The Planck Radiation Law gives the intensity of radiation as a function of wavelength for a fixed temperature.  The Planck law gives a continuous distribution, which peaks at some wavelength.  The peak shifts to shorter wavelengths for higher temperatures, and the area under the curve grows rapidly with increasing temperature.  The diagram below shows the intensity distribution predicted by the Plank law in J/(m2s) for blackbodies at various temperature.  By observing the continuous distribution of the thermal radiation emitted by an object, we can learn its temperature.

PolarizedopticalMicroscopy

Please explore this simple simulations of various molecules interacting with electromagnetic radiation of different wavelength. https://phet.colorado.edu/en/simulations/molecules-and-light Can you identify certain characteristics?

Keyence VHX-6000 Digital MicroscopeZeiss Axioplan Compound Microscope (interfaced with a Keyence VHX-950F)Zeiss Discovery V8 Stereomicroscope (interfaced with a Keyence VHX-950F)WILD M3Z Stereomicroscope (interfaced with Northern Eclipse Software v.8.0 and Camera)

How to uselight microscope

Examining samples by optical microscopy aids us in determining which technique will be the most suitable if further analysis is required.

Optical microscopy, with a history that spans five centuries, is too often overlooked as a fundamental tool by surface analysts. Modern optical microscopes are capable of capturing contrast detail from most surfaces. Lens design has allowed sufficient image brightness that detail can be readily resolved near the optical limit of resolution (0.25µm). Use of a range of on- and off-axis incident light beams greatly extends the possibility of topographic contrast.

Electronmicroscope

Distances in space are often quoted in units of light years, the distance light travels in one year. (a)  How many meters is a light year? (b)  How many meters is it to Andromeda, the nearest large galaxy, given that it is 2.54*106 light years away? (c)  The most distant galaxy yet discovered is 12*109 light years away.  How far is this in meters?

Light microscope

Electromagnetic waves are categorized according to their frequency f or, equivalently, according to their wavelength λ = c/f.  Visible light has a wavelength range from ~400 nm to ~700 nm.  Violet light has a wavelength of ~400 nm, and a frequency of ~7.5*1014 Hz.  Red light has a wavelength of ~700 nm, and a frequency of ~4.3*1014 Hz.

Optical microscopemagnification

Visible light makes up just a small part of the full electromagnetic spectrum.  Electromagnetic waves with shorter wavelengths and higher frequencies include ultraviolet light, X-rays, and gamma rays.  Electromagnetic waves with longer wavelengths and lower frequencies include infrared light, microwaves, and radio and television waves.

Introduction toopticalmicroscopy

What is amicroscope

The velocities of particles with thermal energy are changing almost all the time.  The particles are accelerating.  Accelerating charged particles produce electromagnetic radiation.  The power radiated is proportional to the square of the acceleration.  Higher rates of velocity change result in higher frequency (shorter wavelength) radiation.  The observed intensity of thermal radiation emitted by as a function of wavelength can be described by the Planck Radiation Law (Physics 221).

When light with a continuous distribution of wavelengths passes through a low-density material, the atoms and molecules of the material absorb light waves with the same set of characteristic frequencies that appear in their emission spectrum.  This produces an absorption spectrum, a nearly continuous spectrum with missing lines.  The absorption spectrum can also be used to identify those atoms and molecules and their environment.

Our four optical microscopes, capable of magnifications ranging from 6.5 X to 2000 X, are interfaced to high-resolution colour digital cameras that allow capture of digital images. Our Keyence VHX-6000 digital microscope offers the latest in image stacking, which gives a fully focussed image across a large depth of field, image stitching and a full package of image analysis and metrology options. Our Zeiss microscopes are interfaced with a Keyence VHX-950F which allows for a similar suite of image capture and analysis options. Further high magnification imaging solutions and metrology options are also available using our confocal laser scanning microscope.

When light passes through or reflects or scatters of matter, it interacts with the atoms and molecules.  Atoms and molecules have characteristic resonance frequencies.  The preferentially interact with light waves of exactly those frequencies.   When excited in collisions, atoms and molecules emit light with a set of characteristic frequencies.  This results in a line spectrum.  Only light with a discrete set of wavelengths is produced and the spectrum is not continuous, but consist of a set of emission lines.  That set characterizes the atoms and molecules which produced it and can be used to identify those atoms and molecules and their environment.

Two microwave frequencies are authorized for use in microwave ovens, 900 and 2560 MHz.  Calculate the wavelength of each.