It is customary for synagogues to have a Ner Tomid, a light burning always near the front of the synagogue.
1) Why do we have a Ner Tomid?
2) If it is a reminder of the “ner maarovi” which was one of the lights of the menorah in the Bes Hamikdosh that lasted miraculously from when it was kindled up to the same time the following day Gemoro Shabbos 22b (up until the death of Shimon HaTzaddik), why is it that some modern designs have one central light surrounded in a circle by smaller lights? To be comparable to the menorah there should only be one light that is always alight.