What Is Faster Light Or Electricity?
The speed at which anything can travel has fascinated humankind for centuries. From early attempts to quantify the speed of sailing ships and horses to measuring the velocity of light and electricity, we have long tried to understand the physical limits on speed. Two velocities that have captivated our imagination are the speed of light and the speed of electricity. Their incredible velocities seem to defy logic and push the boundaries of what we believe possible. But how exactly fast do light and electricity travel? And how do their speeds compare?
This article will examine the speeds of light and electricity in detail. We’ll look at the history of measuring these speeds, how physicists calculate them today, and their implications for modern technology. You’ll learn just how blisteringly fast light travels through the vacuum of space as well as how almost unimaginably quickly electricity zips through the wires in your home. And we’ll compare their velocities head-to-head – which is ultimately faster, light or electricity?
Speed of Light
The speed of light in a vacuum, commonly denoted by c, is a universal physical constant that is exactly equal to 299,792,458 metres per second (ref: https://en.wikipedia.org/wiki/Speed_of_light). This speed is considered a physical constant and represents the maximum speed at which all energy, matter, and information can travel.
The first successful measurement of the speed of light was made in 1676 by the Danish astronomer Ole Rømer (ref: https://www.amnh.org/learn-teach/curriculum-collections/cosmic-horizons-book/ole-roemer-speed-of-light). By carefully timing the eclipses of Jupiter’s moon Io, Rømer was able to show that light has a measurable speed and does not travel instantaneously. His calculation of the speed of light was remarkably accurate given the limitations of the equipment available at that time.
Since then, many more precise measurements have been made using advanced techniques like lasers and interferometry. But the speed of light itself is believed to be constant and independent of the motion of the source or observer.
Speed of Electricity
Electricity does not travel at a single speed, but its velocity depends on the medium it is traveling through. In everyday electrical devices, electricity travels through wires as electromagnetic waves at 50-99% the speed of light in a vacuum, which is approximately 186,000 miles per second or 300,000,000 meters per second. The actual speed varies based on the type of cable and conditions. (Speed of Electricity)
Within the wire itself, the electrons that make up the electrical current have a very slow drift velocity, on the order of millimeters per second. However, the overall electromagnetic wave propagates down the wire at nearly the speed of light, rapidly transferring energy from point to point. (What is the Speed of Electricity?)
Factors like resistance, capacitance, and inductance impact how fast the electricity can travel through a material. But in most everyday electrical systems, the electromagnetic waves carrying the energy flow extremely quickly at a large fraction of light speed.
Lightning Speed
Lightning is an electrical discharge that occurs during a thunderstorm. The visible flash we see from a lightning strike actually travels at the speed of light, which is approximately 670,000,000 mph. According to NASA, the speed of light is around 186,000 miles per second [1]. However, the actual lightning bolt itself travels much slower, at around 270,000 mph according to the Met Office [2]. This is still incredibly fast, making lightning one of the fastest natural phenomena on Earth.
The lightning current can travel even farther when it moves through conductive materials like water, metal fences, power lines or plumbing according to NOAA [3]. This allows the electrical discharge to spread out over miles from the initial lightning strike point.
Power Grids
Electricity moves through power lines and grids at nearly the speed of light. According to the Electric Power Research Institute, electricity travels along high voltage transmission lines at a speed ranging from 87% to 99% of the speed of light (source here: How Fast Does Electricity Travel). This equates to approximately 186,000 to 299,000 kilometers per second or 116,000 to 186,000 miles per second.
Power grids consist of interconnected transmission and distribution lines that transmit electricity from power plants to substations and then to homes and businesses. The high voltages used in transmission lines (110 kilovolts or higher) allow electricity to travel extremely fast with minimal energy lost. As electricity gets stepped down to lower voltages for distribution, the speeds gradually decrease. But even at the 120/240-volt levels of household electrical outlets, electricity is still flowing through the wires at around half the speed of light.
So in most everyday electrical systems, electricity moves at incredible speeds that approach the speed of light. This allows electrical devices to function virtually instantaneously, confirming that electricity travels faster than the blink of an eye.
Fiber Optics
Fiber optic cables use light to transmit data at incredible speeds. The speed of light in a vacuum is approximately 299,792 kilometers per second. However, in fiber optics, the speed of light is slightly slower due to the refractive index of the glass fiber. According to research by Kansas State University, the speed of light in an optical fiber is ~2.054 x 108 m/s, corresponding to a refractive index of ~1.4606 [1]. This is still extremely fast and allows fiber optics to transmit data across long distances in milliseconds.
Fiber optic cables contain ultra-pure glass cores that act as waveguides for light. Lasers or LEDs generate pulses of light that represent data, and these light pulses reflect internally down the length of the fiber optic cable. The light carries the data encoded within it to the destination extremely rapidly. This makes fiber optics ideal for high-bandwidth applications like internet backbones, HD video streaming, and telecommunications networks where large amounts of data must be sent quickly.
While electrical signals in copper cables degrade over long distances, light pulses in fiber optics can transmit data across continents with very little signal loss. This allows fiber to reliably move data at nearly the speed of light over thousands of kilometers. The high speeds and long reach of fiber optics are why global communication networks rely extensively on fiber optic connectivity.
[1] https://web.phys.ksu.edu/posters/2009/juma-Adv-Lab-S09.pdf
Speed Comparison
When directly comparing the speeds of light and electricity, light travels significantly faster. The speed of light in a vacuum is approximately 186,282 miles per second (299,792,458 meters per second), making it the fastest known speed in the universe [1]. In contrast, the drift velocity of electrons in a copper wire is on the order of millimeters per second [2]. The electromagnetic waves transmitting electric signals propagate at 50-99% the speed of light, but still far below the maximum speed of light [3]. Overall, light travels over 200,000 times faster than electricity in everyday applications.
To illustrate the vast difference, a beam of light could circle the Earth 7.5 times in just one second. Electricity would take over 130 seconds to travel the same distance along the planet’s surface. When it comes to transmitting information over long distances, light’s incredible speed is unrivaled.
Real-World Impact
The difference in speed between light and electricity matters in applications where near real-time communication is critical over long distances. For example:
Power Grids: Electricity travels through the power grid at near the speed of light, but even small delays can cause issues in balancing supply and demand across the network. Precise timing and coordination relies on monitoring equipment communicating at lightspeed via fiber optic cables (Source).
High Frequency Trading: For stock trades executed in microseconds, the speed advantage of light versus electricity is significant. Fiber optic networks allow data centers to be placed physically closer together to minimize communication delays (Source).
Remote Surgery: Precise robotic control over long distances requires near real-time communication. Any lag caused by electrical delays could negatively impact outcomes, so remote networks often use fiber optics to transmit data at lightspeed (Source).
In these types of time-sensitive applications, the faster speed of light over electricity provides practical advantages in data transmission and coordination.
Future Possibilities
In the future, the speeds of light and electricity may converge as new technologies emerge. Some scientists believe that with advances in photonics, light could replace electricity for computing and information transmission (Stanford Engineering). Photonic chips and optical circuits could allow data transmission at the speed of light, vastly exceeding the speed of electrical signals. Quantum computing also holds promise for light-speed calculations by encoding information in photons.
On the flip side, some theoretical physics concepts like warp drives or wormholes suggest it may be possible to travel at superluminal speeds exceeding the speed of light. If these far-future ideas ever become reality, electrical signals could theoretically travel as fast as light. But currently, these concepts are highly speculative.
In summary, light and electricity may one day converge in speed with breakthroughs in photonics or spacetime travel, but for now, light remains far faster for transmitting information. Yet the future possibilities to unite light and electricity remain intriguing.
Conclusion
In summary, both light and electricity travel at extremely fast speeds that enable modern technology, but light is ultimately faster. The speed of light in a vacuum is a constant at approximately 300,000 kilometers per second. Electricity travels through wires at nearly the speed of light, but slightly slower due to resistance and other factors. While electricity moves fast enough for practical applications like powering appliances, light speed enables lightning, fiber optic communication, and theoretical faster-than-light space travel. There are still many unknowns about harnessing the incredible velocity of light, but its speed will continue enabling innovation in science and technology into the future.
