Viewing 40 posts - 1 through 40 (of 48 total)
  • Physics: Mirrors and lasers.
  • Torminalis
    Free Member

    Is it possible to make a laser powerful enough to burn a hole in a mirror?

    Clong
    Free Member

    Hell yes.

    nickc
    Full Member

    yeah, easily

    molgrips
    Free Member

    Possibly.

    If the light had a powerful enough electric field it might turn the glass into a plasma, which would then dissipate hence ‘burning a hole’ in the glass.

    Plus, in any case the reflective bit of a mirror is a thin sheet of metal at the back, and you can definitely burn a hole in metal with a laser.

    Torminalis
    Free Member

    Fair enough. So, could you uprate the mirror to resist these higher power lasers? surely if they reflect all of the light then they would not burn?

    As you can probably tell, I am not a physicist!

    nickc
    Full Member

    wavelengths.

    cynic-al
    Free Member

    Are you designing a defence system against future laser-weapons?

    Torminalis
    Free Member

    I was actually considering the prospect of a Star Destroyer taking on the Enterprise…

    😳

    Clong
    Free Member

    No possibly about it, its something we do frequently. It does depend on the type of mirror, in your bog standard mirror the silver backing will vaporise long before the glass melts. Theres a lot of other variables though, wavelength, power densities, mode and even the modal distribution will effect what happen to the mirror.

    funkynick
    Full Member

    Well.. if you could make a perfect mirror then no… as it would reflect all of the energy, and not absorb any.

    I suspect that making a perfect mirror might be a bit tricky though!!

    WorldClassAccident
    Free Member

    Can’t you make a near perfect mirror with prisms or something rather than a reflective material

    tonyg2003
    Full Member

    They are using lasers to generate cold fusion. So absolutely yes.

    Del
    Full Member

    unlikely to be able to uprate the mirror ( as you put it ). at high power, any loss induced in reflecting/reflecting the light would create a warming effect. also any contaminants in the path would do the same, creating localized heating, and it all goes downhill Very quickly from there. 🙂

    xc-steve
    Free Member

    Can you not get the mirror to reflect Jessica Alba… therefore making it perfect?!

    molgrips
    Free Member

    See what I said Torm. Any material can be turned into a plasma.

    An atom has a positive nucleus and negative electrons. When you apply an electric field, the electrons get pulled one way and the nucleus the other. If you apply a strong enough field the electrons and nuclei part company, so you have a soup of electrons and nuclei. This soup doesn’t have any atomic bonds any more so ends up like a gas.

    Light is an electric field and a magnetic field in lots of random chunks in all directions. In a laser, all the chunks are aligned so the electric field can be really strong. The more powerful the laser the stronger the electric field.

    If you zap things with lightening, the electric field is very strong indeed and things tend to vapourise. Likewise with a welder.

    (note the above may be b*lx, it’s been a long time!)

    Elfinsafety
    Free Member

    Mmm… Jessica Alba….

    What was the question again?

    Del
    Full Member

    Clong,
    where do you work?

    Clong
    Free Member

    The “perfect” mirror kind of exits. In a traditional ruby laser, a 100% is at one and a 99.9% is at the other, which is how the laser “lases”. But its wavelength specific.

    Del: I work in the big bad oil industry, i design/build lasers to monitor oil flow using fibre optic.

    molgrips
    Free Member

    Cool job!

    WorldClassAccident
    Free Member

    Lasers and Oil – Do you think they would let me play?

    cynic-al
    Free Member

    Torminalis – Member
    I was actually considering the prospect of a Star Destroyer taking on the Enterprise…

    😀

    ourkidsam
    Free Member

    Frickin’ lasers

    IanMunro
    Free Member

    How about if the mirror is underwater?
    I’m just wondering about how to protect myself from Sharks with frickin lasers.

    IanMunro
    Free Member

    Bollocks! 🙂

    fatboyslo
    Free Member

    Torminalis – Member
    I was actually considering the prospect of a Star Destroyer taking on the Enterprise…

    Ah but which Enterprise …. after all there have bee more than a few
    Enterprise NX-01, 22nd century,
    USS Enterprise NCC-1701, Constitution class, 23rd century
    USS Enterprise NCC-1701-A, Constitution class, 23rd century,
    USS Enterprise NCC-1701-B, Excelsior class, late 23rd century,
    USS Enterprise NCC-1701-C, Ambassador class, 24th century
    USS Enterprise NCC-1701-D, Galaxy class, 24th century,
    USS Enterprise NCC-1701-E, Sovereign class, 24th century

    plus reference to others in asssorted timelines ……
    🙄

    </geek mode >

    WorldClassAccident
    Free Member

    What if the lasers were mounted on a plane on a conveyor belt/

    would the backwards thrust of the lasers stop it taking off or would the reflected laser just kill the pilot?

    Elfinsafety
    Free Member

    Don’t be such a stupid idiot.

    CountZero
    Full Member

    What if the lasers were mounted on a plane on a conveyor belt/
    would the backwards thrust of the lasers stop it taking off or would the reflected laser just kill the pilot?

    Deary, deary me…

    elliptic
    Free Member

    Interestingly * using radiation pressure from light to generate thrust is (a) entirely feasible whilst also being (b) the least efficient possible use of energy to do so.

    * This may be a matter of opinion

    philconsequence
    Free Member

    Torminalis – Member
    I was actually considering the prospect of a Star Destroyer taking on the Enterprise…

    for this reason, i’m reconsidering inviting you to my sexy party.

    toys19
    Free Member

    See what I said Torm. Any material can be turned into a plasma.

    An atom has a positive nucleus and negative electrons. When you apply an electric field, the electrons get pulled one way and the nucleus the other. If you apply a strong enough field the electrons and nuclei part company, so you have a soup of electrons and nuclei. This soup doesn’t have any atomic bonds any more so ends up like a gas.

    Light is an electric field and a magnetic field in lots of random chunks in all directions. In a laser, all the chunks are aligned so the electric field can be really strong. The more powerful the laser the stronger the electric field.

    If you zap things with lightening, the electric field is very strong indeed and things tend to vapourise. Likewise with a welder.

    (note the above may be b*lx, it’s been a long time!)

    Molgrips is secretly a nobel prize winning physycist.
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    Not..

    toys19
    Free Member

    a nobel prize winning physycist.

    Doh physicist.

    And toys is a champion speller
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    Not

    chriswilk
    Free Member

    for a good mirror you need a Bragg stack.
    very wavelength specific but can get 99.9999% reflective – it’s how VCSELs work (a type of semiconductor laser).

    farmer-giles
    Free Member

    my nob is very shiny; but i don’t think i want anyone to point a lazer at it?

    Junkyard
    Free Member

    I was actually considering the prospect of a Star Destroyer taking on the Enterprise…

    The enterprise latest class is much much faster so could always run away. It is massively outgunned though A star destroyer crew is 30,000 + so it is a no brainer IMHO. The enterprise might win by cunning and repolarising something with an inverse tachion[spell?] beam if the engines could only take it though.
    The actual physics PHHHT neither know nor care

    molgrips
    Free Member

    I am secretly a nobel prize winning bullsh*t artist.

    Torminalis
    Free Member

    The enterprise latest class is much much faster so could always run away. It is massively outgunned though A star destroyer crew is 30,000 + so it is a no brainer IMHO. The enterprise might win by cunning and repolarising something with an inverse tachion[spell?] beam if the engines could only take it though.
    The actual physics PHHHT neither know nor care

    toys19
    Free Member

    I am secretly a nobel prize winning bullsh*t artist.

    Amen to that, it sounded convincing..

    Onzadog
    Free Member

    I made the mistake of googling this. It would seem that about half the internet is dedicated to this debate! Who’d have thunk it!

    DrRSwank
    Free Member

    Hmmm, maybe I’m thinking too much (or too little) here.

    A mirror reflects light.
    Laser is light.
    If the laser burns the mirror then it was not reflected.
    So the mirror was in fact not a mirror.
    BUT
    Lasers burn things
    So if the mirror reflects the laser.
    Then the laser wasn’t a laser as it didn’t burn it.

    I need to go to the toilet now.

Viewing 40 posts - 1 through 40 (of 48 total)

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