FAQ  Donate 
Members List  
Calendar  
Search  
Today's Posts 
LPF Laser Pointer Company Database 

LPF Database of Laser Pointer Companies 
 LinkBack  Thread Tools  Display Modes 
05152010, 05:06 AM  #17  
 
Gas Guru Join Date: Apr 2010 Location: Nebraska, US
Posts: 4,171
Rep Power: 534  Hmm...somehow I was off by .0135 I need to check my calculations...
 
05152010, 06:02 AM  #18  
 
Banned Join Date: Jan 2009 Location: In A State of Shock.
Posts: 11,884
Rep Power: 0 
Where is PullBangDead when you need him. Just post the answer. Whats wrong with helping your fellow LPFer?  
05152010, 03:57 PM  #19  
 
Class 3R Laser  DON'T READ THIS POST IF YOU WANT TO FIGURE IT OUT YOURSELF. I think the second one is 15.3297, assuming that google is correct. According to google one parsec is equal to 3.26163626 light years, and since it's been almost exactly 50 years all you have to do is divide 50 by 3.26163626 BUT I have gotten three differect values in different parsec to light year converters, so I did the math for myself and I got 3.261563678 light years in a parsec. Now using that value I get 15.33007, or 15.3301. I think that is the right answer.  
05152010, 04:09 PM  #20  
 
Gas Guru Join Date: Apr 2010 Location: Nebraska, US
Posts: 4,171
Rep Power: 534 
I got 3.2481 for part 2 Here's what I did: I got the ammount of kilometers in a light year, then multiply that by 50, then I multiplied THAT by 1000 (to get how many METERS) then divided that by some number (amount of meters in a parsec, can't remember the number) then I got 3.2481. For Part 1: 555nm it's a laser invented by Theodore Harold Maiman, in 1960 using a FAKE ruby (that's all I KNEW, I just didn't know the wavelength), but the only info I got on it was ~555nM, so I couldn't get a decimal place, but, if we're going by significant figures here, then it would REALLY be 555.0, which is to one decimal place, but that's my assumption. Last edited by bloompyle; 05152010 at 04:12 PM.  
05152010, 04:26 PM  #21  
 
Class 3R Laser 
It really just depends on what method laserglow used. I calculated a parsec to be 3.085677488 x 10^16 meters. then the number of meters in a light year to be9460730472580800.
 
05152010, 11:22 PM  #22  
 
Class 1M Laser Join Date: Feb 2009
Posts: 193
Rep Power: 16  Quote:
A website listed 1 Parsec = 3.26163626 light years, so work backwards, if significant figures did come in to play the final answer would in fact look something like 1.0000, thankfully sig figs weren't mentioned, divide 50 into a parsec should give you 15.32972901 parsecs. Since the information came from an unknown origin, I calculated it by hand for trial II. 15.3297 will work on laserglows website, but now I dont really care about the discount now, but rather as what range does the correct answers fall in. By convention 1 Parsec = 30.857 x 10^15 Meters, 1 Light Year = 9.461 x 10^15 Meters, so 1 Parsec at 0.001 precision its 3.261494557 light years, significant digits will kill it to about 3.261 light years, but nevermind this number. 50 divided by 3.261494557 yields 15.33036505 Parsecs, or for all practical purposes I can say it only missed its mark by 0.001 parsecs, but laserglow will not accept it =/  
05152010, 11:34 PM  #23  
 
Gas Guru Join Date: Apr 2010 Location: Nebraska, US
Posts: 4,171
Rep Power: 534 
I went with getting how far light travel in a year (# of kilometers) then multiplied that by 50 for 50 years, then THAT by 1000 to get meters, then divided that by number of meters in a parsec to get 3.2481...try it. EDIT: didn't work... Last edited by bloompyle; 05152010 at 11:38 PM.  
05152010, 11:43 PM  #24  
 
Gas Guru Join Date: Apr 2010 Location: Nebraska, US
Posts: 4,171
Rep Power: 534  Quote:
It's 15.3297, you were right =]  
05172010, 02:23 AM  #25  
 
Class 1M Laser Join Date: Feb 2009
Posts: 193
Rep Power: 16 
well then, have at it gentlemen I sold my Galileo awhiles back... now I miss it, perfect opportunity to put down for a new one  
05172010, 02:45 AM  #26  
 
Junior Member Join Date: May 2010
Posts: 9
Rep Power: 0 
I just went to google and searched "50 light years in parsecs" nice deal, but the CNI group buy seems to be a bit better, no? Too bad they don't stack  
05172010, 03:03 AM  #27  
 
Gas Guru Join Date: Apr 2010 Location: Nebraska, US
Posts: 4,171
Rep Power: 534 
I was going to get a gold with this discount, but I'm not sure....that shipping kills it...
 
05172010, 08:45 AM  #28  
 
Class 3R Laser Join Date: Dec 2008 Location: Norway
Posts: 2,128
Rep Power: 249 
The first one is 694,3 nm
__________________ For sale at BitLasers.com (We accept BITCOIN+PAYPAL and ship WORLDWIDE!): Use coupon LPF10 for additional 10% off! 1300mW Blue 445nm laser: $119 4500mW Light Blue 465nm laser: $329 800mW Forest Green 520nm Laser: $299 750mW RedOrange 635nm Laser: $109 and more.. LasershowGen: Free laser show editor: http://pages.bitlasers.com/lasershowgen/ 2nd place in ILDA Fenning Awards 2015 Helios  Open source, low cost DAC: http://pages.bitlasers.com/helios/  
05172010, 01:53 PM  #29  
 
Class 2 Laser Join Date: Feb 2007
Posts: 496
Rep Power: 59 
Hey guys, thanks for all your efforts. We thought this would be a fun little quiz and it turns out that a lot of people had a good time with this one. And yes, in fact the second question was very easy once you realized that it's been exactly 50 years therefore light would have traveled 50 light years. Working it out with brute force is possible (speed of light in m/s times number of seconds since May 16 1960 or something like this) but a lot more trouble than you really needed to go through. Now, we did need to settle on one particular value for converting light years to parsecs so if you think that you have an answer which is mathematically valid but not accepted by the website please email me and I may still give you the discount if your answer is accurate.
__________________ Justin Hosaki Vice President of Sales and Operations Laserglow Technologies www.laserglow.com jhosaki@laserglow.com 416.729.7976  
05212010, 03:08 PM  #30  
 
Junior Member Join Date: Jan 2010 Location: Australia
Posts: 26
Rep Power: 0 
Sorry, I didnt think the second question was easy at all. I found it a shocker. Its actually pretty difficult and nasty question if you wanted to get an accurate answer (4 decimal places?) We know the speed of light in a vacuum, and we also know the speed of light at sea level atmospheric pressure (slower by approx 30000km/s or so), and I sorta immediately thought you would have to plot the increasing speed as the laser exists the atmosphere against time, regress the plot to a mathematical function against time, and then calculate the total time it takes the laser to exit the atmosphere (presuming the atmosphere is effectively space/gone at 40000m altitude). And THEN use the linear function of the velocity of light in a vacuum against time for the remaining years, which would have been the time it took the laser to exit the atmosphere subtracted from 50 years. Where I was utterly and completely stuck was the pressures/air density (thus speed) at different altitudes. Anyone know the typical pressure/air density at 10000m, 20000m, 30000m? Because I certainly dont. Of course, if you want to treat the question under the assumption that that the speed of the laser is constant throughout its trip (presume speed as it is known in a vacuum) than it does become much much simpler. I take it that Laserglow was happy with the answer in the form of the latter? That is, just presume a constant (vacuum) speed of the laser for 50 years?  
05212010, 03:49 PM  #31  
 
Class 4 Laser Join Date: Nov 2009 Location: Austria
Posts: 5,998
Rep Power: 479  Quote:
Thatīs a $3900 discount on the Herc800!
__________________ 405nm >> Wickedlasers SONAR by lazeerer peak@968mW 445nm >> Kryton Smooth by lazeerer peak@2075mW 453nm >> Lipstick by rhd peak@158mW 473nm >> Optotronics RPLB peak@112mW 515nm >> Skylasers HL peak@41mW 532nm >> Novalasers Alpha HP peak@284mW 589nm >> CNI PGLIIIA peak@89mW 594nm >> Laserglow Rigel peak@4mW 635nm >> MXDL by DTR peak@38mW 642nm >> Saillaser peak@23mW 660nm >> CR2 by lazeerer peak@524mW 685nm >> MXDL by lazereer peak@42mW Above lasers measured with an Ophir nospin LPM          Interested? >> Click onto the laser titles for more information          Note that Imageshack is automatically resizing some of my older pictures back to original fullsize after a while.  
Thread Tools  
Display Modes  
 