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# Laserglow quiz

#### bloompyle

##### 2
Do some research. They're pretty easy to figure out. Especially the second one.
Here's a clue. 3.26163626.
Hmm...somehow I was off by .0135 I need to check my calculations...

#### Tech_Junkie

##### Banned
Where is PullBangDead when you need him.

#### kevinmassey

##### New member
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.

#### bloompyle

##### 2
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.

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#### kevinmassey

##### New member
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.

#### Illuminum3415

##### New member
I got 3.2481 for part 2 Here's what I did:
I got the amount 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.
Part 1 was pure research, Ruby lasers produce a deep red wavelength, the answers posted on wiki.

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 don’t 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 =/

#### bloompyle

##### 2
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...

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#### bloompyle

##### 2
Part 1 was pure research, Ruby lasers produce a deep red wavelength, the answers posted on wiki.

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 don’t 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 =/

It's 15.3297, you were right =]

#### Illuminum3415

##### New member
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

#### manamana

##### New member
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?

#### bloompyle

##### 2
I was going to get a gold with this discount, but I'm not sure....that shipping kills it...

#### Grix

##### New member
The first one is 694,3 nm

#### Justin

##### New member
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.

#### MickyP

##### New member
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?

#### DJNY

##### New member
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?)
Why should it be easy? Man you get a 25% discount on ALL lasers!!! :gun:
That´s a \$3900 discount on the Herc-800!