"I think I've found a track, what do you think?"

Discuss your experiences with and ideas about Stardust@home here.

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plumbium
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Post by plumbium »

Man, those last two really look really promising.

But can anybody understand this movie? It looks like the surface is tilted almost in a spiral.
http://stardustathome.ssl.berkeley.edu/ ... =5327289V1
fjgiie
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Post by fjgiie »

plumbium wrote:Man, those last two really look really promising.

But can anybody understand this movie? It looks like the surface is tilted almost in a spiral.
http://stardustathome.ssl.berkeley.edu/ ... =5327289V1
My guess is that movie is bad focus. It is below the surface all the way.

_______fjgiie
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gmada
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Re: "I think I've found a track, what do you think?"

Post by gmada »

http://stardustathome.ssl.berkeley.edu/ ... =4109634V1
your opinion please, could it be a track at 260,75 ?
fjgiie
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Re: "I think I've found a track, what do you think?"

Post by fjgiie »

gmada wrote:http://stardustathome.ssl.berkeley.edu/ ... =4109634V1
your opinion please, could it be a track at 260,75 ?
It is difficult to say if that is a track at 260, 75 because the focus does not go deep enough to make the circle disappear or fade out. Like you I would have clicked on it even though it could only be an Aerogel fragment. I would grade that track a 4 on a scale of 1 to 10 with 10 being a very good looking candidate for a track and 1 being "Opps, I clicked by accident".


_______fjgiie
startrak
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Re: "I think I've found a track, what do you think?"

Post by startrak »

Out of 28, I'm surprised no one else clicked on this. Looks different to me :?:

http://stardustathome.ssl.berkeley.edu/ ... =6248879V1 at 100/05.
jsmaje
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Re: "I think I've found a track, what do you think?"

Post by jsmaje »

startrak wrote:Out of 28, I'm surprised no one else clicked on this. Looks different to me :?:
Hmm... looks just the same and at the same level as the other surface debris there to me, only a bit bigger, and perhaps demonstrating a version of that common circular focussing artefact (see http://en.wikipedia.org/wiki/Airy_disk).
Will nevertheless be happy to be proved wrong!
startrak
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Re: "I think I've found a track, what do you think?"

Post by startrak »

jsmaje wrote -- Hmm... looks just the same and at the same level as the other surface debris there to me, only a bit bigger, and demonstrating that common circular focussing artefact all-too-often confused with a sub-surface track (see for example http://en.wikipedia.org/wiki/Airy_disk). Would be happy to be proved wrong!jsmaje

Good Lord, do Earthlings actually understand this!!!!!!!! :roll:

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jsmaje
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Re: "I think I've found a track, what do you think?"

Post by jsmaje »

startrak wrote:Good Lord, do Earthlings actually understand this!!!!!!!! :roll:
Clearly not, O Earthling! However, your response actually came between edited versions of my post, which may or may not have made a difference.

If not, what don't you understand? Was it which particular feature in the movie I thought you were referring to, or the focussing artefact?
fjgiie
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Re: "I think I've found a track, what do you think?"

Post by fjgiie »

startrak wrote:Out of 28, I'm surprised no one else clicked on this. Looks different to me :?:

http://stardustathome.ssl.berkeley.edu/ ... =6248879V1 at 100/05.
Below is the URL of the track candidate with mouse pointer on the track. Would not the location be 12,100 ? or did you really mean 100,05 ?

Code: Select all

http://stardustathome.ssl.berkeley.edu/ss_virtual_microscope.php?frame=39&coords=?12,100
The circle at 12,100 does look like a circle and it looks like a circle on the surface. The focus does not go deep enough to make a good guess. I would click on it just because it looks like one of those simulated tracks in the tutorial, except it is not below the surface.

           fjgiie
startrak
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Re: "I think I've found a track, what do you think?"

Post by startrak »

You're right, fjgiie, I did mean 05,100 - not 100,05 -- guess being left handed really has its disadvantages. And my amazement of intelligence is in reference to your suggestion of http://en.wikipedia.org/wiki/Airy_disk.
Thank you for your comments.
jsmaje
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Re: "I think I've found a track, what do you think?"

Post by jsmaje »

Startrak, much as I agree with you about fjgiie's intelligence, I have to own up to being the one having referred to the 'Airy disk' and must apologise, since I now realise it probably wasn't that intelligent after all! That term usually refers to a telescope artefact concerning a 'Point Source', such as a star with no appreciable spatial extent. Nor might an alternative possible reference I could have given to the 'Circle_of_confusion' (which does occurs in microscopy) have been any better, for the same reason. The lesson, though, is that artefacts haunt optics, particularly at the extremes.

It doesn't seem that the above limitations apply to the measureable (albeit micron-sized) features we are dealing with in Stardust movies. Nevertheless, in my experience, it is common that surface debris and other aerogel irregularities do often show a dark rim round a brighter center over just a few focus levels, tailing off, often symmetrically, both above and below (unlike what might be expected of a true track with any depth).

Just what this particular artefact may be called and how explained, I think I had better now leave to someone like Dan before muddying the waters any further! Unless, perhaps, such features are hollow or at least have a lower-density center, in which case focussing through them will naturally show a point, widening into a circle, then back to a point before disappearing...

Meanwhile, as fjgiie implies, comparing the focussing levels of other obvious surface features in your particular movie suggests that the one in question is also on the surface. But who knows...!

John
startrak
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Re: "I think I've found a track, what do you think?"

Post by startrak »

I also want to thank you for your comments, John, and apologize for my confusion. Guess the best thing for me to do regarding Movie 6248879V1 is keep my fingers crossed.
Htorne
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Re: "I think I've found a track, what do you think?"

Post by Htorne »

Please take a look at this

http://stardustathome.ssl.berkeley.edu/ ... =2784126V1

x=315 Y=425

it's only visible in a few frames below the surface. What do you think- :?:
fjgiie
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Re: "I think I've found a track, what do you think?"

Post by fjgiie »

Htorne wrote:Please take a look at this

http://stardustathome.ssl.berkeley.edu/ ... =2784126V1

x=315 Y=425

it's only visible in a few frames below the surface. What do you think- :?:
Hi Htorne,

x goes up to 500 and y only goes to 375, so there is a spot (at x, y) at 430, 292.

Code: Select all

http://stardustathome.ssl.berkeley.edu/ss_virtual_microscope.php?frame=41&coords=?430,292
(code is the URL at bottom of screen with mouse pointer on spot)

I actually think that is a spot on the surface of a low area or an inclusion.

fjgiie
Mikoto
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Joined: Thu Dec 17, 2009 12:14 pm

Re: "I think I've found a track, what do you think?"

Post by Mikoto »

Anyone care to venture an opinion on this one, it looks like a definate track to me just comes into focus far below the surface at approximately 490,30 in the top right corner. However of 34 people only 4 agree.

http://stardustathome.ssl.berkeley.edu/ ... =9321098V1
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