Gravity

Discovery of Speeding Galaxies May Challenge Einstein’s Gravity and Dark Matter

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A present-day near-miss of two spiral galaxies NGC 5426 and NGC 5427, which is possibly comparable to the early flyby of the Andromeda Galaxy past our own Milky Way. Courtesy of © Gemini Image Gallery.

A discovery of fast-moving galaxies, 10 million light years wide, may cause physicists to re-examine Einstein’s theory of relativity. A team from University of St. Andrews in Scotland found the enormous ring of galaxies speeding away from our galaxy much faster than existing physics modeling predicts. In fact, the scientists believe the galaxies are moving so quickly that they are calling this expansion “a mini Big Bang”.

Dr. Hongsheng Zhao and PhD student Indranil Banik co-authored the study, which came from investigating 54 galaxies in what’s called “the Local Group” of the Universe. The scientists explain the unexpected conclusions by proposing that at some point 7 to 11 billion years ago the neighboring Andromeda Galaxy came so close to our own Milky Way Galaxy that they created a “tsunami-like wake,” scattering smaller galaxies with a sling-shot-like effect.

“If Einstein’s Gravity were correct, our Galaxy would never come close enough to Andromeda to scatter anything that fast,”

5 Strange Facts About the Planet Earth

You know what it’s like: You live somewhere all your life but never realize just how great it is until someone comes to visit. While it’s just a shame we don’t get any visitors to marvel at all the peculiarities of our home planet, here are five facts you might still appreciate.

1. EARTH’S A GIANT DYNAMO.

The core of the Earth is a solid lump of nickel and iron, rotating in a sea of molten iron and nickel. This rotation functions the same way winding up a hand-held generator does, giving Earth an enormous magnetic field that extends up to 50,000 kilometers out into space. This magnetic field is crucial for life on Earth, as without it we would be exposed to the full force of the Sun’s radiation. As well as causing cancers and other radiation-aggravated conditions, the radiation’s sheer force would blow our atmosphere into space, as happened with Mercury, and to a lesser extent, Mars. Instead, charged particles are (mostly) harmlessly deflected away, giving rise to the auroras.

It’s not all good though: Any particles that hit the Earth head-on tend to get trapped in the field and can’t get out. These so-called Van Allen Radiation Belts can pose a hazard for astronauts who leave low Earth orbit.

2. IT’S THE DENSEST PLANET IN THE SOLAR SYSTEM.

While Earth may not be the biggest planet in the system, it is the biggest rocky planet in the solar system, and also the densest. Therefore, Earth has by far the highest surface gravity of any terrestrial object in the solar system. This is both a blessing and a curse.

The reason for the high density is the large deposits of heavy elements in the Earth’s makeup. Elements such as lead and uranium are much rarer on other worlds, which gives us a huge advantage in the amount and variety of construction materials available here on Earth. The high gravity has also demanded that humans develop the reflexes and endurance necessary to cope with such gravity, meaning we are far more durable than the potential delicately boned, sloth-like creature we could be had we evolved in low gravity.

Unfortunately, that high gravity makes Earth the worst place…

How Does the Restroom in the International Space Station Work?

How does the restroom in the International Space Station work? Since there is no gravity there, I am assuming things are quite different.

You are right, the absence of gravitational acceleration makes things a bit different.

Below is a picture of one of the toilets used for training purposes on the ground. The one onboard is almost identical.

The first thing an astronaut has to do is make sure he or she is seated properly. You can’t just sit down in space, since there is no down. So, you’ll notice there are straps to hold their feet so they won’t float away, mid-use.

The next thing the astronaut has to do is make sure they are aligned correctly. There…