Stories tagged gravity
Another "Do This At Home" Video!
Hi, All. This is another video from the "Do This At Home" video MASTER!If you like this one, once again, www.youtube.com and search "science experiments to do at home". Well, adios!
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i would count this video as a video that contains "current science". It's all in methods and g-force. If ya wanna see MORE videos like this, again, youtube.com. c ya all!
Gravity Defiyer
Hi Guys! This is a really easy and fun science experiment to do at home. And yes, I tried it, and it's simple and amuzing!
If you want some more of this guys experiments, go to www.youtube.com and search "fun science experiments"
If you reconize his face, you'll see a WHOLE BUNCH of science videos! Well, for now, bye!
Stonehenge: A 19th Century engraving of the mysterious monument.
Courtesy Mark RyanStonehenge is back in the news. Archaeologists working on the mystery-laden prehistoric site located in south central England have now pinpointed the time of its construction to around 2300 BC. This radiocarbon-derived date connects it more closely with burial date of the Amesbury Archer, a wealthy metalworker from Europe’s alpine region, whose tomb was discovered not far from Stonehenge. Examination of the archer’s corpse revealed damage to his knee and other potentially fatal health issues.
This has led Tim Darvill and Geoff Wainwright, the two professors heading the excavation, to believe that the circle of megalithic stones existed as a healing center. Not everyone agrees, but you can find out all the details here. The dig's progress is also being recorded for an upcoming BBC Timewatch documentary.
All very well and good. But scientists remain uncertain as to how these huge stone monoliths were put in place by Stonehenge’s ancient technopeasant builders. Well, Wally Wallington, a retired construction worker in Flint, Michigan, just might have the answer. This following video came to my attention this past weekend, and I find it quite impressive and amazing. See for yourself.
SOURCES and LINKS
BBC website story
More about Stonehenge
Guardian website story
More on the Amesbury Archer
Were you a fan of the Mentos and Diet Coke fountains that EepyBird created? If so, you might tune in to "Samurai Girl" tonight (7pm, ABC) to see EepyBird's experiments with more than 250,000 sticky notes. You can also check out an extended version of the video, complete with how-tos, at EepyBird.com.
Here's a sneak peek, but definitely check the EepyBird site tonight for more.
Black hole in action: Artist's rendition of a distant super-massive black hole warping space while busy eating up stellar material.
Courtesy NASA/JPL-CaltechScientists now have a better idea why stars can still form out of giant molecular clouds being ripped apart by the gravitational pull of a nearby massive black hole.
The observed existence of huge stars in eccentric orbits around the super-massive black hole believed to be located at the center of our Milky Way galaxy has puzzled scientists. How can stars form in such extreme environments? Gravitational forces would be tremendous near the black hole, tearing apart everything in the immediate region.
The computer simulations, done by researchers from St Andrews University in the UK, show how a molecular cloud – a normal stellar nursery – is torn apart by the black hole’s immense gravitation pull. Although the powerful gravity-well eats a huge portion of the gas cloud, the remaining gases are still able to accrete more material and coalesce into stars.
This is possible because as a molecular cloud enters the black hole’s gravitational field it begins to form into a spiraling elliptical disk. The disk’s matter nearest the black hole is sucked into the gravitational vortex, while energy is transferred to the remaining outer material. This transferred energy allows the remnants to retain the eccentric orbital path as they form into huge stars many times the mass of the Sun.
"These simulations show that young stars can form in the neighborhood of super-massive black holes as long as there is a reasonable supply of massive clouds of gas from further out in the galaxy," said co-author Ian Bonnell. The study’s results appear in the current issue of Science.
The stars live fairly short lives - perhaps only about 10 million years. But their existence could help explain some of the mysteries surrounding black holes in galaxies.
LINKS
Story on BBC website
Science magazine abstract
More on super-massive black holes
Stephen Hawking: Photo courtesy Peter Kelemen at FLICKR
Graphic showing weightlessness trajectory: Image source: Sandia National LaboratoriesNow here’s something I’d really like to do sometime, but I guess if anyone should do it before I do it should be gravity’s biggest scholar, Stephen Hawking.
Hawking, the world-famous British theoretical physicist, explainer of black holes and author of the best-selling book, A Brief History of Time, plans to take a ride up into the great Blue Yonder and spend a few brief moments of freedom from gravity’s pull.
Stricken most his adult life with Amyotrophic Lateral Sclerosis (ALS), and wheelchair-bound for decades, Hawking will be aided by a medical team when he takes to the sky this coming spring. Zero Gravity, a Florida-based space tourism and entertainment company will supply the ride up and back from a Cape Canaveral landing strip.
Using a modified Boeing 727 equipped with a special padded area, Hawking and his entourage will fly upward at a steep angle to 32,000 feet then arc over into an equally steep descent of about 8000 feet. During the upward portion of the trajectory, he’ll experience an increased sense of weight (almost twice the normal pull of gravity) but on the downward side of the arc he’ll experience about 25 glorious seconds of weightlessness.
“As someone who has studied gravity and black holes all of my life, I am excited to experience firsthand weightlessness and a zero-gravity environment, “Hawking said, recently.
Astronauts have long trained this way, and some of the scenes in the movie “Apollo Thirteen” were shot on the same kind of flight to give the film an added sense of realism.
About 15 trajectories are experienced in each Zero Gravity ride, which typically lasts about 2 hours from take-off to landing. And don’t let the ride’s nickname (the vomit comet) scare you, only 1-2% of Zero Gravity’s customers are reported to have gotten space sick, The cost of such an adventure runs about $3500 per person (what’s 3 or 4 missed mortgage payments?), but Hawking will get his ride for free, one of the benefits of his celebrity. The company also plans to have two seats on the flight available by charity auction.
The ride could serve as a prelude to Hawking’s dream of someday riding into space. He made an appeal to Sir Richard Branson, founder of Virgin Galactic, to achieve that goal. Virgin Galactic is building a sub-orbital spacecraft that it hopes will begin shuttling passengers into space as early as 2009. And Branson says he will personally pick up the tab for Hawking’s $200,000 ticket! (Looks like I’m going to have start coming up with some of my own groundbreaking scientific theories).
Professor Hawking was born 300 years to the day after the death of Galileo, holds twenty honorary degrees and has held the post of Lucasian Professor of Mathematics at Cambridge since 1979, a position once occupied by none other than Isaac Newton formulator of the law of universal gravitation.
I'd really love to experience weightlessness. What about the rest of you? I think it would be a blast. Maybe I can get the Science Museum to pay for my ticket. Liza?
MORE INFO
Itwire web story
Zero Gravity company website
Microgravity
Stephen Hawking webpage
More on Stephen Hawking
Aboard the vomit comet: This is the same type of plane that Sanchot was operated aboard.
Courtesy NASA
I don't know about you but I think I would be pretty much last on the list to volunteer for surgery on a plane. Especially if that that plane is flying up and down, up and down, thousands of feet each minute to simulate zero gravity.
But that's just what Philippe Sanchot signed up for. Doctors removed a benign tumor from his arm as part of an experiment to see how surgery in space might work. They flew aboard the specially designed plane, Zero-G, which climbs very high and then dives quickly to simulate weightlessness.
The main surgeon on the team said:
"Now we know that a human being can be operated on in space without too many difficulties."
These techniques might be used in the future to remotely preform surgery abroad the space station or other futuristic space craft.
Here are some more random questions we've received from visitors to our website or our exhibits.
Q: Why is the Earth round? I thought it was flat.
A: Nope, the Earth is round. Not perfectly round, though. Planets like Earth are round due to gravity. Gravity pulls with equal strength in all directions, so gravity shapes the planet into a sphere. But, since the Earth rotates, the rotation adds centrifugal effects, which result in the Earth bulging slightly at the equator and flatten slightly at its poles.
Because of these centrifugal effects, the distance from the center of the earth to the surface of the earth is about 0.33% shorter at the poles compared to the equator.
Q: How does gravity work?
A: Gravity is one of the universal forces of nature, and is the tendency of objects with mass to accelerate toward each other. Newton's law of universal gravitation states that each particle of matter attracts every other particle with a force which is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.
More simply, everything that has mass has gravity, and the larger the mass, the stronger the gravity. Earth has stronger gravity than the moon because the mass of the Earth is greater than the mass of the moon.
Q: What is zero gravity?
A: Lots of gravity related questions! Zero gravity, or weightlessness, is best termed microgravity. Astronauts floating in space are not actually weightless, or in zero gravity, because the Earth's gravity is holding them and everything in the spaceship they are in, in orbit. They are actually in a state of free-fall, much like jumping from an airplane except that you are moving so fast horizontally that, as you fall, you never touch the ground because the Earth curves away from you.
Think about it this way. Considering what we learned about gravity above, if you stood on a bathroom scale and then somehow opened some trap doors that dropped both you (still standing on the scale) and the scale out of a plane, both you and the scale would be pulled down equally by gravity. You would not push down on the scale and therefore, your weight would read zero.
Q: Why is the sky blue?
A: Sunlight is scattered across the Earth's atmosphere by a process called "diffused sky radiation". The sky is blue because much more short-wave radiation (blue light) is scattered across the sky than long-wave radiation (red light). Check out this website that explains more about this, and also why the sky appears red during sunsets.
Q: How come the Science Museum you only teach one side of the story? What I mean by this is that not everyone believes in evolution, and you only talk about that side of the story. Why don't you have exhibits on theories other than evolution such as intelligent design?
A: It's in our name. We're The Science Museum of Minnesota. We represent and teach science in our exhibits and programs. We're not saying that there are not other ideas or beliefs out there (intelligent design is not a scientific theory, rather a religious belief), and we respect others and their beliefs. However, as an organization that teaches science, we practice and encourage the teaching of evolution as fundamental to the teaching of sound science and critical thinking. If we were to compromise the scientific explanations of evolution or permitted unscientific alternative explanations into our exhibits or our programs, we would be misrepresenting the principles of science. Here is the Science Museum of Minnesota's official position on evolution.
Q: Do you like pie?
A: Yes. I especially like Key Lime pie.
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