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pikchurn | 8 years ago | on: SpaceX successfully deploys the Star man

Meaning that they didn't launch at the right time to arrive at Mars, due to where Mars is in its orbit currently. It'll pass through the imaginary circle around the sun which is Mars' orbit, it's just that Mars will at a different part of the orbit at that time.

But actually, it seems they decided to just empty the tanks and get as much delta-v as possible, and it'll go all the way into the asteroid belt as a result.

pikchurn | 8 years ago | on: SpaceX successfully deploys the Star man

Actually, no, once the 2nd stage cuts off the trajectory is mostly fixed and we know what orbit it is in. There are, I believe, two more small burns that will be done to adjust the trajectory, but these are more of an adjustment to what kind of Martian transfer orbit it is in. It already has the hyperbolic velocity to leave Earth's orbit, and enter solar orbit with an apogee at the same distance as Mars.

In 6.5 hours SpaceX will have finished everything they wanted to test with this flight I believe, including a number of post-launch checks of various systems and sensors on the payload, and those re-ignition tests of the 2nd stage.

pikchurn | 8 years ago | on: SpaceX’s Falcon Heavy successfully launches

I don't find that surprising. The communication link back is presumably by satellite since it is in the middle of the ocean, and probably a directional antenna because of the high bandwidth. You have any good suggestions for having a reliable connection via directional antenna on a flimsy barge that a rocket is landing on in this middle of the choppy north Atlantic?

pikchurn | 8 years ago | on: RFC: Ubuntu 18.04 LTS Minimal Images

I use containers as lightweight VMs in many places. Generally I see this as a way to get a minimal install that other tools can then configure appropriately, with up to date packages fetched from upstream mirrors directly, instead of installed from CD and then upgraded.

I currently use packer.io to script the creation of a bunch of server images, and for ubuntu I've missed the "minimal install CD" that other distros have. Instead packer has to download a 800MB CD image, in order to install only a few hundred megabytes of uncompressed packages in a bare-bones install, which is then provisioned using some orchestration tool that at its heart uses ssh to login to the virtual machine.

Not having SSH means you need to add in some sort of serial-attach step to manually install sshd, or hook into the install scripts to download sshd as part of the install or whatever. Either way that's additional custom work that is probably common to a great many use cases.

pikchurn | 8 years ago | on: RFC: Ubuntu 18.04 LTS Minimal Images

Posting here rather than the blog because I don't have a google account:

What about adding sshd to the minimal install? If the purpose of this is minimal installs of containers and cloud servers and such, that seems like quite an omission.

pikchurn | 8 years ago | on: The Quantum Theory and Reality (1979) [pdf]

I already told you the added assumption: a theory of wave-form collapse as physical phenomena. Only the Copenhagen interpretation has this. I'm not going to spend my time putting that into formal logic notation to satisfy random person on the internet. Do it yourself.

pikchurn | 8 years ago | on: The Quantum Theory and Reality (1979) [pdf]

That's missing the point. Copenhagen is not mathematically wrong. Alternatives like many-worlds interpretation and pilot wave theory have the same (MWI) or isomorphic (pilot wave) equations. Copenhagen is epistemologically wrong in that it requires strictly more assumptions than is strictly necessary, specifically an theory of wave function collapse. It is "wrong" by Ockham's razor.

pikchurn | 8 years ago | on: The Quantum Theory and Reality (1979) [pdf]

You ignored the "philosophy of science" part. Philosophy of science is how we decide which of two theories is "correct" when they offer the same experimental predictions. See also my reply to a sibling comment.
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