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Comment Re: Including this one? (Score 1) 337

but would it kill Microsoft to change the default behaviour to something more sensible (this can hadly be the only use case where this is an issue)

Science users with thousands of rows of data are a negligible market compared to beancounter-wannabes with a dozen (or maybe even up to 5 dozen) rows of data. So, to answer your question, yes it would kill Microsoft to change the default from behaviour that covers up common wannabe-beancounters errors.

Oh, the fuck-wittery of working round Excel v5 bugs like this to deal with combining hundreds of thousands of lines of data throughout the 1990s. And 2000s. And 2010s. And you an guess what I anticipate fucking with in the 2020s.

Comment Re:Light years (Score 1) 214

Why do astronomers use irregular units like "light years" and "parsecs"

I can't remember the last time I read an astronomy paper (NB : paper, not regurgitated shit in the popular press) which didn't use parsecs and/or AU as the primary description of astronomical distance (with , M-Earth and M-Sol in the mix). For parsecs, the reason is simple : what you measure when establishing distances is parallax, in seconds of arc. Hence PAR-SEC. No?

If converting to metres, then you need to factor in your estimate for the AU, but you only do that conversion when editing the final draft of the paper and the press release You do your working in parsecs. And if the estimate for the length of the AU in metres changes between your observatory time and publication date, then only that derived figure in metres (miles, Egyptian cubits, or whatever) changes NONE of your working or your experimental data changes.

Similar arguments apply to the masses and the AU. You can directly observe e.g. the timing of events in an eclipsing binary (in seconds or days after the start of your epoch of observation), and if you work in units of AU, M-Sol and M-Earth then you get your orbital parameters from those raw observations and Kepler's laws with no conversion factors. You only do the conversions for the proof copy of the paper - possibly not even for the initial copy to go to peer review.

Comment Re:Light years (Score 1) 214

Not an "arbitrary substance", but (1) the most common "substance" in the universe by volume, and (2) probably the simplest "substance" in the universe.

(1) and (2) are probably related, but that's way above my pay grade.

It's also quite a hard substance to get access to without space flight.

Comment Cart and Horse in spatial misalignment (Score 1) 143

Patel argues that when we grow reliant on self-driving cars, things will get far more complicated and futile if we don't make our maps and navigation services better.

No, Mr Patel, a significant number of your potential market/ audience will not become reliant on your product until after map and navigation services are better.

And incidentally, some of us are used to spending time where you don't have electrical power or any mobile phone/ data signal (Iridium excepted, all 9600 bps of it) , and the magnetic field is sufficiently variable that your compass is decidedly dodgy. We carry multiple different location-determining technologies that won't be disabled by simply running out of battery life. Because, that like kills people, you know?

Comment Re:Man up, NASA. (Score 1) 107

so if you just went with the slashdot summary and quote

Haven't people learned to not fucking well do that by now? I mean the site has been going for what - nearly 20 years. There are account holders out there who're legally able to buy booze - drugs in some countries - and who were born after the site was set up. And still there are people fucking stupid enough to only read half TFS and none of TFA.

People wonder why many western nations have problems getting appropriate technical staff, and then they behave in such a stupid mannner. And don't see the connection?

As for the recovery procedures - well with a low-6-digit UID, you were probably around when they recovered SOHO from a similar orientation-power problem. Which doesn't make it any easier (space craft are different; locations are different ; latencies are different ; command sets are different), but it is a task that has been done before. And we've seen it (as have the mission managers at NASA).

Comment Re:I don't get it (Score 1) 127

If you need reaction mass, possibly material for making rocket fuel, non-volatile comet debris for soil and radiation shielding (*), the first place you'd move them to is "near earth". Not directly to LEO though - the cost of moving water or tanks between LEO and (say) Earth-Moon L2 or L3 is far lower than the cost of moving the same mass of water from Earth's surface to LEO. Of course, you'd have a staging area in space (three degrees of freedom) and velocity (another 4 degrees of freedom) for delivery of the dirty snowballs. The precise orbital details vary from comet to comet (or asteroid to asteroid - they're a continuum. See recent discoveries from the Dawn spacecraft.), but you can plot courses from "there" to "here" which use an interaction (or several) with the Moon to minimise the necessary delta-vee, and those lead to the incoming objects congregating around the L2, L3 points. The details change from orbital object to orbital object.

Scatter-gunning LEO without any planning - in exactly the casual way that NASA does at the moment - with comets launched randomly from the snow line, is likely to end badly for someone. But some of these NASA boffins are using a controversial new theory from some English alchemist called "Newton" (obviously an Apple fanboi), and they claim they can plan orbital transfers in considerable detail. Which is stupid, because that would imply that we'd know if the Sun was going to rise tomorrow, or whether a dirtball 7 light-hours away was going to occult a particular star years, before the event.

(*) all of these are things which will be needed, in abundance, for humankind to have any long term (say 100kyr +) future in space. Given the geological record, that duration would have around a 5% chance of having a km-scale object impacting the Earth.

Comment Re:storage, not habitat (Score 1) 127

I doubt they'd be rated, after the stresses of launch, for long-term habitation,

Is anything at all "rated" for long term habitation in space. You'd never get the physical ailments consequent on a 6-month spaceflight past any industrial safety laws. Seriously, not.

but there's going to be ample need for the bulk storage of mass.

You've gone from step 1 to step 100 without showing any of your intermediate working. This blank assertion does not convince me. Would you fill in a few of the steps by which you arrived at that assertion.

perfectly good organics and mass that might be someday useful in orbit, [...] Then the containers themselves could be used as raw material for some hypothetical future process.

Hmm. "GIGO". Not "garbage in, garbage out," but "getting it in and getting it out". Unless you're *only* talking about sewage. But having had to unblock the family shitter more than a few times after the sister blocked it with nappies (EN_US : diapers), I don't relish that task in zero-g. "Who'd use diapers?" I hear you say. Well, having friend who are saturation divers, and never once having heard someone on a spacewalk tell ground control that they need to go inside for a shit ... I think that every EVA, particularly the 6-, 7-, 10- hour ones has generated a moist nappy, and probably one full of shit.

Tanks are good for getting liquids and gasses in and out ; for pastes and solids, not so good.

Also, for long term storage, you're either going to need a gas venting system (in which case you've got a rocket effect which you've got to control ... more complications) or you're going to need to mix "biocide" with it in appropriate amounts. Then, when you want to re-use it (e.g. to manure your eating plants) you need to neutralise the biocide before it kills your carefully maintained microbiological environment.

What is that "zeroth law of science"? Oh yes, "It's not as simple as that."

Comment Re:Why not make server farms? (Score 1) 127

It costs energy to move heat. Expending energy generates heat. Moving heat generates heat.

Condensed version of the Laws of Thermodynamics : you can't win ; you can't break even ; you can't stop playing ; absolutely everything is subject to the Laws of Thermodynamics, including specifically anyone who objects to the tyranny of the Laws of Thermodynamics.

Comment Re:Toxicity (Score 1) 127

Isn't the contents of the tanks kind of nasty?

You're probably thinking of things like hydrazine, or some of the hypergolic mixtures. (A and B are "hypergolic" if mixing A and B results in explosion in milliseconds without needing any initiator, detonator etc. Very good if you want your motor to re-start reliably. The explosion delay is an important characteristic. Milliseconds matter.)

The main fuel in the Centaur stages under discussion are liquid hydrogen ("LH2") and liquid oxygen ("LOX"), but the reliable re-ignition of the engine is controlled by what they refer to as "hypergolic cartridges" - see the engine schematic on page 377 of the Atlas (RT)FM.

Whatever hypergolic mix they use, you don't want to get that shit mixed up with your "intimate lubricant".

Comment Re:easy peasy (Score 1) 127

If you're doing the (larger) hydrogen tank, how 100% sure are you that you're not making an explosive fuel-air mixture, given that hydrogen burns at just a couple percentage concentration?

Well, for the actual system they're considering, it's the larger (volumetrically) part of a single tank, the LH2 and LOX being separated by a "fibreglass honeycomb", which I guess is glued in place after welding together the bottom end of the tank and the main length of the tank body, but before welding on the top end. I'm not sure whether the LOX is in the upper or lower part of the tank.

Unlike most people here (and I think you and I have discussed this before), I've worked with hydrogen gas too (in analytical instruments), so I appreciate what you're saying about it's flammable limits. What I'm wondering is - with relatively minor modifications to the tank's structure, would it be workable to get rid of the dregs of the fuel by pumping O2(g) into the H2(g) headspace of the tank and lighting a flame of O2 burning in hydrogen. So you approach the UEL of [H2] from the other end, and you have your oxygen going into a mix of H2(g) and H2O(g). Any water that condenses out is uninteresting from an explosion safety point of view. For maintaining the desired pressures in the tank, you'd need an inert pressurising gas - N2 being where I'd start from (might need He for thermal reasons ; meh).

Plan B might be to install a mixing fan into the H2 tank which was covered in Pt-coated wire wool, and to use that to agitate the gaseous contents of the H2 tank, again while bleeding in O2. Monitor tank temperature (Pt-resistance wire as in a kathaometer, perhaps ; kill two stones with one bird?) as the Pt assists the reaction ; if it gets too warm, turn off the O2 supply and let some of the water condense out. Again, make efforts to avoid ever having an atmosphere in the tank that isn't a mix of H2(g) and H2O(g).

I bet the procedures for filling a newly-made tank with it's first charge of LH2 are a real fun read. I don't recall anything about it in "Ignition!" - but that concentrated more on exciting fuels like red-fuming nitric and the "mythical monoprop" and less on dull, pedestrian fuels like LH2/LOX.

I'm tempted to change my signature to : 'monopropellant' is an anagram of 'explosive' for all important meanings of "Kaboom!"

Comment Re:I don't get it (Score 1) 127

Your reasoning leading up to "we're going to have to master welding in space" is?

You may be right. But I don't see it as automatically being the case that welding would automatically be stronger, quicker, cheaper or more effective than, say, gluing. We do have some pretty effective glues, for example, and in space, you don't have an oxide or moisture film forming after you abrade the surfaces to join.

Comment Re:I don't get it (Score 1) 127

'cos getting water into LEO is going to be so easy.

A fair enough point. Of course, getting water from the asteroid belt isn't likely to be free either. But if only there were some other reason for learning how to move overgrown dirty snowballs around in space ... like the dinosaurs didn't.

(No, it's not certain that the Chicxulub impactor did for the non-avian dinosaurs - see signature ; I've been following Gerta Keller's work for over a decade - but it sure as hell wasn't a good day for anyone on the planet. Really, knowing - by having done it - how to move multi-kilometre natural objects around in space would be a damned useful skill for a species with a desire to see the distant future. If you're American, you could spend an educational day wandering around in the desert 20-odd miles W of Winslow, Arizona picking lumps of nickel-iron out of the ground and waiting for the 10 megaton energy release. Actually, at 10 megatons, it wouldn't matter much if you walked around in the desert, or sat in a diner in Winslow. Bad hair day, either way.)

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