Ask Ethan: How Many Stars In The Night Sky Still...

Ask Ethan: How many stars in the night sky still...

Science

Ask Ethan: How Many Stars In The Night Sky Still Exist?

When we look out at the Universe, we take for granted that what we see is what’s actually there at that particular moment in time. Yet this isn’t quite the case. There were delays with the Apollo astronauts because light signals took a little over two seconds apiece to make a round trip. The Mars rovers need to robotically pilot themselves, because the multi-minute delays are too great for a human to have to manually change their headings. And if you go beyond the Solar System, the distances to the stars are measured in light years, which means we’re looking back in time whenever we see a distant object. How do we know that what’s there matches what we see? Matt Lanka wants to know: [H]ow many

Forbes

The edge of the universe is closer than scientists...

Science

The edge of the universe is closer than scientists previously thought

The visible universe just shrunk by 320 million light-years in all directions, updating a famous calculation that physicists first made 13 years ago. If you're trying to calculate the size of the cosmos, the speed of light - the fastest anything can go - is a tempting place to begin and end. If you take expansion, recombination, and other variables into account, as physicist J. Richard Gott III and several of his colleagues did in 2003, you get an observable universe that's roughly 45.66 billion light-years in radius - or 91.32 billion light-years wide (if diameter is your thing).

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Lifestyle

Can The Mass Of An Object Ever Change?

What is the difference between “mass” and “rest mass” ? Does this mean that mass is not always the same? This is a good question, and also a good reminder to be careful with one’s language when writing about physics! Most of the time, if you’re reading an article, what we mean by mass and rest mass is exactly the same. Rest mass is a slightly more precise term in its phrasing, meaning specifically the mass of that object when it is at rest, relative to the person measuring its mass. This is almost always how we measure mass. If you’re in a lab (or a kitchen), and you measure an object’s weight on a scale, that object is not moving at any speed. If it is moving at a speed, you should probably

Forbes

Lifestyle

Are Earth Humans The 'Aliens' Early To The Universe's Life Party?

A few months ago there was a theory proposed in the astronomy community that surmised that we humans might be too late for alien life. The theory pretty much stated that alien life is already extinct and we are all that was left of life in the universe. Just like every study about drinking a glass of wine before bed or snorting raw eggs; a new theory proposes that we’re not staggering into the party late with warm beer, but we’re super early, playing guitar in the stairwell to an audience of zero. The theory, authored by Abraham Loeb of Harvard and Rafael Batista and David Sloan of the University of Oxford, states that the chance of life grows much higher in the distant future. Life first became

Forbes

Science

‘Largest structure in the universe’ undermines fundamental cosmic principles

Just in time for the hype surrounding No Man’s Sky, the game that takes cosmic scale to the extreme, a team of astronomers say they’ve discovered what might be the largest structure in the observable universe. The tremendous feature consists of nine gamma-ray bursts (GRB), forming a ring that is streaking across some 5 billion light years through space, according to a paper published in Monthly Notices of the Royal Astronomical Society. The ring’s diameter stretches more than 70 times that of the full moon as seen from Earth. And, as the GRBs each appear to be about 7 billion light years away, the probability that these features are positioned in this way by chance is just one in 20,000, according

Digital Trends

Lifestyle

10 Things You Never Knew About The Earth

The third rock from the sun, our home, planet Earth is full of mysteries. From the secret ocean flowing beneath the Earth's crust, to the science of how life on Earth began, AllTime10s brings you, the 10 things you didn't know about Earth.

All Time 10s