Re: Clavius crater
(round here, of course, this is a _good_ thing)
454 posts • joined 7 Sep 2010
Not just getting the youtube ad-money for your unboxing video, you could sell the packaging too for good money: https://www.theregister.com/2001/02/02/empty_playstation_box_sold/
(If i recall that story correctly - wow that was a long time ago! - the seller had been really, really clear that it was just an empty box...)
Time to repeat my favourite bit from one of the HP - Autonomy documents:
"Ms Whitman ... repeatedly adopted the management approach of ... playing country music to the meeting instructing the senior executives attending to take the meaning of the country music songs and apply them to their own management methods".
Do you think the problem with Quibi was the she did this again? Or that she didn't?
I think there is a school of thought that actually we are already becoming less detectable. Already our radio emissions (at least the non-deliberate ones) are likely reducing in power and/or becoming more directed and hence harder to pick up. (or just moving to optical fibres, etc. and short range radio of various kinds).
My recollection is that our big three "detectables" would be: nuclear EMPs (which peaked a few decades ago); Terrestrial TV broadcasts which are becoming more directed, lower power and more signal efficient (so no big old carrier to easily detect); and early radar systems which are now, again, more efficient, directed, etc.
Our window of easy observability over cosmic distances may have already closed and is a vanishingly short fraction of our existence so far. Taking as a guess that this is also true for other technical civilisations it does suggest that our chances of spotting anything is very small indeed (even if they do exist in vast numbers).
probably, yes. if they had sufficient good data on the asteroids path. Generally they are lumps of rock coming straight in at very high relative speeds. They take so little time to pass through the atmosphere (don't believe Hollywood!) that they don't get diverted by it much. The biggest uncertainly (for certain size ranges, at least) is whether it will make it to the ground in one lump or whether it might explode into fragments on the way in. For example, the Chelyabinsk event from entry to fragmentation was about 15s (after-effects obviously lasted longer).
Satellites are a bit harder as they are very small and it is atmospheric drag that brings them down. For that you need to track them and model the effect of a non-streamlined irregular object interacting with the outer wisps of the atmosphere (which grows and shrinks), etc. So what starts as a very gradual slow down and de-orbit can suddenly suddenly change into a much more rapid descent if it "digs in" or the outer atmosphere is a bit thicker than expected that week, etc. For the last large object that I can recall (which I think was the Chinese prototype space station) the impact estimates were updated regularly and became increasingly accurate as it orbited closer in and the atmospheric effects became more consistent.
Sure, the proof is in the pudding, as they say. But in few years it will be clear whether they intend to deliver on it and we can make our judgement then.
In terms of the information access (health, education), no I'm not interested in everyone on the surface of the earth having access to facebook/google/whatever. But this technology could allow a massive expansion to _existing_ successful education and health programmes run by charities and local governments across the poorer areas of the world.
Imagine: a one-off trip to a remote village could deliver a package of a small generator, a couple of solar panels, a few recycled laptops and smart phones and a satellite linked wifi hotspot. Now there is easy communication to the nearest town or city and, for example, health information by video link, lessons and remote learning for school age children, weather and crop advice to farmers. These schemes _already_ exist but are limited by the technology. i.e. need long range radio links or to be within an easy extension of a existing mobile infrastructure. With Starlink (or similar) there is no longer any need for ground infrastructure of any kind and the only geographic limitation is can the kit get transported there and can a basic low power electricity supply be maintained.
Maybe things have changed since I last read about these schemes and maybe most people are now in feasible range of existing, reliable comms infrastructure of some kind - but I doubt it.
It's not for me to say that these benefits outweigh the downsides of these large satellite constellations, but, yes, I do believe that there are potentially amazing benefits to be had across the globe. Not for me, because I've got my fibre broadband thanks very much, but for others.
I've not managed to find a balanced opinion on this issue (not knocking El Reg here, they are reporting on other peoples statements and are not themselves "space experts"). It seems to divide into "This is the end of all astronomy as we know it and don't come running to us when an asteroid hits us" and "seriously, there is nothing at all to worry about here". Presumably the truth is somewhere in the middle.
I will admit to finding the "oh, it's just for cat pictures" a bit tiresome though. Starlink at least have said that their pricing will probably be based on ability to pay. i.e. cruise ships, airlines, etc. full of (comparatively) rich people will pay full wack to get their cat pictures but remote villages in less developed areas of the world will not. They may even get the equipment/bandwidth for free and can then get access to health information, education, etc., etc. So there is opportunity for genuine global social good to occur here and that does need to be considered along with the other positive/negative aspects of these large shiny constellations...
I've a recollection that we (the UK) had very good drafting lawyers and they wrote the bit about having to be full members to be able to access the full benefits, which the UK was very insistent on. Perhaps we should knock some points off for not considering that in the future we would take ourselves out of full membership and lose the full benefits. But on the other hand we should definitely award points for the fact that there was no way round that rule because we had written it so well!
Not sure about Nitrogen Oxides - you get those from internal combustion e.g. jet engines, petrol/diesel engines because the nitrogen is in there with the fuel and oxygen (and compressed, hot, etc.). Whilst the rocket exhaust is obviously hot, I think the only possibility for nitrogen oxides would just be from the surface of the exhaust reacting with the external atmosphere at normal(ish) pressure. At this point I need to confess to having no idea what difference that makes...
I used to work for a submarine cable manufacturer and, yes, there was a lot of gold plating (for corrosion resistance). Also, there were no connectors - everything had to be soldered or otherwise physically bonded. Soldering to gold plated pins is a lovely experience - even I could get the textbook solder fillet shape!
in principle, possibly. I think it is one of those "surface area that presents for air resistance vs. mass" things. But when in orbit there is the variable density with height issue too. So I think everything can get very non-linear so not much change in distance from the earth can lead to radically different lifetimes. Furthermore, if it was an explosion (residual fuel? pressure tank?) then some bits might be moved into orbits that will decay quicker and other lumps the opposite.
But the perigee at least seems fairly low (422 km) and the ISS orbit (~350 km) requires periodic boosts due to atmospheric drag so, notwithstanding the non-linearity at least it seems the pieces are in the ballpark range to get some drag every orbit...
After a (probably ill-informed) conversation about the dangerous wildlife of Australia I once made a throw-away remark along the lines of "well, at least the plants seem OK". But a little voice in my head said (probably in an Australian accent) "you sure about that mate?". So I checked.
"stinging hairs which cover the whole plant and deliver a potent neurotoxin when touched"
"extremely painful stinging sensation that could last from several hours to 1–2 days"
" 'For two or three days the pain was almost unbearable; I couldn’t work or sleep, then it was pretty bad pain for another fortnight or so. The stinging persisted for two years' "
"Dendrocnide stings have been known to kill dogs and horses that have brushed against them"
There was a more recent (but failed) attempt with a solar particle capture satellite that was supposed to parachute the samples back: https://en.wikipedia.org/wiki/Genesis_(spacecraft)
But I always thought that catching stuff with helicopters was incredibly dangerous especially as the mass of the thing increased. So it's one thing to catch film canisters and sample return canisters but quite another to catch rocket engines...
The guardian article has a picture of the discharge notice as well. Ends with the phrase " [patient] denies further magnets". Which I've assumed to be a sarcastic shortened form of: "He _said_ there were only 4 but, you know, we're dealing with someone who put 2 magnets up their nose and then put 2 more up there because he thought it would help"
I don't think they have said exactly but I believe that there are some differences between the engines so specific ones are required. e.g. not all can relight and possibly not all can throttle down low enough. I think the centre one is pretty much essential at landing time.
If you watched the re-entry burn there was a lot more swinging around than normal which suggests that the problem engine was either one of those 3 or had perhaps been damaged by the explosion(*).
(*) - If you watch a few seconds before the main engines shut down it certainly looks like something exploded - it was a bit fireball-ish...
250ms = 1/4s which I'd have thought was an eternity in the realm of atomic physics.
Perhaps this is more to do with thermal/fluid dynamics (which is presumably a bit more "physical world" speed) than the actual atomic interactions?
Still feels like quite a long time though. I mean, don't most car engine management systems operate on a 100ms timer for example?
I recall someone superimposed that ground-level abort test video onto the one where the Falcon 9 exploded during a static test (the one where the so-called "Facebook" satellite got destroyed). Maybe not very scientifically accurate but did seem to suggest that the capsule abort was sufficient to get clear, presuming that it triggered sufficiently quickly...
Given the light has to reflect off 3 not-intended-to-be-reflective surfaces, how powerful does the laser have to be? I get that the detector could be very sensitive but even that seems tricky. i.e. very sensitive to the laser return but not at all bothered by e.g. sunlight. But there is still going to be several orders of magnitude of loss which suggests that the laser output could well need to be eyesight threatening ...
I'd say the interesting bit was the mechanism to have them move around under their own power. As you suggest, there are probably easier ways to extract uranium from contaminated water. Could be that this is one of those situations where the research is rather academic (but worthwhile!) then it gets jazzed up a bit for the publicity with a token "it could be used for <X>!"
In an ironic twist there are two relevant events on that day you could be referring to!
October 28, 1971 (Thursday)
- The British House of Commons votes 356–244 in favour of joining the European Economic Community.
- The United Kingdom becomes the sixth nation to launch a satellite into orbit, the Prospero X-3, using a Black Arrow carrier rocket.
(I presume you meant the latter...)
a) it says no _employment_ contract. i.e. he is not an employee subject to standard notice periods, etc. There will be some other kind of commercial contract in place to pay him for services but this can have any kind of terms including "walk away without warning"
b) ditto (a). I think this is quite common (but not necessarily right or good) at this level - especially if they are directors for multiple companies
c) yes - this seems like the biggest of the red flags. It's a situation where they've made sure they personally can't lose if WeWork goes down. They still have the rent payments, the buildings and whatever payoffs they've put into their services (not employment!) contracts...
I'll have you know I'm very proud of my 15s of Fire Extinguisher practice where I was allowed (from a safe distance) to put out a Proper Fire (a safely contained gas burner in a far corner of the car park) ! I'm Ready! Bring the Burn!
But seriously, they were very insistent on the "you are not a fireman" and "only do this if it is very low risk" and "only use one fire extinguisher". Apparently it is very easy to get carried away and think "oh, just one more and I've got this!" and the Fire Brigade are a bit fed up with having to rescue people surrounded by 15 empty extinguishers rather than getting on with putting it out.
Well, that was part of the selection process! I recall one anecdote (possibly from the book "The Right Stuff") where they were testing one candidate (possibly John Glen) and he was strapped into the multi-axis spinning chair, carrying out tasks with smoke and flashing bright lights going on, when they dropped a ton of scrap metal onto a big metal plate right behind him. Apparently the only evidence that he'd even noticed was a single big jump on the heart monitor, then back to normal. Some later evidence that "the right stuff" didn't always work well when forming a larger crew but no doubt that at the start of the space programme, "calm under pressure" where "pressure = imminent death" was an absolute necessity...
Also, there is a hint that they are proposing that this could be mildly covert (e.g. the "length of a football field" comment) which could be slightly compromised by the need to hand out safety goggles first...
"Why do I need these?"
"Oh, no particular reason, just a precaution"
"Oh, right, sure..."
"Seriously, don't take them off though."
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