If the earth's direction of rotation is reversed, what would be the 1ST when it is noon at the International Date Line?

1. The International Date Line (IDL) is roughly at 180° longitude. 2. Noon at the IDL means the sun is directly overhead at 180° longitude. 3. Indian Standard Time (IST) is based on 82.5° East longitude. 4. Normally, the Earth rotates from West to East. When it is noon (12:00) at 180°, we need to find the time at 82.5° E. 5. The time difference between 180° and 82.5° E is (180 - 82.5) = 97.5 degrees. 6. The Earth rotates 360° in 24 hours, or 15° per hour. 7. So, the time difference is 97.5 / 15 = 6.5 hours. 8. Since 82.5° E is west of 180°, the time at 82.5° E would normally be 6.5 hours *earlier* than at 180°. So, 12:00 - 6.5 hours = 05:30 hrs IST. 9. HOWEVER, the question states the earth's direction of rotation is reversed (East to West). 10. If rotation is reversed, locations to the East will have *earlier* times, and locations to the West will have *later* times, compared to the sun's position. 11. With reversed rotation, when it is noon at 180°, 82.5° E is still 97.5 degrees away. But now, being west of 180° means it will experience noon *later*. The time difference magnitude is still 6.5 hours. 12. So, the time at 82.5° E (IST) would be 6.5 hours *later* than noon at 180°. 13. Therefore, the time would be 12:00 + 6.5 hours = 18.30 hrs IST.