is it true that someone can blind their eye by pointing their telescope to the sun and looking at it?
402817
Not a myth...........................................
756102
Yes, almost all serious research telescopes are controlled this way.  There are a handful of amateur telescopes which are internet controllable. \n\nbut most require a user name and password, and are for authorized  users only.  The ones that don't are usually very very busy. \n\nYou can see an example of one at \n\nhttp://observatory.space.edu/f4_facilities/f3_internet%20telescope/index.php\n\nand a description of the technology at \n\nhttp://www.atnf.csiro.au/pasa/17_2/mckinnon/
1069808
I'm not an optometrist ... but I'll take a stab at answering the question ... I think by squinting, you are narrowing your field of vision and therefore sharpening your view.  In a sense, it's targeted vision.
349429
Not a sin, but you could go blind....I'd say you should just do it until you need glasses.
592187
Yes. I can tell things about a person just by looking in thier eyes. sometimes i dont see a spark of light and i try to stay away from that person.;
654622
This has been done. As pine stripe notes it depends on when they were blinded. People blinded after about 5 years of age have no problems. People blinded before that have difficulty re-adjusting.\n\nPeople blind from birth are really quite interesting when their site is restored. They never have any ability to judge perspective. They can recognise small cubes up close for example, but they see cubic buildings and truncated pyramids. That's because a building looks like it gets smaller at the top due to perspective. A person blind from birth can never learn to recognise that that is just an illusion. they literally see the building with a small top and large base. They also see railway tracts as converging lines and are fooled by similar tricks of perspective that sighted people automatically adjust for.\n\nWeird stuff.
361226
You are so alone. I used to stare at the sun and be happy. (With my first grade education-- I thought the sun was my friend.) Then, my mom told me I would blind myself and I grew up to realize that I don't like looking at the sun, and I don't get angry. . . Or look back. You are completely alone.
28393
I do believe so. My mom had it. Her doctor advised her to close her good eye with one hand, and 'exercise' the lazy eye by focusing on objects.
904381
I'd say Galileo was a victim of the ignorant Catholic church, not a victim of his own research...although he did harm his eyes by looking at the sun through his telescope without any kind of filter :)\n\nNewton did experiments in optics on his own eyes, sometimes by sticking needles into them.  He had cataracts and other eye problems later on, almost certainly caused by his experiments.  He also went a bit mad later in life, and samples of his hair taken a few years ago showed high levels of lead in his system -- a result of his alchemical experiments.  It almost certainly hastened his death.\n\nJoseph Priestly, who "discovered" oxygen, used to put on a mask to breath the "vapors" of various gases, some of which were highly toxic...he passed out numerous times and nearly killed himself quite a few times.\n\nThere are a lot more -- do a web search and you'll find a bunch.
167324
Yes, it is possible to see a galaxy in a telescope.\n\nDepending on the strength of the telescope, the galaxy will appear very VERY faint and look like a star itself.\nYou probably will not be able to see any with an ordinary telescope in your back yard, or if you do, it will just look like a faint star.
209338
Space telescopes are not prone neither to difraction due to the atmosphere; besides, the air flow in the atmosphere introduces distorsion in the light path. \nThese two things (distortion and loss of light power) limit the effective seeing capability of a telescope.\nOne solution has been space telescopes, just like the Hubble. But another solution has been to construct "virtual" large diameter telescopes: they set an array of smaller telescopes which are far apart from each other (the array spans a few kilometers). Then, first, the total amount of light collected is equal to the sum of the light collected in each telescope. The distortion gets "compensated" among the several telescopes.\nAs far as I know, one such telescope, already operational, is being constructed in Chile. The location was selected for being the dryest on earth.
598668
I've seen somebody got about 400 ºC using little pieces of mirrors over a parabolic structure. Sun light was concentrated in one point
532562
Galileo did something that you should never do.  He looked at the sun through a telescope, which later caused him to go blind.  But over a period of time he observed the sun and he saw sunspots.  If you took a ping pong ball and spun it through the air then it might be hard to tell that it was spinning.  But if you put a spot on the same ping pong ball and then spun it through the air then you would even be able to tell how fast it was spinning. It was the same for Galileo.  He was able to measure how long it took the sun to rotate (about 25 days near the equator).
370278
I too have wondered why blind people wear sun glasses?
828846
It is safer to look at the sun during total eclipse than directly at it. The trouble is you look at it longer and there is where the trouble is.  It is NEVER safe to look at the sun anytime, except indirectly.
1134341
The answer would depend upon the observer's height, or more accurately, the height of the observer's eyes from sea level.  For simplicity's sake, let's use the numbers 1.5m for eye height, 6,375,000m for the radius of Earth, and of course, assume that the planet is a perfect sphere, our observer has perfect eyesight, etc.\n\nThe line of the observer's vision when it meets the horizon forms a tangent to the surface of Earth.  If you draw a line from this point to the center of the planet, and another line from the observer to the center, you form a right triangle.  One leg is 6,375,000m and the hypotenuse is 6,375,001.5m.  So the other leg can easily be computed using the Pythagorean Theorem:\n\nd = sqrt[ (6,375,0001.5)^2 - (6,375,000)^2 ] = 4373.21\n\nSo to our observer, the horizon is about 4.37km away.\n\nNote that this is the limit of vision for objects with zero height, e.g. something painted on the ground (assuming again our observer has perfect eyesight).  S/he can see objects even further away if they do have height.  For example, two observers with identical height will be able to see one another at twice the distance, though it will only be one another's foreheads poking a tiny bit above the horizon.\n\nLarge objects such as buildings, or ships sailing in, may be seen at a much greater distance, and this distance is also made much greater if the observer moves to higher ground.  For example, even going to the top of a small, 10m building (only a single storey) will extend the horizon to 12.1km, and standing atop a 50m cliff extends it to 25.6km.
983826
Yes. The blind man has extra ordinary powers in order to compensate him the blindness. This is a miracle of God as he is deprived by eyes but he has been given extra powers of touch and doing work with hands. YOU must have seen that blilndmen are also much educated and they learn and memorize lessons more perfectly than the person with eyesights. This is a miracle of God.