How do laser pointers work?
Chris's answer may address the physics [I didn't read it all]. I only use gas (HeNe) lasers for my laser graphic light shows. I assume the physics is basicaly the same as gas lasers. A laser diods emits a very pure wavelength. It is not as pure as a gas laser, but the light has a very narrow range of wavelengths/frequencies (bandwidth)It comes out in a fairly wide and oval shaped cone, not the final narrow beam you see.A special lens is used to focus it into a narrow beam. The doide is placed at the lens's focal point. This is complex. The oval shape requiers a highly astigmatic lens. This is because the spread of the beam (divergance) is different for the horizontal and vertical axis.This also means the focal point for one axis (vertical) is different than the other axix (horizontal). The location of the aparent point sources in the diode is different for each axis, so the lens design is complex.The final output is still a slightly oval point of light. Gas lasers have a round spot, so are a little better for drawing lines.Here is an article with more detail. Please note the Theta-1 and Theta-2 for the two axes:[PDF] DTS0043 - Laser Diode Collimators - OZ Opticshttp://www.ozoptics.com/ALLNEW_P... -- Regards, SteveP.S Google is your Friend. I Googled: "laser diode focal length". That link was the third hit.
Can I make a object/text move away from my cursor in PowerPoint?
Yes! Well, kind of. You wouldn't be able to set up the button, etc to run away from your mouse, but what you can do is set up motion paths ahead of time that will cause the button to move. Since you would know where the button is going to move you could just move your mouse a little slower than the button to give the illusion that you are trying to catch the button, when in reality the button has been pre-programmed to move around the slide. To set this up, select whatever it you want to "run away" from your mouse. Select Motion Paths from the custom animation pane and set up the paths to move however you would like. To provide the running away illusion, you may want to select the animation from the animation pane and select Timing from the drop-down menu and then change the duration of the effect to Fast or Very Fast.
How can you insert the square root symbol in Microsoft Word?
In MS Word 20161. Click on Insert from the top menu2. Go to Equation, it is in the Symbols section, at the end3. Click on the Equation button, not the arrow on the right side next to the equation button. 4. A new menu will appear, click on the Radical function, it’s the third from left to right5. Choose square root function, it is the first function 6. A window will appear on the document to enter the equation 7. Move the cursor in the square inside the square root symbol, it will become grey8. Enter the number you require
How to save files from a frozen computer?
There's a file on my computer I've been working on for well over an hour. Without saving (stupid me) I left for a few minutes and when I came back my computer was frozen. The mouse moves and any devices plugged in (that is, my tablet) work, but nothing will respond. Any time I hover over a program (including the entire task bar) the loading sign comes up. The 'thinking' light isn't on and it's really, really frustrating me... Is there some way to open up my program long enough to save my file or is it doomed? I've tried ctrl+alt+del, the windows key, unplugging and replugging various devices, removing/reinserting discs, and random button smashing. Please please please tell me there's something else I can do... (All these things seem to work...the computer just doesn't do anything but identify the new device and go back to being frozen)
What are some lesser known Gmail tips?
Just found out about this little nifty gmail feature found on google Gmail that will be useful to many Quora members:Quote:Using your Gmail address that can give you greater control over your inbox and save you some time and headache. When you choose a Gmail address, you actually get more than just "yourusername@gmail.com." Here are two different ways you can modify your Gmail address and still get your mail:Append a plus ("+") sign and any combination of words or numbers after your email address. For example, if your name was hikingfan@gmail.com, you could send mail to hikingfan+friends@gmail.com or hikingfan+mailinglists@gmail.com.Insert one or several dots (".") anywhere in your email address. Gmail doesn't recognize periods as characters in addresses -- we just ignore them. For example, you could tell people your address was hikingfan@gmail.com, hiking.fan@gmail.com or hi.kin.g.fan@gmail.com. (We understand that there has been some confusion about this in the past, but to settle it once and for all, you can indeed receive mail at all the variations with dots.)For me, the real value in being able to manipulate your email address is that it makes it really easy to filter on those variants. For example you could use hikingfan+bank@gmail.com when you sign up for online banking and then set up a filterto automatically star, archive or label emails addressed to hikingfan+bank.You can also use this when you register for a service and think they might share your information. For example, I added "+donation" when I gave money to a political organization once, and now when I see emails from other groups to that address, I know how they got it. Solution: filtered to auto-delete.—————————————————————————————————————More nifty online business ideas plus some of the best online money making businesses that work, check out my profileNigel Clarkson