Telepath's brainteaser of the day

General physics and astronomy discussions not directly related to Celestia
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Telepath
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Telepath's brainteaser of the day

Post #1by Telepath » 31.01.2006, 05:11

I had a problem with rendering the moon today. It's a pretty serious problem if it can't be fixed.
Here's a picture of it.
If you can't see what the problem is, leave a post in this thread and I'll explain further.

Image

Malenfant
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Post #2by Malenfant » 31.01.2006, 06:35

I can't see anything wrong... the numbers all seem right. I can easily reproduce the view in my copy of Celestia (it's not the view from Earth right now obviously, we're looking at the far side. Right now the view from Earth is of a new moon, a very thin crescent which Celestia is totally incapable of rendering properly).

What's the problem?
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julesstoop
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Post #3by julesstoop » 31.01.2006, 07:06

I can see stars shining through the unlit part of the moon. This only happens with the moon?
Last edited by julesstoop on 31.01.2006, 07:06, edited 1 time in total.
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Telepath
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Post #4by Telepath » 31.01.2006, 07:06

Remember, it's a brainteaser....the answer's in the image.

Do you want to have another look, or do you want a clue?

:wink:

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Post #5by Telepath » 31.01.2006, 07:19

julesstoop wrote:I can see stars shining through the unlit part of the moon.
Well done julesstoop. You passed the intelligence test.--- Of course, it's not possible to see stars thru the limb of the moon!
This only happens with the moon?

It doesn't actually happen in Celestia, so don't worry. (Just checking to see who's awake :wink:)

:lol:

Here's what it should look like:
Image

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Post #6by julesstoop » 31.01.2006, 07:47

I didn't fully pass your little test though. I recognized the fact that the image contained an artefact, in spite of the title of your thread though (and the forum you posted it in) I failed to see you had manipulated it deliberately. :lol:
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Post #7by Malenfant » 31.01.2006, 08:07

Would have been a bit easier to see that if more of the moon was dark - it's fairly close to circular as it is... not that easy to see the 'extra stars' in the small dark area there...
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Telepath
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Post #8by Telepath » 31.01.2006, 08:28

julesstoop wrote:I didn't fully pass your little test though. I recognized the fact that the image contained an artefact, in spite of the title of your thread though (and the forum you posted it in) I failed to see you had manipulated it deliberately. :lol:
Glad you enjoyed my little test anyway. It's a pity you posted the answer so soon. I was hoping to catch a few more suckers. :lol:

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Telepath
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Post #9by Telepath » 31.01.2006, 08:35

Malenfant wrote:Would have been a bit easier to see that if more of the moon was dark - it's fairly close to circular as it is... not that easy to see the 'extra stars' in the small dark area there...


Malenfant....."You are the weakest link" :lol: :wink: 8)

Image

Malenfant
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Post #10by Malenfant » 31.01.2006, 09:33

Telepath wrote:
Malenfant wrote:Would have been a bit easier to see that if more of the moon was dark - it's fairly close to circular as it is... not that easy to see the 'extra stars' in the small dark area there...

Malenfant....."You are the weakest link" :lol: :wink: 8)


Thank you for proving the point I just made. :roll: There's like 10 stars in that dark part, total.

More fool me for thinking you were actually pointing out some kind of bug in Celestia instead of trying to fool people by doing some deliberate post-processing on Celestia's output. Not hugely impressed here.

If you want to do anything more like this, please take it to Purgatory. And just be up front and say it's a doctored image. I don't mind some fun like that if it's touted that way, I just mind it when I waste time reproducing your image in Celestia only to find it's a prank. :roll:
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Telepath
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Post #11by Telepath » 31.01.2006, 12:10

Malenfant wrote:...just be up front and say it's a doctored image. I don't mind some fun like that if it's touted that way, I just mind it when I waste time reproducing your image in Celestia only to find it's a prank

OK just for you....

There's something wrong with the moon today. This could have serious consequences for the European butter mountain. Here's a picture of it.
If you can't see what the problem is, leave a post in this thread and I'll explain further.

****WARNING**** DOCTORED IMAGE FOLLOWS ****WARNING***

**** PRANK FOLLOWS ****

**** DON'T BE FOOLED BY THIS ****

**** THIS IS NOT REAL ?€“ Come on, everyone knows the moon isn?€™t made of cheese! ****

Image

Yup,I can see your point?€¦.that definitely works better.
Thanks, for your participation. Without your replies this thread wouldn't have been 1/2 as much fun. :wink: :lol:

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Post #12by BrainDead » 31.01.2006, 22:53

Regardless of the cheese...

Serious question here. If the moon's surface was as bright as depicted, then
the stars shown around the globe should not appear anywhere near as
bright and as "brilliant" as they do.

Is this correct Dr. Thomas?

The uninitiated may wish to view http://celestiaproject.net/forum/viewtopic.php?t=8788

for further enlightenment.

Thanks again.
Brain-Dead Bob

Windows XP-SP2, 256Meg 1024x768 Resolution
Intel Celeron 1400 MHz CPU
Intel 82815 Graphics Controller
OpenGL Version: 1.1.2 - Build 4.13.01.3196
Celestia 1.4.1

Malenfant
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Post #13by Malenfant » 01.02.2006, 01:05

BrainDead wrote:Regardless of the cheese...

Serious question here. If the moon's surface was as bright as depicted, then
the stars shown around the globe should not appear anywhere near as
bright and as "brilliant" as they do.

Is this correct Dr. Thomas?


Yep. Though keep in mind (on further thought, given what I said in that thread) that the area around the moon in the sky on earth is washed out because of atmospheric scattering. In space you don't have that, which is why if you turn directly away from the moon/light source up there, the stars will be out again (once your eyes adjust to the darkness) - you shouldn't see a glow from behind washing things out.
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BrainDead
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Post #14by BrainDead » 01.02.2006, 11:52

Many thanks for the information. This was something that never
even occurred to me prior to your explanation. Makes perfect sense
now though.

Again, many thanks for the patient explanation.
Brain-Dead Bob



Windows XP-SP2, 256Meg 1024x768 Resolution

Intel Celeron 1400 MHz CPU

Intel 82815 Graphics Controller

OpenGL Version: 1.1.2 - Build 4.13.01.3196

Celestia 1.4.1

delmarco
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Re: Telepath's brainteaser of the day

Post #15by delmarco » 12.03.2006, 02:55

Telepath wrote:I had a problem with rendering the moon today. It's a pretty serious problem if it can't be fixed.
Here's a picture of it.
If you can't see what the problem is, leave a post in this thread and I'll explain further.



I may be late, but without scrolling down I'll say the moon is an oval and not sphere since stars are shown all around the border of the moon when it is obviously not in full.

a real teaser;
How long until the moon crashes into earth, if the centripetal force that counters moon-earth gravitational attraction intantaneously vanishes?
Your Mind Creates This World-


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