Deeply Philosophical Questions 8

[hjgoldstein]

There were also reports of hailstones the size of golf balls falling in the East Midlands

How were hailstones measured before the invention of golf balls?

It is time for pacifists to stand up and fight for their beliefs.

 

[1DMF]

- well after all 'life is like.....'

Are gamma ray burst visible? what is 'visibility'.

Are there creeatures that use Ultra Violet light or other frequencies to see, are we defining 'visible' by the limitations of our own eyes?

"In complete darkness we are all the same, it is only our knowledge and wisdom that separates us, don't let your eyes deceive you."

"If a shortcut was meant to be easy, it wouldn't be a shortcut, it would be the way!"

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[strongm]

>are we defining 'visible' by the limitations of our own eyes?

If we are talking about 'visible to humans' then yes, of course. How could it be otherwise?

>Are there creeatures that use Ultra Violet light

Yes; many insects can see in the ultraviolet range.

>'Deeply Philosophical Questions' , and that is my philosophical view of colour!

But even if we accepted your view that energy and wavelength are the same attribute, or that 'energy of light' is some sort of fixed value, or that objects contain light energy (all of which is what you seem to be trying to say in the statement I picked ony), it is still horribly wrong to pick on wavelength - it is the frequency that is important to the philosophical point you are trying to make.

 

[CajunCenturion]

==> I consider something to be made up of things, not what they are not made up of.
Objects are not made of color. Color is a property of an object that is based on the behavior of the object, not the composition of the object.



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[SamBones]

Why is a chair called a chair or a door a door, they are just labels IMO.

I'm glad someone mentioned chairs!

I believe it was in Douglas Hofstadter's book Godel, Escher, Bach that he mused about what constitutes a "chair". If I draw a simple picture...
[tt]
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...and ask what it is, people will say it's a chair. But it's not really a chair. It's a bunch of lines on a screen. Even as a representation of a chair, it's not a very good one. He questioned, what gives those 11 or so lines their "chairness" so that most people looking at it will immediately say "it's a chair".

Going simpler...
[tt]
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...many people will still say it's a chair. It still has enough "chairness" to be recognized as one.

Then, think about some of those ultra-modern chairs with organic blobby egg shapes and no discernible legs, something like these...

Example Chair 1
Example Chair 2
Example Chair 3
Example Chair 4

People will still look at those and say, "Hey! Look at that chair!" People have no problem picking chairs out of a lineup, no matter how strange the chair is. If you were to try to program a computer to recognize chairs, the problem becomes huge. Sure, the mainstream chairs might be easy for it to spot, but it's going to miss a lot of those weird ones, and there will be a lot of false positives on things like BBQ grills, and automobile bonnets (yes, you can sit on grills and bonnets, but does that add them to the set labelled "chairs"?).

If you haven't read Godel, Escher, Bach, you should. I think everyone in this thread would love it. Anyone interested in intelligence (artificial or otherwise), or perception, should love it. I especially like the part about the conversation with an ant colony (not any individual ant, but the colony as an intelligent collective organism).

Apologies in advance if I'm referencing the wrong book. It's been probably 30 years since I last read it.


John 3:16

 

[SamBones]

And on the topic of black holes, I believe that inside the event horizon, our concepts of space and time break down and don't apply, so things like photons at a certain wavelength don't really make sense. The term "hole" is a misnomer. It's not a hole. It's a collection of matter so dense that it has warped both space and time to something well beyond our day to day experience.

But still wear sunglasses just in case!

 

[SantaMufasa]

Anyone interested in intelligence (artificial or otherwise), or perception, should love it...

Ah, yes, just what is "love"? <grin>

Mufasa
(aka Dave of Sandy, Utah, USA)
“People may forget what you say, but they will never forget how you made them feel.

 

[Qik3Coder]

I've done some quick digging and found, that "Red" is derived from indogermanic "reudh / rudhirà-h" which means "bloody". This root also lead to the word "rust".
"Blue" comes from ancient German "blao" for "shimmering", and "Green" from ancient German "gruoen" => to grow (also: gruoen=>grow).

I've always wondered how different our world would be if we had different colored blood.

Lodlaiden

You've got questions and source code. We want both!
There's a whole lot of Irish in that one.

 

[kwbMitel]

On the blackhole question - I have thought this one out on a number of occasions. I too once believed that black holes contain all of the light that has ever crossed the event horizon. This becomes meaningless however once you imagine what is happening to the wavelength of said light. Because time is warped, the wavelengths simply become longer and longer until thay are flat (no wavelength at all) at the event horizon. Outside of the event horizon they are so redshifted as to be black so no, black holes are actually black.

[red]Here is a new question[/red] - When one observes a spinning wheel with spokes there is a point at which the spin rate equals the visual perception limit and the wheel then appears to be stationary. Is this spin rate constant for all people? If not is there any corrolation with differences in rate with some other factor such as intellegence?

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What's most important is that you realise ... There is no spoon.

 

[Olaf Doschke]

As a physicist I have to say this on your theory, kwbMitel:

While time dilation also is valid for photons, they actually move at the speed of light and not near the speed of light, even in normal space. Still they are equal to a certain wavelength. That is the particle/wave dualism of light. But you can't argue for no color with neither time dilation. What's true is that the particle lifetime of photons in their own so called proper time is 0 (it never ages), as their speed is c. What really happens to photons on a black hole is the same as on earth/soil. It is partly absorbed,partly scattered, but it will never again pass the event horizon to the outside because of the gravity. You can see the gravity effect on light at the eclipse of the sun via the bent positions of stars behind the sun in comparison with their normal position.

See

http://en.wikipedia.org/wiki/Event_horizon:

"The traveling object, however, experiences no strange effects and does, in fact, pass through the horizon in a finite amount of proper time."

Applied on the photons this means their energy equal to their wavelength doesn't change to a lower energy. "any object approaching the horizon from the observer's side appears to slow down". The main word here is "appaers", it just appears so. Indeed light going in to a black hole must gain energy. It can't accelerate of course, as it's already at the highest speed available. But if you talk about the picture you see of an object moving towards a black hole, you talk of photons emitted from that object in your direction, and that is slowered, but you can't talk about the image of a photon you observe moving to a black hole. A photon is not a light bulb emitting light, it's the quantum of light itself and only faces one direction.

The recent finding of the Higgs Boson makes another question more interesting again: Are there Gravitons? And if so, they must emit from black holes, otherwise black holes would have no gravitational effect on the outside, because gravitons are the gravitiy. That again means events inside the black hole, that create Gravitons do effect the outside world.

Also see

http://en.wikipedia.org/wiki/Accretion_disc,

this suggests light can be emitted along the polar axis of a black hole. So overall in my understanding, depending on the reactions, physical or chemical, going on at the black hole surface of it's supermassive part, there could be light emitting in all directions, but it would be bent to fall back to the black hole surface.

Also see

http://www.sciencedaily.com/releases/2011/05/110523074954.htm,

the polar jets and the evolving of black hole spin is not understood. For such jets of xrays to be produced you can think of very fast spins and a very huge magnetic field of black holes, which might override the gravity especially at the poles of course.

Bye, Olaf.

 

[kwbMitel]

Thanks Olaf, and yes I was speaking from the observers point of view, sorry for not being specific. I was expressing the thoughts as my own (as they are). I should have made it more clear that I wasn't expressing it as a fact only what I believe to be. I think I get the jist of your correction/elaboration. It seems I may have got myself confused between observation and actual events (common for me when talking about relativity)

Is it correct (close) to say that due to time dilation effects, the light as observed by a remote party is redshifted into a color indistiguishable from black?

**********************************************
What's most important is that you realise ... There is no spoon.

 

[SamBones]

Yes! A Physicist mentioning the Higgs Boson and Gravitons!

Olaf my friend, when will I be able to buy a flying car? Or at least a Back To The Future hoverboard? It's way past due!

 

[CajunCenturion]

==> Is it correct (close) to say that due to time dilation effects, the light as observed by a remote party is redshifted into a color indistiguishable from black?
Yes, BUT ONLY if you're referring to the light being reflected from a mass that is falling into the black hole. That's not the same as saying the black hole appears black for the same reason. The black hole is not giving off any light that an observer could see, so there is nothing to red-shift. Only the light from objects outside the event horizon gets red-shifted from the perspective of a viewer.

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[CajunCenturion]

Since this is a language forum after all, and we're so wrapped up in black holes, I think it only pertinent to introduce a term that some of you may not be familiar with: spaghettification.

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[flyboytim]

Didn't Hawking once alter the phrase "Physics breaks down in the vicinity of a black hole" to "Physicists break down in the vicinity of a black hole"?

 

[kwbMitel]

Excellent, CajunCenturion, I fanally got something somewhat correct, and thanks for the new term. I had not remembered it eventhough I've read a book that is said to refer to it. (A brief history of time)



**********************************************
What's most important is that you realise ... There is no spoon.

 

[1DMF]

it is still horribly wrong to pick on wavelength - it is the frequency that is important to the philosophical point you are trying to make.

frequency / wavelength whatever, you seem to have some missguided concept that I understand waves or a wave function?

You can have a philisophical debate without having to understand the science, otherwise God wouldn't exist!

but if you want to beleive that light doesn't empart energy onto the objects it touches and doesn't change their colour, go sit in the sun naked and let's see how long you keep beleiving that!

"In complete darkness we are all the same, it is only our knowledge and wisdom that separates us, don't let your eyes deceive you."

"If a shortcut was meant to be easy, it wouldn't be a shortcut, it would be the way!"

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[hairlessupportmonkey]

You can have a philisophical debate without having to understand the science, otherwise God wouldn't exist!

Oh dear..... I.am.go.ing.to.res.ist.the.temp.ta.tion.

Anyway - definitive info on light, and its properties to heat an object due to the energy it absorbs from light.



ACSS - SME
General Geek

 

[1DMF]

Oh dear..... I.am.go.ing.to.res.ist.the.temp.ta.tion.

The tempation to what? We are not mind readers!

Thanks for the link, very informative and states that objects absorb the light and light is made up of colours shown when refracted, and those colours are converted to heat. so the object is made up of the colours it absorbs (well the energy)... Thanks for reaffirming my philisophical beliefs

"In complete darkness we are all the same, it is only our knowledge and wisdom that separates us, don't let your eyes deceive you."

"If a shortcut was meant to be easy, it wouldn't be a shortcut, it would be the way!"

Free Dance Music Downloads

 

[strongm]

>you seem to have some missguided concept

Sorry, I was making the mistake of thinking you at least had some idea what you were talking about. In future I'll just assume that you make stuff up

>but if you want to beleive that light doesn't empart energy

As ever, you impart a meaning to my words that was never stated or even implied.

>and doesn't change their colour

Again, not something I stated or implied. However, since you mention it, the colour of an object that we perceive is reliant on the frequencies of the electrons in the surface of object the light is hitting, the frequency spectrum of the light itself, and, rather more importantly, of our brains* (here's just one example of our brains changing our perception of colour).

>You can have a philisophical debate without having to understand the science

Not really. To be able to have a philosophical debate you have to understand the argument from both sides. And if you do not appreciate why that is then you understand neither what a debate is nor philosophy.

And you certainly can't start trying to make your own point by (mis)using science that you yourself happily state you have no understanding of.



* I'm simplifying; human colour perception, as in how our brains interpret what we see, is a huge subject area

 

[1DMF]

Mike - did the operation hurt or cost much money?

"In complete darkness we are all the same, it is only our knowledge and wisdom that separates us, don't let your eyes deceive you."

"If a shortcut was meant to be easy, it wouldn't be a shortcut, it would be the way!"

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