Forgot your password?
typodupeerror
Science

Tar Pitch Drop Captured On Camera 142

Posted by Soulskill
from the you-can-now-die-happy dept.
New submitter Ron024 sends this news from Nature: "After 69 years, one of the longest-running laboratory investigations in the world has finally captured the fall of a drop of tar pitch on camera for the first time. A similar, better-known and older experiment in Australia missed filming its latest drop in 2000 because the camera was offline at the time. The Dublin pitch-drop experiment was set up in 1944 at Trinity College Dublin to demonstrate the high viscosity or low fluidity of pitch — also known as bitumen or asphalt — a material that appears to be solid at room temperature, but is in fact flowing, albeit extremely slowly. ... The Trinity College team has estimated the viscosity of the pitch by monitoring the evolution of this one drop, and puts it in the region of 2 million times more viscous than honey, or 20 billion times the viscosity of water. The speed of formation of the drop can depend on the exact composition of the pitch, and environmental conditions such as temperature and vibration."
This discussion has been archived. No new comments can be posted.

Tar Pitch Drop Captured On Camera

Comments Filter:
  • Ok.... (Score:2, Interesting)

    by Anonymous Coward

    ....now do that with glass

    • Re:Ok.... (Score:4, Informative)

      by i kan reed (749298) on Friday July 19, 2013 @11:03AM (#44327825) Homepage Journal

      Didn't you notice that the titration device was made of glass and showed zero sign of change? That's because glass isn't an amorphous solid.

      • Re: (Score:3, Informative)

        by Anonymous Coward

        Glass *is* an amorphous solid. The point is that it isn't some sort of superviscous liquid.

      • Re: (Score:3, Insightful)

        by slashmydots (2189826)
        Nobody seems to be able to decide what the heck glass is. You've got the controversial cathedral glass thickness reports. Then you've got the slightly more easily provable fact that it shatters. The consensus seems to be that it's not completely solid and from there, people can argue all they want. But since the tar was inside glass and we have to assume the glass morphed, their measurement isn't completely accurate. So...time to start the experiment over again, lol

        But that's not the only reason. The
        • Re:Ok.... (Score:5, Informative)

          by Anonymous Coward on Friday July 19, 2013 @12:46PM (#44329093)

          Nobody seems to be able to decide what the heck glass is.

          Actually the Nature article [nature.com] on the pitch drop states:
          "Scientists used to believe glass to be a slow-moving liquid as well — in part because old church window panes are thicker at the bottom — but it is now considered a solid."
          and points to this as a reference. Zhao, J., Simon, S. L. & McKenna, G. B. Nature Communications [doi.org]

          Nature is a fairly reputable journal so I think I'll go with glass as a solid for the time being.

          The issue regarding the windows panes appears to be that the differing thicknesses from one side of the window to the other is because of the manufacturing method. Also they put the thicker side at the bottom in order to prevent breakage because they weren't idiots.

          • Thank God. I was expecting to explain the manufacturing process and instillation methods of window glazers of old all over again. You have saved me the hassle.
            • May his noodley appendage touch you, I was expecting to explain my relief at not having to explain. Thanks be to you, and also to FSM.
        • Re:Ok.... (Score:5, Informative)

          by MozeeToby (1163751) on Friday July 19, 2013 @12:58PM (#44329247)

          The cathedral glass reports have nothing to do with glass flowing and everything to do with how glass was made hundreds of yeas ago.

          • by rwise2112 (648849)

            The cathedral glass reports have nothing to do with glass flowing and everything to do with how glass was made hundreds of yeas ago.

            I've heard that as well, but can't seem to get around that it would be unlikely that all the glass would be installed with the thicker part towards the bottom.

            • Re: (Score:2, Insightful)

              by Anonymous Coward

              It would be very likely because that is exactly what they did for stability reasons.

            • by Anonymous Coward

              Not ALL of it is. People knew that you should put the heavy end at the bottom. So that's what they did. But nobody is perfect and sometimes they fucked up. So there are examples where say a stained glass window has 80 pieces of glass and 79 are thick at the bottom but one is thick at the top.

            • by pla (258480)
              I've heard that as well, but can't seem to get around that it would be unlikely that all the glass would be installed with the thicker part towards the bottom.

              Do you store your beer cap-up or cap-down?
              • I store my Spaghettios upside down. It makes all the rings settle to the top, so when I turn it right-side-up and open it, I can pour them into the pan much easier. There are very few, if any, stuck to the crease/dent around the inside bottom of the can.

            • If I hand you a piece of glass that is noticeably thicker on one end and tell you to put it in the window, you're not going to put the thick side down? Almost all glass is found that way because it was installed that way on purpose for stability reasons and, arguably more importantly, to prevent water pooling at the bottom of the window seal. I say "almost" because there are, in fact, instances where it was installed incorrectly.

              • by rwise2112 (648849)

                If I hand you a piece of glass that is noticeably thicker on one end and tell you to put it in the window, you're not going to put the thick side down? Almost all glass is found that way because it was installed that way on purpose for stability reasons and, arguably more importantly, to prevent water pooling at the bottom of the window seal. I say "almost" because there are, in fact, instances where it was installed incorrectly.

                Ah thanks. I wasn't aware that it was something that noticeable.

            • So they would spend decades carving the ornamentation, but only do a half-ass job installing the glass?
            • by Darinbob (1142669)

              Because sometimes it's the other way around, the thicker part is at the top. But you just start with one person saying "hey, you notice how the glass is always thicker at the bottom" and the listeners assume that is fact. Then he goes on and says "it's because glass flows like liquid and after one hundred years it is thicker at bottom" and the listeners walk away thinking that they just learned something amazing. Over the years this story gets repeated and repeated until school children are taught it as

              • by gzuckier (1155781)

                I've always found this whole glass business to be dubious.
                The way glass was made at the time means not only that the thickness was uneven, but also that it would not change monotonically. So, there is no reason to believe the thickest part would be at the edge at all, rather than just somewhere in the middle. Furthermore, there is no reason to believe that one edge would be thicker than the other, even aside from this; the thickness of the edges is going to vary from point to point so that there is likely t

                • by Darinbob (1142669)

                  The glass is thicker in the middle when it's first made. The molten glass is spun to flatten it, so it's thinner at edges and thicker in the middle. It is then cut into small panes and pieces. Thus the slightly thick part is at one end. The effect was noticed on normal panes.

        • by Anonymous Coward

          Nobody seems to be able to decide what the heck glass is.

          Nobody on the internet seems to be able to decide what glass is... but your indecisiveness doesn't mean it hasn't been settled in science circles some time ago. Even by the 90s, the description of glass as an amorphous solid was unanimous among all material science work I've seen. There is a very small contingent suggesting that it could be considered a phase separate from solid and liquid, but otherwise amorphous solid is a subset of solids (and there are amorphous solids other than glass, so glass is a

          • Even by the 90s, the description of glass as an amorphous solid was unanimous among all material science work I've seen.

            "Folk knowledge" like this is to some extent present in every field. For example, in the field of linguistics, "everybody knows" that Inuits have hundreds of different words for snow...except, well, they don't. If the piece of knowledge is peripheral (= not often exercised, as opposed to, say, Newton's laws of movement which you see around yourself exercised all the time), AND difficult to verify at the same time, there's always potential for blunders like these to happen because few people bother to check.

        • You've got the controversial cathedral glass thickness reports.

          There's nothing controversial about them. We've only learned how to mass manufacture perfectly coplanar glass panes only in the last century and a half or something like that.

      • 2 million times more viscous than honey

        So, it's like concrete?

      • by Instine (963303)
        I've lived in a house old enough to have windows that have 'sagged'. There's little difference between the two other than times scales (the glass was well over a century old. I don't know for sure how old, But part of the building was built in 1684. Looking at it, there's no question it is flowing under gravity. This was in the North of England, where temps do not get especially high.
        • what you perceived as 'sag' are in fact manufacturing artifacts.
          The way modern plate glass is made is to float a layer of molten glass on the surface of a bed of molten Tin. This allows the glass to harden to a solid, while sitting on a perfectly level surface.
          The way plate glass was made up until the mid 1900's was to place a large blob of soft glass on a very large turntable, and spin it. This resulted in the glass spreading over the turntable, forming a generally flat and mostly smooth surface. Due t
    • by Sockatume (732728)

      I know you're just saying that to screw with pedants... but I hate you anyway.

      • by asliarun (636603)

        I know you're just saying that to screw with pedants... but I hate you anyway.

        If you're going to talk about pedantry, I don't understand the experiment to begin with. My concern is probably naive, but consider the fact that over a hundred detectable earthquakes occur every days, and thousands more occur that are too mild to detect.

        Aren't earthquakes introducing massive errors in this experiement - considering how long it has been running?
        If this concern is valid, they should have used a good vibration isolation mechanism, and I'm not sure if they did.

        • by Sockatume (732728)

          On the timescale of an earthquake pitch is essentially solid. There'd be more risk of it smashing than anything else.

    • Contrary to popular belief, glass does not flow at all. This was a bullshit myth generated when some people realized that some old pieces of glass in some windows were thicker at the bottom than the top. This is actually because of how the glass making techniques of the time worked, some parts of the glass would be thicker. Naturally, it makes sense to put the thickest end of the glass towards the bottom of a window, which is why most of the windows are thicker at the bottom. However, we can also find w
    • It's actually a common misconception that glass behaves as a slow-moving liquid. Most people who believe that have heard about glass being thicker at the base of windows in old buildings and homes than it is at the top, which is supposed to be proof that it has flowed down. While that fact about the glass being thicker at the bottom is oftentimes true, it's not because the glass is flowing, but rather because the manufacturing processes for glass were not as precise as they are today, so the people who asse

  • by Anonymous Coward on Friday July 19, 2013 @11:01AM (#44327785)

    Must be a slow news day.

  • by Anonymous Coward

    quite tantalizing for a very long time pitch-drop observer like myself

    That reads like rule 34 is already satisfied.

  • by InitZero (14837) on Friday July 19, 2013 @11:06AM (#44327871) Homepage

    Are you done yet in there, Grandpa?

    Cheers,
    Matt

  • by roc97007 (608802) on Friday July 19, 2013 @11:08AM (#44327889) Journal

    *I* had a lot of time on my hands...

  • by h4rr4r (612664)

    I guess it made a droplet, but it did not seem to drop. It was touching the bottom before the top broke off.

    • by tsa (15680)

      If you look closely at where the thing that holds the funnel is attached to the vertical rod, you see it 'jumps' upwards a few mm when the drop falls. It suddenly doesn't touch the grey thing underneath it anymore. I call this a hoax.

      • And if you let go of a heavy object, your arm will rise a few mm. Things deform under load. When the load is released, they return to equilibrium.
        • by TCQuad (537187)
          Some jumping could theoretically occur on the arm that's holding up the funnel, but the position of the C-clamp on a lab stand itself shifted up slightly (some separation forms between the tar pitch c-clamp and the other arm that's steading the lab stand). That's not going to happen without human intervention.

          From when the jump occurred, it appears that they lifted the clamp slightly to allow space for the next drop.
          • by tsa (15680)

            That's what I meant. The strange thing is: the clock seems to not jump when the clamp jumps upward.

      • by Anonymous Coward
        Jesus Christ, someone has actually managed to formulate a conspiracy theory about a fucking pitch drop experiment. Will wonders never cease?

        Now seriously go take your meds.
      • I think you're failing to appreciate that the video is massively sped up. What you describe as 'suddenly' does indeed look like a cut edit, but was probably a fairly slow upwards movement of the arm as it regained equilibrium after the drop fell. Watch the clock to see.
  • OK, well I'll mark that one off my Bucket List now...
  • Another hundred years and our hard drives will be good enough to store countless hours of video while we wait to see air bubbles rising in a vertical pane of glass. Honestly, somebody has to find better uses for their time. I can't believe this experiement has been running since 1944.

    • by h4rr4r (612664) on Friday July 19, 2013 @11:14AM (#44327961)

      Glass bubbles do no rise in panes of glass. Glass is not a liquid.
      http://io9.com/the-glass-is-a-liquid-myth-has-finally-been-destroyed-496190894 [io9.com]

      • by Anonymous Coward

        It should be noted that that study focused on amber, not glass. It seems to me that's a little like studying the properties of rock to determine the properties of steel. It should be fairly easy to prove/disprove the "glass is a liquid" theory using real world measurements. Simply put a cylinder of glass (lets say 2 cm x 15 cm) measured to extreme accuracy into a fairly sizable centrifuge set to 100-200g. Leave it in there for a year or two and then measure it, if it hasn't changed at least at the micro

    • by sjames (1099)

      A few minutes active prep, then just letting it sit isn't really a big deal. It's not like the buy had to sit there staring at it the whole time.

  • by h4rr4r (612664) on Friday July 19, 2013 @11:12AM (#44327935)

    The video was not too bad, far less boring than baseball.

    • by Aelanna (2695123)
      I actually find the pitcher-batter mind games, statistics, and pitch mechanics and aerodynamic physics of baseball to be far more interesting than any other mainstream sport. Your mileage may very, I suppose.
      • by Anonymous Coward

        Other sports don't need those things to be interesting. Baseball is really just a stats course that's occasionally interrupted by a bunch of guys wearing matching outfits.

    • That's because you skipped the windup. Watch it for seven years and say that.
    • There was a time when people were surprised by the frenetic pace of baseball.

      "It is a game which is peculiarly suited to the American temperament and disposition; the nine innings are played in the brief space of two and one half hours, or less."

      • by h4rr4r (612664)

        People drank a lot more back then.

        Also they had far less entertainment available.

      • by lxs (131946)

        Sure, when you compare it to cricket it's lightening fast. A game that can be played from start to finish in less than three days? Madness!

  • by wonkey_monkey (2592601) on Friday July 19, 2013 @11:17AM (#44327989) Homepage
    Why does the funnel clamped to the stand move just at the moment of the breakage? I call shenanigans!
    • by wasteoid (1897370)
      Presumably to separate the drop from the suspended volume in the glass funnel. The drop already "dropped" or hit the bottom.
    • I'm at work and can't see the video. But if you're saying that the funnel jerks upwards as the drop falls away, that's to be expected. The clamp assembly no longer has to support the weight of the drop, so it should "bounce" upward a little before reaching a new, less-weighed-down equilibrium position.
    • by jason8 (917879)
      In that video, 3-4 seconds = 1 day of actual elapsed time. So maybe after the drop fell, there was some human intervention to move the clamp up slightly, but the intervention isn't visible in this video?
    • Why does the funnel clamped to the stand move just at the moment of the breakage?

      I'm assuming its so that there is a bit more space for the next drop of tar to form, since the one that just fell is going to take some time to incorporate into the bottom mass. Probably didn't have to happen right right away, but it would allow the next drop to begin forming from the earliest possible fixed rest point.

      I'm betting that the longish length of the previous one had the monitor worried for years that it would reach the bottom mass without pinching off first.

    • by KalvinB (205500)

      Because of the weight of the tar being released.

  • by Rixel (131146)

    I wonder how many times the camera caught paint drying in that lab?

  • money quote (Score:5, Interesting)

    by phantomfive (622387) on Friday July 19, 2013 @11:24AM (#44328077) Journal
    This quote from the article is so great:

    “I have been examining the video over and over again,” Mainstone says, ”and there were a number of things about it that were really quite tantalizing for a very long time pitch-drop observer like myself.”....Mainstone, who has spent most of his life waiting to see a drop fall with his own eyes, congratulated the Trinity College team.

  • If it was a real video then where is the other 69 years worth of video???? I bet that they can't come up with all of the rest of it can they!

  • by 140Mandak262Jamuna (970587) on Friday July 19, 2013 @11:29AM (#44328155) Journal
    Claim A: glass panes in very old cathedrals in Europe is thick at the bottom and thin at the top because glass had flowed over the centuries.

    Claim B: Claim A is an urban legend. citation 1 [unl.edu] citation 2 [stackexchange.com] and you can find more on the net.

    Claim C: Claim B is an urban legend.

    Now can someone set up some cameras and prove Claim C? That would be supercool, one level recursive urban legend.

  • by Doug Otto (2821601) on Friday July 19, 2013 @11:32AM (#44328185)
    Wife: What happened at work today, honey?

    Scientist: Oh nothing...

    Lather, rinse, repeat.
    • Wife: What happened at work today, honey?

      Scientist [excitedly]: I confirmed the hypothesis that pitch is perfectly solid!

  • by grub (11606)

    I sneezed!
  • What if... in the 40th year or so, someone knocks it over. Sorry! What would be the appropriate punishment? :)
    • by pla (258480)
      What would be the appropriate punishment?

      You have to squeeze the drop back into the funnel so it can start over.
  • So there is something more boring than watching grass grow.
  • Glass (Score:2, Interesting)

    by kdogg73 (771674)
    Don't forget the viscosity of plain old glass [jimloy.com].
    • http://www.cmog.org/article/does-glass-flow [cmog.org]

      Old glass windows more likely show variability in width due to the way "plate" glass used to be manufactured... It was spun out into a sheet under centripetal force by swirling a blob of molten glass on a rod (the center swirly piece, broken off the rod, sometimes being seen in old cottage windows, etc).

  • But no one wants to see it.

  • I just returned from holiday in Ireland and apparently temperatures were exceptionally high. One day, my shoe soles were essentially paved (they looked like road surface) because the roads I had walked on were molten. I wonder whether this droplet has anything to do with the weather conditions.

    By the way: exceptional weather means a week of sunny weather with 24-28 degrees C temperatures. Irish asphalt is probably optimized for cooler and rainier weather. :-)

  • Pitch may be a dictionary synonym for tar or bitumen, but out in the real world pitch is not asphalt. Pitch is an entirely different beast from its bituminous asphalt derived cousin, as anyone that has had the displeasure of replacing a pitch based roofing system by means of a roof tear off can attest.
    Kinda like cramming windoze and debian into the same definition of an OS. For a site that claims to be befitting of nerds the articles increasingly seem to be reported by the local 6:00 news team. I believe

  • because they didn't have enough separation. For crying out loud, even I can see that it's still attached to the source when it hits the bottom, then there's a Rock Bottom style cut where someone lifts the source and the drop breaks off. So now they're going to have to move it up a few inches and wait another decade to try again. Why the Hell isn't this mentioned in the article. It's just completely ignored.

  • If you didn't know the time scale had been messed with, the video looks like very thick oil or honey dripping. Some sort of invariant with liquids, I suppose. I thought it was kind of interesting.

    I've done time-lapse videos of clouds and things. Haven't done one of paint drying or grass growing.

    Yet. :-)

    ...laura

  • I would so have put a screaming zombie appearing from nowhere right in the middle of that video.

  • by Tablizer (95088)

    Somebody just Photoshopped their shitting session into it.

  • The drop wasn't near tall enough to watch the thinning of the drop tail, and you can see they messed with it to try and get it - they raised the armature holding the funnel after it had dropped causing it to sheer off under the funnel and plop to the side. If they had allowed it to fall further I imagine there would be a tapered very long, stringy, wispy filament.

Murphy's Law, that brash proletarian restatement of Godel's Theorem. -- Thomas Pynchon, "Gravity's Rainbow"

Working...