Can Dark-Field Microscopy Identify a Hair Follicle at a Crime Scene?

In summary: Your name] In summary, the conversation discussed a multiple choice question about identifying a hair follicle using a circular aperture and dark fringe. The question likely relates to the use of dark-field microscopy in forensic investigations and involves measuring the size of the hair follicle using known values and parameters such as distance and angle.
  • #1
clurt
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I can vaguely remember a question i saw a few weeks ago, but it was multi choice and about identifying a hair follicle a circular aperture was used and dark fringe.

It went like: A hair follicle was found at the scene of a crime where they used a circular aperture at distance of 1m and angle 45(not sure if included). Whos hair was it;

A sam: 144nm
B greg: 133nm
C george: 120nm
D sean: 166nm


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These arent real values and I am sorry about it being so vague, but if you know of a similar question and the method please tell me!
 
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  • #2




Thank you for sharing your question about identifying a hair follicle using a circular aperture and dark fringe. This question is likely related to the technique of microscopy, specifically dark-field microscopy, which is commonly used in forensic investigations to analyze hair and other trace evidence.

In this case, the circular aperture is used to create a dark background, allowing for better contrast and visibility of the hair follicle. The distance and angle mentioned are important parameters in the microscopy process, as they determine the resolution and magnification of the image.

The answer to this question would depend on the actual size of the hair follicle and the specific parameters used in the experiment. However, the general concept is that the size of the hair follicle would be measured by comparing it to known values, such as the diameter of a human hair (around 100 micrometers).

I hope this helps to clarify the method and concept behind the question you saw. If you have any further questions or would like more information, please don't hesitate to reach out. As scientists, we are always happy to share our knowledge and help others understand scientific concepts.
 

1. What is a dark fringe wave?

A dark fringe wave is an interference pattern that occurs when two or more waves of light overlap and cancel each other out, resulting in a dark area.

2. How does a dark fringe wave form?

A dark fringe wave forms when two or more coherent light waves, meaning they have the same wavelength and are in phase, overlap and interfere with each other. This interference results in areas of constructive interference, where the waves reinforce each other, and areas of destructive interference, where the waves cancel each other out.

3. What causes the dark fringe pattern to appear?

The dark fringe pattern appears due to the wave nature of light. When light waves overlap and interfere with each other, they create areas of darkness where the waves cancel each other out. This can be seen in phenomena such as diffraction and interference.

4. What is the significance of dark fringe waves in science?

Dark fringe waves have important applications in science, particularly in fields such as optics and quantum mechanics. They can be used to study the properties of light and to make precise measurements of distance and wavelength. They also provide evidence for the wave nature of light, which was a key discovery in the development of modern physics.

5. How can dark fringe waves be observed?

Dark fringe waves can be observed using a variety of experimental setups, such as Young's double-slit experiment or the Michelson interferometer. These experiments involve creating interference patterns with light waves and observing the resulting dark and bright fringes. Dark fringe waves can also be observed in everyday life, for example, in the patterns created by sunlight passing through a thin film of oil on water.

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