I said centripital when I meant centrifugal and started a long subthread / argument basically about nothing. Yeah, gravity is the centripital force in an orbit. The balancing, opposite force is what I was calling centripital.

feufeu said:
> centripetal force that is needed for any circular (or curved) movement is provided by the gravitational pull of the moon/earth, e.g. the gravitational force

raymorris said:
> centripetal force balances gravity. Centripetal force is not caused by EARTH'S gravity.

Immerman said:
> No, they're right.

Let me make sure I understand what you believe they are right about. You're saying that earth's gravity causes centripetal force?
So in deep space, away from earth's gravity, there is no such thing as centripetal force? If you fly a sharp curve in deep space, your own momentum won't press you against the outer wall of your ship?

Centripetal force acts enough like like gravity that Einstein theorized it involves the same underlying force as gravity. It's not EARTH'S gravity. Centripetal force exists in deep space, far from the influence of earth's gravity. Because it acts just like gravity does, it can perfectly balance out gravity, with -1G of centripetal force exactly counteracting +1G of gravity, resulting in 0G net.

I did read what you wrote. What I'm talking about is more general, it applies even to a perfectly homogeneous gravitational body.
I'm talking about the minimum gravitational altitude in terms of \frac{Gm_1m_2}{r^2}=\frac{m_2v_{T}^2}{r}.

I notice you conveniently left Xerox out of the Dynabook story. The project originally called "the interim Dynabook" was renamed the Alto. Xerox had done the R&D to develop Kay's idea into a working machine. Around this time, Xerox owned part of Apple, so they invited Steve Jobs and other Apple people to Xerox Parc, where they had a look at the Alto (Dynabook) development version. The Apple folks really liked the GUI idea, so they worked and worked to transform it into something that could work in the real world, made of materials that actually existed. And that's how we got the desktop GUI.

Kay had a wish "I wish for a kid's toy that's tablet sized, with a battery that lasts forever". Xerox and Apple started with the wish and developed something doable - and completely different from Kay's original vision. Kay jad wished for a children's device, Apple and Xerox created the desktop computer GUI for adults, something nobody had asked for.

> Erh... no. The supply side never created jobs. Never has, never will. A job is created if, and only if, there is someone willing and able to pay for the goods and/or services that job creates.

Yeah I remember back in 1980 we were all going into the stores trying to buy ipads and 3D printers. After we consumers did the R&Dand speced out exactly what kind of iPad we wanted to buy, Apple ordered some from China and started selling them.

Wait, maybe I'm remembering wrong. Maybe a bunch of companies hired a bunch of engineers, programmers, and product designers to come up with a variety of different computing devices, hoping that they'd come up with something people wanted to buy. Maybe people did not buy the first few tablet models, so for the first 15 years those companies were losing money trying. Maybe Maybe eventually one company, Apple, developed a version people would buy.

I don't remember for sure, which of those two scenarios actually happened?

> The centripetal force that is needed for any circular (or curved) movement is provided by the gravitational pull of the moon/earth, e.g. the gravitational force.

Think about what that would imply, it would mean that it's impossible to turn in space, away from the earth's gravity. In fact, it woild mean that here on earth you could only turn downward, toward the earth. Nascar drivers couldn't turn left, because all curved movement must curve downward.

G-force and gravity behave in indistinguishable ways, so it appears that they are the same thing (per Einstein). That does not mean that all G force is EARTH'S gravity. Orbital centripital force is gravity(-like), so it can therefore balance the gravity coming from another source (earth), resulting in net zero g aboard the spacecraft.

I looked and found more about it. You could of course fly around the moon at an altitude of 500 meters. Orbit has a specific definition it seems - centripital force being equal and opposite to gravity, so they balance out. Anyone inside the craft therefore feels zero gravity. If gravity pushes your into your seat as the craft flies around, that's not orbit, that's flying around.

      Centripital force is small when you're moving almost in a straight line. Traveling just above the earths's surface, for example, the turn radius is several thousand miles. Therefore, for gravity to be balanced by centripital force, you need to be far enough away that gravity is reduced sufficiently that the small centripital force can balance it.

> One could orbit the (airless) moon at an altitude of 2000 feet

That's what I thought, but former NASA engineer Randall Munroe (of xkcd fame) says you can't. Something about orbital physics involving gravity that I don't understand. I wonder who is right. I'm guessing the guy who did orbital physics for a living, although I don't understand it.

OS X is certified UNIX. You know, the network operating system that was serving clients before Xerox invented the desktop.
I have a 1U OS X. server here that says you're clueless.

> There can no be any 'suspect' in the 'openness' because they have agreed to the license

In some cases, such as document formats, they have patents that apply. The _copyright_ license means you're not violating their _copyright_ by using/modifying/distributing the code, or code that has a similar function, but you're still subject to theor patents, so they can still sue you for millions and billions of dollars. The only protection you have for this code (and any code that reads or writes their format) is an informal promise that as long as they don't mind what you're doing, this year they won't sue you. That's certainly suspect. They might not completely screw everyone who touches their code, but they've reserved the right to do so.

They also have a license which they call "open", but it sure doesn't read like any open source license before. "Hi, my name's Chelsea", their license purrs, with her adam's apple rising. Suspect.

Some systems should be patched asap, of course, and we've patched our most critical systems. However, the bash team is still working out the best way to do a comprehensive fix, one that takes care of related issues as well as the initial exploit. As of Friday evening Red Hat and upstream bash were headed in two different directions. We'll be waiting until probably Monday evening to patch most of our systems, even the bash team decides what they're going to do and that gets implemented in rpms. It's not unreasonable for most OSX users to take care of it Monday or so, especially since most Macs don't have a public facing internet presence.

If you're using OSX for an important public facing web server, you can update it today via configure; ./make; make install

Maybe someone who works in new led technology can answer two questions:

Does / might this apply to to LED light bulbs as opposed to screens?
TFA refers to screens.

If so, care to take a guess as to how long it will take for this to be on store shelves?

Your main point is a good one - there are good reasons for the complexity.

I'm curious about the other thing you suggested. People have been making and breaking ciphers for thousands of years. For thousands of years, every algorithm* has been broken. Why would you say today's won't be? MD5 was believed to be secure for a long time, now it's thoroughly broken. What evidence is there that SHA-3 doesn't have an undiscovered weakness, given that every other algorithm has had some?

Further, quantum computers have now actually factored semiprimes, proving the theorems. So we already know how to break existing keys, given large quantum computers. At this stage, with so little knowledge about what medium-scale quantum computing, is it not hubris to think our kids won't come up with ways to use the new powers of quantum computing to solve problems that we don't yet know how to solve efficiently?

* "every algorithm " meaning all algorithms useful for this purpose. OTPs specifically, aren't applicable to the problem, though they are unbreakable if properly implemented.

OpenSSL's heartbleeed bug was a bug in openssl, a buffer overrun that didn't really have anything to do with ssl. A similar bug in any other server software would be approximately as bad. Where https protocol specified a ping, openssl instead leaked the contents of arbitrary memory locations .

Apple's goto bug was Apple's bug. Again, little to do with the protocol. Ssl/tls/https didn't fail here, the company failed to implement https.

The one "fault" of the protocol in the cited cases could be that it isn't brain-dead simple. Since the standard isn't idiot-proof, idiots can screw it up.

Slippery slope is the argument "if we let them ban filming movies, the next thing you know they'll ban all photography". The fallacious version stops there, just silently assuming that ALL slopes are slippery, rather than asserting that a particular slope is in fact slippery. The non-fallacious version points out that the number of pages of federal regulation has grown by 10,000% in the last few decades - showing that indeed the federal government DOES tend to enact more and more regulation. That slope really is slippery, and it's not fallacious to point that out.

Also GP said the current regulation IS too broad. Lannoc didn't say "if we allow this regulation, next thing you know they'll have a regulation that is too broad". So although Lannoc actually used the words "slope" and "slippery", the argument wasn't slippery slope - he asserts that the current regulation is too broad, not that it will become too broad. He (she?) also asserts that "the slope is getting slippery", rather than implying the assumption that all slopes are slippery, which would be the fallacy.