Sleepalot wrote:
Joe Egginton wrote:

Sleepalot wrote:
"peter clarke" wrote:

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=25&sy=2007

There seems to be something seriously wrong with
the planet on those images - or is it just me?



You are looking onto the top of the planet, so that the artic is in the
centre of the photo.

Yes, so how come the image is oblate? Shouldn't it be circular?



It isn't circular because the Earth is an oblate spheroid, not a sphere.

Joe Egginton wrote:

Sleepalot wrote:
Joe Egginton wrote:

Sleepalot wrote:
"peter clarke" wrote:

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=25&sy=2007

There seems to be something seriously wrong with
the planet on those images - or is it just me?



You are looking onto the top of the planet, so that the artic is in the
centre of the photo.

Yes, so how come the image is oblate? Shouldn't it be circular?

It isn't circular because the Earth is an oblate spheroid, not a sphere.

Aiui, the Earth is flattened at the poles. The edge of the image is
the equator. I still think it should be circular.

--
Sleepalot aa #1385

On Wed, 06 Aug 2008 18:51:07 +0100, Sleepalot
wrote:

Joe Egginton wrote:

Sleepalot wrote:
Joe Egginton wrote:

Sleepalot wrote:
"peter clarke" wrote:

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=25&sy=2007

There seems to be something seriously wrong with
the planet on those images - or is it just me?



You are looking onto the top of the planet, so that the artic is in the
centre of the photo.

Yes, so how come the image is oblate? Shouldn't it be circular?

It isn't circular because the Earth is an oblate spheroid, not a sphere.

Aiui, the Earth is flattened at the poles. The edge of the image is
the equator. I still think it should be circular.

Looks more like 30N to me.


--
Regards, Paul Herber, Sandrila Ltd.
http://www.sandrila.co.uk/ http://www.pherber.com/

In message , Joe Egginton
writes
Sleepalot wrote:
Joe Egginton wrote:

Sleepalot wrote:
"peter clarke" wrote:


http://igloo.atmos.uiuc.edu/cgi-bin/...2&fd=25&fy=200
8&sm=02&sd=25&sy=2007

There seems to be something seriously wrong with
the planet on those images - or is it just me?



You are looking onto the top of the planet, so that the artic is in
the centre of the photo.
Yes, so how come the image is oblate? Shouldn't it be circular?


It isn't circular because the Earth is an oblate spheroid, not a sphere.

The oblateness wouldn't show up on a polar view, and anyway is too small
to be obvious to the naked eye.

My first suspicion is that the image is circular, and the apparent
oblateness is an optical illusion, possibly resulting from the dark
areas at the top and bottom.

After examination of the image in an image editor I find that the
vertical and horizontal diameters of the image of the earth is the same
to within a pixel or two. Suspicion confirmed.
--
Stewart Robert Hinsley

Paul Herber wrote:

On Wed, 06 Aug 2008 18:51:07 +0100, Sleepalot
wrote:

Joe Egginton wrote:

Sleepalot wrote:
Joe Egginton wrote:

Sleepalot wrote:
"peter clarke" wrote:

http://igloo.atmos.uiuc.edu/cgi-bin/...&sd=25&sy=2007

There seems to be something seriously wrong with
the planet on those images - or is it just me?



You are looking onto the top of the planet, so that the artic is in the
centre of the photo.

Yes, so how come the image is oblate? Shouldn't it be circular?

It isn't circular because the Earth is an oblate spheroid, not a sphere.

Aiui, the Earth is flattened at the poles. The edge of the image is
the equator. I still think it should be circular.

Looks more like 30N to me.

Hmm. Yes, it does. Is the Earth oblate at 30N?


--
Sleepalot aa #1385

Stewart Robert Hinsley wrote:

In message , Joe Egginton
writes
Sleepalot wrote:
Joe Egginton wrote:

Sleepalot wrote:
"peter clarke" wrote:


http://igloo.atmos.uiuc.edu/cgi-bin/...2&fd=25&fy=200
8&sm=02&sd=25&sy=2007

There seems to be something seriously wrong with
the planet on those images - or is it just me?



You are looking onto the top of the planet, so that the artic is in
the centre of the photo.
Yes, so how come the image is oblate? Shouldn't it be circular?


It isn't circular because the Earth is an oblate spheroid, not a sphere.

The oblateness wouldn't show up on a polar view, and anyway is too small
to be obvious to the naked eye.

My first suspicion is that the image is circular, and the apparent
oblateness is an optical illusion, possibly resulting from the dark
areas at the top and bottom.

After examination of the image in an image editor I find that the
vertical and horizontal diameters of the image of the earth is the same
to within a pixel or two. Suspicion confirmed.

My method was rather more direct: I held a rule(r) to the screen.
height 118mm, width 140mm.


--
Sleepalot aa #1385

In message , Sleepalot
writes
Stewart Robert Hinsley wrote:

In message , Joe Egginton
writes
Sleepalot wrote:
Joe Egginton wrote:

Sleepalot wrote:
"peter clarke" wrote:


http://igloo.atmos.uiuc.edu/cgi-bin/...2&fd=25&fy=200
8&sm=02&sd=25&sy=2007

There seems to be something seriously wrong with
the planet on those images - or is it just me?



You are looking onto the top of the planet, so that the artic is in
the centre of the photo.
Yes, so how come the image is oblate? Shouldn't it be circular?


It isn't circular because the Earth is an oblate spheroid, not a sphere.

The oblateness wouldn't show up on a polar view, and anyway is too small
to be obvious to the naked eye.

My first suspicion is that the image is circular, and the apparent
oblateness is an optical illusion, possibly resulting from the dark
areas at the top and bottom.

After examination of the image in an image editor I find that the
vertical and horizontal diameters of the image of the earth is the same
to within a pixel or two. Suspicion confirmed.

My method was rather more direct: I held a rule(r) to the screen.
height 118mm, width 140mm.


You might want to look into reconfiguring your display.

(I counted pixels because of the possibility, resulting from the
combination of a wide screen display and a graphics card from the days
of 4:3 displays, that the pitch was different between horizontal and
vertical directions, but any difference is nowhere near 15%.)
--
Stewart Robert Hinsley

Sleepalot wrote:

Stewart Robert Hinsley wrote:


The oblateness wouldn't show up on a polar view, and anyway is too small
to be obvious to the naked eye.

My first suspicion is that the image is circular, and the apparent
oblateness is an optical illusion, possibly resulting from the dark
areas at the top and bottom.

After examination of the image in an image editor I find that the
vertical and horizontal diameters of the image of the earth is the same
to within a pixel or two. Suspicion confirmed.

My method was rather more direct: I held a rule(r) to the screen.
height 118mm, width 140mm.

Additionally, I checked out the polar and equatorial diameters
of the Earth: the difference is less than 0.5%

Otoh, the difference in the dimensions of the image[1] is 16%,
so it's not a"natural" image.

[1] on my screen.



--
Sleepalot aa #1385

Sleepalot wrote:
Paul Herber wrote:
Looks more like 30N to me.

Hmm. Yes, it does. Is the Earth oblate at 30N?

I'm finding this thread very confusing - are we all seeing the same images?

On my screen, it's clearly centred directly above the pole, and it's
clearly circular.
--
Steve Loft
Sanday, Orkney. 5m ASL. http://sanday.org.uk/weather
Free weather station softwa http://sandaysoft.com/
uk.sci.weather FAQs/glossary/etc: http://weatherfaqs.org.uk/

Stewart Robert Hinsley wrote:

(I counted pixels because of the possibility, resulting from the
combination of a wide screen display and a graphics card from the days
of 4:3 displays, that the pitch was different between horizontal and
vertical directions, but any difference is nowhere near 15%.)

Yep, you're right. I was using 800x600 (so I could _see_ stuff)
now I've changed to 1280x800, and the planet is circular again
(but much further away!).

Thanks for sorting that out.

--
Sleepalot aa #1385