Cumulative General Science/Technology Quiz

[Perfection]

Trick question, it's in the brain!

 

[El_Machinae]

Every perception is in the brain. But we need certain nerve impulses to get to the brain to generate those perceptions.

The answer IS actually one of the three cones.

 

[Perfection]

If it's anything like [wiki]Same Color Illusion[/wiki], the rods/cones aren't producing the illusion rather it shows up in the visual perception areas in the brain.

 

[Mise]

Blue ?

 

[Brighteye]

green ?

 

[El_Machinae]

I realise I shouldn't give a question with three potential answers!

Anyway, its our blue rods which are picking up (and integrating) the brightness 'vibe' of each facing. Once the lighting has been extrapolated, the specific colour (in the small square) is then analysed and our consciousness is told what the colour is.

If you didn't have blue cones, you'd easily be able to tell that the colours were actually the same.

 

[Perfection]

Just because blue cones are neccesary doesn't make them reponsible. It's not the cones that make the illusion, its the interpretation of what they send that does.

 

[El_Machinae]

Well, yeah, but you're being too particular. All perception is in the brain, but the brain is trained by its interaction with the environment. "Lighting" is something we learn about, due to changes in lighting. We're fooled by the illusion because we're interpreting a colour due to its supposed lighting, and our ability to interpret lighting is due to our blue cones learning about the environment.

But yes, it's all in the brain.

 

[Perfection]

Not all optical illusions are in the brain! Foir example, [wiki]afterimages[/wiki] are in rods and cones themselves, caused by fatigue.

What you implied that you were looking for, is where does the signal diverge from the incident light on retina (the point where the signal stops being an ideal relection of reality, but in fact an illusion causing us to be fooled), these sorts of phenomena are much higher up the perceptual chain. The cones are working perfectly and don't in any way cause us to be fooled.

 

[GoodGame]

Ok time for a new question, no?

What's air speed of an un-laden.....uh wait...


When water moves in waves, by what two wave forms does the water move?

Bonus: Does a particle of H2O in the middle of a wave tank actually travel around the tank?

 

[Mise]

It's both transverse and longitudinal waves, so the water just below the surface goes round in circles (up and down circles).

A particle of H2O would probably go round in circles too, but wouldn't move around the tank so much I guess... (Assuming idealised waves.)

 

[GoodGame]

Good answer.
http://www.gmi.edu/~drussell/Demos/waves/wavemotion.html

Your turn.

 

[Mise]

What is the most dense solid in existence?

What is the least dense gas in existence? (at s.t.p.)

 

[dutchfire]

Least dense gas: H2 ?

 

[Mise]

Yup! Now for most dense solid.

 

[Genocidicbunny]

Solid hydrogen?

If you're looking for something a little more feasable, iridium

 

[Truronian]

Yup! Now for most dense solid.

Neutron star/ black hole?

 

[nonconformist]

Ununoctium?

 

[Mise]

Solid hydrogen?

Yup!

It's even been hypothesised that metallic hydrogen can be formed, with a separation between atoms less than the Bohr radius.

I don't know whether neutron stars or black holes are more dense than solid hydrogen, but the point of the question was that Hydrogen forms the least dense gas and the most dense solid (of all the elements <-- maybe I should've specified that!).

Stickciv / dutchfire 's up, depending on who asks first I guess.

 

[Brighteye]

But the question asked at STP. Is hydrogen solid then?