Saturday: Hili dialogue

by Grania

 

Good morning and welcome to Saturday!

Ninja Cat is coming

 

Today in history:

Notable birthdays today:

Hili had more deep thoughts this morning, pondering very serious questions.

Hili: To eat or not to eat, that is the question.
A: You’ve already eaten your supper.
Hili: But did I eat all of it?
In Polish:
Hili: Zjeść coś, czy nie zjeść, oto jest pytanie.
Ja: Kolację już zjadłaś.
Hili: Ale czy całą?
From the land of Twitter:
Cats doing what cats do best Twitter

 

 

Physics Twitter

An update on Thule

Canid Twitter

 

Snail Twitter

Bees in motion

Being silly Twitter

And finally, an antidote to that stupid meme doing the rounds on social media lately

Hat-tip: Matthew

35 Comments

  1. Ken Kukec
    Posted January 5, 2019 at 8:15 am | Permalink

    “1925 – Nellie Tayloe Ross of Wyoming becomes the first female governor in the United States.”

    Ross followed her husband as governor of Wyoming in 1925, as did the next two women governors in the United States –“Ma” Ferguson of Texas and Lurleen Wallace of Alabama. It wasn’t until a half century later, in 1975, that a US state elected a woman governor completely on her own: Ella Grasso of Connecticut.

    • Michael Fisher
      Posted January 5, 2019 at 10:49 am | Permalink

      The Portland-based [yes I know, but bear with me] astrophysicist Ethan Siegel runs a lovely site on Medium called STARTS WITH A BANG! & Here is my copy/paste with edits synopsis of his answer from Nov. 2017

      QUESTION: Why Did Light Arrive 1.7 Seconds After Gravitational Waves In The Neutron Star Merger? With a journey of 130 million light years, both signals should move at the speed of light. So why did one get here first?

      As the neutron stars inspiralled and merged to form a black hole, the gravitational wave signal got stronger and stronger. For neutron stars, there’s a “hard” surface made mostly of neutrons (90%) with other atomic nuclei (and a few electrons) at the edge. When those two surfaces collide with one another, it’s anticipated that a severe, runaway nuclear reaction occurs, resulting in:

      ** The expulsion of a significant amount of matter, many times the mass of Jupiter
      ** The formation of a black hole after no more than a few hundred milliseconds
      ** And then the acceleration and ejection of material surrounding the merging objects

      But why did the gamma rays get here afterwards? Why didn’t they simply arrive at the same time as the gravitational waves? There are two possible likely scenarios:

      [1] The gamma rays weren’t emitted until 1.7 seconds after the first contact of the neutron star surfaces
      [2] Or the gamma rays were emitted almost immediately, and were delayed as they passed through the surrounding matter
      [3] or a combo of [1] & [2]
      [4] and/or an unlikely alternative involving exotic physics (like a slightly different speed for gravitational waves and electromagnetic waves)

      MY COMMENTARY:
      That’s the closest ‘we’ have to an answer right now, but we’ll make better guesses as we observe more neutron/neutron mergers [and other types of mergers]. The whole electromagnetic spectrum [not just Gamma which is the highest energy] is emitted at slightly different times & we need to collect data on that & then build mathematical models that match the observations. Nobody really understands what’s going on inside neutron stars – see inside the link at the top for diagrams, pics etc.

      • Ken Kukec
        Posted January 5, 2019 at 11:18 am | Permalink

        Thanks bunches, Michael (though I’m guessing that’s in response to #2 below, rather than to Gov. Nellie Ross). 🙂

    • Michael Fisher
      Posted January 5, 2019 at 10:55 am | Permalink

      Here’s Ethan in full Portland free flow while wearing his kilt. Lovely chap:

      • Ken Kukec
        Posted January 5, 2019 at 11:26 am | Permalink

        I dig the physics & his tonsorial flair!

    • Mark R.
      Posted January 5, 2019 at 1:15 pm | Permalink

      Wyoming touts itself as “The Equality State” because it was the first state to allow women to vote. Yet the only reason they did this was because without the women vote, there weren’t enough voting citizens to meet the population requirement for statehood. So the state being a symbol of equality is a sham, just like touting the “first woman governor”. No surprise, I lived in Wyoming for almost 10 years…it’s a state that lives in its own red bubble. A google just revealed that Wyoming has the highest approval rating for Trump at 64%…and they’ve had the highest approval rating by state since his election. At least there’s less than 600,000 of ’em. To be fair, Trump’s disapproval rating has increased by 9% in WY. It should be no surprise that Trump’s disapproval rating has been skyrocketing in all states.

      • Mark R.
        Posted January 5, 2019 at 1:19 pm | Permalink

        argh…without the “woman” vote.

        I forgot to add there is a statue at the capital building in Cheyenne commemorating the event and it makes no mention of the real reason women were allowed to vote. Sham-state…but has spectacular geology!

  2. Ken Kukec
    Posted January 5, 2019 at 8:53 am | Permalink

    Maybe a physics maven here can answer: when neutron stars collide, why is the gamma ray flash detectable two seconds after the gravitational wave? Both propagate at the rate of c, correct?

    • Posted January 5, 2019 at 11:57 am | Permalink

      Maybe emitting the gamma rays requires some reaction?

      • gravelinspector-Aidan
        Posted January 6, 2019 at 10:53 am | Permalink

        There is that too. If you recall SN1987A, there was a burst of 25 antineutrinos detected at Kamiokande, the Lake Erie detector, and Baksan in the Russian Caucasus over the 13 seconds following 07:35. However the light didn’t arrive until some hours later. The time difference in this case is because the neutrino emission takes place at the time of the core collapse, while the light emission is delayed until the shock wave from the explosion reaches the surface of the star. (The shock wave travels hypersonically, but that’s still slower than the almost speed of light which the neutrinos travel at.)

    • Torbjörn Larsson
      Posted January 5, 2019 at 5:42 pm | Permalink

      Yes, they do (and the putative causes of delay is eminently described in Michael’s comment. This fact was tested by the described collision, the (so far) single neutron star binary collision that has been detected in both gravitational and optical multi-messenger astronomy observations.

      I hear that outcome has in one swoop killed of most “alternative gravity” theories that had lingered on despite general relativity being the foundation for modern cosmology.

      • Ken Kukec
        Posted January 5, 2019 at 7:37 pm | Permalink

        Didn’t the first nail in the “alternative gravity” theories’ coffin come with the observation of dark-matter halos in binary stars?

    • gravelinspector-Aidan
      Posted January 6, 2019 at 9:33 am | Permalink

      c is the speed of light in a vacuum. Even intergalactic space isn’t quite a vacuum. Unless someone managed to get some spectroscopy on the light, it’s hard to say how much matter there was on the route. Whether it’s enough to make up 1.7 seconds over (however many Gpc) … good question.
      IIRC, there is also an interaction in free flight between photons which slightly slows the higher frequency ones. Since the cosmic microwave background is always around, that has a retarding effect.

  3. Randall Schenck
    Posted January 5, 2019 at 9:13 am | Permalink

    Truman’s low popularity during and right after his presidency was due to the Korean conflict and he was swimming against a conservative tide. In that regard he was in the same boat as Obama. The conservative congress stopped much of what Truman was attempting to do just as the congress did the same to Obama.

    I am a little surprised at Michael Beschloss’s review of Truman and the Korean matter. Certainly Truman must take the criticism for some of the chaos and handling at the time, however, we have the luxury of many years to review this period in history. It tells us that Truman also deserves much more credit than he was given at the time. To consider the conflict as simply a draw and not anything like a win is just wrong. Beschloss seems to lean republican on this matter and shows little criticism for MacArthur.

    • Ken Kukec
      Posted January 5, 2019 at 10:16 am | Permalink

      Douglas MacArthur was a brilliant general during WWII, I suppose, and he was the mastermind of the coup de main landing at Inchon during the Korean conflict. But he was a dangerous individual, on the verge of becoming an American Julius Caesar upon his lionized return to the US after his firing by Truman.

      • Randall Schenck
        Posted January 5, 2019 at 10:31 am | Permalink

        I would not say brilliant all the time particularly just at the beginning. He was never held up and judged for his incompetence when the Japanese attacked in the far east at the same time they attacked Pearl Harbor. He had several bombers under his command all lined up nice and pretty for the Japanese to destroy – again, just like at Pearl. The commanders at Pearl paid dearly for their mistakes and MacArthur was simply ignored.

        MacArthur was treated as a separate institution within the Army as if all the rest were afraid of him, even presidents. His incompetence in Korea after the great Inchon landing was complete. Although a bit smarter, he kind of reminds me of Trump in his total passion for himself. His character was just as dangerous as Trump. He thought the republicans would beg him to be president when he returned but that did not happen and he was done.

        • Ken Kukec
          Posted January 5, 2019 at 11:34 am | Permalink

          A lot of the hot air was let out of MacArthur’s balloon during his US senate testimony — under questioning by Georgia Sen. Richard Russell (whose arch-segregationist views I abhor, but whose patriotism I respect) — wherein MacArthur revealed himself ignorant of much of US foreign policy.

          Often it’s best that old soldiers just fade away.

  4. rickflick
    Posted January 5, 2019 at 10:50 am | Permalink

    I have a theory(and it is mine) as to why Thule is brighter at the neck. Clearly the two lobes collided with enough energy to fuse the rock(mud and ice?) in that area. It turned into slush and glazed over as it refroze, with gravel and dust precipitating into the neck. The fresh icy surface gives it the whiteness. Just nod if you agree.

    • Michael Fisher
      Posted January 5, 2019 at 11:06 am | Permalink

      The theoretical bods think that nearly all interactions out there are at very, very, very low relative velocities – they have noticed that there is a lack of impact craters which suggests that everything is orbiting Sol in an agreeable manner with few lane changes or road rage punch ups. That seems right to me.

      Lets see if this works. A picture I drew this morning:
      https://photos.app.goo.gl/inaYRmdpzyEEnqWU7

      • rickflick
        Posted January 5, 2019 at 12:00 pm | Permalink

        Not exactly the kiss of death. Well illustrated. The center of gravity is bound to set up odd centrifugal forces all over the place. Do you suppose a hockey rink could be…never mind.

    • Posted January 5, 2019 at 11:36 am | Permalink

      They would not be two distinct, mostly spherical, bodies if they had collided with any speed. Some team member said something like walking speed.

      Each body must have a reasonable amount of integrity or they would have long ago collapsed into one ball. I suspect this means that when each ball formed the material was in a different state than it is now. For such a small body with very low gravitation to form a ball, the material must be able to flow, something it obviously doesn’t do now.

      The speculation as to why the “neck” is brighter is that very tiny particles on the surface, perhaps kicked up by small collisions, would be able to move to the center of mass, the neck being the closest. They are lighter in color because the particles are smaller (ie, powders are whiter than larger particles of the same material).

      • rickflick
        Posted January 5, 2019 at 12:01 pm | Permalink

        Sounds right.

    • Michael Fisher
      Posted January 5, 2019 at 12:16 pm | Permalink

      Here is my Centre of Mass [Green Cross] diagram embedded for easier viewing. Based on the widths [12 & 9 miles] I calculated the masses to be in the ratio 7 to 3, assuming same density for both blobs:
      back

      • rickflick
        Posted January 5, 2019 at 1:46 pm | Permalink

        Good, but the green center of gravity seems a little too far into the big guy. The red line is r1 + r2 = 10.5 miles.
        3/7 * 10.5 = 4.5 miles. This would put the CG just to the left of the midpoint in your diagram.

        • Michael Fisher
          Posted January 5, 2019 at 3:53 pm | Permalink

          See my new diagram below. The Centre of Mass is 3.15 miles from the centre of Ultima & 2.85 below the surface of Ultima [6 miles radius for Ultima]
          CALCULATION:
          L = distance Left of the fulcrum to Mass Ultima = 7
          R = distance Right of the fulcrum to Mass Thule = 3

          Two equations can be derived:
          [A] L + R = 10.50 miles
          [B] 7L = 3R [Law of the lever]

          Multiply [A] by 3:
          3L + 3R = 31.50 or…
          3R = 31.50 – 3L

          Substitute [B] into [A]
          7L = 31.50 – 3L or…
          7L + 3L = 31.50
          10L = 31.50

          Thus:
          L = 3.15 & R = 7.35

          back2

          • rickflick
            Posted January 5, 2019 at 4:18 pm | Permalink

            OK, got it. I think my stab was too quick and dirty(I actually used the proverbial back of a proverbial envelope).

        • gravelinspector-Aidan
          Posted January 6, 2019 at 9:18 am | Permalink

          The mass varies as the cube of the radius, not the radius. The moment varies linearly.
          In bigger bodies (about 2000km, but that’s variable with composition and stiffness of the materials), you also have to account for the compression of the materials under high pressure. That is very not an easy calculation, particularly when you don’t know the composition precisely. This is quite closely studied on Earth (why do we have a magnetic field? ; incidentally interesting results about it’s variability a few thousand years ago published just before Xmas), but even now people are arguing over how much sulphur is dissolved in the NiFe core, or is it oxygen, or both. And also how much potassium versus U/Th (which is very important for the temperature against time, and hence the rate of growth of the inner core).

          • rickflick
            Posted January 6, 2019 at 10:17 am | Permalink

            Thanks for the follow-up. Interesting stuff.

  5. Michael Fisher
    Posted January 5, 2019 at 11:28 am | Permalink

    Continued:

    Look at the picture I drew & note the green cross – that’s the position of the centre of mass for Ultima Thule i.e. two idealised spheres of equal density & of relative size comparable to Ultima [12 miles width] & Thule [9 miles width].

    Any spherical objects anywhere on the surface of the two idealised spheres will roll towards the join between the spheres because every part of the ‘DoubleSphere’ is uphill from the join point [which is the lowest point in the system, being closest to the Green Cross]. See the illustration in the black box in James Tuttle Keane’s Tweet – he’s saying the same thing with that green arrow in the illustration.

    I interpret his drawing as saying loose material rolls down to the neck & that material is more reflective because it is exposing a fresh side of itself that hasn’t become reddened down the billions of years by radiation**.

    ** There’s something called ‘Space Tan’ where the surface of far out asteroids turn red from cosmic radiation over huge spans of time. It’s some sort of chemical reaction – perhaps surface iron particles are energised by cosmic rays to rust – drawing oxygen from water ice.

    • rickflick
      Posted January 5, 2019 at 12:13 pm | Permalink

      Very plausible. I suspect as the data comes in the color and composition will tend to confirm that.

  6. Posted January 5, 2019 at 11:58 am | Permalink

    Many nice things today, but the neutron stars are the best!

    • Mark R.
      Posted January 5, 2019 at 1:25 pm | Permalink

      Yeah, I had to watch that a couple times for my complete satisfaction. I’d say the Duck on Dog is a close second…then again, I’m a sucker for interspecies “love”.

  7. infiniteimprobabilit
    Posted January 5, 2019 at 3:58 pm | Permalink

    Gosh, am I the first to notice that Ninja Cat is a Weeping Angel?

    cr

    • infiniteimprobabilit
      Posted January 5, 2019 at 4:02 pm | Permalink

      Oops, that was supposed to start at 02:16.

      WP strikes again…

      cr

  8. Torbjörn Larsson
    Posted January 5, 2019 at 5:58 pm | Permalink

    Do you remember the ruckus about the US embassies and its personel claiming attacks? All we have been hearing so far is crickets.

    No, really, the indoors echoed sound recordings have been identified as the Indies short-tailed cricket.

    “The song of the Indies short-tailed cricket “matches, in nuanced detail, the A.P. recording in duration, pulse repetition rate, power spectrum, pulse rate stability, and oscillations per pulse,” the scientists wrote in their analysis.

    Experts on cricket songs said the analysis was well done. “It all seems to make sense,” said Gerald Pollack of McGill University, who studies acoustic communication among insects. “It’s a pretty well supported hypothesis.”

    When the American diplomats first complained of the strange noises in Cuba, they dismissed the possibility that insects were responsible. But short-tailed crickets are exceptional: They have long been known to make a tremendous racket.”

    [ https://www.nytimes.com/2019/01/04/science/sonic-attack-cuba-crickets.html ]

    So, as I think I commented at the time, it seems increasingly likely that the whole affair was a case of group reinforcement.

    Or as the leader of the Jester Court would say, it was a “Witch Hunt!”


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