Microscope Definition and 252 Threads

Greetings- As will become abundantly clear from this post, I know very little about optics, so any and all help will be appreciated. I am a visual neuroscientist and I am attempting to project a visual stimulus through a camera port on a microscope, off a mirror, through the microscope...

Hi all, I have a question about the "missing cone" problem in wide-field microscopy. The Fourier equivalent of the PSF is the OTF. The OTF has a toroidal (doughnut) shape. I'm a little confused by how to interpret the OTF support in the Z dimension. In 2D and considering lateral...

[I could not fit the last "e" into the title] Hi! I am writing a report on TEM, and was asked to consider the effect of accelerating voltage on the resolution. Since resolution in the light microscope is limited by the wavelength of visible light, we obtain much higher resolutions in a TEM...

Hooke's law states that the force required to stretch/compress a spring is proportional to the distance stretched. Meanwhile, electromagnetic interactions between particles obey an inverse-square law with respect to distance. So, if as a spring is stretched, it's composite particles get farther...

Homework Statement A biologist looking through a microscope sees a bacterium at r1→ = 2.2i + 3.7j -1.2kμm. After 6.2s, it's at r2→ = 4.6i + 1.9kμm. a)What is it's average velocity b) What is its average speedThe Attempt at a Solutiona) v→= Δr/Δt v = (r2-r1)/6.2 = (2.4i - 3.7j + 3.1k)μm/6.2s =...

Homework Statement The image formed by a simple two lens microscope is (a) real and inverted. (b) real and upright. (c) virtual and upright. (d) virtual and inverted. (e) none of these. Homework Equations N/A The Attempt at a Solution I was confused on how to understand how...

This is one of my favorite thought experiments. Imagine for a moment, you are a giant looking down at earth, and seeing it as if a person observing organisms from a microscope. imagine the microscope isn't good enough to see people but resolute to make out which look to be grey patches...

An infinity corrected microscope objective has a magnification of 100× for a tube lens with focal length 180 mm. The numerical aperture of the objective is 0.90. Calculate the the diffraction limited spatial resolution if the objective is used with red light (660 nm). (Ans.: f=1.8 mm; d=447...

Hi, I am working with a scanning electron microscope with the SED and it works fine. I have tried on several occasions to use the BSED without any success. All I get is a very faint dark image. Would you be able to give me some advice as to where I am going wrong? Thanks in advance

My question involves understanding why there is a limit to resolution of a microscope. I have a hard time putting what i think is happening into words. My attempt: When light of some wavelength strikes an object on the scale of that same wavelength it gets reflected. Since the details on...

Hi all, I have a couple of questions about the process of kohler illumination (optimised condenser alignment) in brightfield microscopy and how this affects the final resolution attained. Resolution concerns the minimum detectable distance between two objects and the closer to structures...

http://www.dailymail.co.uk/sciencetech/article-2416761/Scientists-claim-evidence-ALIEN-LIFE-Balloon-sent-edge-atmosphere-picks-organisms-come-space.html "British scientists believe they have found evidence alien life after sending a balloon to the edge of space. The team of scientists sent...

Homework Statement Surgeons often use a type of "binocular microscope" [that's a word by word translation]. It consists of a 50mm lens close to the patient and a -15mm right in front of the doctor's eye. The distance between the patient and the 50 mm lens is 400mm and the negative lens is...

I performed a simple experiment to find the focal length of a magnifying glass. Taking a white sheet of paper as a screen and a building as object at infinity, i got a clear image at 12.5 cm, which is approximately the focal length of the lens. Plugging this into the formula for magnifying power...

Hello, A sinusoidally driven and undisturbed cantilever of an atomic force microscope (AFM) oscillates ideally in a sinusoidal fashion but the motion of the cantilever (time-domain trajectory) can become more complicated when it is disturbed by the inter-atomic forces as the cantilever taps...

How do i demonstrate thin film interference with microscope slides? Textbook questions all mention that you will get parallel fringes when you put a hair between two microscope slides. However, i have tried doing so, but don't get the parallel fringes. I used a red laser pointer, and a...

Hi, I can explain why objects reflect, absorb or transmit light by referring to the objects' refractive index (differnece of the refractive index of two media). I'd like to know if there is a microscopic point of vue that can explain why objects reflect light? For example * Light is...

If a piece of mirror is observed under a high magnification optical microscope, then what would one see??

A while back I managed to get (2) very nice surplus Nikon microscopes from UC Davis (CA). Since then I have taken several grass root and compost samples from my yard and mulch pile and cultured them in glass bottles with purified drinking water. I wind up with all kinds of life forms that...

Hi, so I have a little background in biology. I took AP bio in HS and got a 5 and really enjoyed it along the way. I got a microscope for my own amusement and also to maybe spark an interest in my little brother. What I'm having trouble with is finding good densities of moving microorganisms...

Homework Statement The barrel of a compound microscope is 15 cm in length (distance between lenses). The specimen will be mounted 1.0 cm from the objective, and the eyepiece has a 5.0-cm focal length. Determine the focal length of the objective lens. Known: f2=5cm, L=15cm, do1=1cm...

Hi all, So, I'm trying to "hit" the diffraction limit (i.e. view Rayleigh criterion, or Abbe or Sparrow criterion) with my light microscope . Bought the scope off amazon..it's a typical AmScope that has 2000x magnification limit... But the trouble is I can't find a good sample of two spots...

Find the resolving power of a microscope lens in terms of its diameter Homework Statement In this problem, we will find the ultimate resolving power of a microscope. First of all, in order to obtain a large magnification, we want an objective lens with a very short focal length. Second, in...

Time has always baffled me. I have two questions for you. 1. What's the genesis of time? 2. Is time quantum at the microscopic level? Thank you.

Homework Statement The tip of a scanning tunnelling microscope is placed 1.0 nm away from a conducting surface and a potential of dV = 0.03 V is applied to the surface relative to the tip. When the tip is moved laterally to a new position on the surface the tunnelling current increases by...

"The diameter of the eyepiece is greater than that of the objective. This helps to collect more light and gives a brighter image" I thought that increasing the aperture of a lens doesn't increase the brightness of a virtual image. Yes, it will increase the brightness of a real image caught on...

I have an optical microscope and some opaque samples that I want to examine the surface of. I drew up a picture of how the microscope is arranged (attached). There is a series of lenses on a rotating drum that are located underneath the stage where glass slides are placed. The lenses usually...

Hi, When we use an optical microscope, how do we roughly calculate the illuminated spot size on the sample ? Also what is the light power on that spot? And what if I change to fluorescence microscope(epi illumination)? Cause the illuminating light go through the rear side of objective to...

Hey, I'm having trouble finding a clear answer anywhere. When you have a x-ray diffraction pattern, do the dark spots correspond to the positions of atoms? Or do they represent the position of atoms in reciprocal space or something like that? It would seem natural to assume that the peaks are...

I'm reading a little bit about electron microscopes. It states, "the exponential tunnelling factor is proportional to the square root of the mass. So, the lower mass means lower exponential decay of the wavefunction". Would anyone be able to let me know what this exponential tunnelling...

Generally I am on the Physics Forum, but I got my hands on a good microscope a while back and decided to grow some little dudes to look at. My third incubation batch consisted of filtered drinking water and a bit of stuff from my mulch pile. Grew a few interesting little guys and looked them...

Homework Statement You've been asked to build a 14X microscope from a 2X magnifying lens and a 5X magnifying lens. What will be the tube length of your microscope? Homework Equations Meye = 25/feye Mobj = -L/fobj M = (Meye)(Mobj) The Attempt at a Solution First, are you supposed to use the...

Homework Statement A microscope with a tube length of 160 mm achieves a total magnification of 800X with a 40X objective and a 20X eyepiece. The microscope is focused for viewing with a relaxed eye. How far is the sample from the objective lens? Homework Equations M=(Meyepiece)(Mobjective)...

Homework Statement What is the typical rotational frequency frot for a molecule like N2 at room temperature (25°C)? Assume that d for this molecule is 10-10m. Take the atomic mass of N2 to be mN2=4.65x10-26kg. You will need to account for rotations around two axes (not just one)...

When the STM becomes unstable(large variations in the current), what procedures should I take in order to fix it? I am new to the STM, but after a few month`s experience I notice that one of the main problems is stabilizing it. When the tunneling current becomes unstable, I`ve tried to...

I was in my AP Physics class discussing wavelengths of the electromagnetic spectrum and I came up with the idea to attempt a gamma ray microscope. Of course this is extremely dangerous, so I will have to be cautious (and use a lot of lead). Is there a way to produce gamma rays? I know they...

I post in the QM section as an answer in terms of photons rather than just EM waves would be better.

QM started as a non-relativistic theory for microscopic particles. Then there were the attempts to make it relativistic and the results of those attempts suggested that you can't have a relativistic system with a fixed number of particles. But things are a bit different for photons. A...

I have two lenses for my microscope. The object lens which magnifies 63 X. Then there is my eyepiece lens with f=100 mm which focuses the incoming light at an camera. How can I calculate the total magnification? All calculations so far for the eyepiece involve the 25 cm of the human eye, but now...

Homework Statement The eyepiece of a compound microscope has a focal length of 2.50 cm and the objective has a focal length of 1.8 cm. The two lenses are separated by 22 cm. The microscope is used by a person with normal eyes (near point at 25 cm). What is the angular magnification of the...

Homework Statement A thin hair is placed between two microscope slides. When laser light is shined down onto the slides, periodic intensity maxima are seen to span the slides. Which of the following changes will decrease the distance between the maxima? I. Decrease the wavelength of the laser...

Wow! Thanks to all for this great resource. Would it be possible to cast light harmlessly by spontaneously creating microscopic black holes of small enough mass? Or would you necessarily get high-frequency X and gamma radiation along with visible light?

Hi, I am not a native English Speaker, so some words might not be appropriately used below, but I will try my best to explain what I was thinking about. In general, I have never learned how acoustic waves emerge microscopically. The application of the theoretical knowledge I acquired was always...

Hi there! I wonder where the resolution limit for a microscope comes out. I know that the lens can act as a circular aperture of diameter D and so a point source is diffracted in a disk of angular aperture 1.22\lambda/D Two sources are resolved if their distance is greater than (without Abbe...

I wondering what actually happens when you brew coffee (or tea) with hot water. Every source I can find simply talks about how long you need to brew it to "draw out" the flavor or "release" the caffeine. I'm interested in what's actually physically happening to the coffee grounds that makes it...

Hi, dear forum members! It is well known, that if one makes the current carrying wire more thicker, for example 3 times, that means the current goes up also 3 times. Microscopically that seems plausible, because, when we consider that a cross section is made of atoms, then it is apparent, that...

Will we ever be able to describe the microscopic world , without using the notion of probability? What are the boundaries and restrictions that require probability? As technology , new particles, discoveries, dark matter etc materialize will we eventually be able to measure these...

Hi all, I am wondering in the 3D optical transfer function as shown below: http://www.purplebark.net/mra/research/votf/otf-sliced-volume.png The m and n axes represent support of lateral spatial frequencies and the s axes axial. If we were talking about a microscope then it has what's called...

Hi all, this is a follow-up variant to an earlier post https://www.physicsforums.com/showthread.php?p=3804580#post3804580 In that post, I wanted to know what an Earth observer would see for a ship some distance off accelerating towards Earth and then reaching constant velocity. For the...

I am currently a freshman at Penn State University. I have always been greatly interested in astronomy, space, and the universe. Especially cosmology and the "larger pictures" of our existence. I have decided that this is what I want to do with my life...study the universe, help discover new...