The Monterey Bay Aquarium Research Institute (MBARI) posted this video on its Facebook page this weekend and wrote:
To get you in the mood for Halloween, we bring you Deep-sea Nightmares!
Starring the black sea devil (Melanocetus), a skeleton shrimp (caprellid amphipod), the vampire squid (Vampyroteuthis infernalis), a bat-faced crab (Macroregonia macrochira), the fangtooth (Anoplogaster cornuta), a giant sea spider (as big as your open fist; not an actual spider, but an arthropod called a pycnogonid), bacterial ooze (growing on a hay bale placed at 3,000 m for a carbon experiment), the witch eel (Nettastomidae), a slimy mob of hagfish feeding on a dead fish, and the bloody-belly comb jelly (Lampocteis cruentiventer).
Bottom line: from Deep-Sea Nightmares video via Monterey Bay Aquarium Research Institute.
from EarthSky http://ift.tt/2xDkSTn
The Monterey Bay Aquarium Research Institute (MBARI) posted this video on its Facebook page this weekend and wrote:
To get you in the mood for Halloween, we bring you Deep-sea Nightmares!
Starring the black sea devil (Melanocetus), a skeleton shrimp (caprellid amphipod), the vampire squid (Vampyroteuthis infernalis), a bat-faced crab (Macroregonia macrochira), the fangtooth (Anoplogaster cornuta), a giant sea spider (as big as your open fist; not an actual spider, but an arthropod called a pycnogonid), bacterial ooze (growing on a hay bale placed at 3,000 m for a carbon experiment), the witch eel (Nettastomidae), a slimy mob of hagfish feeding on a dead fish, and the bloody-belly comb jelly (Lampocteis cruentiventer).
It’s time to welcome a new batch of researchers to the Cancer Research UK team. Here are some common themes they are researching, and how their work could help cancer patients in the future.
Targeting the faulty genetics of cancer
Dr Serena Nik-Zainal is exploring patterns of faults in DNA from cancer cells called signatures. This will help her understand how DNA is damaged inside cells, and how it’s repaired to help cells survive, which can lead to cancer.
Meanwhile, Dr Andrew Beggs,Dr Ross Carruthers, Dr Laureanode la Vega, and Dr Luca Magnani, are looking at the genetic changes that can help tumours become resistant to treatment.
Beggs is using mini lab-grown tumours called organoids to search for new drug targets to stop bowel cancer becoming resistant to treatment. Carruthers is exploring how brain tumours become resistant to radiotherapy. He’s trying to work out how cells from the most aggressive type of brain tumour, glioblastoma, are able to repair their DNA following radiotherapy and keep growing.
Transcription is a process that takes information from genes in our DNA to make proteins. de la Vega is looking at one molecule that controls transcription and has been thought of as protective against cancer. But recent research suggests in some situations it may actually help cancer cells become resistant to chemotherapy – de la Vega is investigating how this happens. Finally, Magnani is looking at way in which some mutations in the tumours are able to turn their genes ‘on’ or ‘off’ to escape treatments and spread around the body, focussing on breast cancer.
Corrupting healthy cells
Many different types of cell live alongside cancer cells and inside tumours as they grow. Dr AhsanAkram and Professor Tim Underwood are looking at cells called cancer associated fibroblasts, which can help tumours grow and spread.
While Akram is developing a new way to see these cells in lung cancer to help doctors to decide what treatment to give patients, Underwood is trying to understand how oesophageal cancer cells hijack neighbouring healthy cells, and how the genetic changes in the cancer cells help them to do this. Dr Chris Tape is also interested in how the genetic changes in cancer cells help them to corrupt the healthy fibroblast cells and immune cells, focussing on bowel cancer.
Recently, the immune system has emerged as a potentially powerful ally in tackling certain cancers. Dr Sheeba Irshad is investigating how immune cells move within tumours in the lab. By understanding the signals involved, she hopes to find a way to encourage particular immune cells to move into the tumour and kill the cancer cells.
Dr Tobias Janowitz is also investigating new ways to help the immune system tackle pancreatic cancer. He focuses on how tumours change the way that the body uses energy, which can lead to a wasting condition called cachexia. He wants to understand how this hinders the immune response to cancer, which allows the tumour to grow unchecked. By understanding more about these processes in the lab, he hopes to find a way to break this cycle and help tackle pancreatic cancer.
It’s in the blood
Blood stem cells must produce a constant supply of essential blood cells throughout a person’s lifetime, but when their DNA is damaged it can lead to blood cancers.
Dr Meng Wang is investigating how stem cell DNA can be damaged and fixed, which could point to the steps leading to cancer. Meanwhile, Dr Melinda Czeh is looking at how these stem cells change as people get older to try and understand how age increases the risk of acute myeloid leukaemia (AML).
Dr BethPayne is also looking at what happens as people age in relation to AML, having seen some common genetic faults in older people. She wants to understand how these changes can lead to cancer, which could help identify new potential drug targets.
Evolution of cancer
Cancers cells can be cunning, changing as they evolve and become resistant to treatment. Dr Jyoti Nangalia and Dr Andrea Sottoriva are each taking a different approach to studying this evolution, in the hope of finding new ways to stop cancer in its tracks.
Nangalia is looking for genes that are important in a cancer’s evolution. She wants to predict which patients may be at a higher risk of their disease evolving, giving doctors a head start in planning treatment. Sottoriva is trying to map cancer evolution by taking a mathematical and computational approach. He also wants to anticipate which drugs would be best to give as the disease changes, potentially helping to personalise treatment.
Population research
When studying a disease that affects so many people, looking for and studying common themes in the population can be incredibly helpful.
Dr David Muller is looking at large numbers of people with kidney cancer to solve some of the mysteries of the disease. For example, he’s investigating the so-called ‘obesity paradox’ – obesity increases the risk of developing kidney cancer, but kidney cancer patients who are obese appear to have a better prognosis than those of a healthy weight. By looking at large numbers of people with kidney cancer he hopes to gather enough information to help reveal why this is.
Dr Evropi Theodoratou and Dr Samantha Quaife are looking at screening, an important tool for detecting certain cancers early, when they’re easier to treat, or helping prevent the diseases altogether. Theodoratou wants to see if some people may benefit from entering bowel cancer screening earlier by identifying those who may be deemed at a higher risk than the general population.
There’s no national lung cancer screening programme in the UK, but there’s plenty of research going on to understand if there would be any benefit to introducing one. Quaife is investigating if people at high risk of lung cancer would go for screening if it was offered, and what barriers there may be to attending. Should a screening programme be introduced, this will help inform how invitations to screening could be designed to improve engagement by those at high risk and to minimise socioeconomic inequalities in participation.
And finally
Dr Harriet Walter is developing the skills to run early stage clinical trials for blood cancers such as leukaemia and lymphoma as well other hard to treat cancers. Researchers like Walter play a vital role in getting new treatments tested, making sure they’re safe and effective, to give people with cancer more treatment options in the future.
Catherine
If you’re a researcher you can find out more about funding schemes like this on our website.
from Cancer Research UK – Science blog http://ift.tt/2xEsqVK
It’s time to welcome a new batch of researchers to the Cancer Research UK team. Here are some common themes they are researching, and how their work could help cancer patients in the future.
Targeting the faulty genetics of cancer
Dr Serena Nik-Zainal is exploring patterns of faults in DNA from cancer cells called signatures. This will help her understand how DNA is damaged inside cells, and how it’s repaired to help cells survive, which can lead to cancer.
Meanwhile, Dr Andrew Beggs,Dr Ross Carruthers, Dr Laureanode la Vega, and Dr Luca Magnani, are looking at the genetic changes that can help tumours become resistant to treatment.
Beggs is using mini lab-grown tumours called organoids to search for new drug targets to stop bowel cancer becoming resistant to treatment. Carruthers is exploring how brain tumours become resistant to radiotherapy. He’s trying to work out how cells from the most aggressive type of brain tumour, glioblastoma, are able to repair their DNA following radiotherapy and keep growing.
Transcription is a process that takes information from genes in our DNA to make proteins. de la Vega is looking at one molecule that controls transcription and has been thought of as protective against cancer. But recent research suggests in some situations it may actually help cancer cells become resistant to chemotherapy – de la Vega is investigating how this happens. Finally, Magnani is looking at way in which some mutations in the tumours are able to turn their genes ‘on’ or ‘off’ to escape treatments and spread around the body, focussing on breast cancer.
Corrupting healthy cells
Many different types of cell live alongside cancer cells and inside tumours as they grow. Dr AhsanAkram and Professor Tim Underwood are looking at cells called cancer associated fibroblasts, which can help tumours grow and spread.
While Akram is developing a new way to see these cells in lung cancer to help doctors to decide what treatment to give patients, Underwood is trying to understand how oesophageal cancer cells hijack neighbouring healthy cells, and how the genetic changes in the cancer cells help them to do this. Dr Chris Tape is also interested in how the genetic changes in cancer cells help them to corrupt the healthy fibroblast cells and immune cells, focussing on bowel cancer.
Recently, the immune system has emerged as a potentially powerful ally in tackling certain cancers. Dr Sheeba Irshad is investigating how immune cells move within tumours in the lab. By understanding the signals involved, she hopes to find a way to encourage particular immune cells to move into the tumour and kill the cancer cells.
Dr Tobias Janowitz is also investigating new ways to help the immune system tackle pancreatic cancer. He focuses on how tumours change the way that the body uses energy, which can lead to a wasting condition called cachexia. He wants to understand how this hinders the immune response to cancer, which allows the tumour to grow unchecked. By understanding more about these processes in the lab, he hopes to find a way to break this cycle and help tackle pancreatic cancer.
It’s in the blood
Blood stem cells must produce a constant supply of essential blood cells throughout a person’s lifetime, but when their DNA is damaged it can lead to blood cancers.
Dr Meng Wang is investigating how stem cell DNA can be damaged and fixed, which could point to the steps leading to cancer. Meanwhile, Dr Melinda Czeh is looking at how these stem cells change as people get older to try and understand how age increases the risk of acute myeloid leukaemia (AML).
Dr BethPayne is also looking at what happens as people age in relation to AML, having seen some common genetic faults in older people. She wants to understand how these changes can lead to cancer, which could help identify new potential drug targets.
Evolution of cancer
Cancers cells can be cunning, changing as they evolve and become resistant to treatment. Dr Jyoti Nangalia and Dr Andrea Sottoriva are each taking a different approach to studying this evolution, in the hope of finding new ways to stop cancer in its tracks.
Nangalia is looking for genes that are important in a cancer’s evolution. She wants to predict which patients may be at a higher risk of their disease evolving, giving doctors a head start in planning treatment. Sottoriva is trying to map cancer evolution by taking a mathematical and computational approach. He also wants to anticipate which drugs would be best to give as the disease changes, potentially helping to personalise treatment.
Population research
When studying a disease that affects so many people, looking for and studying common themes in the population can be incredibly helpful.
Dr David Muller is looking at large numbers of people with kidney cancer to solve some of the mysteries of the disease. For example, he’s investigating the so-called ‘obesity paradox’ – obesity increases the risk of developing kidney cancer, but kidney cancer patients who are obese appear to have a better prognosis than those of a healthy weight. By looking at large numbers of people with kidney cancer he hopes to gather enough information to help reveal why this is.
Dr Evropi Theodoratou and Dr Samantha Quaife are looking at screening, an important tool for detecting certain cancers early, when they’re easier to treat, or helping prevent the diseases altogether. Theodoratou wants to see if some people may benefit from entering bowel cancer screening earlier by identifying those who may be deemed at a higher risk than the general population.
There’s no national lung cancer screening programme in the UK, but there’s plenty of research going on to understand if there would be any benefit to introducing one. Quaife is investigating if people at high risk of lung cancer would go for screening if it was offered, and what barriers there may be to attending. Should a screening programme be introduced, this will help inform how invitations to screening could be designed to improve engagement by those at high risk and to minimise socioeconomic inequalities in participation.
And finally
Dr Harriet Walter is developing the skills to run early stage clinical trials for blood cancers such as leukaemia and lymphoma as well other hard to treat cancers. Researchers like Walter play a vital role in getting new treatments tested, making sure they’re safe and effective, to give people with cancer more treatment options in the future.
Catherine
If you’re a researcher you can find out more about funding schemes like this on our website.
from Cancer Research UK – Science blog http://ift.tt/2xEsqVK
Every Halloween – and a few days before and after – the brilliant star Arcturus, brightest star in Bootes the Herdsman, sets at the same time and on the same spot on the west-northwest horizon as the summer sun. This star rises at the same time and at the same place on the east-northeast horizon as the summer sun. That’s why – every year at this time – you can consider Arcturus as a ghost of the summer sun.
At mid-northern latitudes, Arcturus now sets about 2 hours after sunset and rises about 2 hours before sunrise.
If you live as far north as Barrow, Alaska, the star Arcturus shines all night long now, mimicking the midnight sun of summer.
If you live in the Southern Hemisphere, you can’t see Arcturus right now. South of the equator, Arcturus sets at the same time and on the same place on the horizon as the winter sun. In other words, Arcturus sets before the sun and rises after the sun at southerly latitudes at this time of year.
If you are in the Northern Hemisphere, try watching this star in the October evening chill. You can envision the absent summer sun radiating its extra hours of sunlight. Not till after dark does this star set, an echo of long summer afternoons. Similarly, Arcturus rises in the east before dawn, a phantom reminder of early morning daybreaks.
At northerly latitudes, Arcturus sets in the west after sunset and rises in the east before sunrise. You can verify that you’re looking at Arcturus once the Big Dipper comes out. Its handle always points to Arcturus.
Halloween – also known as All Hallows’ Eve or All Saints’ Eve – is observed in various countries on October 31, especially in the United States. It’s a big deal for America children, who roam from house to house trick or treating, hoping for candy and other treats.
This modern holiday is based on a much older tradition, that of cross-quarter days.
Cover of ‘Star Arcturus, ghost of summer sun’ coloring book
Every Halloween – and a few days before and after – the brilliant star Arcturus, brightest star in Bootes the Herdsman, sets at the same time and on the same spot on the west-northwest horizon as the summer sun. This star rises at the same time and at the same place on the east-northeast horizon as the summer sun. That’s why – every year at this time – you can consider Arcturus as a ghost of the summer sun.
At mid-northern latitudes, Arcturus now sets about 2 hours after sunset and rises about 2 hours before sunrise.
If you live as far north as Barrow, Alaska, the star Arcturus shines all night long now, mimicking the midnight sun of summer.
If you live in the Southern Hemisphere, you can’t see Arcturus right now. South of the equator, Arcturus sets at the same time and on the same place on the horizon as the winter sun. In other words, Arcturus sets before the sun and rises after the sun at southerly latitudes at this time of year.
If you are in the Northern Hemisphere, try watching this star in the October evening chill. You can envision the absent summer sun radiating its extra hours of sunlight. Not till after dark does this star set, an echo of long summer afternoons. Similarly, Arcturus rises in the east before dawn, a phantom reminder of early morning daybreaks.
At northerly latitudes, Arcturus sets in the west after sunset and rises in the east before sunrise. You can verify that you’re looking at Arcturus once the Big Dipper comes out. Its handle always points to Arcturus.
Halloween – also known as All Hallows’ Eve or All Saints’ Eve – is observed in various countries on October 31, especially in the United States. It’s a big deal for America children, who roam from house to house trick or treating, hoping for candy and other treats.
This modern holiday is based on a much older tradition, that of cross-quarter days.
Cover of ‘Star Arcturus, ghost of summer sun’ coloring book
If you were one of the early stargazers, you might have chosen Algol in the constellation Perseus. Early astronomers nicknamed Algol the Demon Star. Bwahaha!
Of course, like all stars, Algol isn’t the least bit scary. But it’s associated in skylore with a mythical scary monster – the Gorgon Medusa – who had snakes instead of hair. It’s said that she was so horrifying in appearance that the sight of her would turn an onlooker to stone.
The star Algol takes its name from an Arabic word meaning “the Demon’s Head.” This star is said to depict the terrifying snake-y head of the Medusa monster.
Perseus and Medusa
In the mythology of the skies, Perseus – a great hero often depicted mounted on Pegasus the Flying Horse – used Medusa’s head to his own advantage – to turn Cetus the Sea-monster into stone. Perhaps the ancients associated this star’s variable brightness with the evil, winking eye of the Medusa.
Winking? Yes. Algol is a known variable star, which waxes and wanes in brightness.
There are many variable stars known throughout the heavens, but Algol might well be the most famous variable star of them all. This star brightens and dims with clockwork regularity, completing one cycle in 2 days 20 hours and 49 minutes. Plus its entire cycle is visible to the eye alone.
The early stargazers surely knew about its changing brightness and must have smiled as they named variable Algol – a strangely behaving star in a sky full of steadily shining stars – for a mythological demon.
How can you see Algol? It’s easy to find. Our sky chart shows the northeastern sky for autumn evenings, especially around Halloween.
How to find Algol
The conspicuous W or M-shaped constellation Cassiopeia enables you to star-hop to Perseus. Draw an imaginary line from the star Gamma Cassiopeia through the star Ruchbah to locate Perseus and then Algol. At mid-northern latitudes, this star can be seen for at least part of the night all year round. But it’s best seen in the evening sky from autumn to spring. It’s visible in the northeast sky in autumn, shines high overhead in winter, and swings to the northwest sky by spring.
Algol brightens and dims with clockwork regularity, completing one cycle in 2 days, 20 hours, and 49 minutes. Moreover, this variable star is easy to observe with just the unaided eye. At its brightest, Algol shines about three times more brightly than at its faintest. At maximum brilliance, Algol matches the brightness of the nearby second-magnitude star Almach. At minimum, Algol’s light output fades to that of the star Epsilon Persei.
Modern-day astronomy has unlocked the secret of Algol’s mood swings. It’s an eclipsing binary star. This kind of binary is composed of two stars, with each star revolving around the other. From Earth, we see the orbital plane of this binary star almost exactly edge-on. Therefore, when the dimmer of the two stars swings in front of the brighter star, we see Algol at minimum brightness.
from EarthSky http://ift.tt/19gFDW2
The Gorgon Medusa had snakes in place of hair. Eek! Via Wikimedia and Caravaggio
If you were one of the early stargazers, you might have chosen Algol in the constellation Perseus. Early astronomers nicknamed Algol the Demon Star. Bwahaha!
Of course, like all stars, Algol isn’t the least bit scary. But it’s associated in skylore with a mythical scary monster – the Gorgon Medusa – who had snakes instead of hair. It’s said that she was so horrifying in appearance that the sight of her would turn an onlooker to stone.
The star Algol takes its name from an Arabic word meaning “the Demon’s Head.” This star is said to depict the terrifying snake-y head of the Medusa monster.
Perseus and Medusa
In the mythology of the skies, Perseus – a great hero often depicted mounted on Pegasus the Flying Horse – used Medusa’s head to his own advantage – to turn Cetus the Sea-monster into stone. Perhaps the ancients associated this star’s variable brightness with the evil, winking eye of the Medusa.
Winking? Yes. Algol is a known variable star, which waxes and wanes in brightness.
There are many variable stars known throughout the heavens, but Algol might well be the most famous variable star of them all. This star brightens and dims with clockwork regularity, completing one cycle in 2 days 20 hours and 49 minutes. Plus its entire cycle is visible to the eye alone.
The early stargazers surely knew about its changing brightness and must have smiled as they named variable Algol – a strangely behaving star in a sky full of steadily shining stars – for a mythological demon.
How can you see Algol? It’s easy to find. Our sky chart shows the northeastern sky for autumn evenings, especially around Halloween.
How to find Algol
The conspicuous W or M-shaped constellation Cassiopeia enables you to star-hop to Perseus. Draw an imaginary line from the star Gamma Cassiopeia through the star Ruchbah to locate Perseus and then Algol. At mid-northern latitudes, this star can be seen for at least part of the night all year round. But it’s best seen in the evening sky from autumn to spring. It’s visible in the northeast sky in autumn, shines high overhead in winter, and swings to the northwest sky by spring.
Algol brightens and dims with clockwork regularity, completing one cycle in 2 days, 20 hours, and 49 minutes. Moreover, this variable star is easy to observe with just the unaided eye. At its brightest, Algol shines about three times more brightly than at its faintest. At maximum brilliance, Algol matches the brightness of the nearby second-magnitude star Almach. At minimum, Algol’s light output fades to that of the star Epsilon Persei.
Modern-day astronomy has unlocked the secret of Algol’s mood swings. It’s an eclipsing binary star. This kind of binary is composed of two stars, with each star revolving around the other. From Earth, we see the orbital plane of this binary star almost exactly edge-on. Therefore, when the dimmer of the two stars swings in front of the brighter star, we see Algol at minimum brightness.
October 29, 2017 photo by Elena Gissi in Lisanza, Lombardy, Italy.
Over the past couple of weeks, as firefighters have struggled to contain them, wildfires have raged in northern Italy. We received two photos of the unusual sunset skies over northern Italy on October 29, 2017. First, Elena Gissi in Lisanza, Lombardy, Italy wrote:
This photo is not post-processed. The sky was really like this, and one of reasons is the abundance of small particles caused by forest fires occurring some 100 kilometers [60 miles] westward.
Good for photographers… Only for them, though.
Why does the sky look like this? It looks as if there’s actual smoke in the air, for one thing. Also, an intense red sunset can result when smoke particles filter out the shorter-wavelength colors in sunlight – the greens, blues, yellows and purples – and leave the red and orange colors behind. I wonder if, since the rate of wildfires has been increasing globally, someone will coin a name for these swirling, intense red sunset skies occurring near fire sites. We’ve seen multiple photos of them this year, from various spots around the globe. Read more about the way air, dust, aerosols and water drops scatter and absorb the rays throughout their long passage through the atmosphere at sunset, at Atmospheric Optics.
Matteo Curatitoli, whose photo is below, also caught the October 29 sunset. Thank you, Elena and Matteo. We hope the fires are brought under control soon.
Matteo Curatitoli in Ghemme, Piedmont, Italy wrote of the October 29 sunset: “… north Italy’s skies were amazing! It was like someone had painted sand dunes on the sky!”
Bottom line: Swirling, intense red sunset skies due to ongoing wildfires in northern Italy.
from EarthSky http://ift.tt/2iO5DnT
October 29, 2017 photo by Elena Gissi in Lisanza, Lombardy, Italy.
Over the past couple of weeks, as firefighters have struggled to contain them, wildfires have raged in northern Italy. We received two photos of the unusual sunset skies over northern Italy on October 29, 2017. First, Elena Gissi in Lisanza, Lombardy, Italy wrote:
This photo is not post-processed. The sky was really like this, and one of reasons is the abundance of small particles caused by forest fires occurring some 100 kilometers [60 miles] westward.
Good for photographers… Only for them, though.
Why does the sky look like this? It looks as if there’s actual smoke in the air, for one thing. Also, an intense red sunset can result when smoke particles filter out the shorter-wavelength colors in sunlight – the greens, blues, yellows and purples – and leave the red and orange colors behind. I wonder if, since the rate of wildfires has been increasing globally, someone will coin a name for these swirling, intense red sunset skies occurring near fire sites. We’ve seen multiple photos of them this year, from various spots around the globe. Read more about the way air, dust, aerosols and water drops scatter and absorb the rays throughout their long passage through the atmosphere at sunset, at Atmospheric Optics.
Matteo Curatitoli, whose photo is below, also caught the October 29 sunset. Thank you, Elena and Matteo. We hope the fires are brought under control soon.
Matteo Curatitoli in Ghemme, Piedmont, Italy wrote of the October 29 sunset: “… north Italy’s skies were amazing! It was like someone had painted sand dunes on the sky!”
Bottom line: Swirling, intense red sunset skies due to ongoing wildfires in northern Italy.
The past few decades have ushered in an amazing era in the science of cosmology. A diverse array of high-precision measurements has allowed us to reconstruct our universe’s history in remarkable detail.
This line of research has, frankly, been more successful than I think we had any right to have hoped. We know more about the origin and history of our universe today than almost anyone a few decades ago would have guessed that we would learn in such a short time.
But despite these very considerable successes, there remains much more to be learned. And in some ways, the discoveries made in recent decades have raised as many new questions as they have answered.
One of the most vexing gets at the heart of what our universe is actually made of. Cosmological observations have determined the average density of matter in our universe to very high precision. But this density turns out to be much greater than can be accounted for with ordinary atoms.
After decades of measurements and debate, we are now confident that the overwhelming majority of our universe’s matter – about 84 percent – is not made up of atoms, or of any other known substance. Although we can feel the gravitational pull of this other matter, and clearly tell that it’s there, we simply do not know what it is. This mysterious stuff is invisible, or at least nearly so. For lack of a better name, we call it “dark matter.” But naming something is very different from understanding it.
For almost as long as we’ve known that dark matter exists, physicists and astronomers have been devising ways to try to learn what it’s made of. They’ve built ultra-sensitive detectors, deployed indeep underground mines, in an effort to measure the gentle impacts of individual dark matter particles colliding with atoms.
They’ve built exotic telescopes – sensitive not to optical light but to less familiar gamma rays, cosmic rays and neutrinos – to search for the high-energy radiation that is thought to be generated through the interactions of dark matter particles.
And we have searched for signs of dark matter using incredible machines which accelerate beams of particles – typically protons or electrons – up to the highest speeds possible, and then smash them into one another in an effort to convert their energy into matter. The idea is these collisions could create new and exotic substances, perhaps including the kinds of particles that make up the dark matter of our universe.
As recently as a decade ago, most cosmologists – including myself – were reasonably confident that we would soon begin to solve the puzzle of dark matter. After all, there was an ambitious experimental program on the horizon, which we anticipated would enable us to identify the nature of this substance and to begin to measure its properties. This program included the world’s most powerful particle accelerator – the Large Hadron Collider – as well as an array of other new experiments and powerful telescopes.
Experiments at CERN are trying to zero in on dark matter – but so far no dice. Image via CERN.
But things did not play out the way that we expected them to. Although these experiments and observations have been carried out as well as or better than we could have hoped, the discoveries did not come.
Over the past 15 years, for example, experiments designed to detect individual particles of dark matter have become a million times more sensitive, and yet no signs of these elusive particles have appeared. And although the Large Hadron Collider has by all technical standards performed beautifully, with the exception of the Higgs boson, no new particles or other phenomena have been discovered.
At Fermilab, the Cryogenic Dark Matter Search uses towers of disks made from silicon and germanium to search for particle interactions from dark matter. Image via Reidar Hahn/Fermilab.
The stubborn elusiveness of dark matter has left many scientists both surprised and confused. We had what seemed like very good reasons to expect particles of dark matter to be discovered by now. And yet the hunt continues, and the mystery deepens.
In many ways, we have only more open questions now than we did a decade or two ago. And at times, it can seem that the more precisely we measure our universe, the less we understand it. Throughout the second half of the 20th century, theoretical particle physicists were often very successful at predicting the kinds of particles that would be discovered as accelerators became increasingly powerful. It was a truly impressive run.
But our prescience seems to have come to an end – the long-predicted particles associated with our favorite and most well-motivated theories have stubbornly refused to appear. Perhaps the discoveries of such particles are right around the corner, and our confidence will soon be restored. But right now, there seems to be little support for such optimism.
In response, droves of physicists are going back to their chalkboards, revisiting and revising their assumptions. With bruised egos and a bit more humility, we are desperately attempting to find a new way to make sense of our world.
Dan Hooper, Associate Scientist in Theoretical Astrophysics at Fermi National Accelerator Laboratory and Associate Professor of Astronomy and Astrophysics, University of Chicago
The past few decades have ushered in an amazing era in the science of cosmology. A diverse array of high-precision measurements has allowed us to reconstruct our universe’s history in remarkable detail.
This line of research has, frankly, been more successful than I think we had any right to have hoped. We know more about the origin and history of our universe today than almost anyone a few decades ago would have guessed that we would learn in such a short time.
But despite these very considerable successes, there remains much more to be learned. And in some ways, the discoveries made in recent decades have raised as many new questions as they have answered.
One of the most vexing gets at the heart of what our universe is actually made of. Cosmological observations have determined the average density of matter in our universe to very high precision. But this density turns out to be much greater than can be accounted for with ordinary atoms.
After decades of measurements and debate, we are now confident that the overwhelming majority of our universe’s matter – about 84 percent – is not made up of atoms, or of any other known substance. Although we can feel the gravitational pull of this other matter, and clearly tell that it’s there, we simply do not know what it is. This mysterious stuff is invisible, or at least nearly so. For lack of a better name, we call it “dark matter.” But naming something is very different from understanding it.
For almost as long as we’ve known that dark matter exists, physicists and astronomers have been devising ways to try to learn what it’s made of. They’ve built ultra-sensitive detectors, deployed indeep underground mines, in an effort to measure the gentle impacts of individual dark matter particles colliding with atoms.
They’ve built exotic telescopes – sensitive not to optical light but to less familiar gamma rays, cosmic rays and neutrinos – to search for the high-energy radiation that is thought to be generated through the interactions of dark matter particles.
And we have searched for signs of dark matter using incredible machines which accelerate beams of particles – typically protons or electrons – up to the highest speeds possible, and then smash them into one another in an effort to convert their energy into matter. The idea is these collisions could create new and exotic substances, perhaps including the kinds of particles that make up the dark matter of our universe.
As recently as a decade ago, most cosmologists – including myself – were reasonably confident that we would soon begin to solve the puzzle of dark matter. After all, there was an ambitious experimental program on the horizon, which we anticipated would enable us to identify the nature of this substance and to begin to measure its properties. This program included the world’s most powerful particle accelerator – the Large Hadron Collider – as well as an array of other new experiments and powerful telescopes.
Experiments at CERN are trying to zero in on dark matter – but so far no dice. Image via CERN.
But things did not play out the way that we expected them to. Although these experiments and observations have been carried out as well as or better than we could have hoped, the discoveries did not come.
Over the past 15 years, for example, experiments designed to detect individual particles of dark matter have become a million times more sensitive, and yet no signs of these elusive particles have appeared. And although the Large Hadron Collider has by all technical standards performed beautifully, with the exception of the Higgs boson, no new particles or other phenomena have been discovered.
At Fermilab, the Cryogenic Dark Matter Search uses towers of disks made from silicon and germanium to search for particle interactions from dark matter. Image via Reidar Hahn/Fermilab.
The stubborn elusiveness of dark matter has left many scientists both surprised and confused. We had what seemed like very good reasons to expect particles of dark matter to be discovered by now. And yet the hunt continues, and the mystery deepens.
In many ways, we have only more open questions now than we did a decade or two ago. And at times, it can seem that the more precisely we measure our universe, the less we understand it. Throughout the second half of the 20th century, theoretical particle physicists were often very successful at predicting the kinds of particles that would be discovered as accelerators became increasingly powerful. It was a truly impressive run.
But our prescience seems to have come to an end – the long-predicted particles associated with our favorite and most well-motivated theories have stubbornly refused to appear. Perhaps the discoveries of such particles are right around the corner, and our confidence will soon be restored. But right now, there seems to be little support for such optimism.
In response, droves of physicists are going back to their chalkboards, revisiting and revising their assumptions. With bruised egos and a bit more humility, we are desperately attempting to find a new way to make sense of our world.
Dan Hooper, Associate Scientist in Theoretical Astrophysics at Fermi National Accelerator Laboratory and Associate Professor of Astronomy and Astrophysics, University of Chicago
