What the Detection of Gravitational Waves Means

Unless you live under a rock, the announcement in February of this year of the detection of Gravitational Waves by LIGO cannot have escaped your attention. Scientists around the world celebrated the achievement, and public curiosity about what all the scientists were yelling about was high enough that the world’s media ran the story for several days. Physicists and science communicators, whether they had anything to do with the discovery or not, were called upon to explain to the public what all the fuss was about.

If two Black Holes crash in deep space, and there is no detector to hear them, do they still make a Gravitational Wave?

The enormous release of energy from the collision of two Black Holes, detected for the first time

For a public that had never heard of Gravitational Waves before the announcement of their discovery, a key question that needed answering was, “So what does it mean?” Many scientists and science communicators did an outstanding job of answering this question, but their responses often left out an important element, that is, they did not answer the implied question, “what does it mean for me?”

Following the announcement earlier this week of a second Gravitational Wave detection (and another detection candidate), I want to take the opportunity to outline some of the ways in which the discovery of Gravitational Waves directly affects the average member of the public, but in the interest of providing a complete answer, I will first recap the importance of the discovery from a scientific perspective.

1) Amazing Achievement

First of all, the detection of Gravitational Waves is significant because it is direct confirmation of a prediction made 100 years ago by Albert Einstein. Einstein’s General Theory of Relativity is the best model physicists have for describing the action of gravity and the behaviour of the solar system, the galaxy, and the universe. Scientists constantly try to invent new experiments to push our understanding of the universe to the breaking point. It is by knowing the point at which our understanding of the universe fails that we are able to make the greatest progress. General Relativity has survived every test it has been subjected to for 100 years. Even the fact that GPS functions properly is a demonstration that Einstein’s General Theory of Relativity is correct.

In 1916, Einstein used General Relativity to predict that bodies orbiting each other, such as the Sun and Earth or two black holes, warp spacetime such that energy from the two bodies is carried away as ripples in the very fabric of the cosmos. These are Gravitational Waves, and their detection is not only another success for Einstein and General Relativity, but for the power of human ingenuity.

Insert fat joke here.

Gravitational Waves are ripples in spacetime caused by massive bodies in orbit

The LIGO detectors are the most sensitive instruments ever created and represent the culmination of 50 years of work by thousands of scientists. Although the first of the detected Gravitational Wave events represents an explosion 50 times more powerful than the power output of all the stars in the universe combined, the energy of the event has spread out and weakened during the 1.4 billion light-year trip to Earth, and so the LIGO detection represents the smallest amount of energy ever successfully detected. The very fact that humanity has the ability to detect Gravitational Waves is something we, as a species, can be proud of.

Couldn't think of funny alt-text.

The Advanced LIGO detectors in Livingston and Hanford

2) A New Spectrum, a New Science

The two confirmed and one candidate Gravitational Wave detections represent the beginning of a new era in studying the universe, a new way of doing astronomy, Gravitational Wave Astronomy.

All of astronomy, and everything we have discovered about our universe through astronomy, has been done using light. Whether we use radio telescopes, optical telescopes, or gamma-ray telescopes, all of these devices detect energy from the electro-magnetic spectrum, they all detect some form of light. Gravitational Waves are not a type of light. They exist in a completely different spectrum.

The Gravitational Wave spectrum gives astronomers a completely new way of studying the universe because the properties of Gravitational Waves are very different to those of electro-magnetic waves. Unlike light, Gravitational Waves are not absorbed by matter. They pass unhindered through the Earth, interstellar gas clouds, and entire galaxies. Unlike light, they cannot be blocked by stuff getting in the way. Gravitational Waves allow us to see past the bright glare of galaxies, and through vast interstellar dust clouds to corners of the universe our other telescopes will never be able to see.

We can also use Gravitational Waves to study things that don’t emit light. As far as our current theoretical understanding tells us, the collision of two black holes, like the Gravitational Waves events seen so far, should not emit any light. These events, and events like them, can only be studied using the Gravitational Wave spectrum.

Since the end of its first, and now famous, observing run, LIGO has been undergoing upgrades that will roughly double the sensitivity of the detector. With this boost in sensitivity, and based on the three events detected so far, Gravitational Wave physicists expect LIGO to detect around one event per week when it is switched back on later this year. With that amount of data, Gravitational Wave Astronomy will become a field in its own right, and one that will revolutionize our understanding of the universe by studying regions of the cosmos previously invisible to us.

woooooOOOOP!

Gravitational Waves open up a new spectrum with which to study the universe

3) What it means for me

The detection is an amazing technological achievement and Gravitational Wave detectors are some of the most advanced pieces of equipment in the world. To be able to build their detector, scientists and engineers have had to invent new technologies along the way, and these new technologies have a huge range of spin-offs and applications that will impact on our every-day lives.

To build the LIGO detectors, super-reflective mirror coatings and polishing techniques had to be developed, vibration isolators that guard against everything from minor earthquakes to people coughing had to be built, hyper-precise lasers and sensitive read-out systems had to be invented, and all of this had to operate in hard vacuum, even special super-hard glues had to be formulated. To actually detect the signal, advanced analysis software had to be written. This is only a taste of the work involved. The complete list of innovations by Gravitational Wave scientists would take dozens of pages to list like this, and I don’t even know most of them!

With this type and variety of advanced technology in the works, it is almost inevitable that other applications would be found for the scientists’ innovations. Just one example from the University of Western Australia, where I am studying for my PhD, is the Rio Tinto Gravity Gradiometer. This new technology, which will detect ore bodies from an aeroplane by measuring tiny changes in the Earth’s gravitational field, spun-off from Gravitational Wave research at UWA.

This thing sits in the lab across the hall from me.

The VK1 airborne Gravity Gradiometer will detect ore bodies below the ground, and spun-out from Gravitational Wave research

Over the coming decades, technology originally developed for Gravitational Wave detectors will be worth billions of dollars, create many thousands of jobs, and will enrich our every-day lives for generations to come.

 

If you’d like to learn more, you can go here to watch PhD comics explain Gravitational Waves.

Space for Innovation

Australia needs a space program.

As 2015 drew to a close, Prime Minister Malcom Turnbull unveiled the government’s Innovation Statement with a plan to invest $1.1 billion to drive an Australian “ideas boom”. Before this announcement, the government had already commenced its Review of the Space Activities Act 1998 stating that Australia is in a transition ‘to an advanced economy that cultivates and commercialises innovative technologies’ and that ‘there is significant potential for space technologies to play a role in facilitating this transition…’ It is high time Australia invested in a space program.

Australia is the only OECD country that does not have a space agency or coordinated space program. China and India both established space agencies in the mid-20th century which have contributed immensely to the countries’ technological capabilities and economic growth. Even Ethiopia has recognized the huge advantages afforded by a dedicated space program, establishing a space agency in August 2015.

Why does Australia need a space program?

In the 21st century a space program will be a key instrument for sustainable development. For the average person, the impact that space technologies have on their lives is not immediately obvious, often being hidden away behind some product, service, or app, but all of us benefit immensely every day from what space programs have brought us. We would all notice very quickly if we lost our GPS and satellite communication infrastructure, but space technology goes much further. Satellites are used for environmental monitoring, weather prediction, soil monitoring, water and agricultural management, as well as to search for ore bodies, track bushfires, and in disaster planning. This short list barely makes a dent in the complete list of important space technologies, and doesn’t even touch on the spin-offs, the technologies developed by space agencies that have found other uses and applications.

A space program will cultivate scientific thinking and technological innovation, and provide the training to engineers, scientists and students that Australia needs if we want to maximize the progress from our “ideas boom”.

A national space program will ensure that innovative ideas are exploited to their fullest by stabilizing funding to projects under its aegis. A space agency is also necessary if we are going to cooperate with other countries in the exploration and exploitation of space, since an agency with technical expertise that represents the Australian government will be in a position to negotiate with NASA, the ESA and other countries’ space agencies. An Australian space agency will even reduce the time and cost required to purchase flights on other countries’ launch vehicles.

I liked the picture of a satellite.

Out of sight, out of mind: vital technologies are operating overhead all the time.

They’re expensive. Couldn’t the money be better spent on something other than rockets?

When figures like NASA’s $19.3 billion 2016 budget are bandied around, and even a small space mission costs tens of millions of dollars, it often seems that space programs are too expensive to be worthwhile and that there are other problems we should be using this money to solve. However, put in context with other spending, a space program doesn’t appear to be so expensive.

NASA’s $19.3 billion represents only 0.5% of the US government’s spending, while the US military takes more than 15% of the total. The economic return to the USA gained from NASA’s products, patents, services, and spin-offs means that NASA more than pays its way. Australia is in a not-too-dissimilar position, with around A$30 billion being spent on defence. If we were to copy the US, we would direct around $1 billion to a space program. Australia has the money for a space program, it is only a matter of public choice and political will to divert the necessary funds. And that’s not even taking into account that space programs generate revenue for the government. History has shown that space programs are a very good investment. An Australian space program would begin to pay for itself after only a few years.

NASA’s $19.3 billion sounds like a lot less money when you take into consideration the huge range of projects NASA is responsible for. A reasonable summary of NASA’s active and on-going projects would fill a small book. They include climate and crop monitoring, satellite tracking, observational astrophysics, space-vehicle development, aeronautics, launch contracting, running a space-station and driving a nuclear-powered laser-equipped science-car on Mars. Australia is unlikely to match this commitment (at least in the short-term).

Individual space missions, even pioneering interplanetary missions, can be quite cheap when compared to other things we are willing to spend huge amounts of money on. India became the first country to successfully reach Mars orbit on its first go with the Mangalyaan Mars orbiter, which cost only US$73 million. Major blockbuster movies rarely cost less than $100 million these days. James Bond Spectre cost $245 million, the CGI movie Tangled cost $260 million, while Pirates of the Caribbean: On Stranger Tides cost an eye-watering $378.5 million.

Also, we do not have to spend big money on huge projects such as shuttles and space stations like Russia, China, and the US. The UK and Canadian space agencies provide a very good model for a similar Australian organization. We don’t need to have a launch vehicle, we just need to start contributing to international space project collaborations.

A space program is not a luxury. It is a key to a sustainable future and developing scientific thinking.

We should totally build one of these any way.

As cool as it would be to have one of these, this is probably not what an Australian space program will look like.

What have we got to offer?

I have come across the belief that Australia has little it can offer the international space science community (and therefore should leave space up to other countries) disturbingly often, and nothing could be further from the truth. Australia has had a small but outstanding role in space since the 1960s, and in a field as diverse as space research, there is always something we can offer both in international collaborations and from Australia-only projects.

Universities and research organizations across the country already have some involvement in space research. We are world leaders in the development of scramjet technology, we are internationally renowned in radio astronomy and computer sciences, we are participating in space missions such as eLISA and the GRACE follow-on, we have important deep-space tracking facilities, and we have the most productive geodetic observatory in the world.

A space program also affords Australia the opportunity to focus efforts on problems that are unique to Australia. This article in The Conversation from 2013 addresses the reasons why Australia urgently needs a space program to solve our own problems and to stop piggybacking on other countries’ space projects.

Western Australian Space Centre

The Western Australian Space Centre: the site of the world’s most productive laser ranging station.

What should we do?

We need to establish a space agency with its own slice of government funding. This is necessary to produce the funding stability I discussed previously and exploit space research to the full.

The Review of the Space Activities Act needs to provide appropriate recommendations so that future legislation minimizes red tape and makes it easy for Australian agencies and research organizations to conduct research within Australia, and to collaborate with other nations.

We need to start training our students for the space sector. A huge number of brilliant STEM students are being attracted to space science at the undergraduate level, but there are too few programs and training opportunities for all but a few of them to continue down this path. Increased support for space research at all levels of education will be needed to develop and exploit Australia’s intellectual resources and drive innovation.

We need to get the public excited about space through science communication, media attention, and school programs.

The public excitement will only grow as Australia’s space program progresses. By collaborating with NASA, the ESA and other space agencies and contributing to international projects, Australia will be eligible to select its own astronauts. While Australian-born Americans have flown in space, no one has gone to space with an Australian flag on their shoulder. The media attention surrounding Canada’s Chris Hadfield and the UK’s Tim Peake show just how much public excitement is generated by space flight, and with proper science communication efforts, this excitement will feed back into greater support for space science and the benefits it has to offer.

Has anyone got a suggestion for a good name for our space agency?

This is here just because I like this picture.

WRESAT: Australia’s first satellite.