THE UNIVERSE: A SUMMARY

PDF Version: Universe Questions and Answers

1. What is the universe?

The visible universe is huge and contains everything – time, space, and matter – but at the same time is largely empty because it keeps expanding at high speed.

 

2. How did the universe begin?

Fourteen billion years ago, the universe began in a split-second explosion, a Big Bang: energy changed into matter and anti-matter; 300,000 years later, most of the particles had destroyed each other and the temperature had dropped to 3000 degrees Celsius, leaving hydrogen and helium atoms.

 

3. What are galaxies and how did they form?

Most of the universe was invisible for the first 300,000 years until in some places, hot dense gaseous areas coalesced – due to gravity – to form visible stars; some of those stars came together to form galaxies, some of which coalesced to form larger galaxies.

 

4. How is distance measured in space?

The universe is huge; the second nearest star – Proxima Centauri – is 38 trillion kilometres away, so astronomical units – the distance between the earth and the sun – are too large to easily read; instead, astronomers measure in light years – the distance light travels in one year, which is 300,000 kilometres per second or over nine trillion km.

 

5. What is a black hole?

When heavy-weight stars collapse in supernova explosions, invisible black holes are created; they can be more massive than the sun, have no surface and are very dense with such gravitational force that anything that comes near is stretched to the breaking point and cannot escape, not even light; these black holes give off x-rays and help keep galaxies in balance.

 

6. How did life on earth begin?

Ancient rocks show that life on earth began 3,800 million years ago, but scientists are not sure how it began; some think life may have come from space via comets and meteorites containing carbon-based chemicals, while others think perhaps it started in hot springs under the oceans where heat provided necessary energy.

 

7. What is ordinary matter?

Ordinary matter – 15% of the universe – makes everything we can see, smell or touch; it includes all solids, liquids and gases and is made of atoms.

 

8. What is dark matter?

Dark matter – 85% of the universe – doesn’t absorb, emit, or reflect light; it is made of subatomic particles and is spread throughout the universe, reacting only weakly on ordinary matter.

 

 

 

 

Date:                                                                                                                                     Name:

THE UNIVERSE: A SUMMARY  

/ 65   (You will lose 0.5 points for each spelling mistake.)

Bonus =

 

1. What is the universe?                              / 6

The visible universe is huge and contains everything – _________ , _______________ , and ________________ – but at the same time is largely __________ because it keeps _____________ at high ____________.

 

2. How did the universe begin?               / 9

____________________ billion years ago, the universe began in a split-second explosion, a ___________ ______________: energy changed into m___________ and a_____________; __________________ years later, most of the p__________ had destroyed each other and the temperature had dropped to 3000 degrees Celsius, leaving h_________ and h_________ atoms.

 

3. What are galaxies and how did they form? / 8

Most of the universe was i___________ for the first ______________ years until in some places, h___ d________ gaseous areas coalesced – due to g___________ – to form v________ stars; some of those stars came together to form g___________, some of which c______________ to form larger galaxies.

 

4. How is distance measured in space? / 8

The universe is huge; the second nearest star – ______________ ______________ – is ____ trillion kilometres away, so a___________________ units – the distance between the ______________ and the _______ – are too large to easily read; instead, astronomers measure in _____________ years – the distance _____________ travels in one year, which is _________________ kilometres per second or over nine trillion km.

 

5. What is a black hole? / 9

When heavy-weight __________ collapse in supernova explosions, i_____________ black holes are created; they can be more m______________ than the sun, have no s_________ and are very d_______ with such g________________ force that anything that comes near is stretched to the breaking point and cannot e__________, not even light; these black holes give off _____________ and help keep galaxies in __________________.

 

6. How did life on earth begin? / 9

Ancient rocks show that life on earth began ______________________ years ago, but scientists are not sure how it began; some think life may have come from __________ via c___________ and m_____________ containing ______________-based chemicals, while others think perhaps it started in _____ ___________ under the oceans where ________ provided necessary ______________.

 

7. What is ordinary matter? / 8

Ordinary matter – ____________ of the universe – makes everything we can s______, s_________ or t_________; it includes all s________, l__________ and g_______ and is made of a_____________.

 

8. What is dark matter? / 5

Dark matter – ___________ of the universe – doesn’t a____________, e____________, or r___________ light; it is made of _________________ particles and is spread throughout the universe, reacting only weakly on ordinary matter.

 

BONUS: Can you name 20 elements on the periodic table?