space | Technology Bloggers

The Size of Space

13th October 2014 Leave a reply Christopher Roberts

I’m starting with a fact today; two actually.

FACT

According to astronomer Dr Peter Edwards, if our solar system was a grain of sand, then The Milky Way (our Galaxy) would be 1,000 times the size of Durham Cathedral.

Durham Cathedral

FACT

According to NASA there are hundreds of billions of galaxies in our universe.

Need a more visual representation of that? Well luckily for you, the American Museum of Natural History have spent quite a long time developing a digital universe.

Somewhat mind boggling, isn’t it. Dr Edwards doesn’t think the human mind is really built to understand the enormity of the universe. I think I probably agree with him.

In 2012 the Hubble Space Telescope zoomed in on a seemingly empty area of space. This area of space could be covered up with just a single grain of sand if you were looking at it from Earth. Astronomers didn’t think they would discover much, but if you have a super duper space telescope, why not see what it can find?

This is what that seemingly empty bit of space actually looked like when Hubble zoomed in.

Every single speck of light you can see is a galaxy. Yes the 100 or so huge ones in the foreground, but also the millions in the background.

Each of those galaxies contains billions of stars. Yes many of them look insignificantly small, but they are very very far away. So the well used fact that there are more stars in the universe than there are grains of sand on Earth is actually true. In fact there are many billions more stars in space than there are grains of sand on the Earth. Each star is in solar systems filled with matter – from specs of dust to moons and planets.

The title of this article suggests that I will try to quantify the size of space. This isn’t really possible, so all we can currently do is describe its size relative to other things. If I had to use one word to describe space, I think it would have to be enormous.

A key question surrounding space is: is it infinite?

That is an existential question which I doubt we will ever know the answer to, but never the less it is still an interesting question, which is worth considering.

The theory that the universe is a sphere – like the Earth – is a popular one, and I can understand the logic in this, if you keep going, eventually the universe will loop you back around to where you started. But then my problem with this theory is we can go beyond the Earth. We can travel around the Earth, but space travel proves that we can move in 3 dimensions, straight and sideways on Earth and then upwards into space. If you got to the very edge of the universe, what would happen if you went upwards? If there isn’t an upwards, what is there?

New Scientist states that from all current data, it seems that the known universe has a diameter of about 93 billion light years. That’s pretty big, but by no means infinite. So if this estimate is correct – which is ridiculously unlikely – what comes after that? A big wall with a no entry sign? Just empty space? Another universe? Who knows…

That’s Your Lot

See you next week for the next in the series.

Space – A Series

6th October 2014 Leave a reply Christopher Roberts

Space. It’s a big old space.

Insert awesome picture of space to keep people interested. Check.

The Carina Nebula – Picture taken by The European Southern Observatory (ESO).

What happens here on Earth is insignificant in the universe. That doesn’t mean things that happen here are unimportant – far from it – but in reality, we are tiny. Nothing we have done or can do has much of an impact on the universe. Nothing that happens here on Earth affects the marvellous enormity, complexity and vastness of space.

Our lives, this entire planet, our solar system and even galaxy are tiny. Nobody really knows how tiny – relatively – because nobody knows how big the universe is. Or at least how big it is it a specific point in time – given its changing and expanding nature.

I really enjoy learning about space, so I have decided to write a series about space.

In this series I plan to cover some of space’s big topics; including:

How big (or indeed small) are we really?
Information on the International Space Station
Will humans ever live on other planets?
Black holes
The future of space exploration
How has our knowledge of space changed things on Earth?

Key Terms

There are a few terms I will be using a lot during the course of this series. To help keep us all on the same page, here is how I am going to define them.

Space
Everything everywhere! Anything that exists, exists in space. Space can be a completely empty vacuum or it can be full of matter, or waves such as light and sound. If there is something, or the potential for something to be there, it is space.

Matter
Stuff. Things made of atoms. Tangible objects. Not including electromagnetic waves; like light.

The Universe
The zone of activity in space which contains all known matter.

A Galaxy
A collection of billions of solar systems.

A Solar System
A collection of matter, orbiting a star. That matter includes planets and smaller structures like asteroids.

A Planet
A large body which orbits a star.

Next Week

I have already written next weeks post, so I can tell you with all certainty that I will be exploring the size of the universe. See you then.

Asteroid Hunting

21st February 2013 3 Replies Jonny Hankins

Many of you will have seen the video of the meteor that exploded into the atmosphere above Russia last week, and I would just like to offer an overview of the event from a practical scientific prespective.

The meteor was about 15 metres across, and as such too small to detect. As we all saw though a meteor of this size can do extensive damage. It weighed about 7000 metric tonnes, travelling at 18 Km per second and exploded at a height of between 15 and 20 Km. This is pretty close to the ground if you think that an aeroplane flies at about 10Km and we are certainly not dealing with somewhere where nothing happens.

The force of the explosion was about 30 times that of the Hiroshima bomb, a pretty devastating blow by all counts. We should think ourselves lucky that it did not happen over a major city.

Trees blown over after the 1908 meteor impact

In 1908 in Tunguska also in Russia a much larger meteor hit. This one was about the size of the DA14 meteor that flew past Earth later on the same day last week, and it blew trees down over an area of about 2000 square Km. Once again it hit over Siberia so less damage than could have occurred, but if you think that the event of last week over Russia only threw out about 5% of the force of this one than we don’t need much imagination to envisage the possible catastrophe. Several photos are available around the net and I offer one above. There are also plenty of huge craters to see.

NASA have the Near Earth Program, and they have the mission of monitoring the many things that fly close to Earth.

It is not an easy job though as you might imagine, they use ground based telescopes so can only see something that is big enough to reflect enough light, and last week’s hit came directly in line with the sun, so practically impossible to see.

NASA has managed to identify 90% of near Earth asteroids that are more than 1 Km across, and something of this size might threaten life on Earth itself if it hit. There are more than a million near Earth asteroids however that are 20 metres across or more but very few of these have been identified and mapped.

The B612 Project is hoping to put a telescope into Space before 2018 that will be able to spot something of that size, but until then they will go largely unseen.

Keeping on a related topic last May I put a post up about asteroid mining, and recently the BBC has carried some updates on this project.

It is currently a 2 horse race, but it seems very speculative. And I remember a song about horses of this type.

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