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Photos capture life inside a drop of seawater

smithsonianmag.com

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Re: Photos capture life inside a drop of seawater

#171

Post by bee_rider »

daveslash wrote: post #60

My wife and I get into the ocean pretty often -- sometimes, every day. But when I leave my swimming attire hanging in the bathroom for more than a couple of days ( I try not to do that, but sometimes forget ), it starts to smell really fishy . My wife asks why it smells so bad after 2 days, but not immediately after getting out of the ocean. I tell her The ocean is a soup of life, and when you get out there are milli…

Despite the smells, there are few bodies of water that I’d rather swim in than cold oceans, as far as nasty little germs and whatnot go.

Re: Photos capture life inside a drop of seawater

#172

Post by Night_Thastus »

dylan604 wrote: post #54

These pics remind me of an indy game way back on the PS3 called Flow[0]. It was designed as a low stress, low impact, and a fairly calming game. You were a small underwater creature that swam around collecting things to become a bigger creature. You used the 3-axis feature of the controller instead of the d-pad and joysticks. [0] https://en.wikipedia.org/wiki/Flow_(video_game)

I remember playing this back when it was a flash game! Lovely stuff. :)

Re: Photos capture life inside a drop of seawater

#174

Post by dekhn »

oh_sigh wrote: post #168
dekhn wrote: post #141

When I was a kid, my school took us the boston science museum and I wandered off to the microscope exhibit. The museum collected and displayed a bunch of things from Boston Bay, and looking in- as a kid learning about computers- it seemed like some of the "animacules" behaved in complex ways- like a computer program with sensor input and mechanical actuators. Some would spiral endlessly while others would zip forward…

Did you write up any details about your microscope build? Or could you provide a good launching point for that?

No, I haven't, because I don't want to support users with something I'm teaching myself with (it changes quickly as I learn that I did something wrong). In short, I use aluminum extrusion on optical breadboard to build a rigid frame and then mount linear stages based on stepper motors, smooth rods and 3d printed bearings and mounts. This forms a 3-axis stage to move the sample (could be a slide, or a dish, or whatever) which I control using FluidNC (normally intended for CNC) and some hand-written Python scripts for the UI/camera interfacing. It uses industrial vision cameras.

Most components are fairly inexpensive- at least compared to scientific systems- but aren't cheap for a typical hobbyist. The breadboard is >$200, the extrusion is another $100, the cameras at least $250, and my total personal time investment (converted to salary dollars) would be ludicrous.

The important advantage of my design is that I control the closed loop camera/motor control stack (with machine learning inline), and I can raster scan to make large field of view stitches with the camera moving constantly and super-short light exposures.

Here's an example video tracking a tardigrade (keeping its snout as close to the center as possible) I made with the previous generation: https://www.youtube.com/watch?v=LYaMFDjC1DQ

Re: Photos capture life inside a drop of seawater

#179

Post by ericbarrett »

dekhn wrote: post #174
oh_sigh wrote: post #168

Earlier quoted context omitted.

Did you write up any details about your microscope build? Or could you provide a good launching point for that?

No, I haven't, because I don't want to support users with something I'm teaching myself with (it changes quickly as I learn that I did something wrong). In short, I use aluminum extrusion on optical breadboard to build a rigid frame and then mount linear stages based on stepper motors, smooth rods and 3d printed bearings and mounts. This forms a 3-axis stage to move the sample (could be a slide, or a dish, or whateve…

Fascinating. What is it eating starting at ~36:00?

Re: Photos capture life inside a drop of seawater

#180

Post by dekhn »

ericbarrett wrote: post #179
dekhn wrote: post #174

Earlier quoted context omitted.

No, I haven't, because I don't want to support users with something I'm teaching myself with (it changes quickly as I learn that I did something wrong). In short, I use aluminum extrusion on optical breadboard to build a rigid frame and then mount linear stages based on stepper motors, smooth rods and 3d printed bearings and mounts. This forms a 3-axis stage to move the sample (could be a slide, or a dish, or whateve…

Fascinating. What is it eating starting at ~36:00?

Algae. It's a mixture of https://www.carolina.com/invertebrates/water-bear-tardigrade... and https://www.carolina.com/algae/chlorella-living/152069.pr

Then I use a special tool (really just a mouth tube that has a glass tube at the end) to single tardigrade to a glass-bottom petri dish that goes into the scope. I take movies, then label ~hundreds of frames manually with "tardigrade" "algae" and "junk" then fine-tune an existing object detector with those frames. The centroid of the object detection provides the direction to move the stages to center the detected object.

The other mode is fast scanning, which I described above (move the camera continuously over a large field of view, pulsing the LED quickly/periodically and dropping any empty frames).

(at work I get to play with grown-up microscopes and they are another class entirely; precision machines with extraordinary capabilities and price tags to match)

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