Geek Jokes

[ajprice]

[Clockwork Cupcake]

ajprice said:

Standing by for some spod to start dissecting the joke and postulating that the moon doesn't reflect all wavelengths of sunlight (otherwise it would look like sunlight not moonlight) and hence whatever vampires are sensitive to isn't in moonlight.

Personally, it made me chuckle. Just like the Astley Paradox joke did too.

[Lily the Pink]

Clockwork Cupcake said:

Standing by for some spod to start dissecting the joke and postulating that the moon doesn't reflect all wavelengths of sunlight (otherwise it would look like sunlight not moonlight) and hence whatever vampires are sensitive to isn't in moonlight.

Personally, it made me chuckle. Just like the Astley Paradox joke did too.

Never had you down as a spod, CC. But then I'm not sure what a spod is.

More importantly, would we not all prefer it if science did not save Thumbsnap ?

[Clockwork Cupcake]

Lily the Pink said:

More importantly, would we not all prefer it if science did not save Thumbsnap ?

[Halmyre]

Clockwork Cupcake said:

ajprice said:

Standing by for some spod to start dissecting the joke and postulating that the moon doesn't reflect all wavelengths of sunlight (otherwise it would look like sunlight not moonlight) and hence whatever vampires are sensitive to isn't in moonlight.

The sunlight impinging on the moon is absorbed and re-emitted, so it's not the same light...

[Brother D]

[Skyedriver]

[Silver Smudger]

Halmyre said:

Clockwork Cupcake said:

ajprice said:

Standing by for some spod to start dissecting the joke and postulating that the moon doesn't reflect all wavelengths of sunlight (otherwise it would look like sunlight not moonlight) and hence whatever vampires are sensitive to isn't in moonlight.

The sunlight impinging on the moon is absorbed and re-emitted, so it's not the same light...

Are you saying the moon is photoluminescent ?

[havoc]

Halmyre said:

The sunlight impinging on the moon is absorbed and re-emitted, so it's not the same light...

Quoted for posterity.


Or, more precisely...absolutely not. Nope. No-siree.


SOME sunlight is absorbed by the moon, sure...same applies to everything except a (theoretical) perfect reflector. But NO light is re-emitted by the moon. The ONLY light we see from the moon comes from simple reflection.

[ZesPak]

Indeed... Re-emitting would require fluorescence?
I also thought it was simple reflection.

[Rostfritt]

ZesPak said:

Indeed... Re-emitting would require fluorescence?
I also thought it was simple reflection.

The Moon is apparently as reflective as a lump of coal, so I don't think it glows in any way.

[67Dino]

ZesPak said:

Indeed... Re-emitting would require fluorescence?
I also thought it was simple reflection.

Simple reflection is re-emitting too. At the atomic level energy can be thought of as being absorbed by an atom, which moves up an energy level and then drops down again and emits a photon out again. It’s actually a bit more complicated - the subject of quantum electrodynamics covers it - but the idea of ‘simple’ reflection only really exists at the larger scales.

Fluorescence differs in that it usually involves light being remitted at a longer wavelength.

[havoc]

Are you sure that happens in the visible wavelength?

I can imagine there being re-emission (radiation) in the IR wavelengths...but with visible wavelengths???

[Clockwork Cupcake]

67Dino said:

Simple reflection is re-emitting too.

No it's not! They are completely different concepts!

[Gman20]

havoc said:

Are you sure that happens in the visible wavelength?

I can imagine there being re-emission (radiation) in the IR wavelengths...but with visible wavelengths???

Quantum physics doesn't care what radiation you use for seeing and what you use for cooking your dinner.
The same thing happens.

[Clockwork Cupcake]

Gman20 said:

Quantum physics doesn't care what radiation you use for seeing and what you use for cooking your dinner.
The same thing happens.

Quantum Physics is used to explain stuff that behaves differently to the real* world.

(*- As in the macro level at which we inhabit)

[67Dino]

Clockwork Cupcake said:

67Dino said:

Simple reflection is re-emitting too.

No it's not! They are completely different concepts!

Obviously you can’t label and trace an individual photon so any behaviour is probabilistic rather than real, but think the concept of absorption and re-emission is as good as a way I know it describing what happens when a photon meets an atom. That said, my QED is nearly 3 decades old, so if there’s a more modern way of describing reflection then be interested to hear it.

[Nimby]

67Dino said:

Obviously you can’t label and trace an individual photon so any behaviour is probabilistic rather than real, but think the concept of absorption and re-emission is as good as a way I know it describing what happens when a photon meets an atom. That said, my QED is nearly 3 decades old, so if there’s a more modern way of describing reflection then be interested to hear it.

But that would require a white substance to have electron orbitals differing in energy corresponding to every possible wavelength in white light.

Edited by Nimby on Saturday 27th February 22:18

[67Dino]

Nimby said:

67Dino said:

Obviously you can’t label and trace an individual photon so any behaviour is probabilistic rather than real, but think the concept of absorption and re-emission is as good as a way I know it describing what happens when a photon meets an atom. That said, my QED is nearly 3 decades old, so if there’s a more modern way of describing reflection then be interested to hear it.

But that would require a white substance to have electron orbitals differing in energy corresponding to every possible wavelength in white light.

Not as I understand it. Perhaps the best way to answer this is with a question: what’s the alternative? If not an exchange of energies with the atom, then what is it that the photon hits that it ‘bounces off’? And how would you know it’s the same photon that came back? But like I say, I’m rusty on this stuff, so hopefully someone here is better able than I am to explain the moment of interaction between photon and atom.

Or perhaps even tell a joke...

[Dr Jekyll]

Perhaps if we understood the mechanism by which sunlight destroys vampires then we would be better able to assess the risks of moonlight to members of the blood consuming community.