[Bored chemist]

You dont to do staining nonsense either.so old fashioned.

So, you don't see anything.
OK.
That answers the question of why they don't do it.
They are more clever than you and they realise that it would be a waste of money.

Clinical  (and research + other) labs throughout the world  do Gram stains every day-because it works.
It's not the only sort of staining- but that's beside the point.
It's not "old fashioned"- it's "time proven"
Bacterial are thin and nearly colourless, so there's very little chance of seeing them without staining.
You can, sometimes, replace staining with dark field microscopy (there are other techniques too, apart from the one you mentioned. Fluorescence microscopy is a dark field technique too and it requires staining.)
However, dark field microscopy ironically only works when the field is light.
The field- the background of the sample, the slide and the water (or plasma or whatever) that the sample is embedded in- has to be transparent.

Martian mud isn't going to meet that criterion.
So you can't use it.
Also, it may have escaped your notice, but the surface of a semiconductor slice is very smooth and homogeneous.
The surface  of Mars isn't.
So the automated machines that could scan one would die as soon as you tried to scan the other.

[profound (OP)]

You dont to do staining nonsense either.so old fashioned.

So the automated machines that could scan one would die as soon as you tried to scan the other.

why you so worried about the life of a bacterium?

[Bored chemist]

You dont to do staining nonsense either.so old fashioned.

So the automated machines that could scan one would die as soon as you tried to scan the other.

why you so worried about the life of a bacterium?

Learn to read.
What I said was "automated machines that could scan one would die"

[profound (OP)]

You dont to do staining nonsense either.so old fashioned.

So the automated machines that could scan one would die as soon as you tried to scan the other.

why you so worried about the life of a bacterium?

Learn to read.
What I said was "automated machines that could scan one would die"

why would an automated machine 'die' after scanning a microbe?

i have a scanner which scans papers.it does not die after scanning one.

[Bored chemist]

You dont to do staining nonsense either.so old fashioned.

So the automated machines that could scan one would die as soon as you tried to scan the other.

why you so worried about the life of a bacterium?

Learn to read.
What I said was "automated machines that could scan one would die"

why would an automated machine 'die' after scanning a microbe?

i have a scanner which scans papers.it does not die after scanning one.

No, really, learn to read.
What  I said was "the surface of a semiconductor slice is very smooth and homogeneous.
The surface  of Mars isn't.
So the automated machines that could scan one would die as soon as you tried to scan the other."

[profound (OP)]

You dont to do staining nonsense either.so old fashioned.

So the automated machines that could scan one would die as soon as you tried to scan the other.

why you so worried about the life of a bacterium?

Learn to read.
What I said was "automated machines that could scan one would die"

why would an automated machine 'die' after scanning a microbe?

i have a scanner which scans papers.it does not die after scanning one.

No, really, learn to read.
What  I said was "the surface of a semiconductor slice is very smooth and homogeneous.
The surface  of Mars isn't.
So the automated machines that could scan one would die as soon as you tried to scan the other."

scan what other?

[chiralSPO]

I believe what the kind chemist is saying is: you can't use a microscope specialized for microchips to look at dirt. Microchips are very regular from one to the next, varying by maybe a nanometer. Random-ass clumps of martian dirt (or earth dirt, or whatever) is likely to have particles that vary over a scale of nm to µm to mm. You can't look at a 1 µm tall particle as close as you might like if there is a 95 µm tall bit of grit next to it (you don't want to run your objective lens literally into the dirt if no one is there to polish it). And if you're going to go through the process of having a robot collect, filter, grind, sort, and mount before even taking a look, how much of Mars do you think we're going to be able to see one grain at a time?

[Bored chemist]

scan what other?

You really should try reading.
What I said was "the surface of a semiconductor slice is very smooth and homogeneous.
The surface  of Mars isn't."
So the automated machines that could scan one would die as soon as you tried to scan the other."
I only talk about two surfaces there that a  microscope system might scan.
 surface of a semiconductor slice and
The surface  of Mars

It's simple enough to make a machine scan the surface of a very smooth semiconductor slice.
If you tried using the same machine to scan the rocky surface of Mars, you would kill the machine.

[profound (OP)]

scan what other?

You really should try reading.
What I said was "the surface of a semiconductor slice is very smooth and homogeneous.
The surface  of Mars isn't."
So the automated machines that could scan one would die as soon as you tried to scan the other."
I only talk about two surfaces there that a  microscope system might scan.
 surface of a semiconductor slice and
The surface  of Mars

It's simple enough to make a machine scan the surface of a very smooth semiconductor slice.
If you tried using the same machine to scan the rocky surface of Mars, you would kill the machine.

you cant kill a machine.you level the slice.or simply have a guard.or a leveler mudflap.

[chiralSPO]

Oh yes, of course... mudflaps! Why didn't I think of that? Every automated microscope comes with the mudflap attachment, I just never knew what it was for...

[profound (OP)]

Oh yes, of course... mudflaps! Why didn't I think of that? Every automated microscope comes with the mudflap attachment, I just never knew what it was for...

NASA reduced to a shoebox a massive mass spectrometer.

An automated microscope can constructed similarly.

 NASA is mostly staffed by desk jockeys with little insight and imagination.Even if they come up this idea it will be drowned in an old bogeys committee meeting.

Automated microscopes already exist as explained above.Your objections are largely fueled by moribund thinking or petty jealousy that you did not post it first.

Other people have also suggested it in addition to me as you can google it.

It has been met by a rear guard action to put up lame excuses as to why it should not be done with thinking fueled by Victorian era objections

[alancalverd]

Scanning chips for defects is easy because you (or at least I) know what a chip should look like.

Perhaps you can tell us what alien life looks like?

The advantage of chemical sensors is that we have a good idea of what life smells like.

[Colin2B]

you cant kill a machine.

On my outboard motor I have a kill cord. It does what it says.

Your objections are largely fueled by moribund thinking or petty jealousy that you did not post it first.

No, he just didn't want to be considered a fool who doesn't understand the basic physics of microscopes.


There is a lot he does understand:


He understands the relationship between magnification and subject-objective distance. At these magnifications a surface with irregularities the size of 0.2mm will damage a lens, so the surface would need to be ground as flat as a microscope slide. At magnifications greater than about 500x light is refracted too much as it passes through air to yield good resolving power, so oil immersion lenses are used and the objective almost touches the subject.


He understands that surface scanning requires reflected light, so discussion of transmitted light techniques such as brightfield and darkfield are irrelevant.


He understands that both human and automated scanning systems use differences in colour and contrast between the subject and background. Both systems use staining to enhance both colour and contrast.


Automation of miniaturised sample processing and slide preparation would be an interesting area of investigation.

Other people have also suggested it in addition to me as you can google it.

LOL I have no desire to count the number of people who don't understand basic physics.

[chiralSPO]

Your objections are largely fueled by moribund thinking or petty jealousy that you did not post it first.

No, he just didn't want to be considered a fool who doesn't understand the basic physics of microscopes.

There is a lot he does understand:

He understands the relationship between magnification and subject-objective distance. At these magnifications a surface with irregularities the size of 0.2mm will damage a lens, so the surface would need to be ground as flat as a microscope slide. At magnifications greater than about 500x light is refracted too much as it passes through air to yield good resolving power, so oil immersion lenses are used and the objective almost touches the subject.

He understands that surface scanning requires reflected light, so discussion of transmitted light techniques such as brightfield and darkfield are irrelevant.

He understands that both human and automated scanning systems use differences in colour and contrast between the subject and background. Both systems use staining to enhance both colour and contrast.

Automation of miniaturised sample processing and slide preparation would be an interesting area of investigation.

Thank you Colin for taking the time to clarify my meaning, you did an excellent job at it. I did not take the time to make myself so clear, and instead resorted to some degree of snark, assuming that the shortcomings I foresaw would similarly be identified by others without additional explanation. For any who were confused by my earlier statement, I apologize.

[Bored chemist]

NASA reduced to a shoebox a massive mass spectrometer.

An automated microscope can constructed similarly.

Just play a quick game of "count the moving parts" and you will realise that's nonsense.
Come to think of it, based on past experience, you won't realise how dumb your comment was; but others will.

[profound (OP)]

Scanning chips for defects is easy because you (or at least I) know what a chip should look like.

Perhaps you can tell us what alien life looks like?

The advantage of chemical sensors is that we have a good idea of what life smells like.

Perhaps you can tell us what a stranger looks like?

The disadvantage of chemical sensors is you can never be sure weather it is chemical or biological in nature as explained above.

What a huge and expensive joke the viking probes turned out to be.They could never decide the if results obtained were chemical or biological.

[alancalverd]

Perhaps you can tell us what a stranger looks like?

In terms of gross morphology, like me, obviously. And by definition an alien doesn't. 

The disadvantage of chemical sensors is you can never be sure weather it is chemical or biological in nature as explained above.

The difference being what?

[profound (OP)]

Perhaps you can tell us what a stranger looks like?

In terms of gross morphology, like me, obviously. And by definition an alien doesn't. 

The disadvantage of chemical sensors is you can never be sure weather it is chemical or biological in nature as explained above.

The difference being what?

you should that difference instead of asking.

[alancalverd]

Being a very intelligent, experienced and well qualified scientist, I know biology is an aspect of chemistry and physics. But I am amused by the halfbaked opinions of others, so perhaps you will tell us the difference between molecules of a biological and "chemical" origin in whatever intellectual universe you inhabit. 

[Bored chemist]

The disadvantage of chemical sensors is you can never be sure weather it is chemical or biological in nature as explained above.

That's wrong on two counts.
You need to learn to spell "whether".
But much more importantly, the chemical clues are not- as you imply- specific to any particular life form.
Do you understand that any disequilibrium indicates the presence of life (or, at least- something weird).
For example, the Earth's atmosphere contains oxygen and also methane.
Over geological time the two compounds should have reacted.
Yet they are still both there.
It doesn't tell you where the two gases come from- but it does tell you that something is making at least one of them continuously.
Maintaining a non- equilibrium system is strong evidence of life.
The clever bit is that you can look at the atmosphere (or water etc) anywhere on the planet and find the evidence.
You don't have to tak a zillion samples of teh surface then carefully microtome them and mount them on slides so you can put them through an automated microscope and then search for heaven knows what because we don't know what a Martian looks like.
It's really bloody clever.
The guys at NASA are good at thinking of clever tricks like that.

Am I right in thinking you didn't understand that before?