The initial link works perfectly for me. FF 40.0.2, adobe flash disabled, java disabled, javascript disabled.
(technically, all plugins and addons are on "ask to activate", but for this site/gifv/gif no popup comes)

[QUOTE=ewmayer;408336]For some bizarre reason I am unable to get the image to animate in FF (I have animation disabled by default via the about:config menu, but changing that setting back from 'none' to 'normal' does not work here), and Safari, even more bizarrely, gives me a 'this image has been removed' error message.
...
[b]Edit:[/b] OK, finally managed to view the animation, by downloading the file - 83MB, sheesh. Even then, FF, refused to open the downloaded file, citing some kind of fatal badness, but Safari worked OK. Now that I've seen the dynamics, looks like classic gyroscopic instability - the 'handle' attached to the main body means the principal axis is slightly off-aligned - to me.[/QUOTE]

[QUOTE=retina;408342]Because that website is :poop: and uses JS to be "clever".
Looking at the source shows the URL to the actual GIF: [url]http://i.imgur.com/t9fmJTO.gif[/url]
Which is actually just the same URL with the trailing v removed.[/QUOTE]

[QUOTE=LaurV;408347]The initial link works perfectly for me. FF 40.0.2, adobe flash disabled, java disabled, javascript disabled.
(technically, all plugins and addons are on "ask to activate", but for this site/gifv/gif no popup comes)[/QUOTE]

The initial link is to a [URL="http://www.webmproject.org/about/faq/"]webm file[/URL]. It is only 1.04 MB The gifv is [URL="http://imgur.com/blog/2014/10/09/introducing-gifv/"]imgur's embracing of that format[/URL]. Opera has no problem with the file. This is the perfect example of where the webm format shines. And the large size of the gif shows where it is not so good.

[QUOTE=Uncwilly;408355]The initial link is to a [URL="http://www.webmproject.org/about/faq/"]webm file[/URL].[/QUOTE]
[STRIKE]Where, in which post? For me the discussion started with Spherical's post, wondering about the knob, and then Ernst replying he can't open it. The link points to a gifv, I clicked it and it opens...[/STRIKE]
I'm idiot, sorry, ignore that. I interpreted wrong your post, you were only clarifying what gifv means, but I was looking for a previous link, before SC's post :redface:
Now I clicked your second link and learned something new..

[QUOTE=ewmayer;408336]

But in any case, from your description it sounds like perfectly normal precession to me - is there a reason you think otherwise?

[b]Edit:[/b] OK, finally managed to view the animation, by downloading the file - 83MB, sheesh. Even then, FF, refused to open the downloaded file, citing some kind of fatal badness, but Safari worked OK. Now that I've seen the dynamics, looks like classic gyroscopic instability - the 'handle' attached to the main body means the principal axis is slightly off-aligned - to me.

[/QUOTE]

Precession I get, but its the pause in the flip-flop that I haven't worked out (and haven't tried, yet). The part of the knob that attaches to the equipment is roughly horizontal, aimed to the image right at first. Once its spinning, the handle does a fast 180 flip so that part is now aimed left, pauses for a while, then a fast flip back, pause, flip, etc. Its the pauses I want to work out. Its flipping rapidly, but slows down and pauses, implying a stable orientation, but then rapidly re-orients, and pauses. If there are two stable orientations, why would it oscillate between the two, rather than settle in to one or the other...Sorry- Guess my brain just isn't visualizing something right; not enough coffee yet, perhaps.

Norm

[QUOTE=Spherical Cow;408403]Precession I get, but its the pause in the flip-flop that I haven't worked out (and haven't tried, yet). The part of the knob that attaches to the equipment is roughly horizontal, aimed to the image right at first. Once its spinning, the handle does a fast 180 flip so that part is now aimed left, pauses for a while, then a fast flip back, pause, flip, etc. Its the pauses I want to work out. Its flipping rapidly, but slows down and pauses, implying a stable orientation, but then rapidly re-orients, and pauses. If there are two stable orientations, why would it oscillate between the two, rather than settle in to one or the other...Sorry- Guess my brain just isn't visualizing something right; not enough coffee yet, perhaps.

Norm[/QUOTE]

Re. 'implying a stable orientation' - No, it's only a metastable one. Picture a frictionless roller coaster on a sinusoidal-elevation track with just a little velocity at the top of each 'hump'. It will slow down nearly to a 'stable' position atop each hump, but not stop - those are the metastable quasi-equilibria. OTOH the bottoms of the humps (the flips) it just blasts right through. (An imperfect analogy, but best I came up with off the top o/f my head.)

[QUOTE=ewmayer;408438]Re. 'implying a stable orientation' - No, it's only a metastable one. Picture a frictionless roller coaster on a sinusoidal-elevation track with just a little velocity at the top of each 'hump'. It will slow down nearly to a 'stable' position atop each hump, but not stop - those are the metastable quasi-equilibria. OTOH the bottoms of the humps (the flips) it just blasts right through. (An imperfect analogy, but best I came up with off the top o/f my head.)[/QUOTE]

As you say, imperfect analogy, but a good one that does actually help the visualize the pauses. Helped way more than the second cup of coffee.

Norm

anew type of glass,original link from twitter ( university of chicago)

[url]http://news.uchicago.edu/article/2015/08/13/molecular-scientists-unexpectedly-produce-new-type-glass[/url]

[QUOTE=ewmayer;408267]I believe 'physics-ignorant nonsense' is the technical expression.[/quote]
Maybe you should use Google before playing the troll.

Here's an interesting one about the quest for room temperature superconductors. For the first time ever they've made a superconductor that can operate at a temperature that's been known to exist on the surface of planet Earth in the past. Antarctica, unfortunately, but still.

So let's give a RA RA for arbitrary goals.(Put that there to try to deal with the trolls)

[url]http://phys.org/news/2015-07-hydrogen-sulfide-superconducting.html[/url]

I know people say you shouldn't let a bully, in this case ewmayer, bait you. But, hey, I'm human...

If anyone decides they're interested in my self-named concept of vacuum-based buoyancy, which I DID NOT come up with because of ignorance, maybe they could help me track down posts about internal structures created to keep "balloons" from imploding from outside pressure. Because implosion is the biggest concern by far when it comes to this area of science.

[url]https://en.wikipedia.org/wiki/Vacuum_airship[/url]

Hmmmmm, in this Wikipedia entry, it talks a bit about gradually changing air pressure to effect buoyancy.

[QUOTE=jasong;408648]If anyone decides they're interested in my self-named concept of vacuum-based buoyancy, which I DID NOT come up with because of ignorance, maybe they could help me track down posts about internal structures created to keep "balloons" from imploding from outside pressure. Because implosion is the biggest concern by far when it comes to this area of science.[/QUOTE]This has been studied before by many people. Even with the strongest materials known being used for the scaffolds and the coverings thick enough to contain a vacuum they end up weighing more than a simple piece of foil and some helium.

[size=1][color=white]With the power of ignorance everything is possible.[/color][/size]

[QUOTE=retina;408650]This has been studied before by many people.[/QUOTE] Years ago I remember seeing a discussion on using vacuum flotation to bring large asteroid chunks to the surface of the earth. Rather than looking to make things go up, it would be used to more gently land material. A large diameter metallic sphere would be produced in space. It would be brought to earth, likely using some atmospheric braking. Then most/much of the velocity will be lost by rocket/mass driver/new tech. As it slides downward, the vacuum will give some buoyancy. Slowly air will be allowed to enter the sphere to drop in nicely onto the desired location on earth.
This was in an old [URL="http://www.analogsf.com/index.html"]Analog[/URL] magazine. Since the differential between the outside and the inside of the sphere was always low, (and it never has to deal with more than 1 atm) it could handle the load. I deal with tanks frequently that are over 150 atm inside.