Global Humanity Looks to Unity of Minds in Crisis: Massacres of Muslim Worshipers in Christchurch, New Zealand

"And if we do act, in however small a way, we don’t have to wait for some grand utopian future. The future is an infinite succession of presents, and to live now as we think human beings should live...

Dr Mahboob A Khawaja, PhD. - avatar Dr Mahboob A Khawaja, PhD.

New TAFE program for Aboriginal health-care students sees a near perfect completion rate

If we are to close the gap in health outcomes for Aboriginal people, we need to develop and staff culturally competent health-care services.from shutterstock.comA customised scholarship program develo...

Kylie Gwynne, Associate Professor and Research Director, Poche Centre for Indigenous Health Faculty of Medicine and Health, University of Sydney - avatar Kylie Gwynne, Associate Professor and Research Director, Poche Centre for Indigenous Health Faculty of Medicine and Health, University of Sydney

Two million Aussies delay or don't go to the dentist – here's how we can fix that

When did you last visit the dentist?By Concept Photo/ShutterstockDental care in Australia is a policy anomaly; for some reason, the mouth is treated very differently to other parts of the body. About ...

Stephen Duckett, Director, Health Program, Grattan Institute - avatar Stephen Duckett, Director, Health Program, Grattan Institute

We need a new definition of pornography - with consent at the centre

In a search of social science literature on pornography, none of the definitions reviewed mentioned consent.ShutterstockWe all think we know what pornography is, whether we oppose it, use it, or toler...

Sarah Ashton, PhD Candidate, Monash University - avatar Sarah Ashton, PhD Candidate, Monash University

Women can build positive body image by controlling what they view on social media

It is possible to limit your bombardment with images of bodies that feel way out of reach – so choose wisely who you follow. hannah grace / unsplash, CC BYSocial media use is often described as ...

Rachel Cohen, Clinical Psychologist and PhD Candidate, University of Technology Sydney - avatar Rachel Cohen, Clinical Psychologist and PhD Candidate, University of Technology Sydney

Ultra low wage growth isn't accidental. It is the intended outcome of government policies

This is the first in a three-part mini-symposium on Wages, Unemployment and Underemployment presented by The Conversation and the Academy of the Social Sciences in Australia.The long debate over the c...

John Quiggin, Professor, School of Economics, The University of Queensland - avatar John Quiggin, Professor, School of Economics, The University of Queensland

Curious Kids: why bats sleep upside down, and other stories of animal adaptation

Zzzzzzz...Flickr/Ryan Poplin, CC BY-SACurious Kids is a series for children. If you have a question you’d like an expert to answer, send it to curiouskids@theconversation.edu.au You might also l...

Amy Edwards, Post Doctoral Researcher, La Trobe University - avatar Amy Edwards, Post Doctoral Researcher, La Trobe University

'Give us a sniff, love': giving marsupials scents from suitors helps breeding programs

A baby eastern barred bandicoot pokes its head out of its mother’s pouch. M. Parrott, Zoos Victoria, Author providedSmell is a vital part of sexual attraction for all kinds of animals (including...

Marissa Parrott, Reproductive Biologist, Wildlife Conservation & Science, Zoos Victoria, and Honorary Research Associate, BioSciences, University of Melbourne - avatar Marissa Parrott, Reproductive Biologist, Wildlife Conservation & Science, Zoos Victoria, and Honorary Research Associate, BioSciences, University of Melbourne

Youth homelessness efforts get a lowly 2 stars from national report card

Despite a ten-point roadmap and bold commitments, Australia has not stayed on track to reduce youth homeless over the past decade.Roman Bodnarchuk/ShutterstockA National Report Card on Youth Homelessn...

David MacKenzie, Associate Professor, Department of Social Science, Swinburne University of Technology - avatar David MacKenzie, Associate Professor, Department of Social Science, Swinburne University of Technology

View from The Hill: A truly inclusive society requires political restraint

“Standing against hate” requires robust leadership from the politicians.AAP, CC BY-NCTerrible tragedies test leaders to the full. Anyone watching from afar must be impressed with the way i...

Michelle Grattan, Professorial Fellow, University of Canberra - avatar Michelle Grattan, Professorial Fellow, University of Canberra

NSW election neck and neck as voters face a 1950s-style 'I'll see you and raise you' campaign

On Saturday, March 23, the people of New South Wales will head to the ballot boxes for a state election. It is looking increasingly close, with polls showing government and opposition neck and neck on...

David Clune, Honorary Associate, Government and International Relations, University of Sydney - avatar David Clune, Honorary Associate, Government and International Relations, University of Sydney

Ultra low wage growth isn't accidental. It is the intended outcome of government policies

This is the first in a three-part mini-symposium on Wages, Unemployment and Underemployment presented by The Conversation and the Academy of the Social Sciences in Australia.The long debate over the c...

The Conversation - avatar The Conversation

Christchurch attacks are a stark warning of toxic political environment that allows hate to flourish

When lives are tragically cut short, it is generally easier to explain the “how” than the “why”. This dark reality is all the more felt when tragedy comes at the hands of murd...

Greg Barton, Chair in Global Islamic Politics, Alfred Deakin Institute for Citizenship and Globalisation, Deakin University - avatar Greg Barton, Chair in Global Islamic Politics, Alfred Deakin Institute for Citizenship and Globalisation, Deakin University

Can a senator be expelled from the federal parliament for offensive statements?

In the wake of comments about the Christchurch massacre, members of the public have raised the question of whether a senator can be expelled from the Senate for making offensive statements. It is now...

Anne Twomey, Professor of Constitutional Law, University of Sydney - avatar Anne Twomey, Professor of Constitutional Law, University of Sydney

The psychology of fear and hate, and what each of us can do to stop it

New Zealand Prime Minister Jacinda Ardern has travelled to Christchurch after yesterday's terror attacks.NZ Prime Minister's office, CC BY-SAAs an immigrant to New Zealand, I am saddened and outraged ...

Stephen Croucher, Professor and Head of School of Communication, Journalism, and Marketing, Massey University - avatar Stephen Croucher, Professor and Head of School of Communication, Journalism, and Marketing, Massey University

Why overhauling NZ's gun and terrorism laws alone can't stop terrorist attacks

Grieving members of the public following a shooting at the Masjid Al Noor in Christchurch.EPA/Martin Hunter, CC BY-SAMy research focuses on terrorism in or affecting New Zealand. Until yesterday, my p...

John Battersby, Police Teaching Fellow, Massey University - avatar John Battersby, Police Teaching Fellow, Massey University

Random Thoughts V

If Planned Parenthood was selling puppy body parts they would be shut down yesterday. The thirties and forties are a blur with work and family.  The fifties start to slow down and in the sixties yo...

Dr. Robert Owens - avatar Dr. Robert Owens

Christchurch mosque shootings must end New Zealand's innocence about right-wing terrorism

Members of the Armed Offenders Squad push back members of the public following a shooting at the Masjid Al Noor mosque in Christchurch.AAP/Martin Hunter, CC BY-SATonight, New Zealand police continue t...

Paul Spoonley, Pro Vice-Chancellor, College of Humanities and Social Sciences, Massey University - avatar Paul Spoonley, Pro Vice-Chancellor, College of Humanities and Social Sciences, Massey University

Why news outlets should think twice about republishing the New Zealand mosque shooter's livestream

Like so many times before with acts of mass violence in different parts of the world, news of shootings at two Christchurch mosques on Friday instantly ricocheted around the world via social media. Wh...

Colleen Murrell, Associate Professor, Journalism, Swinburne University of Technology - avatar Colleen Murrell, Associate Professor, Journalism, Swinburne University of Technology

A telescope can reveal the beauty of the universe, such as the Moon’s craters, Saturn’s rings, and the glowing gas of the Orion nebula. But a telescope isn’t just for sightseeing – it is also a scientific instrument.

If you’ve just received a telescope as a present then it’s probably better than any used by the Italian scientist Galileo Galilei (1564-1642). A small telescope with a modern camera can be more capable than professional telescopes from just a century ago.

image An illustration of Galileo Galilei with a telescope. Iryna/Shutterstock

You can use your telescope to see astrophysics in action, such as the planets travelling around the Sun, see how stars have different colours and even detect worlds orbiting distant stars.

Read more: What to look for when buying a telescope

At the eyepiece

Look through the eyepiece of your telescope and you can retrace the beginnings of astrophysics.

Galileo only had a tiny telescope with a lens just a few centimetres across. Yet he mapped the Moon, saw Saturn’s rings, and discovered Jupiter’s four largest moons – Io, Europa, Ganymede and Callisto – now known as the Galilean moons.

Galileo was also persecuted for advocating the theory that the planets (including Earth) orbit around the Sun, at a time when the popular belief was that Earth was the centre of the universe.

His observation of the phases of Venus are among his most compelling pieces of evidence that Earth and the other planets of our Solar System orbit the Sun.

image Galileo charted the apparent size and phases of Venus with his small telescope. NASA

If the planets travel around the Sun, as Galileo believed, then sometimes the Sun will be (almost) between us and Venus, so we can view most of the daytime side of Venus. At other times, Venus will be between us and the Sun, and will appear as larger (since it’s closer) crescent.

Venus is never too far from the Sun in the sky (indeed it’s lost in the Sun’s glare during January 2018), and is only visible near sunrise or sunset. The phases of Venus, which resemble those of the Moon, can be seen with even a small telescope.

There are plenty of guides on how to find Venus (and other planets, stars, constellations, galaxies and so on) including Sky and Telescope, apps for Android and Apple devices and the free Stellarium computer software.

Use any of these to find Venus, and then use your telescope to see the phases of the planet as Galileo did four centuries ago.

The lives of stars

Understanding the lives of stars was the biggest puzzle for astrophysicists during the early 20th century. One of the first clues is the fact that different stars have different colours, which tells us they have different temperatures.

Even without a telescope, you can see the red star Betelgeuse and the blue star Rigel in the constellation of Orion. Betelgeuse has a surface temperature of 3,000℃, while Rigel’s surface is at 12,000℃.

Why do different stars have different temperatures? Measuring the luminosities of stars with different colours provides a critical clue. Look at open star clusters such as Pleiades and you will see that (with some exceptions) the brightest stars are blue.

image The most luminous stars in the Pleiades star cluster are blue. Flickr/Joel Tonyan, CC BY-NC-ND

Blue stars are often the most luminous (and most massive), and their high temperatures result from the rapid fusion of hydrogen into helium. Some blue stars are 100 times as bright as the Sun.

These stars live for just millions of years, as they are using their hydrogen fuel so rapidly. In contrast, some dull red stars may live for tens of billions of years.

What about the exceptions – the very luminous stars that are red, such as Betelgeuse? Some stars have run out of hydrogen in their cores, and instead fuse hydrogen in shells and/or fuse helium in their cores.

These stars can become enormous in size but have (relatively) cool surface temperatures. These red giants are also approaching the end of their lives.

Strange new worlds

So far your telescope has been used for simple observations of stars and planets. With the addition of some more equipment you can use your telescope to detect planets around distant stars.

To do this you need a good digital camera, the ability to track a star for a few hours, and some free software for your computer.

The first planets orbiting other stars were detected in the 1990s and now thousands of such worlds are known. Some of these planets orbit stars that are 100 times fainter than the unaided eye can see, and such stars are easily seen with small telescopes.

Read more: Google’s artificial intelligence finds two new exoplanets missed by human eyes

But what about the planets? Well, at predictable times planets pass between us and their stars, making the stars dim by about 1%. You can’t see that tiny change in brightness with your eye, but you can record it digitally.

If you can take digital images of a star with a planet and several neighbouring stars, then you can use computer programs (such as OSCAAR) to measure how the star dims relative to its neighbours. You can thus see the passage of a distant world around its star.

You don’t need a big telescope to detect a planet orbiting a distant star, and a bit of DIY can help.

Read more http://theconversation.com/you-too-can-be-an-astrophysicist-with-your-new-telescope-86065