Science is Cool....

[Fish]

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.

Why should I care?:

[Fish]

Big bang theory: how dinosaurs had sex



DINOSAURS WERE THE LARGEST animals to ever walk Earth, and they ruled the planet for more than 160 million years. The long-necked Argentinosaurus, with back vertebrae almost 2m high, possibly grew to 30m long and weighed up to 80 tonnes. Perhaps the ground really did shake for them when they mated?

So how did these giants do the deed, and what evidence do we have to reconstruct their sex lives?

The internet offers vague speculation. One website claims they probably didn’t have penises so must have used cloacal kissing, juxtaposing their massive bottoms together for the interchange of seminal fluid to the female, as do most frogs and many birds.

I disagree with this view, as evidence from living animals, close relatives of dinosaurs, implies they must have mated using copulation, and that males must have had very large and flexible penises.

Did dinosaurs mate like humans?

We now know with confidence that the meat-eating theropods, such as Tyrannosaurus and kin, were the group that gave rise to the first birds about 160 million years ago.

This has been established from a large number of exquisite fossils showing various feathered dinosaurs and early dinosaur-like birds from sites in northern China.

Crocodiles and their kin evolved from the last common ancestor with the dinosaur-bird group, so crocs can’t be regarded as “descendents of the dinosaurs” as some crocodile park ads would have us believe.

All male crocodiles have a penis and most primitive living birds also possess one, so it follows that dinosaurs must also have had a penis. The majority of living birds though have secondarily lost the penis. For them a mating is a simple, quick cloacal kiss where sperm is rapidly passed to the female.

So how did the dinosaurs do it? Biomechanics experts such as Professor McNeill Alexander of The University of Leeds claim that the weight of the male would have rested on the females hips to mount from behind as elephants do, but the resulting stresses would have been massive.

Professor Roger Seymour from the University of Adelaide studied giraffes mating and proved that the male’s blood pressure is roughly twice that of other mammals. Their hearts need be proportionately 75% larger due to the physiological constraints of the long neck and highly perched head.

How the largest animals mate

Bearing this in mind, he suggested that long-necked dinosaurs could only have mated in a particular way. A dinosaur with, say, a 10m-long neck would have seven times the normal mammalian blood pressure. So rear mounting is not a big problem if one keeps the neck horizontal.

Just imagine a 70-tonne giant sauropod fainting after loss of blood pressure to the head at the time of orgasm while mounting its mate. Yes, the earth would have most certainly shaken for them.

Recent molecular studies of the major bird groups find that ostriches and other primitive flightless birds are indeed the most ancient members of the living birds, with ducks and geese and some other waterbirds also very old lineages.

All these primitive living birds possess a penis, with ducks having the most bizarre types – a regular sized Argentine lake duck has a corkscrew-shaped organ with a brush on the tip that measures up to 42cm long.

Bizarre sex lives of ducks

Muscovy ducks can also explosively evert their penises in 0.3 second to 20cm long – roughly the same speed as driving at 70kph.

So, it’s quite likely their distant extinct ancestors, the meat-eating theropod dinosaurs, also mated using an eversible penis, most likely a terrifyingly large one.

For an animal the size of Tyrannosaurus (14m long) to mate effectively, the male organ would need be in the order of at least 2m long, and a lot more if it happened to be cork-screw shaped like a duck’s.

It’s not unlikely that one day palaeontologists will find a fossilised dinosaur penis. Extraordinary soft-tissue preservation in fossils are coming to light each year along with new fossil sites being discovered.

Greater detail can be resolved in fossils using new technologies, such as micro-CT and synchrotron tomography. Recently, 380 million-year-old fossil fishes from Australia were found to have complete sets of muscles preserved.

I truly believe the day will come, probably when we least expect it, when a remarkable new dinosaur fossil pops up solving the age-old mystery of how dinosaurs really did do the deed.

[Dave Lane]

Lots of cool stuff happened this last week. Credits for the image and links go to Hashem Al-ghaili

Science Summary of The Week

➤ HIV Vaccine: http://is.gd/TDeptG
➤ Mysterious Structures: http://is.gd/GcFZfH
➤ Mouse Lifespan: http://is.gd/K5iYFv
➤ Cancer Vaccine: http://is.gd/YRGZ9m
➤ Moon Probe: http://is.gd/TKgONG
➤ Largest Volcano: http://is.gd/1dL1Fd
➤ Virgin Galactic: http://is.gd/cPuoqR
➤ 3D-Printed Kidneys: http://is.gd/3lrnxO

Enlarge This Graphic : http://is.gd/i45IEs

[jiveturkey]

Say whut!

http://gizmodo.com/our-universe-migh...ium=socialflow



Scientists are proposing a radical new way of think about how the universe began. In a new imagining of the Big Bang theory, they think it could have been the result of a four-dimensional star collapsing in on itself to form a black hole, which then proceeded to spew its guts out and, kindly, form our universe.

The standard Big Bang theory has some limitations. The singularity—the idea that everything came from essentially nowhere—is one of them. The fact that the universe is at an almost uniform temperature is another, because that doesn't square with the speed at which the universe has expanded. So physicists often ponder alternative theories that could explain the origin of our universe.

And that's just what Niayesh Afshordi, an astrophysicist with the Perimeter Institute for Theoretical Physics in Canada, has done. Here's, roughly, what he proposes:

Our three-dimensional universe floats as a membrane in a "bulk universe" that has four dimensions.
That "bulk universe" has 4D stars, which go through the same life cycles as our normal 3D ones.
The most massive ones explode as supernovae, and their central core collapses into a black hole, like in our universe—just in 4D.
The 4D black hole has its own 4D "event horizon," a boundary between the inside and the outside of a black hole.
In a 3D universe, the event horizon appears to be 2D. In a 4D universe, it appears to be 3D. (Do you see where this is going?)
The 4D black hole, then, blows apart, with the leftover material forming a 3D membrane, surrounding a 3D event horizon, which expands—and is essentially our universe.
So, according to the theory, our universe is the vomited-up guts of a 4D black hole. The expansion of the event horizon explains our universe's expansion; the fact that its creation stems from another 4D universe explains the weird temperature uniformity. You can take a second to process all that, it's okay.

Of course, it's speculative; it's pretty tricky, after all, knowing for sure what happened at the birth of our universe, and the work's yet to be peer reviewed, but the researchers think it has promise. Plus, there's something comforting in the notion that we're all just spatters of stellar vomit. [arXiv via Phys.org]

Image by ESO/M. Kornmesser

[jiveturkey]

If this was a year earlier we could have put a fire Pioli satellite in orbit.

[Fish]

[Fish]

How Do You Pour Water Up Into a Glass?
BY RHETT ALLAIN09.12.138:24 AM



What the heck? Did gravity reverse itself to make this water flow UP? No, not quite. But this trick is indeed impressive. I’ve looked at this same phenomena before, but let’s go over it again. (I saw the above image on Richard Wiseman’s blog.)

Does the Water Fall Up?
No. In fact, the water is falling down. Yes, I know it doesn’t look like it’s falling. That’s because the camera is in an accelerating reference frame of the plane. If you take a little piece of water (a drop) and let go, it will accelerate towards the Earth with an acceleration of 9.8 m/s2. However, the plane is also accelerating downward with an acceleration greater than 9.8 m/s2. Maybe this diagram will help.



If you could just see the water from a stationary reference frame (maybe a floating hot air balloon), you would see the water indeed falling down. Now, I remember that I said “falling down” and not “moving down”. The water actually might be moving up. The key is that even though it is moving up, it is accelerating down. The plane also is accelerating down. As long as the downward acceleration of the plane is greater than the water, the water will move into the cup above it.

What if the acceleration of the plane and the water were the same? Then the water and the cup wouldn’t get any closer. It would look similar to this dog in a plane that is accelerating down.



Yup. Weightless. You can read more about weightlessness in space in this post.

So, the plane is flying straight down? No. You have to be careful here. The plane is ACCELERATING down. Most likely the plane is flying in a vertical circle. And yes, flying in a circle is an acceleration towards the center of the circle.

What About Fake Forces?
There is another way to look at this problem. We like to think of the momentum principle when dealing with forces (some people would call this Newton’s second Law – but I think that is archaic terminology). This says that a force changes the momentum of an object and I can write it like this:



However, there is a catch. This momentum principle only works if the reference frame (or view point if you wish) is not accelerating itself. But fear not. There is a way to cheat so that we can still use the momentum principle IN an accelerating reference frame (which we physicists call a non-inertial reference frame). The cheat code for this case is a fake force.

Consider a tossed ball in an upward accelerating elevator. Here are the two ways I could look at that ball.



In both views, the ball is in the air for the same time and reaches the same distance from the top of the elevator. To make this work with a fake force, the fake force must be in the opposite direction as the acceleration of the reference frame.

La te xi t 1
Wouldn’t it be cool if you could actually look at a tossed ball both inside and outside an accelerating elevator at the same time? Oh, you can. Even better – I did this a while back.

Back to the case of the upside-down airplane, I can draw this diagram for the pouring water.



As long as the fake force is greater than the gravitational force, the water will “fall up” (in the reference frame of the plane).

If fake forces are so useful, why don’t introductory physics textbooks use them? The answer is simple. Although fake forces can be used for accelerating frames, they are also a bit dangerous. One of the problems introductory students (and normal people too) have is that they like to make up extra forces. The current teaching strategy is to always associate each force due to an interaction with another object. When you add in fake forces, this isn’t as clear. So, the best bet is to stick with “real” forces.

[Fish]

Why A Little Mammal Has So Much Sex That It Disintegrates
by Ed Yong



It’s August in Australia, and a small, mouse-like creature called an antechinus is busy killing himself through sex. He was a virgin until now, but for two to three weeks, this little lothario goes at it non-stop. He mates with as many females as he can, in violent, frenetic encounters that can each last up to 14 hours. He does little else.

A month ago, he irreversibly stopped making sperm, so he’s got all that he will ever have. This burst of speed-mating is his one chance to pass his genes on to the next generation, and he will die trying. He exhausts himself so thoroughly that his body starts to fall apart. His blood courses with testosterone and stress hormones. His fur falls off. He bleeds internally. His immune system fails to fight off incoming infections, and he becomes riddled with gangrene.

He’s a complete mess, but he’s still after sex. “By the end of the mating season, physically disintegrating males may run around frantically searching for last mating opportunities,” says Diana Fisher from the University of Queensland. “By that time, females are, not surprisingly, avoiding them.”

Soon, it’s all over. A few weeks shy of his first birthday, he is dead, along with every other male antechinus in the area.

The technical term for this is semelparity, from the Latin words for “to beget once”. For semelparous animals, from salmon to mayflies, sex is a once-in-a-lifetime affair, and usually a fatal one. This practice is common among many animal groups, but rare among mammals. You only see it in the 12 species of antechinuses and a few close relatives, all of which are small, insect-eating marsupials. (Although they look like rodents and are colloquially called marsupial mice, antechinuses are more closely related to kangaroos and koalas than to mice or rats.)

Why? Why do these marsupials practice suicidal reproduction, and why are they the only mammals that do so?

The question has vexed biologists for three decades, and many have offered answers. Some say that females don’t survive very well after breeding, so males are forced to hedge their bets by mating with as many as possible. Other suggest that it’s just a feature of the group, which have become locked into a weird breeding system through some unknown quirk of their evolutionary history. Yet others think the males are being altruistic, sacrificing themselves to leave more resources for the next generation.

But Fisher, who has been studying antechinuses for decades, favours a different idea. Her team gathered data on the lives and environments of a wide variety of 52 insect-eating marsupials, from the fully semelparous antechinuses, to relatives where a small number of males survive past their first sexual liaisons, to species that breed repeatedly.

It’s their diet that matters. These animals feed on insects, and some experience a glut of food once a year but very little at other times. This seasonality increases the further you get from the equator. The species with the most seasonal menus also had shorter breeding seasons, and their males were more likely to die after mating.

Fisher thinks that as the ancestors of antechinuses spread south through Australia and New Guinea, they encountered strong yearly fluctuations in their food supply. The females were better at raising their young if they gave birth just before the annual bonanza, and were well-fed enough to wean their joeys. Their mating seasons shortened and synchronised, collapsing into a tight window of time.

That probably wouldn’t have happened if they were placental mammals like shrews or mice, which could have produced several litters during the peak of food. But they were marsupials: their babies are born at an incredible early stage and rely on their mothers’ milk for a long time. A baby shrew suckles for days or weeks; a baby antechinus does so for four months. The females could only fit in one litter during the annual peak.

This had a huge impact on the males, which were forced to compete intensely with each other in a matter of weeks. They didn’t fight. Rather than using claws or teeth, they competed with sperm. The more they had, the more females they impregnated, and the more likely they were to displace the sperm of earlier suitors. Indeed, Fisher found a clear relationship between suicidal reproduction and testes size. The biggest testes of all, relative to body size, belong to species whose males die en masse, followed by those where a minority survive to mate again, and then by those with several breeding seasons.

The males that put the greatest efforts into sperm competition fathered the most young. It didn’t matter if they burned themselves out in the process, if they metabolised their own muscles to fuel their marathon bouts. These animals are short-lived anyway, so putting all their energy into one frenzied, fatal mating season was the best strategy for them. Living fast and dying young was adaptive.

This idea was first proposed in 1979 but Fisher’s data, although mostly correlative, provides fresh support for it. She certainly finds it more plausible than the idea that the males are selflessly sacrificing themselves for the next generation. After all, the males usually live outside the females’ home ranges, so are unlikely to compete with their own young for resources.

“Antechinus mating habits have appeared in many documentaries, and the explanation of males selflessly sacrifing themselves to increase food supply for young is the one given in all the ones I have seen,” says Fisher. “I hope that documentaries and textbooks now start to give an evidence-based explanation of sexual selection.”

[Fish]

Radical OOKP surgery implants tooth with lens into blind man Ian Tibbetts eye and restores sight: he sees twin sons' faces for first time



A BLIND British man has had his sight restored after pioneering surgery that involved implanting one of his teeth into his eye.

Ian Tibbetts, 43, who first damaged his eye in an industrial accident when scrap metal ripped his cornea in six places, had his sight restored by the radical operation, chronicled in the new BBC documentary The Day I Got My Sight Back.

The surgery allowed Mr Tibbetts to see his four-year-old twin sons, Callum and Ryan, for the first time, a moment he describes as "ecstasy".

The procedure, called osteo-odonto-keratoprothesis, or OOKP, was conducted by ophthalmic surgeon Christopher Liu at the Sussex Eye Hospital in Brighton, Sussex. Mr Tibbetts and his wife Alex agreed to the revolutionary surgery after all other options had failed, leaving Mr Tibbetts depressed and out of work.

The complex surgery is a two-part procedure. First, the tooth and part of the jaw are removed, and a lens is inserted into the tooth using a drill. The tooth and lens are then implanted under the eye socket. After a few months, once the tooth has grown tissues and developed a blood supply, comes the second step: part of the cornea is sliced open and removed and the tooth is stitched into the eye socket. Since the tooth is the patient’s own tissue, the body does not reject it.

"The tooth is like a picture frame which holds this tiny plastic lens," documentary maker Sally George told the BBC.

After the bandages came off, Mr Tibbetts' sight gradually returned, and he saw his sons' faces for the first time.

"I just cried, gave them a big hug and a kiss. They were totally different than what I’d pictured in my mind," he said.

"They were just shapes. I couldn’t make them out. I had to actually learn to tell them apart by their voices,” he told the Independent.

“I could tell whichever one it was by the way they spoke and sometimes by how quickly they moved. I had a picture in my head of what they looked like but they were better. I’m a bit biased there."

Now, Mr Tibbetts' vision is now about 40 per cent, and although at first strangers stared at his new eye - which is pink, with a black pupil, he no longer is bothered by the attention.

[Fish]

[Fish]

Jellyfish 'pulverizing' robots trained in Korea to hunt down their prey



The aquatic killer 'bots have been developed to combat the increasing menace of jellyfish swarms

Scientists in South Korea have developed a team of aquatic robots dedicated to thinning out the numbers of jellyfish swarms. Known as the Jellyfish Elimination Robotic Swarm (or JEROS) the sea-bound robots use a combined GPS and camera system to detect jellyfish before catching them in nets.

“Once caught, the jellyfish are pulverized using a special propeller,” reads a press release from the Korea Institute for Science and Technology, the home of the project.

The JEROS system is estimated to be three times more economical than manual removal of the jellyfish, with the robots – which travel at a speed of 6 knots or 7mph – eliminating around 400kg of the invertebrates an hour.

The researchers also experimented with arranging their killer ‘ bots into swarms, with a video showing a group of three individuals controlled as one.

The team has been led by Professor Myung Hyun, who has been working in response to the growing danger to businesses and individuals from swarms – or blooms, as they are technically known - of jellyfish.

Writing in the journal of Advances in Intelligent Systems and Computing , Hyun describes jellyfish as “a great menace to the oceans ecosystem, which leads to drastic damage to the fishery industries.”

“To overcome this problem,” writes Hyun, “a jellyfish removal system with trawl boats equipped with the jellyfish removal net has been suggested."

"However, the system needs large ships which need to be operated by a lot of human operators. Thus, this paper represents the design and implementation of an autonomous jellyfish removal robot system, called JEROS.”

The problem of marauding jellyfish is not specific to Korean shores either: last week the Oskarshamn nuclear plant in Sweden was shut down after the pipes that transport water to cool the turbines were clogged by tonnes of jellyfish, and in 2006 the same fate even befell a US aircraft carrier, the nuclear-powered USS Ronald Reagan.

In her recent book ' Stung! On Jellyfish Blooms and the Future of the Ocean’, marine biologist Lisa-ann Gershwin describes how overfishing and climate change have created the perfect ocean conditions for jellyfish: reports from 2006 estimated a total biomass of fish in the ocean as 3.9 million tons, whilst the total jellyfish biomass was around 13 million tons.

Quoted in a review of her book by Tim Walker, Gershwin writes:

“We are creating a world more like the late Precambrian than the late 1800s—a world where jellyfish ruled the seas and organisms with shells didn’t exist. We are creating a world where we humans may soon be unable to survive, or want to.”

With this in mind, the creation of a swarm of ruthless jellyfish hunters seems like quite a sensible idea, though the video below of JEROS in action is not suited for those sympathetic to the clueless jellies.

Awesome video...

[Cephalic Trauma]

Originally Posted by Fish

2-5 lbs of normal flora is the estimation I've seen (which is very similar to yours, but it just puts it into perspective).

[Fish]

Originally Posted by Cephalic Trauma

2-5 lbs of normal flora is the estimation I've seen (which is very similar to yours, but it just puts it into perspective).

We are all organic bacteria mechs, ambling about for sex and food....

[ThaVirus]

Originally Posted by Fish

They have a Discovery Channel special called "Monsters Inside Me" or something on Netflix. Anyone watched it?

[Cephalic Trauma]

Originally Posted by Fish

We are all organic bacteria mechs, ambling about for sex and food....

There is some evidence suggesting that bacterial infections can play roles in different behaviors, so there's some truth to that.

Another semi-related interesting fact: you share the same gut flora with those you live with. This comes in handy when treating life threatening C diff colitis using fecal transplant, but it leaves you wondering how the gut flora get there in there first place. Kind of gross, if you think about it.

[Fish]

What if the Moon was as close as the International Space Station?

The International Space Station orbits at roughly 420 kilometers (260 miles) above the surface of the Earth. What would it look like if the Moon circled about our planet at a similar distance? Pretty damn epic, that's what.



At this distance the Moon would rise in the west and set in the east, The Moon Orbits the Earth counterclockwise when viewed from the North pole looking *down*. the same direction that the earth rotates. Normally the Moon orbits much slower than the earth rotates so it rises in the east and sets in the west, however at 420km it orbits much faster, faster than the earth rotates underneath, therefore it will rise in the west and set in the east.

The Moon would also orbit very quickly, although yetipc1 notes that time in the animation has been sped up.

Of course, the Moon could never circle our planet so closely. For one thing, there's the Roche Limit to consider – the distance at which the tidal forces of a larger celestial body (the Earth, in this case) win out over the gravitational forces holding a smaller body (the Moon) together. The Earth-Moon Roche limit is a little over 18,000 kilometers, about 1/20th the distance of its current orbit. Venture any closer than that, and the Moon is liable to be ripped apart, potentially turning Earth into a ringed planet. Plus, even if the Moon could orbit our planet at so near a distance without disintegrating, there's still the question of what effect its gravitational forces (which would be felt hundreds of times more keenly) would have on proceedings here on Earth.

Still, it's a great thought experiment, and a really fantastic animation – incredibly well-planned and executed. And for those wondering, at no point in the animation is the Moon actually transparent. What you're seeing is a well-animated example of a phenomenon known as Earthshine, whereby the Moon is illuminated not only directly, by the Sun, but indirectly by sunlight reflected off the Earth. yetipc1 explains what you're seeing:

When the Moon eclipses the Sun, the camera exposure is adjusted so that you can see the Light of the earth reflecting back upon the moon... it is Blue on the left side because the moon is flying over the Gulf of Mexico, and is white/tan on the right side because that part is over the United States . it is Dark in the middle because it is casting a huge shadow, and that shadow does not reflect light back on the Moon. I didn't quite expect it to look like this, it was a nice surprise

As the Moon dips below the horizon, the sliver of illumination is also the result of planetshine.