Home

Light sources  

  RSS

mendel
(@mendel)
Active Member
Joined: 8 months ago
Posts: 10
16/01/2019 12:34 pm  

The laser power is given as 10,000mW and 30,000mw respectively in the equipment sheet. I assume this means 10 mW and 30 mW? These are Class 3b lasers, and care must be taken to never turn the laser on when people could look into directly into the beam or a direct reflection (a diffuse reflection should be ok). I would really like to know their aperture angle so I can compute which kind of brightness to expect over 16 km distance.

I doubt the tactical spotlight will be seen in daylight, as its intensity over 16.3 km is 0.003% of its intensity from 100m distance.

I suggest taking a large mirror to Brighton, the setting sun should provide a strong light source that can be reflected towards Worthing. To reflect the sun from Worthing towards Brighton, two large mirrrors are required. (I suggest using hiking compasses to determine the approximate direction.)

Nautical twilight starts at 6:08pm, so I expect that the darkness may facilitate observations at this point; unfortunately, the brightest sky is going to be behind Worthing at this time. Also unfortunately, the tide is going to be coming back, with half tide expected at 7pm. It's clearly not the best date for night observations.

Some people can tell time by the sun, but I could never make out the numbers.


Quote
Dr John D
(@dr-john-d)
Member Moderator
Joined: 8 months ago
Posts: 7
17/01/2019 12:10 am  

Evening Mendel

Are you coming to the experiment?

As long as it isn't foggy, all should be good

Dr John


ReplyQuote
mendel
(@mendel)
Active Member
Joined: 8 months ago
Posts: 10
17/01/2019 9:05 am  

To tell you the truth, I am still undecided; since it requires crossing the channel, it's going to be a major undertaking for me. It would be fun, though.

 

As a side note, I had hoped for more of the 9 topics listed in the forum statistics to have left the moderation queue by now; and I was trying to log in on my other device and was unable to find a link for that.

Some people can tell time by the sun, but I could never make out the numbers.


ReplyQuote
Share:
  
Working

Please Login or Register