MBS free laser show IN your bedroom!

Gary · Post by **Gary** » Tue Mar 22, 2011 5:31 pm

Check out the video here:

http://singaporeseen.stomp.com.sg/stomp ... droom.html

The comments also really LOL. Best so far I think is put mirror and reflect back at them.

Perhaps MBS will do a better job bringing awareness to light pollution and trespass issues than local amateur astronomy groups.

Post by **acc** » Tue Mar 22, 2011 9:58 pm

Those green lasers from the show are really crass!

vivid · Post by **vivid** » Fri Apr 08, 2011 8:09 pm

Yeah man, in many countries they have now banned the import of high powered laser pointers to the masses. Even if you got them in, you can get arrested even with careful usage outside the house. Say for astronomy, you are having careful fun (pls note the word careful fun) with a 445nm blue laser, perhaps too bright for laser pointing but maybe not for moon pointing LOL! You can be in some serious trouble.

But these buggers who are licensed and trained, can get a ~ 25W beam to the HDB. Perhaps they purposely diverged the beam, but what if one day the settings changed by mistake with a careless technician? Someone checks out the lightshow and BAM!

Checkout the HDB lights which look pretty dim, the actual laser intensity is brighter than depicted
in the photos.

superiorstream · Post by **superiorstream** » Sat Apr 09, 2011 5:58 pm

Strange;someone deleted my opinion again--but not actually opinion but facts about the danger of laser.

Post by **acc** » Sat Apr 09, 2011 6:01 pm

Superiorstream, if you just state facts or opinions and leave politics out of this forum, your posts won't be deleted. Same applies to fizzy123's post.

Please respect the rules of this forum. Thank you.

http://www.singastro.org/viewtopic.php?t=650

superiorstream · Post by **superiorstream** » Sat Apr 09, 2011 6:42 pm

This LASER thing is serious matter and might even involve legal matter if it cause blindness to anyone--not politics.Thats why question is ask of whos approval is it--that chap will have to be responsible if someone is blinded by it or someone house is set fire by the horizontal beam that shine into his house.Will fire insurence pay compensation if cause by external laser?
Here for the danger of Laser
1)Laser light are coherent light--with a high energy density and a strong electric/magnetic field.As such it can cause cell mutation,skin cancer etc.Only those in the few micro-watt range with large beamwidth are 'safe'iff not directly look at.
2)Green/blue laser has high energy per photon and ALL laser should not be directly look at.If you do;it will cause IRREVERSIBLE damage to the eye light sensitive cell and will result in a SLOW,and uncurable blindness.Check out the fate of the early worker in laser in the academic journal.
3)In the states,there are various codes--look at your electronic products-governing use of class1/class2 lasers etc.They are not for fun,but for public safety and should/must be strictly adhered to.We are also human and so pls adhere to such rules here.

To be continue later.

superiorstream · Post by **superiorstream** » Sun Apr 10, 2011 9:24 am

4)25Watt?Vow.Dont compare laser light power with light from an ordinary light bulb.These laser light being generated from the population inversion phenomena have very STRONG and ORIENTATED varying electric field that can cause CHEMICAL changes on the surfaces it encounter.A 5 watt laser can easily burn newspaper and above 7 watt can cut hole in metal and cause glass to crack if such concentrated light passes through it.As known,chemical are bonded together by covalent or ionic bonds(all electric in nature);thus it means that such light can even affect the gene of your cell,and cause it to mutate.Even the scattered light from such light can do this.In the States,we wear goggle and long sleeve to prevent such exposure.Exposuring the general public to such powerful light(>2Watt) is really irresponsible.

superiorstream · Post by **superiorstream** » Sun Apr 10, 2011 9:38 am

5)How do they get approval from the authority and get that laser imported?We also have laser show in other places--like Hong Kong--but only for about 10 min(at 8pm) and the laser is shine UPWARD;not HORIZONTALLY/DOWNWARD at people flat and for hours ,even till 2am?We have the rights to ask the authority why and request an IMMEDIATE stop to such irresponsible actions.This is our right and has nothing to do with politics.This is a question of health hazard.
To be continue.......

Post by **acc** » Sun Apr 10, 2011 5:35 pm

Chia, thanks for keeping politics off your last three posts and please continue to keep it that way.

Now, I can't help but notice that you must have done lots of research to find out what harm lasers can do. But my own reading also shows that there are means to make lasers safe for entertainment, e.g., through use of appropriate types and power of laser, enforcing minimum viewing distances and laser scanning (whereby a high power laser beam is optically split into light sheets or multiple beams of light to dilute its power). Over long distances, the laser's power will be attenuated by beam divergence and scattered by dust and humidity in the air. Laser shows have been in Singapore for a few decades and I have personally been in shows where laser beams were scanned into the audience. When was the last time anyone was harmed by one?

FYI, laser shows are regulated by NEA (http://app2.nea.gov.sg/data/cmsresource ... 899106.pdf).

Personally I find the laser show crass and spoils the skyline. If I have my way, at the minimum, the scan height should be raised so no one is bothered by beams shining into their homes. But if you are so concerned about safey, it will be more productive to write to NEA than to raise unnecessary alarm here. If you do write to them, please keep us updated here...