# Does the speed of light ever drop below 299 792 458 m s?

## Does the speed of light ever drop below 299 792 458 m s?

The short answer is that it depends on who is doing the measuring: the speed of light is only guaranteed to have a value of 299,792,458 m/s in a vacuum when measured by someone situated right next to it. But let’s approach the question by considering its various meanings.

How much is the speed of darkness?

This mysterious energy makes up 80 percent of all matter in the universe. In a 2013 study, scientists determined that dark matter should have a speed of 54 meters per second, or 177 feet — slow compared to the speed of light [source: Armendariz-Picon and Neelakanta].

### How fast is the speed of dark?

Darkness travels at the speed of light. More accurately, darkness does not exist by itself as a unique physical entity, but is simply the absence of light.

Why is the speed of light 299?

The speed of light is 299 792 458 m/s because people used to define one meter as 1/40,000,000 of the Earth’s meridian – so that the circumference of the Earth was 40,000 kilometers.

#### What is the exact speed of light in meters per second?

299,792,458 metres per second
In particular, the value for the speed of light in a vacuum is now defined as exactly 299,792,458 metres per second.

What is the speed of smell?

The speed of smell is the time taken to identify an olfactory stimulus as a scent, smell or stench. The delicious smell of summer rain may not be apparent for minutes after a cloudburst. The amorous scent of one’s lover may prompt a response in seconds.

## Can a human survive light speed?

So will it ever be possible for us to travel at light speed? Based on our current understanding of physics and the limits of the natural world, the answer, sadly, is no. So, light-speed travel and faster-than-light travel are physical impossibilities, especially for anything with mass, such as spacecraft and humans.

How do I calculate speed?

The formula for speed is speed = distance ÷ time. To work out what the units are for speed, you need to know the units for distance and time. In this example, distance is in metres (m) and time is in seconds (s), so the units will be in metres per second (m/s).

### What is the maximum speed of light?

But Einstein showed that the universe does, in fact, have a speed limit: the speed of light in a vacuum (that is, empty space). Nothing can travel faster than 300,000 kilometers per second (186,000 miles per second). Only massless particles, including photons, which make up light, can travel at that speed.

What is the exact speed of light in km s?

Light from a stationary source travels at 300,000 km/sec (186,000 miles/sec).

#### Why is the speed of light 299 792 458 m / s?

The speed of light is 299 792 458 m/s because people used to define one meter as 1/40,000,000 of the Earth’s meridian – so that the circumference of the Earth was 40,000 kilometers. Also, they used to define one second as 1/86,400 of a solar day so that the day may be divided to 24 hours each containing 60 minutes per 60 seconds.

Why is the speed of light measured in m / s?

Why is a metre 1 / 299792458 of the distance light travels in a sec in a vacuum? The speed of light is 299 792 458 m/s because people used to define one meter as 1/40,000,000 of the Earth’s meridian – so that the circumference of the Earth was 40,000 kilometers.

## What is the speed of light in a vacuum?

SOLUTION: The speed of light in a vacuum is 299,792,458 meters per second. Write the formula in scientific notation. Question 239949: The speed of light in a vacuum is 299,792,458 meters per second. Write the formula in scientific notation.

What is the speed of light in 10 significant figures?

186000 miles per second to 3 sig figs. What is the Speed of light in 10 significant figures? 1,079,252,848 km/h or 299,792,457.8m/s What is the speed of light with 7 significant figures? 299792500 m/s What is the wave speed of visible radiation?