Monthly Archives: February 2016

What would happen if Earth fell into a black hole?

Black holes have long been a source of much excitement and intrigue. And interest regarding black holes will surely grow now that gravitational waves have been discovered.

Many of the questions I am asked regard how “true” science fiction concerning black holes might be, and whether worm holes, such as those featured in Stargate, are real or not. Invariably though, the one item that is almost assured to come up are the largely gruesome ways in which black holes might theoretically affect human beings and the Earth itself.

Mass, charge, spin

There are three properties of a black hole that are (in principle) measurable: their mass, their spin (or angular momentum) and their overall electronic charge. Indeed, these are the only three parameters that an outside observer can ever know about since all other information about anything that goes in to making up a black hole is lost. This is known as the “no hair theorem”. Put simply: no matter how hairy or complex an object you throw in to a black hole, it will get reduced down (or shaved) to its mass, charge and spin.

Of these parameters, mass is arguably the most significant. The very definition of a black hole is that it has its mass concentrated in to a vanishingly small volume – the “singularity”. And it is the mass of the black hole – and the huge gravitational forces that its mass generates – which does the “damage” to nearby objects.

Space spaghetti

Spaghetti. Nice to eat, but not nice to turn in to. Matsuyuki/flickr

One of the best known effects of a nearby black hole has the imaginative title of “Spaghettification”. In brief, if you stray too close to a black hole, then you will stretch out, just like spaghetti.

This effect is caused due to a gravitation gradient across your body. Imagine that you are headed feet first towards a black hole. Since your feet are physically closer to the black hole, they will feel a stronger gravitation pull towards it than your head will. Worse than that, your arms, by virtue of the fact that they’re not at the centre of your body, will be attracted in a slightly different (vector) direction than your head is. This will cause parts of the body toward the edges to be brought inwards. The net result is not only an elongation of the body overall, but also a thinning out (or compression) in the middle. Hence, your body or any other object, such as Earth, will start to resemble spaghetti long before it hits the centre of the black hole.

The exact point at which these forces become too much to bear will depend critically on the mass of a black hole. For an “ordinary” black hole that has been produced by the collapse of a high mass star, this could be several hundred kilometres away from the event horizon – the point beyond which no information can escape a black hole. Yet for a supermassive black hole, such as the one thought to reside at the centre of our galaxy, an object could readily sink below the event horizon before becoming spaghetti, at a distance of many tens of thousands of kilometres from its centre. For a distant observer outside the event horizon of the black hole, it would appear that we progressively slow down and then fade away over time.

Bad news for Earth

What would happen, hypothetically, if a black hole appeared out of nowhere next to Earth? The same gravitational effects that produced spaghettification would start to take effect here. The edge of the Earth closest to the black hole would feel a much stronger force than the far side. As such, the doom of the entire planet would be at hand. We would be pulled apart.

Equally, we might not even notice if a truly supermassive black hole swallowed us below its event horizon as everything would appear as it once was, at least for a small period of time. In this case, it could be some time before disaster struck. But don’t lose too much sleep, we’d have to be unfortunate to “hit” a black hole in the first place – and we might live on holographically after the crunch anyway.

Mind the radiation

Interestingly, black holes are not necessarily black. Quasars – objects at the hearts of distant galaxies powered by black holes – are supremely bright. They can readily outshine the rest of their host galaxy combined. Such radiation is generated when the black hole is feasting on new material. To be clear: this material is still outside the event horizon which is why we can still see it. Below the event horizon is where nothing, not even light, can escape. As all the matter piles up from the feast, it will glow. It is this glow that is seen when observers look at quasars.

But this is a problem for anything orbiting (or near) a black hole, as it is very hot indeed. Long before we would be spaghettified, the sheer power of this radiation would fry us.

Life around a black hole

For those who have watched Christopher Nolan’s film Interstellar, the prospect of a planet orbiting around a black hole might be an appealing one. For life to thrive, there needs to be a source of energy or a temperature difference. And a black hole can be that source. There’s a catch, though. The black hole needs to have stopped feasting on any material – or it will be emitting too much radiation to support life on any neighbouring worlds.

What life would look like on such a world (assuming its not too close to get spaghettified, of course) is another matter. The amount of power received by the planet would probably be tiny compared to what Earth receives from the Sun. And the overall environment of such a planet could be equally bizzare. Indeed, in the creation of Interstellar, Kip Thorne was consulted to ensure the accuracy of the depiction of the black hole featured. These factors do not preclude life, it just makes it a tough prospect and very hard to predict what forms it could take.

The Conversation

Kevin Pimbblet, Senior Lecturer in Physics, University of Hull

This article was originally published on The Conversation. Read the original article.

From chrome plating to nanotubes: the ‘modern’ chemistry first used in ancient times

The ancient Babylonians were the first to use sophisticated geometry – a staggering 1,400 years before it was previously thought to have been developed. Sadly, these mathematical innovations were forgotten as the Babylonian civilisation collapsed and were only rediscovered this year as scientists took a close look at ancient clay tablets.

This surprising finding made me wonder about what other scientific methods that we put down to modern minds were actually discovered by ancient civilisations. So I decided to hunt down some of the most advanced uses of chemistry.

Qin Dynasty chrome plating

The mirrored shine of chrome-plated metal is almost a symbol of the modern era. A thin chrome layer coats metals and plastics in kitchens, bathrooms and cars. Credit for chrome-plating technology goes to George Sargent who published a method in 1920 that lead to the commercial plating that dominated the Art Deco period and beyond. In fact, other famous chemists including Robert Bunsen dabbled with chrome plating in the mid-19th century. But all of these may have been beaten to the shine by the metallurgists of the Qin dynasty in China some 2,000 years before chrome had even been identified in the West.

Qin dynasty sword. Photo credit: Mark Lorch CC BY-ND

In the 1970s, razor sharp swords coated in a thin layer of chromium oxide were unearthed along with the the famous Terracotta army. The Chinese suggest that their 1st dynasty weapon smiths coated officers’ weapons to protect them from corrosion. And indeed, two millennia later the blades are untarnished. However, whether this is really the case or in fact the chromium layer slowly formed from a peculiarity of the blade’s composition and the fires that ravaged the buried terracotta army is a matter of debate.

Roman concrete

Concrete is the mainstay of modern buildings, but ancient civilisations also used it to great effect. Concrete is a composite, meaning that it is made from two or more materials; cement is mixed with sand and gravel, which then sets into whatever structure is required. The most famous ancient concrete buildings are probably the Pantheon and Colosseum in Rome. Both are composed of fine volcanic ash mixed with lime (calcium hydroxide).

Colesseum in Rome. Photo credit Diliff/wikimedia, CC BY-SA

Together these make the cement, which sets and binds fist sized pieces of limestone together. This particular recipe produces a network of crystals that resist propagation of cracks, the bane of modern concrete. The result is an incredibly enduring material that is, in many ways, superior to today’s concrete. A testament to this is the majestic roof of the Pantheon, which, at 43 metres across, is still the world’s largest unreinforced concrete dome.

Damascene nanotubes

Carbon nanotubes are the strongest and stiffest materials known. They consist of cylinders with walls that are just one atom thick. When used within composite materials they can massively enhance the strength of an object resulting in super strong and light components, some of which you can find in wind turbines, sports gear and vehicles.

18th Century Persian-forged Damascus steel sword. Photo credit. Rahil Aplipour Ata Abadi/ wikimedia

In 2006 researchers discovered that the people of Damascus were making use of nanotubes in their steel hundreds of years ago. The result was beautiful blades covered in swirling patterns. And more importantly for the soldiers of the time was the exceptional durability and the razor-sharp edges the steel held. We now know the exact composition of Damascus steel, yet modern metallurgists have failed to reproduce it so far.

Egyptian pigments

William Perkin is credited with producing the first organic dye (using chemists’ meaning of the word organic – in other words, carbon-containing chemicals) when he accidentally discovered purple mauveine while trying to make quinine in 1856.

Pyxis made out of Egyptian blue from 750-700BC. Shown at Altes Museum in Berlin. Photo credit: Bairuilong/wikimedia, CC-BY-SA

But the first synthetic pigment of any type was probably made by the Egyptians as early as 3000BC. By heating a mixture of sand, ash, calcium carbonate (possibly from shells), and a copper containing ore to temperatures of over 800°C they manufactured blue calcium copper silicate. This could be then be used in glazes to produce a stunning range of hues.

Greek atomic theory

The incredible technologies devised by craftsman and artists of ancient civilisations are astounding. Much of it can’t be bettered by modern techniques. But what separates science from skilled craft is an understanding of the underlying mechanisms involved in the making of the material. Underpinning this understanding in modern chemistry is the atomic theory often credited to John Dalton in the early 19th century. But philosophers of old also had a good crack at thinking about the nature of matter. And in fact atomism has sprung up multiple times in antiquity. Most notably from the Greek philosophers Democritus and Leucippus who speculated that everything is composed of physical, indivisible and invisible atoms back in the 5th century BC.

Mark Lorch, Senior Lecturer in Biological Chemistry, Associate Dean for Engagement , University of Hull

This article was originally published on The Conversation. Read the original article.

New technique could halt the spread of cancer to bones

A leading biomedical scientist at the University of Hull has discovered a method to halting “rolling” prostate cancer cells, preventing bone destruction.

Dr Justin Sturge observed these cells “rolling like balls” over human bone surfaces where they often plant new tumours. By blocking the Endo 180 receptor, which can drive the cells’ abnormal movement, Dr Sturge and his team stopped this rolling of the prostate cancer cells, so that they couldn’t move any further.

This discovery could lead to new treatments for patients who have primary bone cancer or in preventing other cancers spreading to bones.

Dr Sturge, a Senior Lecturer in the School of Biological, Biomedical and Environmental Sciences, is leading research into a molecule called Endo180, a receptor on cancer cells which plays an important role in helping cancer to spread to other parts of the body, especially the bones.

Globally more than 1 million deaths each year from cancer occur after the cancer has spread to the bones, also known as metastasis.

These new findings have been published in the scientific journal Clinical & Experimental Metastasis, led by Dr Sturge and co-researchers from the University of Hull and Imperial College London.

After observing the cancer cells moving in a rounded fashion on human bone [see Video 1] rather than crawling along like they did on the other types of surface tested, the research team turned their attention to blocking Endo180.

The research team found that after ‘genetic silencing’ of the Endo180 receptor, the prostate cancer cells were stopped from rolling over the bone.

In a subsequent commentary published in The Journal of Pathology, Dr Sturge explains how blocking Endo180 with antibodies can prevent bone destruction in cancer patients who are at risk of metastasis or have developed primary bone tumours such as osteosarcoma, the most common primary bone cancer in adolescents.

Dr Sturge said: “Skeletal bone is an attractive site for secondary tumours to grow, and is also home to spontaneous primary cancers. Our research explains how cancer cells can thrive in this environment.

“Our discovery stops the cancer cells in its tracks. The cells became stuck to the bone, they couldn’t move anymore.

“There is now hope that these findings could lead to Endo180-based treatments to stop tumours growing in the bone, increasing the chances of extending the lives of thousands of patients.”

The results are the latest findings from Dr Sturge’s research into Endo180. Earlier this year Dr Sturge published two papers, in Molecular Cancer Research and The Journal of Pathology, which identified Endo180 as a monster molecule in prostate cancer. In this work he used three-dimensional models of human prostate cancer to uncover the cellular mechanics behind the deadly effects of Endo180. This seminal work has paved the way for new diagnostics and treatments to be designed for future clinical use.

Dr Sturge’s research on Endo180 has been funded by Prostate Cancer UK, Breast Cancer Now Worldwide Cancer Research, The Rosetrees Trust, The China Scholarship Council, The Saudi Arabian Cultural Bureau and Fundação para a Ciência e a Tecnologia.