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The Lounge>Science is Cool....
Fish 09:43 PM 05-21-2012
This is a repository for all cool scientific discussion and fascination. Scientific facts, theories, and overall cool scientific stuff that you'd like to share with others. Stuff that makes you smile and wonder at the amazing shit going on around us, that most people don't notice.

Post pictures, vidoes, stories, or links. Ask questions. Share science.

This is in support of the Penny 4 NASA project. If you enjoy anything you learned from this thread, consider making a donation and signing the petition.

Why should I care?:

Baby Lee 04:17 AM 02-26-2019
Science Meme!!! Cutting Edge!!

scho63 09:57 AM 03-21-2019
I wasn't sure what thread this belongs in but this is the best one I found. This is an incredible discovery and really cool.

Mariner's Astrolabe from 1503 shipwreck is world's oldest

A rare navigational tool has snagged a Guinness World Record as the oldest mariner's astrolabe.

The astrolabe dates to between 1496 and 1501; it sank to the bottom with a shipwreck in 1503 near the coast of the island of Al-Ḥallānīyah, in what is now Oman. The find is one of only 104 historical astrolabes in existence.

"It is a great privilege to find something so rare, something so historically important," David Mearns, an oceanographer at Blue Water Recovery, said in a 2017 statement after the astrolabe was first analyzed. Mearns, who led the archaeological excavation of the wreck, added, "It was like nothing else we had seen." [The 25 Most Mysterious Archaeological Finds on Earth]

A maritime disaster

International Journal of Nautical Archaeology
Mariner's astrolabes are circular devices that sailors used to measure the altitude of the sun or stars, which allowed them to calculate their ship's latitude. The instrument that was just inducted into the Guinness World Records was discovered under a layer of sand in the Arabian Sea in 2014. The astrolabe went down with a ship under the command of a Portuguese commander named Vicente Sodré, who was the uncle of the famous explorer Vasco da Gama.

Sodré and his brother, Brás Sodré, were commanding a subfleet of five ships in the 4th Portuguese India Armada in 1503. The two men were supposed to be patrolling off southwestern India, protecting a couple of trading outposts. Instead, the commanders went rogue and headed to the Gulf of Aden, where the officers and their men looted several Arab ships. The brothers then headed to Al-Ḥallānīyah and stopped to make some repairs. In May 1503, an enormous wind blew in, smashing two of the ships, the Esmeralda and the Sâo Pedro, into the rocks of the island. Vicente Sodré died in the wreck; Brás Sodré also died — on the island — although historical records do not provide the cause of death.

The disaster was famous because the ships went down laden with cargo and left Portugal's trading outposts open to an attack by Indian forces. In 1998, archaeologists surveyed the area where the ships were thought to have sunk and found what looked to be a wreck site. It wasn't until 2013, however, that the Oman government and researchers could arrange an excavation in the remote area. Over the next two years, archaeologists recovered almost 3,000 artifacts from the site, including a ship's bell inscribed with the year 1498.

Navigation by the stars
The astrolabe was found under 1.3 feet (0.4 meters) of sand in a natural gully near the wreck site. The artifact measures 6.9 inches (17.5 centimeters) in diameter and is festooned with the Portuguese coat of arms and an armillary sphere — a representation of the position of celestial objects around Earth . (The armillary sphere was a common Portuguese emblem and is still part of the country's flag.) The metal used in making the astrolabe is an alloy made mostly of copper, with a little zinc, tin and lead.

Years of damage by saltwater and tides erased most of the other markings on the astrolabe. To uncover what could no longer be seen by the naked eye, researchers at the University of Warwick in England used laser scanning to detect the tiniest grooves and etchings on the disk. Their results, published in the International Journal of Nautical Archaeology, revealed 18 scale marks on the upper right of the disk, which would have allowed the navigator to measure the angle of the sun or stars.

The first recorded use of an astrolabe was on an expedition by a Portuguese explorer in 1481, the researchers wrote, but the earliest versions were likely wood and did not survive the ages. The Sodré astrolabe had to be made before February 1502, when the squadron left Lisbon. The armillary sphere was an emblem of Dom Manuel I, the king of Portugal from late 1495 to 1521; the astrolabe was probably manufactured during his reign, at around 1496 at the earliest, the researchers concluded. The 1498 ship's bell and the dates of coins found at the wreck site all support that date range, they wrote.

According to the University of Warwick, that ship's bell will also be taking a place of honor in the Guinness World Records as the oldest ship's bell ever discovered.

Hydrae 10:05 AM 03-21-2019
Very cool, thanks for sharing that!
65TPT 03:14 PM 03-29-2019

GloryDayz 04:41 PM 03-29-2019
Originally Posted by 65TPT:
Very cool..
Donger 05:41 PM 03-29-2019
Originally Posted by 65TPT:
Very cool, but how long would it take to accelerate to 30% of the speed of light using this Halo Drive?
Fish 06:58 PM 03-29-2019
At those speeds, hydrogen becomes lethal. Would need a great deal of currently nonexistent tech at least...

Originally Posted by :
Highly relativistic speeds are desirable for interstellar travel. Relativistic time dilation would reduce the subjective duration of the trip for the travelers, so that they can cover galaxy-scale distances in a reasonable amount of personal time. Unfortunately, as spaceship velocities approach the speed of light, interstellar hydrogen H, although only present at a density of approximately 1.8 atoms/cm3, turns into intense radiation that would quickly kill passengers and destroy electronic instrumentation. In addition, the energy loss of ionizing radiation passing through the ship’s hull represents an increasing heat load that necessitates large expenditures of energy to cool the ship. Stopping or diverting this flux, either with material or electromagnetic shields, is a daunting problem. Going slow to avoid severe H irradiation sets an upper speed limit of v ~ 0.5 c. This velocity only gives a time dilation factor of about 15%, which would not substantially assist galaxy-scale voyages. Diffuse interstellar H atoms are the ultimate cosmic space mines and represent a formidable obstacle to interstellar travel.

'Hamas' Jenkins 07:57 PM 03-29-2019
I wish I had taken a photo of the inside of a cyclotron I recently saw. The beam path had blasted through the target and started burning a hole in the shielding, and that was at only a few percent of light speed.
listopencil 08:16 AM 04-05-2019

Rain Man 09:00 AM 04-05-2019
I've always wondered what would happen if you opened a shaken soda under pressure.

I was at the Smithsonian a while back, and they had on display a styrofoam cup that had been left in a submersible that went down to some deep depth where it was under extreme pressure. The amazing thing was that it didn't crush the cup, but rather it miniaturized it. My theory is that it collapsed all of the air that's evenly distributed in styrofoam, and because the material bound it together, it pulled in on itself.
Attached: Submersible Cup Small.jpg (301.2 KB) 
Fish 11:09 PM 04-05-2019
We are likely within a few years of a HIV/AIDS vaccine.

HIV Remission Achieved in Second Patient

A second person has experienced sustained remission from HIV-1 after ceasing treatment, according to a study published today in Nature.

The case report, carried out by researchers at UCL and Imperial College London, together with teams at the University of Cambridge and the University of Oxford, comes ten years after the first such case, known as the ‘Berlin Patient.’

Both patients were treated with stem cell transplants from donors carrying a genetic mutation that prevents expression of an HIV receptor CCR5.

The subject of the new study has been in remission for 18 months after his antiretroviral therapy (ARV) was discontinued. The authors say it is too early to say with certainty that he has been cured of HIV, and that they will continue to monitor his condition.

“At the moment the only way to treat HIV is with medications that suppress the virus, which people need to take for their entire lives, posing a particular challenge in developing countries,” said the study’s lead author, Professor Ravindra Gupta from the University of Cambridge, who led the study while at UCL.

“Finding a way to eliminate the virus entirely is an urgent global priority, but is particularly difficult because the virus integrates into the white blood cells of its host.”

According to the World Health Organization, there were approximately 36.9 million people worldwide living with HIV/AIDS in 2017 and only 59% of these are receiving ARV. Drug-resistant HIV is a growing concern. Almost one million people die annually from HIV-related causes.

The report describes a male patient in the UK, who prefers to remain anonymous, and was diagnosed with HIV infection in 2003 and on antiretroviral therapy since 2012.

Later in 2012, he was diagnosed with advanced Hodgkin’s Lymphoma. In addition to chemotherapy, in 2016 he underwent a haematopoietic stem cell transplant from a donor with two copies of the genetic mutation (or ‘allele’) that prevents expression of CCR5.

CCR5 is the most commonly used receptor by HIV-1, the most common and most harmful type of HIV. People who have two mutated copies of the CCR5 allele are resistant to the HIV-1 virus strain that uses this receptor, as the virus cannot enter host cells.

Chemotherapy can be effective against HIV as it kills cells that are dividing. Replacing immune cells with those that don’t have the CCR5 receptor appears to be key in preventing HIV from rebounding after the treatment.

The transplant was relatively uncomplicated, but with some side effects including mild graft-versus-host disease, a complication of transplants wherein the donor immune cells attack the recipient’s immune cells.

The patient remained on ARV for 16 months after the transplant, at which point the clinical team and the patient decided to interrupt ARV therapy to test if the patient was truly in HIV-1 remission.

Regular testing confirmed that the patient’s viral load remained undetectable, and he has been in remission for 18 months since ceasing ARV therapy (35 months post-transplant). The patient’s immune cells remain unable to express the CCR5 receptor.

Dr Hoi Ping Mok, and Dr Fanny Salasc from the Department of Medicine at the University of Cambridge tested for virus that is ‘latent’ and may not be found by conventional lab assays. The researchers are part of Professor Andrew Lever’s lab, which has developed a highly sensitive assay for latent virus.

“This is the most reliable assay there is to demonstrate that there really are no hidden reservoirs of HIV that might be temporarily ‘sleeping’ and might reactivate at a later date,” said Professor Lever. “Our Cambridge lab is unique in the UK in being able to carry out this assay.”

The patient is only the second person documented to be in sustained remission without ARV. The first, the Berlin Patient, also received a stem cell transplant from a donor with two of the CCR5 alleles, but to treat leukaemia. Notable differences were that the Berlin Patient was given two transplants and underwent total body irradiation, while the UK patient received just one transplant and less intensive chemotherapy.

Both patients experienced mild graft-versus-host disease, which may also have played a role in the loss of HIV-infected cells.

“By achieving remission in a second patient using a similar approach, we have shown that the Berlin Patient was not an anomaly, and that it really was the treatment approaches that eliminated HIV in these two people,” said Professor Gupta.

The researchers caution that the approach is not appropriate as a standard HIV treatment due to the toxicity of chemotherapy, but it offers hope for new treatment strategies that might eliminate HIV altogether.

“We need to understand if we could knock out this receptor in people with HIV, which may be possible with gene therapy,” said Professor Gupta.

“While it is too early to say with certainty that our patient is now cured of HIV, and doctors will continue to monitor his condition, the apparent success of haematopoietic stem cell transplantation offers hope in the search for a long-awaited cure for HIV/AIDS,” said Professor Eduardo Olavarria from Imperial College Healthcare NHS Trust and Imperial College London.

The research was funded by Wellcome, the Medical Research Council, the Foundation for AIDS Research, and National Institute for Health Research (NIHR) Biomedical Research Centres at University College London Hospitals, Oxford, Cambridge and Imperial.

The research team is presenting the findings today at the annual Conference on Retroviruses and Opportunistic Infections (CROI) in Seattle.
Fish 09:49 AM 04-06-2019
No clue what to expect. But it sounds pretty cool...

Scientists set to unveil first picture of a black hole

The world, it seems, is soon to see the first picture of a black hole.

On Wednesday, astronomers across the globe will hold "six major press conferences" simultaneously to announce the first results of the Event Horizon Telescope (EHT), which was designed precisely for that purpose.

It has been a long wait.

Of all the forces or objects in the Universe that we cannot see—including dark energy and dark matter—none has frustrated human curiosity so much as the invisible maws that shred and swallow stars like so many specks of dust.

Astronomers began speculating about these omnivorous "dark stars" in the 1700s, and since then indirect evidence has slowly accumulated.

"More than 50 years ago, scientists saw that there was something very bright at the centre of our galaxy," Paul McNamara, an astrophysicist at the European Space Agency and an expert on black holes, told AFP.

"It has a gravitational pull strong enough to make stars orbit around it very quickly—as fast as 20 years."

To put that in perspective, our Solar System takes about 230 million years to circle the centre of the Milky Way.

Eventually, astronomers speculated that these bright spots were in fact "black holes"—a term coined by American physicist John Archibald Wheeler in the mid-1960s—surrounded by a swirling band of white-hot gas and plasma.

At the inner edge of these luminous accretion disks, things abruptly go dark.

"The event horizon"—a.k.a. the point-of-no-return—"is not a physical barrier, you couldn't stand on it," McNamara explained.

"If you're on the inside of it, you can't escape because you would need infinite energy. And if you are on the other side, you can—in principle."

A golf ball on the moon

At its centre, the mass of a black hole is compressed into a single, zero-dimensional point.

The distance between this so-called "singularity" and the event horizon is the radius, or half the width, of a black hole.

The EHT that collected the data for the first-ever image is unlike any ever devised.

"Instead of constructing a giant telescope—which would collapse under its own weight—we combined several observatories as if they were fragments of a giant mirror," Michael Bremer, an astronomer at the Institute for Millimetric Radio Astronomy in Grenoble, told AFP.

In April 2017, eight such radio telescopes scattered across the globe—in Hawaii, Arizona, Spain, Mexico, Chile, and the South Pole—were trained on two black holes in very different corners of the Universe to collect data.

Studies that could be unveiled next week are likely to zoom in on one or the other.

Oddsmakers favour Sagittarius A*, the black hole at the centre of our own elliptical galaxy that first caught the eye of astronomers.

Sag A* has four million times the mass of our sun, which means that the black hole is generates is about 44 million kilometres across.

That may sound like a big target, but for the telescope array on Earth some 26,000 light-years (or 245 trillion kilometres) away, it's like trying to photograph a golf ball on the Moon.

Testing Einstein

The other candidate is a monster black hole—1,500 times more massive even than Sag A*—in an elliptical galaxy known as M87.

It's also a lot farther from Earth, but distance and size balance out, making it roughly as easy (or difficult) to pinpoint.

One reason this dark horse might be the one revealed next week is light smog within the Milky Way.

"We are sitting in the plain of our galaxy—you have to look through all the stars and dust to get to the centre," said McNamara.

The data collected by the far-flung telescope array still had to be collected and collated.

"The imaging algorithms we developed fill the gaps of data we are missing in order to reconstruct a picture of a black hole," the team said on their website.

Astrophysicists not involved in the project, including McNamara, are eagerly—perhaps anxiously—waiting to see if the findings challenge Einstein's theory of general relativity, which has never been tested on this scale.

Breakthrough observations in 2015 that earned the scientists involved a Nobel Prize used gravitational wave detectors to track two black holes smashing together.

As they merged, ripples in the curvatures of time-space creating a unique, and detectable, signature.

"Einstein's theory of general relativity says that this is exactly what should happen," said McNamara.

But those were tiny black holes—only 60 times more massive than the Sun—compared to either of the ones under the gaze of the EHT.

"Maybe the ones that are millions of times more massive are different—we just don't know yet."
Bowser 10:31 AM 04-06-2019
"It's like a hole. And it's black."
BigCatDaddy 02:09 PM 04-06-2019
Originally Posted by Bowser:
"It's like a hole. And it's black."
Holds up a black piece of paper as the press oohs and aahs :-)
Fish 08:59 AM 04-10-2019
And there it is.... just look at that blackness....

First ever black hole image released

Astronomers have taken the first ever image of a black hole, which is located in a distant galaxy.

It measures 40 billion km across - three million times the size of the Earth - and has been described by scientists as "a monster".

The black hole is 500 million trillion km away and was photographed by a network of eight telescopes across the world.

Details have been published today in Astrophysical Journal Letters.

Prof Heino Falcke, of Radboud University in the Netherlands, who proposed the experiment, told BBC News that the black hole was found in a galaxy called M87.

"What we see is larger than the size of our entire Solar System," he said.

"It has a mass 6.5 billion times that of the Sun. And it is one of the heaviest black holes that we think exists. It is an absolute monster, the heavyweight champion of black holes in the Universe."

The image shows an intensely bright "ring of fire", as Prof Falcke describes it, surrounding a perfectly circular dark hole. The bright halo is caused by superheated gas falling into the hole. The light is brighter than all the billions of other stars in the galaxy combined - which is why it can be seen at such distance from Earth.

The edge of the dark circle at the centre is the point at which the gas enters the black hole, which is an object that has such a large gravitational pull, not even light can escape.

The image matches what theoretical physicists and indeed, Hollywood directors, imagined black holes would look like, according to Dr Ziri Younsi, of University College London - who is part of the collaboration.

"Although they are relatively simple objects, black holes raise some of the most complex questions about the nature of space and time, and ultimately of our existence," he said.

"It is remarkable that the image we observe is so similar to that which we obtain from our theoretical calculations. So far, it looks like Einstein is correct once again."

But having the first image will enable researchers to learn more about these mysterious objects. They will be keen to look out for ways in which the black hole departs from what's expected in physics. No-one really knows how the bright ring around the hole is created. Even more intriguing is the question of what happens when an object falls into a black hole.

Prof Falcke had the idea for the project when he was a PhD student in 1993. At the time, no-one thought it was possible. But he was the first to realise that a certain type of radio emission would be generated close to and all around the black hole, which would be powerful enough to be detected by telescopes on Earth.

He also recalled reading a scientific paper from 1973 that suggested that because of their enormous gravity, black holes appear 2.5 times larger than they actually are.

These two previously unknown factors suddenly made the seemingly impossible, possible. After arguing his case for 20 years, Prof Falcke persuaded the European Research Council to fund the project. The National Science Foundation and agencies in East Asia then joined in to bankroll the project to the tune of more than £40m.

It is an investment that has been vindicated with the publication of the image. Prof Falcke told me that he felt that "it's mission accomplished".

He said: "It has been a long journey, but this is what I wanted to see with my own eyes. I wanted to know is this real?"

No single telescope is powerful enough to image the black hole. So, in the biggest experiment of its kind, Prof Sheperd Doeleman of the Harvard-Smithsonian Centre for Astrophysics, led a project to set up a network of eight linked telescopes. Together, they form the Event Horizon Telescope and can be thought of as a planet-sized array of dishes.

Each is located high up at a variety of exotic sites, including on volcanoes in Hawaii and Mexico, mountains in Arizona and the Spanish Sierra Nevada, in the Atacama Desert of Chile, and in Antarctica.

A team of 200 scientists pointed the networked telescopes towards M87 and scanned its heart over a period of 10 days.

The information they gathered was too much to be sent across the internet. Instead, the data was stored on hundreds of hard drives that were flown to a central processing centres in Boston, US, and Bonn, Germany, to assemble the information. Prof Doeleman described the achievement as "an extraordinary scientific feat".

"We have achieved something presumed to be impossible just a generation ago," he said.

"Breakthroughs in technology, connections between the world's best radio observatories, and innovative algorithms all came together to open an entirely new window on black holes."

The team is also imaging the supermassive black hole at the centre of our own galaxy, the Milky Way.

Odd though it may sound, that is harder than getting an image from a distant galaxy 55 million light-years away. This is because, for some unknown reason, the "ring of fire" around the black hole at the heart of the Milky Way is smaller and dimmer.
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