2. Mutual dependence: Science & Technology
Technology…the pragmatist
Does it work?
Is it useful?
Is it sustainable?
Science…the idealist
What is it?
How does it work?
What does it tell us?
Regents Biology
3. Mutual dependence: Science & Technology
Microscopes
Electron microscopes
Higher resolution
Dead samples
Expensive
Optical (light) microscopes
Lower resolution
Live samples
Less expensive
Regents Biology
4. Micrographs
Scanning electron micrograph (SEM) of
various Pollen. Public domain image
reference: Dartmouth Electron Microscope
Facility, Dartmouth College
Regents Biology
5. Size matters
Regents Biology
micron = micrometer = 1/1,000,000 meter
diameter of human hair = ~20 microns
Miss N, Show them
the interactive!!
50. Magnification
Magnification = ocular lens x objective lens
A microscope has an eyepiece lens with a power
of 20X. The objective lens being used has a
power of 10X. What is the total magnification?
Regents Biology
51. Using Scale Bars
Using a scale bar:
The image at right is of a virus-like
particle. The bar represents 50nm.
It is observed under x200.
Calculate the actual size of the
image.
Regents Biology
50nm
52. Using a scale bar:
Image is 50nm in diameter
Regents Biology
50nm
Using Scale Bars
53. A specimen is 1cm in
diameter under a power of
x600. What is the actual size
of the specimen?
Regents Biology
54. Magnification: I AM
Regents Biology
Image size
Actual size Magnification
Watch yo units!!
Measure with ruler
Need to figure this out
Given to us
55. 1. Measure the size of the image.
…..1cm (10mm)
2. Find the actual size of the sample
I/AM
I=10mm
M=600
A=?
A=10mm/600 = 0.0167mm
=16.67 μm
Regents Biology
Technology and science are often used interchangably, but this requires some clarification.
Technology emerged before science. Materials were used to produce and used long before there was an understanding that different materials had different properties that could be used for different purposes.
Modern science often is the opposite. Scientific understanding is often the basis for technological development. These developments in technology in turn drive developments in science.
So technology applies the question: “does it work?” to its pursuit. Science is less bothered by the knowledge for the sake of knowledge
Desprite their mutual dependence, they are based on different values.
Science: evidence, rationality and the quest for deeper understanding
Tech: practical, appropriare and useful and an increasing emphasis on sustainability
Technology and science are often used interchangably, but this requires some clarification.
Technology emerged before science. Materials were used to produce and used long before there was an understanding that different materials had different properties that could be used for different purposes.
Modern science often is the opposite. Scientific understanding is often the basis for technological development. These developments in technology in turn drive developments in science.
Both electron and light microscopes are technical devices which are used for visualizing structures that are too small to see with the unaided eye, and both types have relevant areas of applications in biology and the materials sciences. And this is pretty much it. The method of visualizing the structures is very different. Electron Microscopes use electrons and not photons (light rays) for visualization. The first electron microscope was constructed in 1931, compared to optical microscopes they are a very recent invention.
