The Phantom City

Ran across this story about the computer aboard Apollo 11, and a fortuitous 0.1-second difference.

LUMINARY was never completely bug free. Allan told me about a fascinating series of events that could have easily prevented the first moon landing and might have caused disaster. Allan was the principal designer of the LM’s descent guidance program which steered the LM by gimballing and throttling the descent engine. Whenever the computer commanded the engine to increase or decrease thrust, the engine (and LM) reacted after a short time lag. Allan’s descent program needed a routine to accurately estimate the new thrust level, which could be accomplished by reading the “delta-V” (change in velocity) measured by the LM’s accelerometers. He wrote a short routine that took into consideration, i.e., compensated for, the engine’s lag time, which TRW’s “interface control document”, full of useful information for the programmers, said was 0.3 seconds. It took 0.3 seconds for the LM’s descent engine to achieve whatever thrust level the computer might request. The final version of the thrust routine, which was put into the LM, was written by Allan’s friend Don Eyles. Eyles was sufficiently enthusiastic about the programming challenge that he found a way of writing it which required compensating for only 0.2 of the 0.3 seconds. The IBM 360 simulator showed Eyles’ program worked beautifully. His routine was aboard Apollos 11 and 12 which landed successfully. However, telemetry transmitted during the landings later showed something to be very wrong. The engines were surging up and down in thrust level, and were barely stable. A guy at Johnson Space Center called Allan and informed him that the LM’s engine was not a 0.3-second-lag engine after all. It had been improved some time before Apollo 11′s launch such as to lower the lag time to only 0.075 seconds. Correction of this item in the interface control document had simply been overlooked. Once this discrepancy was discovered, theIBM 360 simulator was reprogrammed to properly simulate the actual, faster engine. Running on the simulator, Don Eyle’s thrust program, with the 0.2-second compensation, exhibited the surging that had occurred on the real flights. But here’s the most interesting fact: the simulator also showed that had Allan Klumpp chose to “correct” Don Eyles’ program by compensating for the full 0.3 seconds that was printed in the document, the LM would have been unstable and Apollo 11 would never have been able to land. By pure luck, Don Eyles was creative enough to write the thrust routine in a way that kept the LM just inside the stability envelope and allowed successful landings!

Full post at tech-archive.net’s sci.space.history archive.

Seriously?

I just ran across this little requirement in signing up for a service that I’m now nervous about using:

Username: 3+ lowercase letters and numbers, starting with a letter.
Password: 8+ Alpha Numeric characters & must include – 1 uppercase, 1 lowercase, and a number.
Special Characters are not accepted!

No special characters?!? I haven’t been this annoyed since I figured out my database IDE couldn’t handle a schema password with an @ in the name.

Testing to see if glial progenitor cells — the early form of neurons and glia in the brain — can be integrated into human brains that are missing these vital building blocks, scientists have injected human progenitor cells into mouse brains.

The human progenitor cells went to the correct locations and performed the correct function in the mouse brains…but then this happened:

The human progenitor cells are larger, more complex, and have more staying power than mouse progenitor cells in the brains of mice. Which means that over time, the brains of mice injected with these cells are becoming more…human. Goldman’s collaborator (and spouse) Maiken Nedergaard and her team at the Center for Translational Neuromedicine, also at U Rochester, has tested these mice to see if their humanised brains make them smarter. The hu-mice do seem to condition more quickly, and show signs at the molecular level of differences in synaptic connections that suggest they might be cognitively different.

Anyone else shuddering at the concept of “hu-mice?”

Courtesy of In The Field, at Nature.com

…killed by a health care reform bill, pronounced dead at the age of 233. Who knew democracy was so fragile? Who knew our great American traditions of relatively non-violent political change would be so easily broken. All by one bill.

Goodbye, America…killed by a piece of government legislation, passed by a majority of the House and Senate, two bodies that we have the opportunity to radically change every two years simply by voting…not even a Constitutional amendment….

I’ll miss you, but I’ll fondly remember how you survived such challenges and changes as the income tax, driver licenses, and the 1980′s military buildup…

…going to war on the basis of government deception, losing our right to question law enforcement, hippies, sexual immorality, AIDS…

…the first $5 trillion in national debt, the stock market crashing, subversive communism, the arms race, over-population, race riots…

…Nazis, immigration, a Civil War, electing Democrats/Republicans/Whigs/etc., Islamic fundamentalist terrorists, Islamic secular terrorists…

…Anarchists, polio, Appalachian poverty, unions, nuclear war, anthrax in the mail, Communist terrorists, militias, oil crises…

You have been truly magnificent. I apologize for the weakness of my generation: Our inability to accept change, our flair for dramatic hyperbole, our inability to think about the future, our lack of strategic thought, our lack of faith in you, ourselves, our institutions, and our humanity.

We’ve let you down, and now you’ll die, because we no longer believe in anything but ourselves, our complaints, and our fame.

What we can hope is that you ignore our lack of faith, our ingratitude, and our lack of inner fiber long enough for us to realize that rhetoric is not reality, that we still have power through the franchise of the vote, and that America is not so easily destroyed or forsaken. Remind us it’s morning in America whenever we damn well say it is, and that no piece of legislation, no political party, no court ruling is the end, no matter whether we like it or not. Keep holding out for us, and maybe we, or another generation, will grow up and be worthy of your ideals.

Now, this part breaks the flow of the post, but it needs to be said: I don’t care what your opinion about health care reform, socialism, religion, or right and wrong is, as long as you state it reasonably. But lately, I’ve heard people talking about civil war, and I want to state one thing: Cut back the hyperbole, because if you’re serious, if you decide to take up arms against America, I and the rest of the unfortunately quiet majority will resist you, and you will fall into the dustbin of history.

I might not be a fan of everything we do in America, but that doesn’t mean I don’t care about its enemies, about the people who hate us. There are far more people who hate America inside our country than out, and most define themselves as the True Americans. Wrong. If you were, you’d already be in power. The rest of us…we’re actually pretty proud of our country, our political system, and our beliefs, even if we don’t agree with something that feels absolutely vital.

Anyway, I’ve just been disgusted by the rhetoric. I’ve lived here for forty years, almost, and I know we’re always a dramatic people, but it’s time to shut up so we can actually listen and think.

New Scientist mentions a study where old mice are rejuvenated by being conjoined with young mice and sharing their blood supply.

Have we learned nothing from science fiction and horror? If there’s one lesson to be taken from hundreds of stories, it’s that creating a Fountain of Youth by harvesting from the young always turns out to be a bad idea.

Subject line from today. Refreshingly straightforward. Disturbingly familiar.

“You have not had sex with a Russian girl? Come to us and you shall have it!”

I might think different after a while, but I was kind of interested in MacWorld’s live coverage of the event, so I decided to write down some thoughts to see if they survive as time goes on.

• I really hope at some point they come out with the iPatch.
• The iPad is an iPhone I can’t fit in my pocket and can’t use to make phone calls.
• The iPad is an expensive, but lighter and shinier, netbook where I have to pay extra for an hardware keyboard and comparable storage.
• The iPad has access to the Apps store, so I can run iPhone apps without having to squint at them.
• Maybe the iBookstore can force Amazon to start supporting epub?
• I’d get one over the Kindle DX at a similar price. I don’t know about Kindle 2.0 at its current price point.
• Unlike the iPhone, I could use it for extended reading. One also assumes the Amazon Kindle app will still work.
• iWork apps are kind of cool. Could use it for presentations at work.
• I love the data plan pricing, particularly the pre-pay option.
• I kind of wonder about the whole 250MB plan. That could be fine on the iPhone, but I suspect people would use video on this more frequently.
• Might have been an awkward design at 16:9, but I was a little surprised at the 4:3-ish screen ratio. Oh well, it’s not a TV.
• Games will be prettier, faster, and more involving, but I’d need to pick one up to see whether the size would be awkward for a handheld.

I like this gadget, but I just can’t see where it would improve my life in the age of the iPhone and netbooks. I’ve already got light-enough computing in a form factor that’s been around forever, and I’ve got good-enough ubiquitous data access.

But, that all being said, it’s one step closer to that future of computerized houses, touchpads, and jetpacks I’ve been hoping for since I was a kid, so I appreciate it for that.

Update: Almost forgot…if it’s running the iPhone OS, I’m guessing no Flash. Maybe more pressure to adopt some HTML5 alternatives?

Update, redux: I’m getting slightly irritated by the sheer number of blog posts I’ve read lauding the iPad as high-tech at a cheap price. Really? At the base level, it’s a 1GHz processor, 16GB of flash storage, 1024×768 multi-touchscreen, and Wireless-N. It’s not delivering high-tech…it’s delivering good-enough tech in a better form factor than we’ve been used to. That’s called design, and Apple does that regularly.

BTW, I have figured out an awesome use for the iPad in my life: A computer my mom would regularly use. She’s not a big fan of mice, or touchpads, or the pointy cursor, but a large touchscreen would be awesome for her. Now, if AT&T would actually deliver 3G to Reidsville, NC, getting her on the Internet would be easy. As it is, we’d have to get cable or DSL and a wireless router in her house.

Twitter: I really want to use Twitter to comment on Twitter suffering a denial-of-service attack. That isn’t happening. I wonder if the attack is actually that impressive, or if it’s just taking advantage of something about Twitter’s setup?

NetNewsWire and Google Reader: If you like to get your feeds through a desktop client, but still want to have access to them elsewhere, NetNewsWire 3.2 Beta now syncs with Google Reader. Apparently Newsgator is confident enough in it to shut down their own online feed reader. I’m not sure whether I prefer it to Google Reader, or how well it works yet. (I can confirm it downloads the feeds. I haven’t tested the syncing beyond that, however.)

One thing to mention about NetNewsWire 3.2 Beta that I had trouble finding anywhere else: When it tells you your Google login will be kept in the keychain, it means it. I’d enter my login, and the login window would pop back up like I hadn’t done anything. Turned out, my keychain had somehow gotten set to another user, and NetNewsWire wasn’t happy it couldn’t save the login info. Repairing the keychain using Keychain Access (I think that’s the name) worked.

GitHub: The comparison table for GitHub plans just shocked me for no good reason. It runs from most expensive on the left to free on the right. I’m used to the other way around, so my first thought was that the base paid GitHub plan was $200 a month. Nope, that would be $7.

Steelcase: I’ve been trying to get Lorrie interested in something like an Aeron chair for the office for quite a long time, but no dice. However, Steelcase won her interest all on their own. Good job, Steelcase. I probably need to start using my desk again as well. So hard to do when you can sit in a recliner and use your laptop.

Update: Wow, the Twitter/Facebook/etc. attack was on one user? That’s a lot of electronic capital expended.

Update, again: Closing comments. Too much spam coming in on this one.

IN CONGRESS, July 4, 1776.

The unanimous Declaration of the thirteen united States of America,

When in the Course of human events, it becomes necessary for one people to dissolve the political bands which have connected them with another, and to assume among the powers of the earth, the separate and equal station to which the Laws of Nature and of Nature’s God entitle them, a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation.

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. Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causes; and accordingly all experience hath shewn, that mankind are more disposed to suffer, while evils are sufferable, than to right themselves by abolishing the forms to which they are accustomed. But when a long train of abuses and usurpations, pursuing invariably the same Object evinces a design to reduce them under absolute Despotism, it is their right, it is their duty, to throw off such Government, and to provide new Guards for their future security.–Such has been the patient sufferance of these Colonies; and such is now the necessity which constrains them to alter their former Systems of Government. The history of the present King of Great Britain is a history of repeated injuries and usurpations, all having in direct object the establishment of an absolute Tyranny over these States. To prove this, let Facts be submitted to a candid world.

He has refused his Assent to Laws, the most wholesome and necessary for the public good.
He has forbidden his Governors to pass Laws of immediate and pressing importance, unless suspended in their operation till his Assent should be obtained; and when so suspended, he has utterly neglected to attend to them.
He has refused to pass other Laws for the accommodation of large districts of people, unless those people would relinquish the right of Representation in the Legislature, a right inestimable to them and formidable to tyrants only.
He has called together legislative bodies at places unusual, uncomfortable, and distant from the depository of their public Records, for the sole purpose of fatiguing them into compliance with his measures.
He has dissolved Representative Houses repeatedly, for opposing with manly firmness his invasions on the rights of the people.
He has refused for a long time, after such dissolutions, to cause others to be elected; whereby the Legislative powers, incapable of Annihilation, have returned to the People at large for their exercise; the State remaining in the mean time exposed to all the dangers of invasion from without, and convulsions within.
He has endeavoured to prevent the population of these States; for that purpose obstructing the Laws for Naturalization of Foreigners; refusing to pass others to encourage their migrations hither, and raising the conditions of new Appropriations of Lands.
He has obstructed the Administration of Justice, by refusing his Assent to Laws for establishing Judiciary powers.
He has made Judges dependent on his Will alone, for the tenure of their offices, and the amount and payment of their salaries.
He has erected a multitude of New Offices, and sent hither swarms of Officers to harrass our people, and eat out their substance.
He has kept among us, in times of peace, Standing Armies without the Consent of our legislatures.
He has affected to render the Military independent of and superior to the Civil power.
He has combined with others to subject us to a jurisdiction foreign to our constitution, and unacknowledged by our laws; giving his Assent to their Acts of pretended Legislation:
For Quartering large bodies of armed troops among us:
For protecting them, by a mock Trial, from punishment for any Murders which they should commit on the Inhabitants of these States:
For cutting off our Trade with all parts of the world:
For imposing Taxes on us without our Consent:
For depriving us in many cases, of the benefits of Trial by Jury:
For transporting us beyond Seas to be tried for pretended offences
For abolishing the free System of English Laws in a neighbouring Province, establishing therein an Arbitrary government, and enlarging its Boundaries so as to render it at once an example and fit instrument for introducing the same absolute rule into these Colonies:
For taking away our Charters, abolishing our most valuable Laws, and altering fundamentally the Forms of our Governments:
For suspending our own Legislatures, and declaring themselves invested with power to legislate for us in all cases whatsoever.
He has abdicated Government here, by declaring us out of his Protection and waging War against us.
He has plundered our seas, ravaged our Coasts, burnt our towns, and destroyed the lives of our people.
He is at this time transporting large Armies of foreign Mercenaries to compleat the works of death, desolation and tyranny, already begun with circumstances of Cruelty & perfidy scarcely paralleled in the most barbarous ages, and totally unworthy the Head of a civilized nation.
He has constrained our fellow Citizens taken Captive on the high Seas to bear Arms against their Country, to become the executioners of their friends and Brethren, or to fall themselves by their Hands.
He has excited domestic insurrections amongst us, and has endeavoured to bring on the inhabitants of our frontiers, the merciless Indian Savages, whose known rule of warfare, is an undistinguished destruction of all ages, sexes and conditions.

In every stage of these Oppressions We have Petitioned for Redress in the most humble terms: Our repeated Petitions have been answered only by repeated injury. A Prince whose character is thus marked by every act which may define a Tyrant, is unfit to be the ruler of a free people.

Nor have We been wanting in attentions to our Brittish brethren. We have warned them from time to time of attempts by their legislature to extend an unwarrantable jurisdiction over us. We have reminded them of the circumstances of our emigration and settlement here. We have appealed to their native justice and magnanimity, and we have conjured them by the ties of our common kindred to disavow these usurpations, which, would inevitably interrupt our connections and correspondence. They too have been deaf to the voice of justice and of consanguinity. We must, therefore, acquiesce in the necessity, which denounces our Separation, and hold them, as we hold the rest of mankind, Enemies in War, in Peace Friends.

We, therefore, the Representatives of the united States of America, in General Congress, Assembled, appealing to the Supreme Judge of the world for the rectitude of our intentions, do, in the Name, and by Authority of the good People of these Colonies, solemnly publish and declare, That these United Colonies are, and of Right ought to be Free and Independent States; that they are Absolved from all Allegiance to the British Crown, and that all political connection between them and the State of Great Britain, is and ought to be totally dissolved; and that as Free and Independent States, they have full Power to levy War, conclude Peace, contract Alliances, establish Commerce, and to do all other Acts and Things which Independent States may of right do. And for the support of this Declaration, with a firm reliance on the protection of divine Providence, we mutually pledge to each other our Lives, our Fortunes and our sacred Honor.

Text courtesy of The National Archives.

Each summer I go through the same experience of getting really annoyed with how hot my hair is, and thinking about shaving it off. So, I decided to blog some of the reasons I can think of for not doing it, for future reference.

1. I’m a little afraid that, if my hair started growing back, it would end up looking like Notre Dame QB Jimmy Clausen‘s hair did his freshman year. Seriously, that dude had some weird spiky hair going on.

2. I’ve had the same hairstyle since sixth grade. Why change now? And would it even be possible, or would my hair actively resist change? Maybe it’s like Superman’s hair by now?

3. These are things I’m afraid I would find on my scalp, if I could see it: A birthmark, a barcode, a vestigial third eye, tattooed messages of things I didn’t really need to remember anytime soon. (Memento. Excellent movie. See it.)

4. Too much work. I’m already lazy about shaving my face. And still bad at it. I can’t imagine trying to shave the back of my head. I’d need transfusions.

5. Seriously, my beautiful hair? What if it doesn’t come back? I’ll never be that pretty again.

6. There is potential that light reflecting off the whiteness of my scalp could cause an air and ground navigation hazard.

7. Yul Brynner looked awesome bald. On the other hand, hair is my evidence I’m not a large, mobile, noisy potato.