"The colors of the spectrum, then, "are not Qualifications [alterations] of Light … (as 'tis generally believed), but Original and connate properties." When you purchase through links on our site, we ...

The speed of light is a fundamental constant, approximately 299,792,458 meters per second. It's the same for all observers and hasn't changed measurably over billions of years. Nothing can travel ...

Can we turn back time? Ask a savvy physicist, and the answer will be “it depends.” Schemes for retrograde time travel abound but usually involve irreconcilable paradoxes and rely on outlandish ...