The Astronomy Thread

caldrail

Ad Honorem
Feb 2012
5,192
True colour? No such thing. Colour is the perception of reflected light interpreted by the brain. There is no colour in the real universe - it's all inside our head - a perceptual imaging trick by the brain to discriminate between different wavelengths of light readily.
 
Nov 2011
8,848
The Dustbin, formerly, Garden of England
There was quite a bit of hoo-hah a couple of years back about the colour rendition of images from Mars. Space probes can rarely take pictures in "true colour" apparently, but are rendered according to the needs of the scientists involved--most of what we see published is in "false colour" adjusted to give "an approximation" of what we might see with the naked eye.
Some interesting explanations here.

The Insider - NASA's images of Mars are the wrong color

True or False (Color): The Art of Extraterrestrial Photography

There are several you tube videos on the subject, but they are quite tedious.
 
Dec 2010
1,990
Oregon
Hmmm...

It's tempting to delve into the 'what is real vs. what is false data' issue, but I'll never be mistaken for a philosopher, plus this approximates the discussion Dark Star's crew had with their troublesome bomb late in the movie.

And we all know well that worked out.
 
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caldrail

Ad Honorem
Feb 2012
5,192
There is genuine research on how species perceive their surroundings. Fascinating stuff. Apparently bats are able to create an internal image of their surroundings by their sonar, adding to their eyesight's capabilities (which probably aren't brilliant to begin with). They're literally seeing with their ears. We know that sharks can perceive electrical fields, birds can perceive magnetic fields, and all these senses are linked in some way to internal imaging.
 
Oct 2014
859
Westeros
True colour? No such thing. Colour is the perception of reflected light interpreted by the brain. There is no colour in the real universe - it's all inside our head - a perceptual imaging trick by the brain to discriminate between different wavelengths of light readily.

You, sir, are a pedant.

While it is true, that what we refer to as an object's color is actually the one color it is not, as it is technically only the color wavelengths that are reflected to our eyes, the term "color" is unavoidable as verbal or written description of how the objects looks. Unavoidable. Absolutely necessary.

We scientists use the term daily, even chemists--who are more aware than anyone of an element's true nature--use the word when describing one of the elements on the Periodic Table. (for example, they call sulfur "yellowish."

It's like me saying that if Knarly Dan put your head through a wall for being smarmy, it won't really hurt you, since that wall is technically 99% empty space! (Yes, it is comprised of atoms, which in turn make molecules. An atom is vastly empty space; if it's nucleus was a football laying at the 50-yardline on a football field, the electrons swirling around it would be somewhere around the perimeter of the exterior stadium walls, and would be about the size and weight of rice grains.)
So.....pontificating on the fallacy of color perception does nothing to constructively add to an otherwise excellent thread. We all knew what the OP was referring to, and what was meant by it. Getting overly-literate often derails instead of enhances effective communication.
 
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Dec 2010
1,990
Oregon
Actually, I appreciated Caldrail's input. It was both interesting and thought-provoking.

So terms like 'pedant,' 'pontificating,' and 'smarmy' are conducive to civil discussions about sciency matters. Who knew?
 
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Dec 2010
1,990
Oregon
The first man on PLUTO

As is often the case, Mail Online's headline is misleading. However

American astronomer Clyde Tombaugh discovered the icy world in 1930
Upon his death in 1997 he requested that his ashes be carried into space
His remains are inside a container fixed to Nasa's New Horizon's probe
They have spent nine years travelling 3.67 billion miles towards Pluto
 

Lowell2

Ad Honorem
Jun 2014
6,541
California
Closest known flyby of star to our solar system: Dim star passed through Oort Cloud 70,000 years ago -- ScienceDaily Astronomers from the US, Europe, Chile and South Africa have determined that 70,000 years ago a recently discovered dim star is likely to have passed through the solar system's distant cloud of comets, the Oort Cloud. No other star is known to have ever approached our solar system this close -- five times closer than the current closest star, Proxima Centauri. They analyzed the velocity and trajectory of a low-mass star system nicknamed "Scholz's star."

one would presume that some gravitational perturbations must have occurred during this passage, but this isn't discussed in the article. (I do note that the toba eruption occurred at about this same time, but it could be coincidence. [ame=http://en.wikipedia.org/wiki/Lake_Toba]Lake Toba - Wikipedia, the free encyclopedia[/ame] )
 

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