Posts by: Hamish Johnston

Killer asteroid bust-up, exposing academic plagiarism, #IAmAPhysicist and more

Time-lapse image of the asteroid Euphrosyne as seen by NASA’s WISE space telescope

Time-lapse image of the asteroid Euphrosyne as seen by NASA’s WISE space telescope, which is used by NEOWISE to measure asteroid sizes. (Courtesy: NASA)

By Hamish Johnston

First-up in this week’s Red Folder is a tale of killer asteroids, hubris and peer review from the Washington Post. The science writer Rachel Feltman has written a nice article about a claim by physicist-turned-entrepreneur Nathan Myhrvold that NASA’s research on asteroids that could potentially collide with Earth is deeply flawed. On Monday, Myhrvold posted a 111-page preprint on arXiv that argues that asteroid radii measured by NASA’s NEOWISE project are far less accurate than stated by NASA scientists. What’s more, Myhrvold seems to suggest that NEOWISE scientists have “copied” some results from previous asteroid studies.

Myhrvold began his career as a theoretical physicist and, after a stint as Microsoft’s chief technology officer, founded an intellectual-property firm. He has never worked in the field of asteroids, yet he has taken great exception to some of the physics and statistical analysis underlying the NEOWISE results. His paper has been submitted to the journal Icarus, but has not yet passed peer review – unlike the NEOWISE results. In her article, Feltman ponders why Myhrvold is actively promoting his controversial work – he was featured in a New York Times article on Monday – before it has passed peer review. She also speaks to several NEOWISE scientists, who are not amused.

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Skateboard videos reveal the physics of doing an ‘ollie’

Free-body problem: how do skateboarders do an "Ollie"?

Free-body problem: how do skateboarders do an “ollie”? (Courtesy: Paulo Simeão Carvalho/Physics Education)

By Hamish Johnston

Here’s a problem for keen students of classical mechanics: how can a skateboarder cause their board to leap into the air by pressing down on it with their feet?

What I’ve described is a trick called the “ollie”, which first emerged on the skateboarding scene in the late 1970s and is now an essential part of the skating repertoire. There’s a fascinating paper in the journal Physics Education, which shows how digital videos of people doing an ollie can be analysed to get to grips with the physics underlying the trick.

The above image shows six video frames of someone executing an ollie – with time moving from right to left over a period of about 2 s. If you delve into the paper, you will find out how its authors – Marco Adriano Dias, Paulo Simeão Carvalho and Deise Miranda Vianna – used video images to track the motion of the tail of the board as well as its front and back wheels. This was then compared to a free-body diagram analysis of the forces of the board.

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Mercury’s transit across the Sun has begun, check out our guide on how to view it safely

 

By Hamish Johnston

The transit of Mercury across the face of the Sun has begun. Alas here in Bristol the skies are grey and I have been watching a live feed of the transit from the Royal Observatory in Greenwich – which has been blessed with clear skies. That’s a real shame, because I had brought a small telescope into work and I was looking forward to projecting a magnified image of the Sun onto a screen to see the transit for myself.

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IBM wants you to use its quantum computer

 

By Hamish Johnston

Starting today, members of the public will be able to run programs on IBM’s quantum processor. Users can access the device – which comprises five superconducting quantum bits (qubits) – via the US-based company’s “IBM Quantum Experience” website.

Described as a “cloud-enabled quantum computing platform”, IBM says that users will be able to run algorithms and experiments on IBM’s quantum processor, manipulate individual qubits, as well as access quantum-computing tutorials and simulations.

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The most expensive object on Earth, publish or perish, and a physics Magna Carta

Gold coast: the Hinkley Point C power station will be build next to existing reactors in Somerset (Courtesy: CC BY-SA 2.0/ Richard Baker)

Gold coast: the Hinkley Point C power station will be built next to existing reactors in Somerset. (CC BY-SA 2.0 Richard Baker)

By Hamish Johnston

What will soon be the most expensive object on Earth? The answer, according to Greenpeace, is the Hinkley Point C nuclear power station that is slated for construction in south-west England. According to the BBC, the environmental group reckons the station will cost £24bn ($35bn) whereas EDF – the company that will build it – puts the construction cost at £18bn. In contrast, the Large Hadron Collider at CERN cost a mere £4bn. While the price tag on Hinkley Point C – which should produce 3.2 GW of electricity by 2024 – is eye watering, building a reactor on the cheap is not really an option.

Still, Hinkley Point C will not be the most expensive object ever built by humans. That honour goes to the International Space Station, which the BBC says cost nearly £78bn. There’s something comforting in knowing that the single highest expenditure ever has been on science – maybe civilization isn’t doomed after all.

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Putting a bouncy castle in space and other extraterrestrial adventures

A space station made from four B330 inflatable pods, which are the white cylinders (Courtesy: Bigelow Aerospace)

Artist’s impression of a space station comprising four B330 inflatable pods, which are the white cylinders. (Courtesy: Bigelow Aerospace)

By Hamish Johnston

It’s never been a better time to be a space enthusiast, as more and more countries are unveiling space programmes and it seems like a new mission is launched or announced just about every week.

But if you are like me and find the constellation of mission names – the various acronyms, mythical beasts and dead scientists – overwhelming, then the space physicist Chris Arridge has put together “Five human spaceflight missions to look forward to in the next decade” for The Conversation.

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Physics saves humanity, the large rainfall collider and other environmental highlights on Earth Day

Gravity's pull: could the LHC be used as a giant rain gauge? (Courtesy: CERN)

Gravity’s pull: could the LHC be used as a giant rain gauge? (Courtesy: CERN)

By James Dacey and Hamish Johnston

Today is Earth Day, so let’s temporarily rename this regular Red Folder column as the Green Folder. Either way, today we’re going to focus on the Earth and environmental issues. The official website of Earth Day – an initiative now in its 46th year – has details about the various initiatives and events taking place around the world today.

First, let’s pay tribute to a physicist whose work had a profound influence on the climate and energy debate in the UK and beyond. Sir David Mackay died on 14 April aged 48 following a battle with cancer. Mackay is remembered among other things for his pragmatic approach to energy and his 2008 book Sustainable Energy: Without the Hot Air (free access) was hailed for its rigour and refreshing absence of rhetoric. Mackay’s writings attracted the interest of the British government who appointed him as chief scientific adviser to the Department of Energy and Climate Change in 2009, a post he held for five years. Ever prolific, Mackay was blogging about his experiences right up until two days before his death.

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Cosmic rays, diamond anvils and spintronics in Utah

Gardens at the University of Utah

A blooming marvellous afternoon at the University of Utah.

By Hamish Johnston in Salt Lake City

Yesterday afternoon I hopped on a tram bound for the University of Utah. As you can see in the above photo, spring has sprung in Salt Lake City and the campus was resplendent in blossoms with views over snow-capped mountains.

I was at the university to film several 100 Second Science videos with Utah physicists including Shanti Deemyad, who studies the properties of matter under extremely high pressures. She is particularly interested in understanding the quantum properties of solids at temperatures near absolute zero – properties that can be enhanced when materials such as lithium are squeezed at pressures that are more than 10 million times greater than Earth’s atmosphere. This is done using a diamond anvil and Deemyad’s lab has 20 or so of them.

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LIGO could soon detect one gravitational wave per week

The LIGO detectors in Louisiana

The LIGO detectors in Louisiana (above) and Washington are currently being upgraded. (Courtesy: LIGO/Caltech)

By Hamish Johnston at the APS April Meeting in Salt Lake City 

I came to Salt Lake City hoping to glean a few golden nuggets of information about what future gravitational-wave detections we can expect from LIGO. What I found is that the collaboration is as tight-lipped as ever about discussing potential results. That’s fair enough and I understand the caution. However, I was hoping that the researchers would have loosened up a bit after their February announcement of the first gravitational-wave detection and share a little more with the general public.

So, what have I learned?

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HAWC spots TeV gamma ray flare

A TeV gamma-ray flare spotted by HAWC

Now you see it, now you don’t: a TeV gamma-ray flare spotted by HAWC. (Courtesy: Michelle Hui)

By Hamish Johnston at the APS April Meeting in Salt Lake City 

Talk about luck. Just 10 days before the April Meeting the High-Altitude Water Cherenkov (HAWC) gamma-ray observatory lit up with the detection of a galaxy that produced large numbers of teraelectronvolt (TeV) gamma rays for just one day (see image).

Dubbed Markarian 501, HAWC astrophysicists believe that the flare could be driven by a supermassive black hole at the centre of the galaxy. However, they admit that they don’t really understand how such flares occur.

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