Create new document with 6x6 pixels size. With 1px black pencil tool, draw a line on bottom of image.
Go to Edit - Define Pattern, click OK
Close this document without saving (will not need it anymore), then create new document, square and about 3 times bigger than your original artwork - so if you made it 1024x768, make new document 3000x3000 pixels. Go to Edit menu - Fill, set Use to Pattern, then in
Custom Pattern list find the pattern you just created.
Now entire document is filled with lines.
Go to Filter menu - Distort - Twirl. Set Angle to about 100-150, apply. Now we have nice curved lines, shown here at 25% zoom. select part of this image, somewhere near center, copy to clipboard (Ctrl-C).