The Science News Digest
The science news this week unveils test-tube sperm, shrinking sheep and why JK Rowling could have had it right all along...
Giant jumpers to shrinking sweaters
Climate change is making its effects better and better known, but few are as strange as the conundrum of St Kilda’s shrinking sheep.
Scientists have been studying the wild Soay sheep since the mid-1980s, and have been perplexed by the fact that a typical ewe has been diminishing by between 80g and 100g a year.
“According to classic evolutionary theory, they should have been getting bigger” said Professor Tim Coulson, of Imperial College, who led the study. The sheep fatten up during the summer, to see them through the harsh winters. “Larger sheep tend to be more likely to survive and reproduce than smaller ones, and offspring tend to resemble their parents” added Coulson.
However, milder winters and earlier springs have turned this logic on its head. These are allowing smaller lambs to survive the long winters, and the average body size of a ewe has shrunk by about 5 per cent over the last 24 years.
How far this will continue is difficult to say. “It’s a little bit early to predict that we’ll be having Chihuahuas running round herding pygmy sheep in, say, a hundred years from now” concluded Professor Coulson.
Read all about it in the Independent.
-------------------------------
Ball-breaking research
New possibilities for treating male infertility are drawing nearer, as the Times reports how scientists have created synthetic human sperm from embryonic stem cells.
“This is an important development as it will allow researchers to study in detail how sperm forms and will lead to a better understanding of infertility in men” expressed Professor Nayeria, leader of the team at Newcastle University. “This understanding could help us develop new ways to help couples suffering infertility so they can have a child which is genetically their own”.
The creations have some of the biological characteristics of natural sperm; however other scientists have been doubtful that they are the real thing. Professor Nayeria accepts further investigation into the synthetic cells is needed.
The team say it will be at least five years before the technique is perfected. However its use as a treatment will require a change in the law; utilising such derived sperm for reproduction was banned by the Human Fertilisation and Embryology Act last year.
The proposal’s ethics are also being questioned.
"This is an example of immoral madness. Perfectly viable human embryos have been destroyed in order to create sperm over which there will be huge questions of their healthiness and viability”, condemned Josephine Quintavalle from Comment on Reproductive Ethics.
Others disagree. John Harris, Professor of Bioethics at the University of Manchester, said he didn’t see any problems. “Eventually it will be used to solve male infertility and that will be wholly beneficial”.
-------------------------------
2°C or not to be?
Developed and developing nations have agreed that global temperatures should not rise more than 2°C above 1990 levels. Above this point, the Earth’s climate system would become dangerously unstable, say the UN.
The declaration came from the G8 summit, where many countries discussed steps and targets to cut emissions. Us President Barack Obama, who chaired the meeting, said: “We recognise the scientific view that the increase in global average temperature above pre-industrial levels ought not to exceed 2°C”.
A target to cut emissions by 80% by 2050 was agreed by G8 members.
However they failed to persuade developing countries to accept targets of cutting emissions by 50% by the same date. UN Secretary General Ban Ki-moon critised the G8 climate efforts, saying strong and ambitious 2020 cuts also needed to be established.
RK Pachauri, chair of the Inter-govermental Panel on Climate Change said more details were needed. “It certainly doesn’t give you a road map on how you should get there but at least they’ve defined the destination” he told the BBC.
It’s thought rich nations need to determinedly pave the way on cuts, or developing nations will not sign up to 2050 goals. Developed nations had a “historic responsibility to take the lead” stressed Barack Obama.
-------------------------------
Planets on the pull
A contentious idea that tweaks fundamental physical laws could be experimentally proven, by subtle changes in the orbits of our planets.
Stars orbiting at the edge of spiral galaxies travel faster than we think they should; according to conventional gravitational theory they should be flung out into space. Something else must be keeping them on track.
One answer to this is dark matter. Another suggestion is modified Newtonian dynamics, or MOND.
MOND predicts that below a certain acceleration, gravity switches to a stronger form. This means that stars with slower acceleration at galaxy edges experience stronger gravity.
However the theories have been difficult to test, as they manifest themselves over huge, galaxy-scale distances.
But now Mordehai Milgrom, who conceived MOND, claims forms of his theory predict an effect within our own solar system.
Milgrom says Newton’s laws predict a region between our sun and the centre of the galaxy where the gravity from both cancels out. This area is also where any MOND-predicted departures from Newtonian gravity will most clearly show up. If there is gravity here, where there should be none, MOND exists.
MOND predicts the force in the area will gradually change the elliptical orbits of the planets, causing them to trace a flower petal pattern over time.
The theory cannot yet be tested, as we need to observe more full orbits of some of our outer planets. However, if proved, it will change our understanding of the fundamental laws of physics.
Read more in New Scientist.
-------------------------------
Dancing dinosaurs
The names ‘Banjo’, ‘Matilda’ and ‘Clancy’ are unlikely to strike fear in many people. But parallel to the convention of naming hurricanes the likes of ‘Tanya’, ‘Kyle’ and ‘Colin’; these monikers are for 3 newly discovered dinosaurs, including a flesh-eating predator.
The remains were dug up in Queensland’s outback, and date back 100m years to the middle of the Cretaceous period.
Banjo – formally known as Australovenator wintonensis – is the carnivore of the group, and even bigger than the velociraptor. He is also the most complete meat-eater ever found in the country. “The cheetah of his time, Banjo was light and agile” commented palaeontologist Scott Hucknell, at Queensland Museum. “He could run down most prey with ease.”
The two herbivores are both new types of titanosaur, the largest animals to ever walk the earth. Clancy – or Witonotitan wattsi – was a giraffe-like, tall, slender beast whilst Matilda – Diamantinasaurus matildae – was more hippo-like.
The names were plucked to honour characters of the song ‘Waltzing Matilda’, and also its composer, Banjo Paterson.
John Long, a palaeontologist at Museum Victoria, called the finds amazing. He added that they put Australia back on the map of big dinosaur discoveries.
Get to know them better with the Guardian.
-------------------------------
Cloak and mirrors
And to finish off, one that thousands of Harry Potter fans could get very excited about. Scientists have created an ‘illusion device’ which makes one object look like another, teasing that sci-fi fantasies such as invisibility cloaks or ‘holes’ in solid walls could become reality.
Researchers have explored this idea before, creating an ‘invisibility cloak’ which bent microwaves around a central cavity. Any object in this cavity was rendered effectively invisible.
Now scientists are pushing the boundaries further. “Invisibility is just an illusion of free space, of air” said Che Ting Chan, at the Hong Kong University of Science and Technology, who co-authored the study. “We are extending that concept. We can make it look like not just air but anything we want”.
The new device distorts light bouncing off an object. This light then travels through a metamaterial – matter that can bend light in any direction - which makes the object seem invisible. Next the light travels through a different part of the metamaterial, creating an allusion of something else.
So a cat could appear to be a dog, or a military plane could be very effectively camouflaged.
There are some challenges before the device become practical, but it’s thought these can be overcome. “I don’t see any obstacles to this device being built” commented John Pendry, the physicist at Imperial College London who devised the theory behind invisibility cloaking.
New Scientist uncovers more.
Giant jumpers to shrinking sweaters
Climate change is making its effects better and better known, but few are as strange as the conundrum of St Kilda’s shrinking sheep.
Scientists have been studying the wild Soay sheep since the mid-1980s, and have been perplexed by the fact that a typical ewe has been diminishing by between 80g and 100g a year.
“According to classic evolutionary theory, they should have been getting bigger” said Professor Tim Coulson, of Imperial College, who led the study. The sheep fatten up during the summer, to see them through the harsh winters. “Larger sheep tend to be more likely to survive and reproduce than smaller ones, and offspring tend to resemble their parents” added Coulson.
However, milder winters and earlier springs have turned this logic on its head. These are allowing smaller lambs to survive the long winters, and the average body size of a ewe has shrunk by about 5 per cent over the last 24 years.
How far this will continue is difficult to say. “It’s a little bit early to predict that we’ll be having Chihuahuas running round herding pygmy sheep in, say, a hundred years from now” concluded Professor Coulson.
Read all about it in the Independent.
-------------------------------
Ball-breaking research
New possibilities for treating male infertility are drawing nearer, as the Times reports how scientists have created synthetic human sperm from embryonic stem cells.
“This is an important development as it will allow researchers to study in detail how sperm forms and will lead to a better understanding of infertility in men” expressed Professor Nayeria, leader of the team at Newcastle University. “This understanding could help us develop new ways to help couples suffering infertility so they can have a child which is genetically their own”.
The creations have some of the biological characteristics of natural sperm; however other scientists have been doubtful that they are the real thing. Professor Nayeria accepts further investigation into the synthetic cells is needed.
The team say it will be at least five years before the technique is perfected. However its use as a treatment will require a change in the law; utilising such derived sperm for reproduction was banned by the Human Fertilisation and Embryology Act last year.
The proposal’s ethics are also being questioned.
"This is an example of immoral madness. Perfectly viable human embryos have been destroyed in order to create sperm over which there will be huge questions of their healthiness and viability”, condemned Josephine Quintavalle from Comment on Reproductive Ethics.
Others disagree. John Harris, Professor of Bioethics at the University of Manchester, said he didn’t see any problems. “Eventually it will be used to solve male infertility and that will be wholly beneficial”.
-------------------------------
2°C or not to be?
Developed and developing nations have agreed that global temperatures should not rise more than 2°C above 1990 levels. Above this point, the Earth’s climate system would become dangerously unstable, say the UN.
The declaration came from the G8 summit, where many countries discussed steps and targets to cut emissions. Us President Barack Obama, who chaired the meeting, said: “We recognise the scientific view that the increase in global average temperature above pre-industrial levels ought not to exceed 2°C”.
A target to cut emissions by 80% by 2050 was agreed by G8 members.
However they failed to persuade developing countries to accept targets of cutting emissions by 50% by the same date. UN Secretary General Ban Ki-moon critised the G8 climate efforts, saying strong and ambitious 2020 cuts also needed to be established.
RK Pachauri, chair of the Inter-govermental Panel on Climate Change said more details were needed. “It certainly doesn’t give you a road map on how you should get there but at least they’ve defined the destination” he told the BBC.
It’s thought rich nations need to determinedly pave the way on cuts, or developing nations will not sign up to 2050 goals. Developed nations had a “historic responsibility to take the lead” stressed Barack Obama.
-------------------------------
Planets on the pull
A contentious idea that tweaks fundamental physical laws could be experimentally proven, by subtle changes in the orbits of our planets.
Stars orbiting at the edge of spiral galaxies travel faster than we think they should; according to conventional gravitational theory they should be flung out into space. Something else must be keeping them on track.
One answer to this is dark matter. Another suggestion is modified Newtonian dynamics, or MOND.
MOND predicts that below a certain acceleration, gravity switches to a stronger form. This means that stars with slower acceleration at galaxy edges experience stronger gravity.
However the theories have been difficult to test, as they manifest themselves over huge, galaxy-scale distances.
But now Mordehai Milgrom, who conceived MOND, claims forms of his theory predict an effect within our own solar system.
Milgrom says Newton’s laws predict a region between our sun and the centre of the galaxy where the gravity from both cancels out. This area is also where any MOND-predicted departures from Newtonian gravity will most clearly show up. If there is gravity here, where there should be none, MOND exists.
MOND predicts the force in the area will gradually change the elliptical orbits of the planets, causing them to trace a flower petal pattern over time.
The theory cannot yet be tested, as we need to observe more full orbits of some of our outer planets. However, if proved, it will change our understanding of the fundamental laws of physics.
Read more in New Scientist.
-------------------------------
Dancing dinosaurs
The names ‘Banjo’, ‘Matilda’ and ‘Clancy’ are unlikely to strike fear in many people. But parallel to the convention of naming hurricanes the likes of ‘Tanya’, ‘Kyle’ and ‘Colin’; these monikers are for 3 newly discovered dinosaurs, including a flesh-eating predator.
The remains were dug up in Queensland’s outback, and date back 100m years to the middle of the Cretaceous period.
Banjo – formally known as Australovenator wintonensis – is the carnivore of the group, and even bigger than the velociraptor. He is also the most complete meat-eater ever found in the country. “The cheetah of his time, Banjo was light and agile” commented palaeontologist Scott Hucknell, at Queensland Museum. “He could run down most prey with ease.”
The two herbivores are both new types of titanosaur, the largest animals to ever walk the earth. Clancy – or Witonotitan wattsi – was a giraffe-like, tall, slender beast whilst Matilda – Diamantinasaurus matildae – was more hippo-like.
The names were plucked to honour characters of the song ‘Waltzing Matilda’, and also its composer, Banjo Paterson.
John Long, a palaeontologist at Museum Victoria, called the finds amazing. He added that they put Australia back on the map of big dinosaur discoveries.
Get to know them better with the Guardian.
-------------------------------
Cloak and mirrors
And to finish off, one that thousands of Harry Potter fans could get very excited about. Scientists have created an ‘illusion device’ which makes one object look like another, teasing that sci-fi fantasies such as invisibility cloaks or ‘holes’ in solid walls could become reality.
Researchers have explored this idea before, creating an ‘invisibility cloak’ which bent microwaves around a central cavity. Any object in this cavity was rendered effectively invisible.
Now scientists are pushing the boundaries further. “Invisibility is just an illusion of free space, of air” said Che Ting Chan, at the Hong Kong University of Science and Technology, who co-authored the study. “We are extending that concept. We can make it look like not just air but anything we want”.
The new device distorts light bouncing off an object. This light then travels through a metamaterial – matter that can bend light in any direction - which makes the object seem invisible. Next the light travels through a different part of the metamaterial, creating an allusion of something else.
So a cat could appear to be a dog, or a military plane could be very effectively camouflaged.
There are some challenges before the device become practical, but it’s thought these can be overcome. “I don’t see any obstacles to this device being built” commented John Pendry, the physicist at Imperial College London who devised the theory behind invisibility cloaking.
New Scientist uncovers more.
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