September 9, 2013
As you may know, a mirrored curve in a surface (concave) can focus light and magnify as well. Makeup type mirrors come in handy when you need to see yourself, biglike. There are formulas that can calculate the amount of magnification which is basically comparing the size of the object (your real face for example) to the size of the image (the magnified face). How does 10x look to you? Helpful when you can’t put on those reading glasses.
I have a Stirling Engine (supposed to be my son’s) that has a solar collector. It’s one of those bowl-shaped mirrors that concentrates sunlight which then makes the engine work if I get it aligned with the sun just right. But what if you are an architect and you design a tall curved building with mirrored windows? The result is some intense sunlight that has burned part of a Jaguar car parked in front of the building along with burning other things. When the sun is at the right location in front of that building the heat that is focused can reach the boiling temperature of water. Just having light reflect off a flat mirrored window into your face is bad enough but focusing the light to be hot enough to melt or burn plastic or boil water?
This makes me wonder about skyscrapers in general. What’s the purpose of building the highest? I know. We’re no different than those guys who wanted those huge pyramids but no one wants a pyramid anymore. It’s all about how much you can put in one place and call it useful. This London “fryscaper” as it’s been called is also known as the walkie talkie building because it also has that shape. If we really wanted to make the best use of the structure I think the architect might have been onto something but just didn’t do it the right way. Concentrated solar power (aka, CSP) could have been a secondary goal to generate heat for the building or run some generator for electricity. What really is a green building if it can’t use some of that sun instead of heating up the bricks on it or reflecting it on it’s neighbors?
This also made me wonder (I do that a lot) how much of the sun can we collect in a mirror and focus that light somewhere to be useful instead of frying the sidewalks and people. Apparently there’s a lot of real energy producing “plants” already doing this. We just need the architects and concentrated solar power engineers to meet up so they can put this all in one building.
August 24, 2013
Most of us have probably seen those beautiful pictures of galaxies and nebulas that seem to frequently show up on websites. Maybe I’m just noticing them more since I’m interested in them. And until I became interested in them I never thought much about how the pictures were taken. The hubble telescope, as well as other research telescopes, get those pictures from special instruments that can detect a wide range of wavelengths….sorta detecting like our eyes but the detectors on the telescopes can receive other wavelengths that we can’t see. You know the antenna on cars? Or in your cell phones? Or satellite dishes? They detect wavelengths we can’t see. The hubble telescope detects all kinds of signals (wavelengths) from ultraviolets to infrareds and beyond. Our bodies do detect ultraviolet and infrared but not our eyes so we do have some special detectors. Our skin can darken from ultraviolet rays and we can detect heat as an example of infrared. But we don’t see those, we only feel them or notice the results later.
Here’s an example of infrared detection here on earth. The colors you see in the picture are industry standard representations that show cool as blue colors and red as warm in these infrared detectors. I previously wrote a post about hot and cool colors which differ from how they are used below.
And here’s an example of an ultraviolet detector for the sun (glasses with photochromic coatings like Transition lenses also work by UV activating):
The hubble telescope detectors are quite a bit more advanced obviously. These telescopes don’t take pictures like our cameras. How then can we explain all the colors in the hubble pictures that we see if they aren’t colors that our eyes can’t detect? What the scientists get from many of these telescopes is a bunch of monochromatic (more than 50 shades of gray too) black and white boring pictures and data (boring to you and me). There’s a lot of artistic license that goes into making these pictures as beautiful as they are and makes them definitely more exciting to look at. That is the purpose too. Astronomers enhance the telescope data to visually represent different gases that are in the nebula or different energies that are detected in galaxies. How these colors are chosen is also somewhat artistic as well. Enhancing depth using contrasting shades helps the overall effect.
If you want to read a little more about how these colorful pictures are created I’ve got some links below! Oh, pictures of Mars more closely represent what we might actually see with our own eyes compared to those galaxy and nebula pictures.
and this one about early artistic methods: http://io9.com/
potentially hazardous near-Earth object 1998 KN3, (the bright green dot upper left)