Unraveling the Cosmic Speed Limit: The Fascinating Journey of Light-Speed Discovery and Its Implications

 For many years, experts thought that light traveled at an infinite speed. This belief seemed logical, as turning on a light appears to produce instant illumination. However, in the 17th century, Danish astronomer Ole Rømer proposed that light had a finite speed and calculated its value while working at the Paris Observatory under the direction of Giovanni Domenico Cassini. Rømer's calculations were based on his observations of Io, one of Jupiter's most famous moons. In this article, we will explore the speed of light and why it cannot be surpassed.

Scientists have established that Io completes a full orbit around Jupiter in 1.76 days. Rømer discovered that the time taken for this orbit varied throughout the year, with the moon taking longer to orbit Jupiter when Earth was further away and speeding up when the planets were closer. This led Rømer to conclude that light's speed was not infinite, as it took time for light to travel between Jupiter and Earth.

Rømer's hypothesis initially failed to convince his fellow scientists. To prove his point, he predicted that Io's eclipse on November 9, 1676, would occur 10 minutes earlier than what other scientists had calculated based on the moon's previous orbits. Rømer's prediction came true, and even Cassini had to accept that light's speed was not infinite. Rømer estimated that light took 22 minutes to travel the diameter of Earth's orbit, calculating its speed to be 220,000 kilometers per second – an incorrect measurement, but the closest approximation to its actual value of 299,792.458 km/s.

Some researchers propose the existence of particles called "tachyons" that could travel faster than light. However, even if these particles existed, they would be unable to decelerate. Over a century ago, Einstein demonstrated that an object's energy (E) relates to its mass (m), leading to the famous relativity formula E=mc'2, where c represents the speed of light.

This equation reveals that energy and mass are interchangeable, with energy transforming into mass when an object accelerates. As a result, increasing an object's speed requires more energy. As we approach the speed of light, we need enormous amounts of energy to continue accelerating. For instance, an 80 kg person would have a mass of 2 tons if they traveled at 99.9% of the speed of light.

Attempting to propel this person beyond the speed of light would cause their mass to increase exponentially while their speed remained virtually unchanged. This is why we cannot surpass the speed of light (or even attain it with our current technology).