And You Will Never Know It for They Will Be From Outer Space

It tin can stretch your mind to ponder what's really out there. Stijn Dijkstra/EyeEm via Getty Images

Curious Kids is a serial for children of all ages. If you have a question you'd like an expert to answer, send it to curiouskidsus@theconversation.com.

What is beyond outer infinite? – Siah, age 11, Fremont, California

Right to a higher place you is the sky – or as scientists would call it, the atmosphere. Information technology extends most xx miles (32 kilometers) above the Earth. Floating effectually the atmosphere is a mixture of molecules – tiny $.25 of air so small y'all accept in billions of them every time you breathe.

Above the temper is infinite. It's called that because information technology has far fewer molecules, with lots of empty space between them.

Have you lot ever wondered what it would exist similar to travel to outer infinite – so continue going? What would you find? Scientists like me are able to explain a lot of what you'd come across. Simply there are some things nosotros don't know yet, like whether space merely goes on forever.

Planets, stars and galaxies

At the offset of your trip through space, you lot might recognize some of the sights. The World is part of a grouping of planets that all orbit the Sun – with some orbiting asteroids and comets mixed in, likewise.

A diagram of the solar system, showing the sun and its orbiting planets.

You might know that the Sun is actually only an average star, and looks bigger and brighter than the other stars but because information technology is closer. To get to the adjacent nearest star, you lot would have to travel through trillions of miles of space. If you could ride on the fastest infinite probe NASA has ever made, it would still take yous thousands of years to get in that location.

If stars are like houses, then galaxies are like cities full of houses. Scientists estimate there are 100 billion stars in Earth's milky way. If you could zoom out, fashion beyond Earth'due south galaxy, those 100 billion stars would blend together – the manner lights of urban center buildings exercise when viewed from an airplane.

Recently astronomers have learned that many or fifty-fifty nigh stars have their ain orbiting planets. Some are even like Earth, so it'south possible they might be home to other beings likewise wondering what's out there.

An epitome showing detail of 1 galaxy, simply visually implying at that place are many more than.

You would have to travel through millions of trillions more than miles of space just to reach another milky way. Most of that infinite is almost completely empty, with but some stray molecules and tiny mysterious invisible particles scientists call "nighttime matter."

Using large telescopes, astronomers see millions of galaxies out there – and they just keep going, in every direction.

If you could watch for long plenty, over millions of years, it would wait like new space is gradually being added betwixt all the galaxies. You can visualize this by imagining tiny dots on a deflated balloon then thinking nearly blowing it up. The dots would keep moving farther autonomously, only like the galaxies are.

Is there an end?

If you could go on going out, every bit far as you wanted, would you only keep passing by galaxies forever? Are there an infinite number of galaxies in every direction? Or does the whole affair eventually end? And if it does stop, what does it cease with?

These are questions scientists don't have definite answers to notwithstanding. Many call back it's likely y'all would merely go along passing galaxies in every direction, forever. In that example, the universe would be space, with no stop.

Some scientists recollect information technology's possible the universe might eventually wrap back around on itself – so if y'all could only go on going out, you would someday come back effectually to where y'all started, from the other direction.

I mode to recollect about this is to picture a globe, and imagine that you are a beast that tin move simply on the surface. If you start walking any direction, east for example, and simply keep going, eventually y'all would come up dorsum to where you began. If this were the instance for the universe, it would mean it is not infinitely big – although it would still be bigger than you lot can imagine.

In either case, yous could never get to the end of the universe or space. Scientists now consider it unlikely the universe has an finish – a region where the galaxies stop or where there would be a barrier of some kind marker the end of infinite.

Just nobody knows for sure. How to answer this question volition demand to be figured out by a future scientist.

Hi, curious kids! Practise y'all have a question you'd similar an skilful to answer? Ask an adult to send your question to CuriousKidsUS@theconversation.com. Please tell united states your name, age and the city where y'all live.

And since curiosity has no age limit – adults, permit us know what you're wondering, too. We won't be able to answer every question, but we volition do our best.

This article has been updated to correct the distances to the nearest star and galaxy.

This article is republished from The Conversation, a nonprofit news site dedicated to sharing ideas from academic experts. It was written by: Jack Singal, University of Richmond.

Read more:

• The art of Aphantasia: how 'mind blind' artists create without beingness able to visualise

• Why your zodiac sign is probably wrong

• Why do people look into space with telescopes just not binoculars?

Jack Singal does non piece of work for, consult, own shares in or receive funding from whatsoever company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their bookish appointment.

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Source: https://news.yahoo.com/does-outer-space-end-forever-122040757.html

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