User talk:205.123.145.30

November 2020
Hello, I'm Materialscientist. I wanted to let you know that I reverted one of your recent contributions—specifically this edit to Light barrier—because it did not appear constructive. If you would like to experiment, please use the sandbox. If you have any questions, you can ask for assistance at the Help desk. Thanks. Materialscientist (talk) 16:47, 20 November 2020 (UTC)
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