Walking Across the Universe

Have you ever thought about walking, or trotting, across the whole Universe? I have. Now to start you on the Universe, the Observable Universe is the amount of the Universe we can see from earth. Also, a light-year is the distance light travels in one year, which is 5.88 trillion miles! That little section is a whole 93.016 billion light-years (550 sextillion miles) in diameter! Nobody can even estimate how big the entire universe is, but it is probably at least 23 trillion light-years across. So saying the Universe is that big, let’s estimate how long it would take to walk across the Universe.

We’ll say there’s a flat straight road going right across, no resting periods and no food is needed, and you can breath normally, and you’re constantly walking at a pace of 4mph. It would take about 3,856,373,706,725,747,097,862 (3.86 sextillion) years to travel across, if the Universe weren’t expanding.

Scientists know the Universe is expanding at a rate of 163,000mph! Not even the SR-71, or X-15 can fly that fast! NASA’s X-43A can go nearly mach-10, but that’s still way slower than the Universe is expanding! The only way you can travel across the Universe is if you’re able to figure out how to travel faster than 163,000mph (mach-208.531778).

You’re probably wondering how scientists know the Universe is expanding. Have you heard of the Doppler Effect? When cars pass they start with a higher pitch sound and after passing it’s lower pitch. It’s similar with light. As it gets farther away it turns more red. This is know as red-shift. So purple would turn more blue while yellow would turn more orange. Hopefully that makes sense.