Slashdot Mirror

I love how slashdotters with absoloutely know knowledge of a field dismiss a widely established claim using nothing but the burning power of blind ignorance.

Toxic light is a new one. Having no substance, light can't carry any toxins. The light might fry the specimen.

But no rational definition of toxic applies here.

Light, it turns out does cause toxic effects:

http://www.microscopyu.com/ref...

It's a well known effect called "phototoxiciy". And it's a huge problem in live cells, especially when they express something like GFP.

I'm afraid I don't see how 3D printing brings any benefit here - a laser cutter or CNC machine fed with durable, stabilized sheets of plastic would be faster and produce *far* more durable pages.

Of course you're right. Etching by laser on solid sheets of plastic or slow-corrosion metal is the thing. Just desperately trying to come up with ways in which 3D printing might be useful to salvage the time I've spent reading about it. Never mind all the time others have spent trying to make it work.

If you want to place a barrier between knowledge levels, call them 'magnification-stops' in your approach where certain technology and knowledge obtained by the years like 1700, 1800, 1900, 1950, 2000 is encoded with successive difficulty --- then if history is any clue you're best bet is to change medium and method at each stop.

Optics for example. The advancement from a lens allowing the eye to discern Mars clearly to one able to construct a great microscope may be an accident of local geology, quartz and silica, or a single individual's experiments in glass manufacture. There could even be an alternate history where mercury in spinning dishes is optics. You have a clean progression to 100x magnification with a single stage, then it takes compound lenses and take it to 1000x You can push it a little further by using filters to reduce the color component, but you hit the wall of visible light.

Now to break that Reading Rainbow 800-1000x barrier we're in the realm of coherent photons using lasers to 'read' (project and reflect through optics) or scatter (holography). And further on into using streams of electrons where the only usable means optick is electromagnetism shaped by precisely wound coils and some gruesome electronics.

Could there be a single object that is an Easy Reader through all possible optical resolutions, but also incorporates successive levels, the greatest of which is only readable with electrons? That is a challenge but do-able since you can read through things with electrons. The visible stages act as protection for this fragile inner layer.

Perhaps for the intermediate stages requiring laser technology the colorful yet color-challenged field of 2 dimensional holography might offer a solution... something that resembles Asimov's Prime Radiant without the computey stuff, where a coherent beam of laser light will scatter off of foil and project material onto the wall, and precise movement of the object or the beam will 'scroll'.

This being Slashdot, I have to suggest that at some point the Thing will might digital, where we apply leverage to Hamming and Huffman for encoding and error correction... BUT now the content is sub-coded in a series of arbitrary choices that represent our evolution of information technology... and not necessarily anyone else's. To one familiar with the optick perusal of language-symbols, going digital, which we've done gradually -- to those who have only our Prime Radiant as a guide -- it would be a wall of incomprehensibility that would take time to crack.

I just had this idea that at some low resolution text might offer a delicious recipe for Taco Sauce, and a tiny dollop of this concoction makes its way into a tiny space between the letters... completely obliterating the 13th century.

Completely losing the 13th century has happened before. The circumstances surrounding its disappearance (but not its present whereabouts) can be seen here in the brief clip from the 1975 movie "R

Second that. "Child friendly" in this case means "cheap enough that if he breaks it it won't be a big deal." I had a cheap plastic "kids" microscope when I was a kid from Fischer price or something like that. It was less useful than a magnifying glass. I used it as a toy gun mostly. That didn't deter me from it: I'm a cell biologist today, but I would have loved a real microscope.

This dissecting microscope looks pretty cool.

I woudn't rule out compound scopes though. If he's interested in paramecia and bacteria, microbes, he's interested in plenty of things that are going to be visible with a compound microscope. A drop of pond water, you can generally see more with the compound scope than you can with the dissecting scope.

Also, somewhat unrelated, show him this virtual microscope and Nikon small world galleries.

Hmmm. I believe you, but that smacks of a defect in digital cameras.

Remember, ADCs can operate at 24 bit resolutions, greater than the 16 bits per colour plane than is needed for most HDR images, and can operate at that resolution at speeds of hundreds of thousands of measurements per second. In principle, that means you can make far more accurate measurements of the voltage. Two pixels A and B measuring 1/250th of the difference at the higher speed than they would at the lower speed shouldn't (in principle) matter if you are capable of discerning differences 1/256th the size than you could with cameras designed specifically for the higher speed.

The sensitivity of the CCD itself obviously matters, since you can't measure a difference smaller than the smallest increment the CCD can measure before thermal and external noise mean you cannot distinguish what is a real increment and what is just noise. (This chart of various CCD types is useful, although I'm unsure how old it is and light-sensitive technologies improve all the time. http://www.microscopyu.com/articles/digitalimaging/images/ccdintro/ccdintrofigure10.jpg)

With modern systems, I see no obvious reason for a camera designed to work at 250 fps to need any more light than a camera designed to work at 24 fps, PROVIDED the necessary sensitivity is present AND noise is kept to a minimum AND the image is then contrast-stretched so that the much smaller increments as measured are mapped onto the corresponding large increments you would have had had more photons hit the sensor.

What you're saying is that basically no such camera exists - or, if it does, it's not in the hands of film-makers. I can see that high-speed cameras exist, that 3CCD cameras exist, and that the components needed to make a high-speed camera that creates HDR images that are perceptually the same as regular-speed cameras exist. Ergo, if no such camera has been built (at least at reasonable prices), then someone needs to build it. I do not believe for an instant that given the massive strides in photo-sensitive technology, ADC technology, etc, that this should be impossible at sensible prices.

I've thought about doing something like this, the problem is that although I can see no reason why a camera couldn't be built, it costs money (and lots of it) to found a startup and do the R&D to actually make such a product, so it has merely remained a thought. The well-publicized high-speed cameras also appeared to mean any such project would largely reinvent the wheel anyway. Why build from scratch, the hard way, what someone is already mass-producing?

Honestly, such a project would be outside of my skill set to complete, even though I can see how the overall design would have to work and some aspects would be relatively trivial for me. But you can't sell 1/10th of a camera. No use to anyone. (There's also a heap-load of other things like that, where I can see how to make things actually work -- I could even make Lightfleet's network design work -- and can certainly design small sections but cannot do the whole thing and cannot afford to put together the kind of startup that would be capable of doing the whole thing.)

These problems are technically solved - not by me, it's all lego blocks by that time, all I'm doing is putting the lego blocks together and carving maybe a couple of filler pieces here and there. Anyone can do that. Ok, if spotting that apples only fall downwards is a "hard" problem (that says a lot for average intelligence!) then maybe not everyone. Just most. There is no sane, rational or remotely intelligible reason why a properly-mapping high-speed camera should not be in the hands of every film-maker on the planet.

http://www.microscopyu.com/tutorials/java/dic/bias retardation/index.html

That's the link I failed to format properly, to an interactive Java tutorial demonstrating the power of DIC (Differential interference contrast).

Not only that but spider webs are covered with antiseptic agents too.

There's a small summary and a nice picture at http://www.microscopyu.com/galleries/smz1500/spide rsmall.html

The website development and graphics are all contracted out. Only the content is developed in-house, by a scientific writer, so that we can be sure that it is both correct and well written. We can't ask web developers to check the content. I assume the legal department also checks it for any statements that various regulatory authories might object against. (Or adding SEC-required disclaimers etc.) I think that this in itself is a good model.

The biggest potential problem that I see is a tendency of upper management to try to influence detail design, and their unfortunate tendency towards glitz: Flash animations, rolling menus, ticker bars, high-resolution graphics, and the like. These might consume a lot of time and money and only rarely contribute to a good website. (One of the few happy exceptions I have seen is Nikon's microscopy training website, which is great.) But my personal preference would be for a site that is styled in a minimalistic way, light and fast.

The green/amber part you were looking at may have been a protective coating applied when the microprocessor was packaged. Regardless, microfabricated chips can indeed be technicolored marvels.

Most materials used in microfabrication are either transparent (insulating layers) or grey (metallization), but resulting devices can appear coloured due to optical interference. Colours present in structures of a microfabricated device are related to the thickness and composition of the patterned thin-film coatings that form the device. For a single thin film, thickness can be determined from, for example, the Michel-Lévy interference colour chart if the birefringence of the thin film material is known. Variations in colour across a film indicate non-uniform thickness. The colour resulting from several layers of patterned thin-films is more complex to predict, but the same basic principles apply.

High-end microscopes go a step further than these chip makers and use high-index low-dispersion oils instead of water as explained at formulas and intro tutorial. Replacing the air between the lens and wafer with a denser high-index fluid increases magnifaction and increases the efective aperture of the optical systems. A larger aperture increase the theoretical resolution of the system.

High-end microscopes go a step further than these chip makers and use high-index low-dispersion oils instead of water as explained at formulas and intro tutorial. Replacing the air between the lens and wafer with a denser high-index fluid increases magnifaction and increases the efective aperture of the optical systems. A larger aperture increase the theoretical resolution of the system.