[HN Gopher] Long-distance and wide-area detection of gene expres...
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Long-distance and wide-area detection of gene expression in living
bacteria
Author : mailyk
Score : 67 points
Date : 2025-10-01 15:15 UTC (7 hours ago)
(HTM) web link (www.asimov.press)
(TXT) w3m dump (www.asimov.press)
| advisedwang wrote:
| Critically this only works for the bioengineered microbes that
| produce marker molecules that the hyperspectral cameras can
| identify. This doesn't work for random microbes out and about.
| igleria wrote:
| Then we infect every microbe with that biomarker and make hell
| real for germophobics?
|
| Or a less dumb application: lab leak monitoring
| dylan604 wrote:
| There are people pushing for the use of microbes in farm land
| instead of chemical fertilizers. These markers would be
| useful to see what plots are treated or not.
| m3047 wrote:
| Here's a company which produces biomarkers (which it can
| disperse as aerosols or via other means) which it can then
| detect in air or other samples: https://www.safetraces.com/
|
| (I have no commercial connection with them.)
| robotresearcher wrote:
| The title here and the first image in the article are annoyingly
| misleading.
|
| The authors report being able to detect _populations of many
| microbes_ that they _genetically engineered to produce lots of
| detectable molecules_ and they _sprayed in patches on top of the
| soil_.
|
| So this could be a valuable thing. But the damn article shows an
| aerial image inlaid with a microscope image with individual
| organisms resolved, which is very very far from what is reported
| here.
|
| It's science reporting. Science is cool already. There's no need
| to give misleading hyperbolic impressions. Bah.
| happyPersonR wrote:
| That makes a lot more sense, otherwise the SNR from 90 meters
| away seems like it would be ... enormous.
| moralestapia wrote:
| We can see Uranus from Earth which in on a similar
| size/distance order of magnitude :).
| HarHarVeryFunny wrote:
| Actually the angular size of Uranus seen from earth is
| almost a million times larger than a microbe seen from 90m
| (not that TFA was about seeing a single microbe, or seeing
| a microbe at all for that matter).
| moralestapia wrote:
| Can we do the math? I know that burden's on me but I feel
| I might be wrong, my back of the napkin calculation puts
| them within 10-100x.
|
| 1 micrometer (1E-6) to 50,700 km (1E6)
|
| 90 meters (1E2) to 2.8 billion km (1E12)
|
| Edit: Oh yeah but size/distance does not decay linearly
| ...
| HarHarVeryFunny wrote:
| I was lazy and asked Claude, although I didn't check the
| math.
|
| **
|
| Uranus subtends a much greater angle than a microbe at 90
| meters. Let me work this out: Microbe from 90 meters:
|
| A typical bacterium is about 1-5 micrometers (let's say 2
| mm = 0.000002 meters) Angular size = (size / distance) in
| radians = 0.000002 / 90 [?] 2.2 x 10-8 radians Converting
| to arcseconds: [?] 0.0000046 arcseconds
|
| Uranus from Earth:
|
| Uranus is about 2.6-3.2 billion km from Earth (depending
| on orbital positions) Its diameter is about 51,000 km At
| closest approach, Uranus subtends approximately 3.7
| arcseconds Even at its farthest, it's still around 3.3
| arcseconds
|
| So Uranus appears about 800,000 times larger in angular
| size than a bacterium at 90 meters away! This is why we
| can see Uranus through telescopes (and technically with
| the naked eye under perfect conditions, though just
| barely), but we absolutely cannot see individual bacteria
| without a microscope--the angle they subtend is far, far
| too small for our eyes to resolve.
| penteract wrote:
| 2.2 x 10-8 radians is 0.0045 arcseconds [1]. That answer
| is off by 3 orders of magnitude.
|
| [1] https://frinklang.org/fsp/frink.fsp?fromVal=2.2*10%5E
| -8+radi...
| moralestapia wrote:
| :O
|
| So what would be the difference on magnitude between the
| bacteria and Uranus, then?
|
| Edit: nvm, I just read your other comment.
| HarHarVeryFunny wrote:
| Thanks.
|
| That was the latest greatest Sonnet 4.5 ... not quite
| great enough evidentially.
|
| I just asked it to "check the radians to arcsec
| conversions", and it realized the error.
| moralestapia wrote:
| "You're absolutely right!"
| penteract wrote:
| Angular size is proportional to size/distance, so the
| calculation you're trying to do is correct; however,
| 50700 km is more than 1e7 meters so the angular sizes
| differ by about 3 orders of magnitude.
| dylan604 wrote:
| A leading reason touted as evidence the moon landing was
| fake is that we can't see the stuff supposedly left on
| the moon. Once you start going into angular resolution
| and the physics of optics you've already lost the
| argument.
| outworlder wrote:
| You don't "lose" an argument just because the other side
| doesn't have the attention span to understand what you
| are saying.
| dylan604 wrote:
| Sure, but you'll never win. So whether you want to call
| it "lose" the argument or just apply "lose" to the amount
| of time and/or your own sanity, it's still a loss. You
| will definitely not be changing the other party's mind.
| TrainedMonkey wrote:
| There is but a sliver of atmosphere between Earth and
| Uranus... and all of the atmosphere between sensing
| apparatus and microbes 90m away. I am curious how moon
| would look like if there was the atmospheric scattering the
| entire way there. Or if would even be able to spot Mars /
| Venus if we had a constant 1 atm the entire way.
| dylan604 wrote:
| How could it be constant 1 atm all the way to the moon.
| Wouldn't having an atmosphere as thick as 240km mean the
| pressure on the surface would be much greater than 1 atm?
| initramfs wrote:
| I do agree- i hate when an article doesn't include a thumbnail
| that Google News might indicate includes, but in this case,
| they just buried the lede, which is slightly different, and
| sometimes just as annoying:
| https://substackcdn.com/image/fetch/$s_!PKJG!,w_1456,c_limit...
| moffkalast wrote:
| It's a nose, they invented a nose for robots. That's pretty
| neat.
| tomhow wrote:
| We updated the title to match the research paper, thanks.
| nachox999 wrote:
| engineering microbes for drone-detectable spectral signatures
| truly is a visionary leap in biosensing, but its real test lies
| in navigating biology's unpredictability and society's caution
| HPsquared wrote:
| I can see algal blooms from miles away.
| hinkley wrote:
| I can practically hear the germaphobes breathing heavily.
| cozzyd wrote:
| [flagged]
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