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Submission + - Modified Gravity vies with Planet9 to explain Solar system structure- and fails. (arxiv.org)

RockDoctor writes: One of the serious contenders to the majority opinion Matter/ Dark Matter/ Dark Energy hypothesis for explaining the structure of the universe is the "MOdified Newtonian Dynamics" or MOND hypothesis in which the gravity field strength decreases not according to a 1/(radius^2) factor, but according to some other function of (radius), which would then explain the movements ("Dynamics") of galaxy-scale structures — the original evidence for postulating the existence of Dark Matter. This hypothesis dates back to 1983 — before the observations that prompt the Dark Energy hypothesis — and has been championed mainly (but not only) by physicist Mordehai Milgrom. While it is definitely not "mainstream" physics, it is certainly a respectable hypothesis.

One way to look for MOND effects is to look closely at the outer Solar system, where distances are larger than can be examined on Earth, but things are close enough for small effects to be measurable from Earth. And in a new paper published on Arxiv, people have done just that. The known "Extreme Trans-Neptunian Objects" ("ETNO"s — closest separation from Sol outside Neptune's orbit ; furthest separation 150 ~ 1500 AU) are closely clustered in direction — the evidence that Batygin, Brown, Sheppard and Trujillo have used in the last five years as evidence for a ninth planet in the Solar system. (No, Pluto is not a planet. Unless you want it to be about 10th or 11th in a 100+ planetary system.) It was possible that the MOND hypothesis might explain the orientation of the ETNOs, so the idea has been examined in detail (paper) — and found it less than 1% likely to explain the observations.

MOND remains an attractive type of hypothesis to explain the observational evidence of the universe's structure without postulating major changes in our understanding of physics. But again, it has failed at the test of new data types. Which still leaves physics with no viable alternative to the Matter / Dark Matter/ Dark Energy hypothesis.

Comment When (did) change happen ? (Score 1) 1

They [telephone customer service staff] required a full bank account number to identify the customer. When this information was refused and a supervisor was requested, no supervisor was available. Although the phone number called was correct and I made several tries (reaching the same person each time), I could not clearly verify that the party reached was actually a Metavante employee, as the security process breach observed would be unusual for a banking company.

Are you implying that this procedure is a change from previous (Intuit) procedures? (I've never knowingly used any such service, so wouldn't know SOPs).

Comment Re:Big dig (Score 1) 138

So the boston big dig is 3.5miles so about 3 times the length.

The Boston big dig has to avoid collapsing buildings above and beside the dig. That is somewhat less of a problem on any random hillside in Norway.

Is that dig still going on? I remember it being a thorough-going row last time I was in America - '90 or '91.

Comment Re:seems cheap (Score 1) 138

Unless, of course, it cost more to move the aggregate (gravel/ sand mix, for mixing with cement to make concrete) to it's destination than the stuff is worth. And there are a *lot* of aggregate deposits in Norway, thanks to all those glaciers and their nice efficient water flows for sorting the aggregate by size. Blasting debris typically has a very wide range of grain sizes - from boulders to dust - which hinders it's use for making concrete.

Comment Re:Bullshit. (Score 1) 151

Police see an online ad but can't find the location of the "trafficked girl"...when all they'd need to do is call and ask ...

for her to be delivered to $Address$ with a 10cm butt-plug, a litre of vodka, and a tube of cherry-flavoured lube.

(The latter items being sufficiently unique that the specific combination itself is identifying information and you can arrest everyone in the parking lot.)

Comment Re:White-Yellow Whip Star? (Score 1) 124

If it's a white dwarf (WD), it's going to have an internal strength (stiffness) somewhere well above that of steel, but more importantly, very strong forces pulling it's material back together.

My non-calculated estimate on the WD's shape is that it would be a prolate ellipsoid of rotation, with the long axis pointing towards the primary. Not necessarily directly at the primary - there might be some displacement due to the residual rotational angular momentum of the WD.

Comment Re:No it doesn't put it in bloody perspective (Score 1) 124

The Moon would be ripped apart by the stresses produced in accelerating it towards the Earth. Your model wouldn't last long - probbly only a short fraction of an orbit.

But why do you need a fluid dynamics model? Consider a rock (a "test particle") on the far side of the Moon, and the forces on it - it's gravitational attraction by the Moon ; ditto from the Earth ; it's inertia. Will the forces on the test particle push it into the Moon, or away from the Moon? Repeat for next particle, with a slightly smaller Moon mass. You're treating the Moon as a strengthless agglomeration of weakly-interacting particles - which is one way of looking at a fluid.

Comment Re:And so it begins... (Score 1) 407

If you are working inside a machine or cabinet, then yes, you'd power it down.

You power it down, then you put a padlock (to which you, and only you hold a key) though the isolating switch so that you need to physically break the isolator to be able to de-isolate the machine. Then you do the same to the hydraulic and pneumatic supplies, as well as the electrical supply. If mechanical power (e.g., belt drive from an overhead torque distribution system) is part of the supply, that gets locked-out too.

End of shift and the job is still continuing? Well, your replacement maintenance worker goes around the system with you, and where you remove one of your padlocks, they install one of theirs. Or, if there's only one shift, you go home taking the keys with you.

It's not fool-proof (I've had to attend a funeral courtesy of 3000psi of stored pressure putting a valve part though a guy's chest), but it is fairly effective at stopping machines from killing people. It's also at least 3 generations old.

Comment Re:Offsite backups become more and more important (Score 1) 299

No, the smart move in this case was to empty you place of anything they could steal and then carry on like an lunatic pork chop and force them to execute the warrant and then simply bring all the stuff back.

If the warrant has been worded properly, then it would cover seizing the person's goods, chattals and work equipment, wherever it is.

So the situation would work like this - the police force entry to the workplace and home (simultaneously, at 05:00 ; that's standard practice) ; they find nothing that is included on the warrant ; they can safely conclude then that the person named in the warrant is guilty of "attempting to defeat the ends of justice" (that's a big enough charge to proceed direct to being remanded in jail, no bail, no communication except with lawyers) ; the police then continue in hot pursuit of the missing equipment by raiding the neighbours (at 06:00 that same morning) as possible accessories, any known friends and associates. See how many times your friends, neighbours and families put up with that sort of thing happening at intervals of a few months, with all computing or photographic equipment being seized "for investigation" - for up to two years.

They're the police. They're not your friend, and they do not tolerate resistance.

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