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View Full Version : "Dim" as well as Dark Matter? Oh, for an Occam!



JohnD
2005-May-29, 04:56 PM
All,
The Apod for today, 29th May, is about the Sagittarius Dwarf Tidal Stream and the Milky Way swallowing a neighbour galaxy. In the last line the text refers to "dim and dark matter" both adjectives hyperlinked. However, the 'dim' link takes one to a previous APOD about the Aquarius Dwarf Galaxy, with no mention of 'dim matter'. That to 'dark matter' doesn't work. I presume that there is an error in these links, but am none the wiser about 'dim' matter

Has cosmology now resorted to another anomolous form of matter? Haven't they heard of Occam's Razor?

John

01101001
2005-May-29, 05:19 PM
Here is a link to the APOD in question (http://antwrp.gsfc.nasa.gov/apod/ap050529.html).

Sometimes astrophysicists speak and write with ordinary language that isn't specialized jargon. I think this may be a case. To me, "dim matter" refers to matter that isn't bright, like me, you, planet earth, interstellar gas. It's stuff that is there, ordinary matter, that isn't luminuous.

A quick Google search on "dim-matter" seems to indicate the same.

I believe you can return your Occam's razor to its sheath.

A Thousand Pardons
2005-May-29, 05:43 PM
However, the 'dim' link takes one to a previous APOD about the Aquarius Dwarf Galaxy, with no mention of 'dim matter'. That to 'dark matter' doesn't work. I presume that there is an error in these links, but am none the wiser about 'dim' matter
The Aquarius Dwarf Galaxy is described as "faint", and the dark matter link works for me, at least now.

Brady Yoon
2005-May-29, 05:59 PM
Sometimes, I wonder if dark matter is needed at all. Maybe the answer is right under our noses.

A Thousand Pardons
2005-May-29, 06:03 PM
aha, dork matter

I'll be famous

Zachary
2005-May-29, 06:20 PM
Has cosmology now resorted to another anomolous form of matter? Haven't they heard of Occam's Razor?

John

Hah, I thought that when it came to cosmology Occam's Razor was thrown out of the window :lol:

A Thousand Pardons
2005-May-29, 06:30 PM
Hah, I thought that when it came to cosmology Occam's Razor was thrown out of the window
Not just cosmology. Occam's Razor is not a scientific principle, period. The process is too subjective--how would you use it to distinguish between Newton's laws and Einstein's?

Not you, him.

Zachary
2005-May-29, 06:42 PM
Hah, I thought that when it came to cosmology Occam's Razor was thrown out of the window
Not just cosmology. Occam's Razor is not a scientific principle, period. The process is too subjective--how would you use it to distinguish between Newton's laws and Einstein's?

Not you, him.

Well quite clearly Einstein's are the simplest. Of course objects gain mass as they approach 300000000 ms^-1. And it's quite clear to me that my computer has a wavelength :lol:

mickal555
2005-May-29, 11:21 PM
I think the razor was ment to be used as a thing agenst WOO_woooooooooooo's