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

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Sharqua
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Post by Sharqua » Mon Aug 07, 2006 3:36 pm

jsellers wrote:This thread has so far been a great read...Firstly, congrats dd and thank you cthiker for revising your position. I too have a similar movie that I tagged and would love anyone here to let me know what they think of it:

http://stardustathome.ssl.berkeley.edu/ ... e_id=35086

It has many of the same characteristics of dd's movies but has an even clearer focus on segments of the trail--giving a clue to the angle. I sure hope it's not just an inclusion. It does, however, lack the trail length of dd's find, so please let me know what you think. Also, because I flagged this movie and it appears on my events page, does this necessarily mean that I was the FIRST to flag it?? I wasn't sure if I was just agreeing with an earlier flag.
Wow. Niiiice. I do believe that's what we're looking for!

The way to tell if you were the FIRST to flag it is to look immediately and see if the number of agreements is only 1. If it's more than 1 when you first flag it, then somebody else found it first.

-Shar

Sharqua
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Post by Sharqua » Mon Aug 07, 2006 3:46 pm

FYI,

I've brought both of these to the attention of the admin staff. If I hear something back, I'll let you know.

These are rare as a needle in a haystack. That second one was as clear a track as I've ever seen.

-Shar

PocketLint
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Not so sure

Post by PocketLint » Mon Aug 07, 2006 3:52 pm

The 'trail" has none of the signs. It goes out of focus almost right away.

Any true track should have displaced gel that leaves a ring along the path of the 'tunnel'
Remember, the actual particle is too small to see. You are looking for the track that one might leave in the gel.

Kind of like a super model walking in a crowd of people. As they spread out you can see her wake but because she is standing sideways you will never see her with the naked eye.

Depending on the obliqueness of the entry angle, the ring that stays in focus will stay in the same position (where all other blips shift around) or will travel down the track. An entry that is almost tangent to the gel surface will have a long 'tunnel' where a 'head-on' entry will no 'tunnel' effect but appear as a dark ring, one that is possible so small that it appears as a dot, that stays in focus (does not disburse) for a few frames while the focus is below surface.

But in the end, the gel track will be seen as a shadow above and at the surface of the gel. any thing that comes into focus at the surface most likely will not be the target of this search.

It may not always look like a ring as it could be a very small particle and therefore a very small wake.
Anything that comes into focus at the end range of below surface (in my opinion) is worth clicking on or at least targeting as a bad focus as the experts should re-evaluate those sections of gel.

If a possible track comes into focus along with others are obviously not tracks (huge blobs, long strings, ect..) then the odds are that it is not a track but some anomaly in the gel all at the same physical level. The chances of more than one dust particle being in the same frame is so out there that it is more likely that Dustbuster would get a date on a Friday then that would be a true track.


Just my 2 cents...

Sharqua
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Re: Not so sure

Post by Sharqua » Mon Aug 07, 2006 3:59 pm

I respectfully disagree. The tracks for those two particles are over a hundred microns long. That's a deep track turned on its side. IMHO if you were to run that track straight on into the gel, the particles wouldn't be visible.

The tunnels are clearly visible. Imagine the tunnel on its side and you get... a ring.

Remember, they don't know exactly what to expect! How else would you get that tunnel with a particle at its terminus? It had to have happened somehow.

Umm... you CAN see the tunnels in each movie, right? They jump right off the screen at me.

:mrgreen:

-Shar

beetlenaut
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Post by beetlenaut » Mon Aug 07, 2006 4:08 pm

The whole key to this is looking for stuff below the surface. In this one, the surface is just coming into focus at the bottom of the range. It doesn't matter what it looks like because it's on the top of the gel. Click "bad focus" for these.

PocketLint
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Ok

Post by PocketLint » Mon Aug 07, 2006 4:09 pm

I can see your point and I'm happy to change my method of search.

But based on what I got from the training movies.. This is not a track.

I WOULD have clicked on it. Just to be sure so don't get me wrong.


But I would not have expected it to be a true track. For the terminus to be visible then I would have expected the track to be longer before the particle came into focus. The gel is just not that deep.
Looking closely at the possible track, the complete track falls out of focus almost evenly along the entire track. For that to happen, the entry trajectory must have been almost parallel to the gel surface. Again indicating a much longer trail before the particle was trapped.

studebaker
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Post by studebaker » Mon Aug 07, 2006 4:25 pm

The focus is bad. And it looks like inclusions.

beetlenaut
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Post by beetlenaut » Mon Aug 07, 2006 4:48 pm

I clicked on one similar one, but I'm pretty sure it's not a track. Check out the speck at the bottom left. It's looks the same as the "track" a couple steps before it comes into focus at which point its a dark speck. There is another fainter circle up and to the right of the "track" that doesn't come to focus and another speck in the top right corner that does. There seems to be a lot of dust under the surface of the gel.

PocketLint
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nope

Post by PocketLint » Mon Aug 07, 2006 5:00 pm

I would have to say no, that is not a track..

It IS worth clicking on though...

The thing I see is that there is another blip that is also coming into focus at near the same time (in the lower left area).

the killer would be to see the target for a frame or two after it came into focus to see if it stayed in focus.

good eye

PocketLint
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#2

Post by PocketLint » Mon Aug 07, 2006 5:28 pm

I need to qualify that my comments where based on the first link..

Now #2 look good... Very good to be a hit!!

VonBraunGuy
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Post by VonBraunGuy » Mon Aug 07, 2006 5:29 pm

So far, this is the most likely candidate I've personally seen for a particle track:

http://stardustathome.ssl.berkeley.edu/ ... e_id=16490

So far I've flagged 19 movies as possibly having tracks, usually with two to seven agreements out of 40-60 views. This last one, however, has 37 ( :!: ) agreements out of 47 views. That was exciting to see. As I was the 37th to view the movie I'm technically not the particle's (assuming it is one) discoverer, but it sure is exciting to think that I've really seen one of these things!

Good luck to all on their track searches. 8)
Give me a lever long enough, and I will move the world.

dd
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Post by dd » Mon Aug 07, 2006 7:47 pm

Very nice catch and surprisingly similar to mine. Cool! :o

Let's do some homework again: the slope is about 6 steps per 50um and the surface is 18 steps away. The track is thus about 150um long. This is consistant with 'my' first track. The particle size and trajectory angle are similar too (I don't know what this could mean...)

jsellers: could you check the ratio of people who saw this track?

If we got two hits in a few days this is very encouraging. But let's not forget we're speculating a lot here. Let's hope! ;-)

jcbc
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Post by jcbc » Mon Aug 07, 2006 7:47 pm

This was the second one that I tagged (I wish I could take away the first one; I don't know what I was thinking :oops: ) and I think there were already 4 or 5 agreements (I can't remember exactly). Still my best one; the rest that I have tagged are inclusions (no trails, just a speck coming into focus below the surface), misclicks :oops: , or just strange features.

Happy searching,
JCBC

jcbc
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Post by jcbc » Mon Aug 07, 2006 7:50 pm

dd wrote:jsellers: could you check the ratio of people who saw this track?
Well, I'm not jsellers, but since it's in my list, I can tell you that it has 25 agreements in 65 viewings.

JCBC

dd
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Post by dd » Mon Aug 07, 2006 9:15 pm

25 agreements?! This is more than the 7 agreements on a false positive mentioned in another thread so at least there is some SNR for the scientists to work with. Somehow even if we're not individually wise we do have some collective wisdom. Maybe... :)

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