What are the chances of finding a particle?

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DustTrailFinder

Post by DustTrailFinder »

Bosniac,

I redid the tutorial last night, with an emphasis on the one that eluded me the first time through, #10. I think that someone else referred to that movie before, from the capture by an orbiting Russian spacecraft of a particle of greater mass than is expected from the Star Dust collector.

After completing the tutorial for the second time, I've found that my main problem was to try to highlight various focuses while the frames were still downloading. That seemed to short circuit the download of all the frames for some reason and I could not retrieve all of them after performing this maneuver. This time I let all the frames load before looking at the movies and it all worked very well, including finding the seemingly more difficult trail of the particle in the tutorial #10.

In the interest of finding as many actual trails as possible, I would recommend that participants go through the tutorial more than once.

fjgiie
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Post by fjgiie »

Hi All, one question or request.
In the Tutorial Session, movie # 11, 60 microns to the left of "below surface",
I would like to know if this is a track, or a maybe? Or did I give part of the upcomming test away?

All take care

öö
ζ
~

Sun Tzu II
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Post by Sun Tzu II »

Whoa, you've got sharp eyes.
Amazing how much interest specks of dust can spark

DustBuster
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Post by DustBuster »

fjgiie wrote:Hi All, one question or request.
In the Tutorial Session, movie # 11, 60 microns to the left of "below surface"
There are some similiar pits(?) on movie #7 the same distance over and down just about as much. If these are truly tracks, the particles are extremely small, and possibly not big enough for a good sample.

Franz
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Post by Franz »

fjgiie wrote:Hi All, one question or request.
In the Tutorial Session, movie # 11, 60 microns to the left of "below surface"
This question nicely illustrates two points mentioned in other threads.

First that the low quality imaginary will cause tiny anomalities to get blurred, so what fjgiie pointed could be virtually anything http://stardustathome.ssl.berkeley.edu/ ... ?p=231#202.

Second the need of point and annotation tools to indicate anomalities that live on the edge of detection which might otherwise be overseen during rechecking http://stardustathome.ssl.berkeley.edu/ ... ?p=233#233.

canucit
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MOVIE #10

Post by canucit »

:? #10 looks more like #5 with earth dust in/on the string of chevrons
useing the tip of the arrow in movie #10 as the reference point can someone point out the micrometeorite captured in space in an aerogel collector that was on the Russian space station?

fjgiie
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Re: MOVIE #10

Post by fjgiie »

canucit wrote::? #10 looks more like #5 with earth dust in/on the string of chevrons
useing the tip of the arrow in movie #10 as the reference point can someone point out the micrometeorite captured in space in an aerogel collector that was on the Russian space station?
Hi canucit,
movie #10 go to bottom of focus and then back up on focus 6 blue lines.
top left at end of skid is a black grain. I believe this is the particle referenced. Top left of the whole frame, 190 microns from tip of arrow.

fjgiie
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Post by fjgiie »

Hi DustBuster,
There are some similiar pits(?) on movie #7 the same distance over and down just about as much. If these are truly tracks, the particles are extremely small, and possibly not big enough for a good sample.
It took me this long to see the very small pits(?) you reference. When the focus is brought down lower, these disappear. One of the Stardust@home scientist will need to tell us what this is. My guess is that it/they is not a track.

fjgiie
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Re: What are the chances of finding a particle?

Post by fjgiie »

schlockading wrote:I was wondering what the statistical chances of discovering a particle for a single person are if the focus movies are searched on a regular basis.
50,000 Searchteam members searching for 40 tracks.

40 out of 50,000 people = One chance out of 1250

(The other 50,000 are not searching as hard as this 50,000)

__________________________
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Wolter
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Post by Wolter »

The very first lines of the tutorial:

How do I look for interstellar dust particles?

When a hypervelocity particle enters the top surface of an aerogel collector, it makes a track many times its own size as it slows and stops in the aerogel.

The particles themselves are too small to see. You will be using a Virtual Microscope (VM) to look for the tracks made by the particles rather than the particles themselves. The tracks are just below the surface of the aerogel.

Also when looking at the foto of the cometary dust partical
Image
you will see that the track is most prominent just below the surface and the partical is not visible and most likely burried deeper than the focus will alow you to search

So keep your eyes open for tracks and not for particals.
Just dusting... Image

DiamondGirl
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Identifying tracks

Post by DiamondGirl »

I also found that the valid tracks become clearer as you go below surface, while the false positives (cracks, dings, etc.) lose focus or stay blurry. That's the one constant I found as I went through.

Like someone said - best to let the moderator respond, but wanted to mention it in case it helps someone going through the tutorial. :)

fjgiie
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Post by fjgiie »

To: ALButterworth, Bryan Mendez, Mattp
Could one of you answer this question?

fjgiie asked
In the Tutorial Session, movie # 11, 60 microns to the left of "below surface",
I would like to know if this is a track, or a maybe? Or did I give part of the upcomming test away?
Thanks

Wolter
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Post by Wolter »

Why looking for something that is not there?
The tutorial is meant to teach you how to look. It clearly states what's what so you can get a feel of what to expect. If there where 2 tracks in movie 11, both would be tagged. Since there is only one tag, there only one track.

Testing your skills, that is, to let you search for unmarked tracks, will be done when registration is opened in a few weeks.
Just dusting... Image

bmendez
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Post by bmendez »

Hello All,

Thanks again, Wolter, you are exactly right. In tutorial slide #11 the only track is the one marked. The feature you asked about, fjgiie is a surface feature since it goes out of focus as you go beneath the surface.

DiamondGirl, your observation is also very keen. Most of the things that might be mistaken for tracks are surface features and will not be in focus beneath the surface.

-Bryan
"I am made from the dust of the stars, and the oceans flow in my veins"
- RUSH

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