orbital speed? That will tell us the magnitude of kinetic energy we're talking about. And, once the numbers are crunched, we're talking about 2.685 x 10^33 Joules.

That's a totally nonsensical number. Once numbers get sufficiently large, they cease to have any real meaning. I can't relate that immensity to anything within my, or anyone else's experience. So, we go to find something else sufficiently gigantic that we might be able to use as a yardstick. For this purpose the Sun's total power output might serve. The Sun's power output is, on average, 3.846 x 10^26 Watts.

OK, that's another stupidly big number. But we can divide energy by power to get time. Which is ... 80.8 days.

And, friends, when you collect the Sun's entire power output for eighty freaking days, there is NO WAY to apply that much energy gently. That's like using a atom bomb to gently crack an egg. Or using a 120mm smoothbore tank gun to gently drive a finishing nail. It just ... no. You can't get there from here.

The same thing applies to stopping the Earth's rotation around its axis, which appears to be another popular Google search. People really seem to be afraid that this is a real thing ... which they shouldn't. Stopping the Earth from spinning isn't near as hard as stopping it in its tracks, but it's still so damn hard that it'll take totally stupid amounts of energy to do it. The Earth's rotational energy is 2.138 x 10^29 Joules ... yet again another ridiculously huge number. But we can divide that by the Sun's power output to get an idea of how it relates. It works out to 9 hours, 16 seconds.

And again, the after-effects of such stoppage become irrelevant. The friction of so much energy applied all at once would melt the crust to magma. (Which goes back to the point that there's no way to apply such a stupendous amount of energy gently.) What comes after is kind of beside the point. The rock under your feet suddenly becoming liquid is a much more immediate problem than anything that might happen afterwards.

Besides, no one's ever going to have that much energy all in one place to begin with. You can rest easy now, and stop worrying about this ever happening.

Now, all this reminds me of one of my favorite cheesy '70s sci-fi series ... Space: 1999. The premise, if you'll recall, was that the Moon got blasted out of Earth's orbit.

It was a different time.

So, we'll need some numbers. First, the Moon's mass: 7.348 x 10^22 kilograms. And its orbital speed: 1.022 kilometers per second. The escape velocity at that distance is 1.414 times the orbital velocity, so the escape velocity is 1.445 km/sec. Now, we can compute the kinetic energy before and after the event, and see how much additional energy is required. That works out to be 3.834 x 10^28 Joules. Again, an unbelievably stupendous meaningless number. But we link it back to the Sun's power output, and we get about a minute and a half.

Yeah. No way in Hell is a nuclear waste dump generating that kind of kaboom.

Not that I care. That show is still one of my guilty pleasures.

Monday, January 05, 2015

Fifteen for '15

It's one of those funny things that you really can't seem to quantify or prove, but nevertheless that everyone seems to agree upon: the older you get, the shorter a year gets. No one knows why. But everyone I've ever talked to about it agrees that it's so.

Anyway -- here we are, again. Another new year. Another old one gone to the discard pile. Except that it doesn't really feel all that new. That's something else that happens as you get older. I remember there used to be a magical feeling about approaching midnight on New Year's Eve. Like there was something special about the numbers rolling over to zero. That vanished for me somewhere between thirty-five and forty-five, not entirely sure where.

Having a teenager might have had something to do with it. That'll drive you to cynicism, alcoholism, or (often) both.

But I'm here to tell you, it gets better. They do grow up. They even -- Deo Gratia -- become rational adults.

And so, without further ado, fifteen observations for 2015.

ONE -- I'm going to be doubting the wisdom of this motif come 2020 or thereabouts. Maybe even sooner.

TWO -- Henceforth, I will be referring to Kim Jong-Un as The Great Hambino. When his government stops acting like a hobo on crank, he can have his name back.

THREE -- Big year ahead in spaceflight. For me, the highlight will probably be New Horizon's Pluto/Charon encounter in July. They've woken the ship up from the eight-year hibernation it's been in since the Jupiter fly-by in 2007, and the team is getting ready to begin its science mission in February. This is an encounter that means a lot for those of us who grew up when Pluto was the ninth planet, and to date the only one we haven't seen close up. That ends in July.

FOUR -- But wait, there's more! Dawn will be entering orbit around the dwarf planet Ceres in March, having left Vesta in September of 2012. Despite having been launched a year later than New Horizons, Dawn will end up being the first spacecraft to have a close encounter with a dwarf planet. On the other hand, Ceres may not be as interesting as Pluto ... but then again, it might. We don't know ahead of time what we'll find, which is part of what makes the trip worthwhile.

FIVE -- While the Dragon 2.0 won't fly this year, tomorrow morning we'll get to find out if they can land a Falcon first stage on an autonomous ocean barge or not. SpaceX is saying they have a 50-50 shot of this thing working right the first time. But I sure wouldn't put money on them not being able to figure it out within a flight or two. Once they work the bugs out, this will allow SpaceX to recover, refurbish, and re-use an enormous chunk of flight hardware that everyone else just throws away. Good news for SpaceX, as well as its shareholders and customers; mildly worrisome for everyone else in the business.

SIX -- It will be a while before anything is known for sure, but my guess is that Scaled Composites will identify what went wrong with VSS Enterprise, fix it, and be ready to go back into test by the end of the year. But that depends on a number of things -- the final NTSB report and whether or not Richard Branson wants to press ahead being the two most important ones.

SEVEN -- And last but not least, the planet-hunter Kepler isn't down for the count, after all. They've managed to work out a mode of operation that will allow some observations to go forward, even with its reduced capability. It may be several years before my #4 observation from last year comes to fruition -- that'll probably require much more capable sensors than we currently have -- but I'm still optimistic we'll find a habitable world Out There fairly soon.

EIGHT -- Nothing new to report on the fusion energy front ... yet. But keep an eye on this. The fact that a company as big as Lockheed has laid its name and reputation on the line tells me that they've got a solid path forward. The odds are that we won't hear anything new until it's demonstration time. This points back to items #5 through #7 from last year, and I'll say it again: while concern is warranted about our power future, panic isn't. More and more, it's looking like we'll have the tools we need when we need them.

NINE -- This is a partial call-back to #5 above ... but I just wanted to point out how far 3-D printing has come. The thrusters they're going to use both for contingency aborts and precision landings? Made by 3-D printing, with metal. Not plastic, metal. Also, a 3-D printer has been delivered to the International Space Station. I wasn't aware that was even possible. Early 3-D printing technology required gravity in order to do its thing. Apparently, they've figured out a way around that. Interestingly enough, the first thing they made with their new 3-D printer was a part for the printer ... which tells me we're that much closer to being able to build a machine that can rebuild itself. Cool, and scary, all at the same time.

TEN -- Please, merciful God, spare us Clinton vs. Bush in 2016. Surely there are other candidates. But I fear that may be how the primaries shake out.

ELEVEN -- What a difference a year makes. Several years of 8-8 futility, and all of a sudden the Cowboys turn into an unstoppable-on-the-road juggernaut. Which sets up an interesting situation this coming Sunday in Green Bay -- the irresistible force meets the immovable object. The Cowboys are undefeated on the road. The Packers are undefeated at home. One of those streaks ends on Sunday.

TWELVE -- Somewhat related: is anyone out there still questioning the wisdom of drafting Zack Martin instead of Johnny Manziel? Anyone? Anyone? Bueller?

THIRTEEN -- While the lower gas prices are nice, something's going on behind the scenes that no one's quite figured out yet. We know that Saudi Arabia spun their taps wide open, what we don't know is why. There are a few possibilities, ranging from the highly likely to the improbable. Increasing the supply drops the price, that's obvious. Question is, who benefits? And who's hurt? Is this intended to put some hurt on the Iranians? Maybe, and a weakened Iran would be a good thing for the Saudis. Do they want to put a squeeze on the Russians? Maybe, insofar as they've provided Iran with backing. Do they want to drive prices low enough to put the resurgent American oil industry in a bind? I tend to think that's an unintended consequence, but I'm just guessing. Low prices put advanced recovery techniques, such as fracking and tar sands, at an unfavorable place on the price curve. But if they see that as such a threat, then ... maybe they're drawing down low enough that it's "smoke 'em while you got 'em" time. But if their reserves were getting that low, the smart play would be to lean it out as long as possible, wouldn't it? In any case, this bears close attention, and you should probably keep an eye on it.

FOURTEEN -- When Autocorrect gets good enough to make this site obsolete, then it's time to worry about Artificial Intelligence.

FIFTEEN -- (Added 11Jan15) Yep. Definitely regretting this motif.

Friday, January 02, 2015

Sesquicentennial, Part XLII: The Penultimate Campaign


"An army marches on its stomach." -- Napoleon Bonaparte

Atlanta had fallen, but John Bell Hood knew that wasn't necessarily the end. Sherman's men needed food, and supply. These, he'd have to get from the North. So, reasoned Hood, if he stood astride Sherman's line of supply, he'd have to come out and give battle on Hood's terms. It was with this general intent that Hood marched to the northwest, more or less leaving Georgia the way Sherman came in.

Sherman mounted a brief, half-hearted attempt to follow, then apparently gave it up as a bad idea. This perplexed Hood. He attacked Union forces at Spring Hill, then at Franklin, finally attacking Nashville itself in mid-December, but not a peep came from Sherman. Did Sherman care nothing for his lines of supply?

Hood, in the end, accomplished nothing but the destruction of the Army of Tennessee as an actual fighting force. I wonder if Hood knew what Sherman's plan actually was.

Because Sherman had deduced the dread secret of industrial-age war. Armies marched on their stomachs, yes. But that's a sword that cuts both ways. There are more ways than one to deny Lee's army of its supply. And there are more ways than one of supplying his own men at the same time. And Georgia's rich farmlands had not, as yet, felt the hard hand of war...

This was the bold plan he'd advanced to Grant and Lincoln, so bold that it bordered on suicidal rashness: cut loose. Head southeast towards Savannah, relying on the farmlands themselves for his sustenance. On the way, tear up telegraph wires, rail lines, and anything else of military significance. He had over sixty thousand men, even after cutting General Thomas and his men loose to keep Hood occupied in Tennessee. He had detailed maps drawn up, using data from the 1860 census, showing where the richest farms and plantations were, and what they'd be likely to have.

"I can make this march," Sherman wrote in a telegram to Grant, "And I will make Georgia howl!"

In opposition, General William Hardee could only muster some thirteen thousand troops with which to defend Georgia and the Carolinas. In open country ... that wouldn't be much of a fight. Hardee, not being an idiot, wasn't about to fight in open country. He fortified the approaches to Savannah as best he could, and awaited Sherman's arrival.

There were a few skirmishes along the way, but nothing really worth mentioning. The March itself remains somewhat controversial. His supporters have called Sherman the first modern general, the first to truly understand that by attacking the Confederacy's logistical underpinnings, he was taking the most direct path possible to defeating the Confederate armies in the field. His detractors call him many things -- some not repeatable in a family publication -- but also lay the charge of war criminal at his feet for making war upon civilians. He had an answer for them:

"You cannot qualify war in harsher terms than I will. War is cruelty, and you cannot refine it; and those who brought war into our country deserve all the curses and maledictions a people can pour out. I know I had no hand in making this war, and I know I will make more sacrifices to-day than any of you to secure peace. But you cannot have a peace and a division of our country. If the United States submits to a division now, it will not stop, but will go on until we reap the fate of Mexico, which is eternal war. The United States does and must assert its authority, wherever it once had power; for if it relaxes one bit to pressure it is gone, and I believe that such is the national feeling."

Sherman believed that what he called "Hard War" (and what we would call today "Total War") made for a shorter conflict, and would lead to a swifter peace with less overall bloodshed. And to be sure, Sherman had drawn up orders to the effect that civilians were to be left unmolested, so long as they did not impede the army's march. Their excess produce would be confiscated, to be sure, but their persons were to be safe.

By mid-December, Sherman's army was arrayed outside of Savannah, and Sherman went about the business of reducing the fortifications that prevented his access to the sea -- and with it, communication with the Union Naval forces in command there. On December 17th, having made contact with Admiral John Dahlgren, he issued an ultimatum to General Hardee in Savannah. Surrender and accept generous terms, or resist and face obliteration. Hardee took a third option: he and his troops slipped out and escaped. In his stead, the mayor of Savannah surrendered the city to Sherman.

A few days later, Sherman telegraphed Lincoln:

"I beg to present you as a Christmas gift the City of Savannah, with one hundred and fifty guns and plenty of ammunition, also about twenty-five thousand bales of cotton."

Unwritten, but obviously implied and easily seen by anyone paying attention, was the fact that a Union army would roam at will through the Confederate heartland. That the Confederate army was powerless to defend the Confederacy. This is the point Lee had hoped to make with his two invasions of the North ... but didn't swing enough heavy iron to make the point stick.

Sherman had heavy iron to swing, and plenty to spare. The only question remaining was, who's next?

Actually, that's a trick question. Sherman was heading North, along the coast, to link up with Grant. South Carolina would be next to feel the sting. And there wasn't a blessed thing Jefferson Davis could do to stop him.