The Astronomy and Physics thread. And things of the like.

[Blzer]

Re: The Astronomy and Physics thread. And things of the like.

I don't know anything about this other than it popping up on my YouTube home page.

SpaceX to Launch Falcon Heavy Rocket


<iframe width="560" height="315" src="https://www.youtube.com/embed/DPfHHls50-w" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>


Wheels up in ten!

[countryboy]

Re: The Astronomy and Physics thread. And things of the like.

http://www.msn.com/en-us/video/science/jupiter-is-about-to-be-so-close-you-can-see-its-moons/vi-AACx558?ocid=DELLDHP17

[PVarck31]

Re: The Astronomy and Physics thread. And things of the like.

<iframe width="560" height="315" src="https://www.youtube.com/embed/mmbUwdam-UI" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Very cool

[slickdtc]

Re: The Astronomy and Physics thread. And things of the like.

Apparenrly there’s a huge meteor that will be passing by within 3.5 million miles. A lot, but relatively “close” in space distance. Something like 15 moon distances away.

Also, heard we have caught some transmissions from some super far off galaxy or system. They’re patterned, which makes it all the more interesting. It’s happened before, but it’s rare.

[PVarck31]

Re: The Astronomy and Physics thread. And things of the like.

Apparenrly there’s a huge meteor that will be passing by within 3.5 million miles. A lot, but relatively “close” in space distance. Something like 15 moon distances away.

Also, heard we have caught some transmissions from some super far off galaxy or system. They’re patterned, which makes it all the more interesting. It’s happened before, but it’s rare.

The signals are called Fast Radio Bursts. (FRBs) We detected the first one in 2007. Only a handful have been repeating, but none like this. It's repeating every 16.35 days. The location is a galaxy a half a billion light years away, which is actually the closest we have picked one up from.

Unfortunately we should probably get the whole alien thing out of our heads. These signals present signs of being from a natural source, not artificial. We can tell by the shape of the wave.

Couple theories right now are a neutron star orbiting a black hole. And a binary star system, with the second star being a neutron star orbiting it.

It sucks it's most likely not aliens. But it's still cool that we are finding cool new things in the universe all the time.

[Caulfield]

Re: The Astronomy and Physics thread. And things of the like.

Couple theories right now are a neutron star orbiting a black hole. And a binary star system, with the second star being a neutron star orbiting it.


It sucks it's most likely not aliens.

it doesn't suck nearly as bad as having a black hole close enough to 'hear' lol.

[PVarck31]

Re: The Astronomy and Physics thread. And things of the like.

it doesn't suck nearly as bad as having a black hole close enough to 'hear' lol.

Lol, Space is scary.

There are actually much closer back holes to us. Our very own super massive black hole, Sag A* in the center of our galaxy is only 25,000 light years away. But the actual closest to us is called V616 Monocerotis at a measly 3,000 light years away. But it's kinda of a baby at only 9 times the mass of the sun. Sag A* is four million solar masses.

[PVarck31]

Re: The Astronomy and Physics thread. And things of the like.

Every single dot is a galaxy with billions of stars.

[Blzer]

Re: The Astronomy and Physics thread. And things of the like.

[PVarck31]

Re: The Astronomy and Physics thread. And things of the like.

If you do the math, if all of those galaxies have billions of stars almost all stars have planets, in our galaxy we know there are about 40 billion terrestrial (rocky) planets that could be similar to earth and be in the habitable zone. So we use that number as a base, but it could vary widely. We think the Andromeda galaxy might have over 100 billion terrestrial planets. But we will use 40. We now think there are over 2 trillion galaxies in the universe. But it's probably a lot more. 40B X 2T=10 to the 26th power. This is about a septillion terrestrial planets in the universe.

This doesn't mean they are all earth-like or are able to sustain an atmosphere and have liquid water on the surface. It just means that these planets are candidates to be habitable worlds. A good example of what a lot of these planets could be, is Mars. Mars it technically in the habitable zone here. But it obviously can't sustain an atmosphere and keep the surface at a comfortable temperature. Although we are pretty sure that Mars was pretty much just like Earth at one point.

But even when you eliminate the non-habitable terrestrial planets, that still leaves unimaginable numbers of planets that are most likely just like earth, or even more habitable than earth.

So no, we can't be alone. The numbers all add up to almost a certainty that we are not alone.

And if there are any math people in here, feel free to check my math. I could be off.

[Caulfield]

Re: The Astronomy and Physics thread. And things of the like.

Every single dot is a galaxy with billions of stars.

‘‘you said keep your eyes out of focus, which is misleading. you want DEEP focus!’’


‘‘I see something that could be a spaceship. is it round? is it pointy?’’

[ImTellinTim]

Re: The Astronomy and Physics thread. And things of the like.

If you do the math, if all of those galaxies have billions of stars almost all stars have planets, in our galaxy we know there are about 40 billion terrestrial (rocky) planets that could be similar to earth and be in the habitable zone. So we use that number as a base, but it could vary widely. We think the Andromeda galaxy might have over 100 billion terrestrial planets. But we will use 40. We now think there are over 2 trillion galaxies in the universe. But it's probably a lot more. 40B X 2T=10 to the 26th power. This is about a septillion terrestrial planets in the universe.

This doesn't mean they are all earth-like or are able to sustain an atmosphere and have liquid water on the surface. It just means that these planets are candidates to be habitable worlds. A good example of what a lot of these planets could be, is Mars. Mars it technically in the habitable zone here. But it obviously can't sustain an atmosphere and keep the surface at a comfortable temperature. Although we are pretty sure that Mars was pretty much just like Earth at one point.

But even when you eliminate the non-habitable terrestrial planets, that still leaves unimaginable numbers of planets that are most likely just like earth, or even more habitable than earth.

So no, we can't be alone. The numbers all add up to almost a certainty that we are not alone.

And if there are any math people in here, feel free to check my math. I could be off.

The numbers also say it's basically impossible that those entities have found us.

To put how far things in space are away from each other into perspective, when the Milky Way eventually passes by/through another galaxy there is basically a 0% chance any of the stars will collide with each other.

[Jr.]

Re: The Astronomy and Physics thread. And things of the like.

The numbers also say it's basically impossible that those entities have found us.

To put how far things in space are away from each other into perspective, when the Milky Way eventually passes by/through another galaxy there is basically a 0% chance any of the stars will collide with each other.

Only if you assume any other life forms in the universe have technology comparable to ours.

[jfsolo]

Re: The Astronomy and Physics thread. And things of the like.

The numbers also say it's basically impossible that those entities have found us.

To put how far things in space are away from each other into perspective, when the Milky Way eventually passes by/through another galaxy there is basically a 0% chance any of the stars will collide with each other.

Only if you assume any other life forms in the universe have technology comparable to ours.

The distance argument is rational, but of course only within the context of using our own limitations and deficiencies as a species as a benchmark. Given our origins, what we've done and hopefully will do in the future is beyond extraordinary, but we don't even know what we don't know about the universe.

[PVarck31]

Re: The Astronomy and Physics thread. And things of the like.

The numbers also say it's basically impossible that those entities have found us.

To put how far things in space are away from each other into perspective, when the Milky Way eventually passes by/through another galaxy there is basically a 0% chance any of the stars will collide with each other.

I wouldn't say impossible, but I get your point, and it very well could be true.

Just my take on it would be to compare our technologies and what we can see, because that's all we can really do.

We have found over 4,000 exoplanets Pretty much all in the Milky way, and almost all looking in one direction. So it's kind of a line from Earth going to the inner part of the Galaxy. Some have been in other areas, but most were found by Kepler looking at one patch of space for years.

So we can detect these planets, thousands of light years away using the transit method. We see the light from their star dip in a repeating fashion at a certain time. So we know it's there. We can even roughly determine the chemical composition, whether it's rocky, or a gas giant. When the James Webb launches in hopefully 2021, it will be able to image these planets and read their chemical compositions accurately.

So basically what I'm saying, is that if there are intelligent extraterrestrial civilizations as advanced or more advanced than us. They shouldn't have a problem knowing we are here. Or at the very least, know our planet exists.

Back to your point. And it's a good one. Depending on how many extra terrestrial civilizations there are, they could be so wide spread that even if they can see our planet they probably couldn't find out anything about it. Kinda like we know about exoplanets now. We cannot say for sure any planet we have discovered even has liquid water. We are almost 100% sure tons of them do, mostly because we have found water all over our own solar system.

Again, to your point, there is a physicist named Bryan Greene. By no means should his take be taken as gospel, but he says he believes there are definitely extra terrestrial alien civilizations out there, but he thinks there may only be a hand full in each galaxy. He said maybe 3 to 5 or so. Give or take.

So if that's true, communication would be almost impossible with our current level of technology.

TL,DR Aliens might be able to find us, but they might not. lol