How To See A Virus!

stated clearly presents the invention that let us see viruses and beyond all throughout history diseases have been mysterious and terrifying unable to see the bacteria and viruses that cause many of our illnesses we created myths to explain our suffering some believed that diseases were caused by demons witches or work curses sent down to punish humankind with the invention of the first microscopes the fog of confusion began to clear a microscope as any tool that allows us to see details and objects that would otherwise be too small to see with our eyes alone it's hard to say who invented the first microscope because people have probably been playing around with magnifying lenses ever since clear glass was invented but it could be argued that the first person to really promote the use of microscopes as serious tools of science was artist and researcher Robert Hooke in 1665 he published a book called micrographia it was filled with beautiful drawings he made while gazing through his microscope in the book he reported apparently for the first time that razor blades aren't really that sharp if you look at him close-up that insects have strange compound eyes and that plants appeared to be made of tiny structures that he called cells several years later a fabric merchant named Antony van Leeuwenhoek started designing his own microscopes so he could better examine the quality of fabrics he was buying curiosity led him to examine many subjects aside from fabric and he eventually discovered microorganisms he reported seeing tiny creatures that scientists of his time did not know existed he found them living in pond water they lived in fear they lived in his own saliva and a number of his other bodily secretions he called these critters animal cules it's a lovely mashup of the word animal and molecule instead of being grossed out by what he found or embarrassed by the fact that he spent so much alone time with his own bodily fluids Antony van Levon was proud of what he found he wrote about his discoveries in scientific letters to the Royal Society England's most prestigious scientific organization they published his letters and these went on to change our understanding of disease forever all of the microscopes described so far and most of the microscopes you find in a high school or college classroom are what we call light microscopes or optical microscopes this is because their lenses Bend normal visible light in order to function though they can be used to see cells and many microorganisms including bacteria they are not powerful enough to see most viruses to understand how they work and why they have limitations we first need to know a bit about vision in general anything we would call a light source the Sun a light bulb a candle is constantly emitting photons tiny packets of light it's often helpful though it's not technically accurate to think of a photon as a little squishy ball that travels at the speed of light in a straight line when it hits something depending on what it hits it can either bounce off pass through or be absorbed a burning candle spits out billions of photons per second in all directions which then bounce off objects until the photons are absorbed lining the back of the inside of your eyeball as a photon detection screen made of cells your retina when photons bounce off an object happen to go directly through your pupil and strike your retina they are absorbed and a message is sent to your brain saying light of this color hit the retina here your brain is constantly piecing thousands of these signals together to form a moving picture in your mind here's the important takeaway from all of this site works because lots of little projectiles are bounced off of objects in the environment and then absorbed into a detection screen if you want to build a seeing machine you can use just about anything as your projectiles you could even use gummy bears instead of photons if you wanted to so long as lots of projectiles can be bounced off the object you want to see and so long as your projectiles can leave a mark on some kind of detection screen there is more to building a good seeing machine as you may have noticed this one can only show the rough outline of a flat object and in real life it wouldn't even do that nearly as well as it does in this cartoon but one thing worth understanding now is that if you want a clear picture each of your projectiles should be smaller than the object that you want to see sadly the wavelength of a photon of visible light is far larger than many things that scientists want to look at photons are far larger than atoms larger than most proteins and even larger than most viruses to overcome this problem in the 1930s Ernst Ruska and max null created the world's first functioning electron microscope these microscopes shoot electrons at their subjects instead of photons electrons are up to 100,000 times smaller in wavelength than photons of visible light here we see an electron microscope image of pollen grains these actually could be seen with a light microscope as well but not in nearly this creative detail smaller still here we see HIV the virus that causes AIDS here we see the Ebola virus and here we see the new guy in town thanks to the invention of the electron microscope humankind has been brought face-to-face with viruses our ancient invisible foe as wonderful as this advancement was scientists continued pushing further still in the 1980s an entirely new way of seeing was invented when researchers at IBM produced the first scanning probe microscope there are now many types of scanning probe microscopes but they all work in essentially the same way they see by feeling the bumps and valleys along the surface of an object with a tiny metal probe much like a man who is blind reads Braille with his fingertips data collected from the probe as it scans is used to generate an extremely high-resolution image here we see not cells not viruses but individual atoms the elements of matter itself in 2009 with funding from the National Science Foundation physical chemist ara up carryin along with his colleagues founded the castle Research Center chemistry at the space-time limit he chose team members from among the world's greatest microscope innovators including dr. Kumar Wickramasinghe who engineered microscopes for IBM dr. Nia know a guy who specializes in imaging biological molecules and dr. Wilson Howe known for having built several of his own scanning probe microscopes from scratch the purpose of the Castle Research Center is to push the limits of what we can see through a microscope to do this they have combined the use of visible light with scanning probe microscopes now as I'm sure you recall photons of light are far too large to see individual atoms and molecules but Castle researchers found that if photons are aimed at a properly built probe a silver needle shaped in just the right way the probe will guide photons to its apex and compress them two dimensions much smaller than their usual size at the apex near the sample photon quanta are absorbed and re-emitted this allows even individual atoms to be seen in other words castle researchers found a way to shrink light the various machines they built all work slightly differently and have a variety of jargon rich names but in general they are referred to as chemists scopes they let us record not just the shapes of molecules but also the motions of atoms inside them they let us measure the molecular motions that power chemical reactions in the field of quantum physics chemistry record a molecules quantum behavior in the field of biology chemistry read an organism's DNA once perfected this will be far better than the tedious error-prone methods of DNA sequencing that scientists use today last but not least in the field of medicine chemists cups are now allowing us to see viruses so clearly that not only can we tell different species apart we can tell different strains of the same species apart this allows us to watch how viruses evolve over time and figure out just when new vaccines might need to be produced from simple lenses allowing us to see that insects have compound eyes to the light shrinking chemische cope allowing us to see virus evolution microscopes have come a long way each step clearing the fog of our confusion I am John Perry and that is a brief history of the microscope stated clearly mission is part of a series sponsored in part by the National Science Foundation and the castle Research Center that's chemistry at the space-time limit along with this video series castle and the National Science Foundation have funded the creation of an amazing online video game called bond breaker in the game you are a proton and you go on a bunch of little adventures learning powerful concepts in chemistry and nuclear physics as you go I've shown you clips of the game before but a new version was just released and it is wonderful go check it out at test-tube games.com there is a link down in the video description teachers use this in your classrooms it's free [Music] you

Channel: Stated Clearly

Views: 31,956

Rating: 4.8978524 out of 5

Keywords: Microscope, history of science, virus, electron microscope, scanning tunneling microscope, Robert Hooke, antonie van leeuwenhoek, animalcules

Id: bjcewKLlb2Y

Length: 10min 22sec (622 seconds)

Published: Tue May 12 2020