Thu Feb 19, 2026 4:13 pm Show me objects in the natural world that illustrate the laws of physics and chemistry: ice crystals, waves, snow-flakes, sand patterns, dunes... There is a special beauty to these...
No man-made objects allowed!
Here are some of mine:
wave interference
fractal sand patterns
swirls of the current
wave resonance on the sand
white light is broken into its constituents at a thin liquid air interphase
water crystals
Submissions will be closed on Thursday the 26th of February 2026 at 16:13:50 UTC
Posting Photos for a Contest
1. Photos must be hosted on pbase.com
2. Maximum of 3 photos per contest.
3. Photos must be embedded in your post. See the following link for how to do this http://forum.pbase.com/viewtopic.php?t=18022
4. Post only medium versions of your picture using the PB-Image button
5. The host is not eligible for their own contest.
6. Any picture you've taken is eligible, regardless of date taken and camera, as long as it hasn't already won another contest.
7. You can do all the post processing you want.
Winning and Running a Contest
1. If you enter the Show and Tell Contest, please note the closing date and be sure to check back to see if you won.
2. If you win the Show and Tell Contest and cannot run the next one, please notify the person running the contest immediately, so they can notify the second place winner.
3. If you decide to run the next contest, please post the new contest within 24 hours.
4. When the contest ends, please post the winners within 24-48 hours. (If you keep an eye on entries during the week, you will have a good idea of your favorites by the time the contest ends, and be able to more quickly post your winners.)
5. If you know you will not be able to post a contest, judge it, and post winners, within these timeframes, please do not start one. Instead, notify the person running the contest, so they can pass it on to the second place winner.
6. Pick first, second, and third place winners. You may include up to 5 honorable mentions.
7. Include these rules in the body of your contest.
Competition History available at https://forum.pbase.com/viewtopic.php?f=9&t=42757
