space questions

[Damocles]

Because they don't really exist in the way that they're in your head and are instead an excitation of a quantum field. A single quantum field that spans the Universe.

Remember that the speed of light is only a speed limit for things that carry information. This doesn't carry any information.

 

[TCIB]

I am gonna sit down now and have a cup of tea.

That helps actually i forgot that "nothing" moves faster than light.

I was having a debate with myself before about quasars! Namely we always say "nothing escapes a dark star, not even light".
So are quasars material actually ejected from the core or is it just kinda blown away like a person stepping onto a windy avenue the second it crosses the event horizon?
I came to the conclusion it is ejected as the energy transfer and mechanics don't seem to fit with it being radiated away.
I guess we do not know that really or do we ?

 

[Damocles]

I am gonna sit down now and have a cup of tea.

That helps actually i forgot that "nothing" moves faster than light.

I was having a debate with myself before about quasars! Namely we always say "nothing escapes a dark star, not even light".
So are quasars material actually ejected from the core or is it just kinda blown away like a person stepping onto a windy avenue the second it crosses the event horizon?
I came to the conclusion it is ejected as the energy transfer and mechanics don't seem to fit with it being radiated away.
I guess we do not know that really or do we ?

Nothing escapes a black hole because it has a large gravitational attraction. That is to say, it sufficiently warps space time that nothing has the energy past a certain point to still get out of it as the energy required is more than the speed of light. A black hole's effects in spacetime looks like the grades near Bart Simpson.

This is why light has no mass yet still cannot escape it - the "pulling down" of spacetime means that any light that was travelling anywhere near it will still get caught in the fabric that gets pulled down.

As the black hole is huge and spaghettification occurs to any objects around it, we can conclude that the "accretion disc" made of gas that is encircling it must be going extremely fast. As it moves extremely fast and "friction" causes it to heat up, it will produce a shitload of light. This isn't anything inside the event horizon that is emitted, just the light in the ergosphere and the "jets".

The "jets" if you like are still an unproven mechanism but it is currently thought that an electromagnetic effect caused by charged particles moving extremely fast and shooting off on their axis of rotation and emitting radiowaves. We see the same effect on Earth and this Wikipedia article about the phenomena (Synchrotron radiation) might help you see it in your head.

 

[TangerineSteve17]

Cheque please! :/

Actually I will cheque this quasar stuff out, but right now I think that'd be like trying to eat the jelly before I've had my starter :)
small steps for Steve. If there is anything more fascinating than this phsyics/cosmology sciencey stuff I can't think of it.

Seeing as though i'm here, another stupid question. I have read the reason we aren't pulled into the sun is because we are moving/orbiting and there is no friction, so we aren't even getting closer to the sun (except during part of the ellipse).
Anyway my question is, if other planets were destroyed by asteroids and the like, Jupiter, Saturn, and those further away from us, could their gravitational pull on the earth (which i hope has some effect on pulling us away from the sun) when it's gone mean we could succumb to the suns gravity and it pull us too close to survive?

 

[foetus]

Holy shit Damocles...you are one smart mofo. Seriously.

 

[Damocles]

I have read the reason we aren't pulled into the sun is because we are moving/orbiting and there is no friction, so we aren't even getting closer to the sun (except during part of the ellipse).

The Earth is actually moving away from the Sun due to two factors. The first is that the Sun is losing mass because its mass ("fuel") is being converted into energy which will make the orbit of the Earth bigger. The other one is to do with the tidal interactions and how our orbit will be longer as we slow down the rotation of the Sun.

Even on a cosmological scale these effects are so small to hardly matter.

Anyway my question is, if other planets were destroyed by asteroids and the like, Jupiter, Saturn, and those further away from us, could their gravitational pull on the earth (which i hope has some effect on pulling us away from the sun) when it's gone mean we could succumb to the suns gravity and it pull us too close to survive?

All objects in the Universe have a gravitational effect on each other, even if that is too small to mention. Your body has a gravitational effect on the Sun and vice versa. The issue though is that the inverse square law of gravity states that your personal effect on things like the Sun, Pluto and another galaxy billions of light years away is too small to be measured. But it is not 0. Remember again the "fabric" of spacetime and its "depression" is what gravity literally is. The depression caused by your body will never be dissipated back to exactly 0 just like even if you put an ant on a trampoline it may only warp it by less than the length of a single atom but it IS warping it.


The short answer to your question here is yes. Saturn and Jupiter exhibit an effect on the orbits of the inner rocky worlds and if you "deleted" them two giants then the orbits would change. Initially, Mercury would go into a sort of "spirograph" type orbit around the Sun with its apogee becoming closer and closer to a collision with Venus which will annihilate Mercury leaving Venus as the innermost world, again changing the dynamics of the system. At this point, Earth's orbit will become even longer (about 10% more than now in distance wise) until Venus eventually smacks into Earth leaving us as the inner most planet on a spirographic path until we hit Mars. Would take about 1000 years overall according to my simulator.

The thing to remember is the Solar System as it is now has had several billion years to have its orbits become regulated so nothing smashes into each other. Removing one of those variables will change the orbit of everything.

 

[TangerineSteve17]

Thanks for the answer D. Pretty scary when you think about it, if the giant planets get annihilated and what it would mean for us. I also read Jupiter helps us, by sucking in potential earth bound comets and redirecting them. It's like everybody's got one another's back so to speak.

Something about Venus being the only planet in the system to spin clockwise too, not read a definitive reason for that yet though, just that it actually does spin anti-clockwise like Earth but it's been knocked upside down.

 

[TCIB]

Thanks for that Damocles it does help actually so cheers hehe.

I sometimes try to imagine what it would be like on a planet right next to the disc but still in a decent orbit.
The noise, the light, i know we could not exist there but it would be pretty damned cool to see it.

 

[Damocles]

Thanks for the answer D. Pretty scary when you think about it, if the giant planets get annihilated and what it would mean for us. I also read Jupiter helps us, by sucking in potential earth bound comets and redirecting them. It's like everybody's got one another's back so to speak.

True but it's also a double edged sword. At the edge of our Solar system there is a large amount of comets and asteroids that never had the chance to smash into things and form planets. There's another another belt just past the rocky planets. Small fluctuations in the orbits of Jupiter or its Moons brought on by any number of phenomena can actually ricochet these into the path of the inner worlds.

The best way I can describe the Solar System is that it was a formerly chaotic place with things smashing into each other all the time but that was so long ago that most things that could smash into each other have already smashed into each other. Only extremely long orbit comets or ones knocked out of their regular orbit can really hit things and there's very few out there that can alter orbits greatly. Everything as it is currently is in a gravitational balance with each other. If you delete anything then everything else in the Solar System is effected.

Something about Venus being the only planet in the system to spin clockwise too, not read a definitive reason for that yet though, just that it actually does spin anti-clockwise like Earth but it's been knocked upside down.

Venus and Uranus. Nobody really knows why but the prevailing ideas are either that it collided with a massive object which knocked it off its regular spin (which is a pretty dustbin diagnosis for that field), or the one I'm more fancying which is the atmosphere of Venus changed the spin ever so gradually over time which slowed the spin then sped it up in the opposite direction. I read a great paper about that that I'll see if I can dig out. Equally fascinating is the idea that Jupiter and Saturn knocked Uranus off its regular spin. There's a paper here about it but it's math heavy

 

[TangerineSteve17]

You weren't kidding about that paper D. Very heavy stuff (not just the maths) for a layman, way too advanced for me unfortunately.

Problem I had with picturing the universe comes from watching spacey movies. Like Contact and MIB etc they often have a zoom-in or zoom-out sequence, just billions of stars in swirling galaxies making it all look chaotic. As has been pointed out in this thread, in our solar system things that could've collided have already done so. If I'd just stopped to think I could've come to that conclusion. Ah well. So it's pretty orderly now.

I think I thought of meteors and asteroids as just going anywhere they wanted, silly really if I'd have just thought more about gravity.

That Russian meteorite last year wasn't detected was it. It was too small, I read, to reach the Earth's floor, so despite the power, not too much damage was done. I wonder if we'd miss an asteroid coming, they reckon one lands every 100 million years. I wonder how they can know that, won't it be less and less likely as time passes?
I hope I live till 2061.
There is a total eclipse on March 20th this year. Not sure where you get the full effect but in Manchester it says it's partial but nearly total so I hope somewhere in the UK has a complete eclipse.