Cause of death: Electromagnetic radiation or the effect of the gravitational wave?

[Darth Richard II]

Wow. OK, uh, carry on.

[Egalitarianism Always]

21 minutes ago, Altherion said:

If you could somehow focus 0.1 solar masses exclusively on the Earth, then yes, there'd be a problem. But in general, gravity spreads out according to the inverse square law so you'll always be picking up that factor of 1e-22 m^-2 (not to mention the gravitational constant which is another ~1e-10 in SI units).

I can't think of any tricks to do with a single solar mass that would cause noticeable gravitational effects a hundred million kilometers away. Electromagnetic radiation, on the other hand, can be quite deadly without needing to blow up the Sun. For example, consider the Carrington Event which, were it to happen today, would probably fry a significant fraction of our electronics.

You must have heard of the Carrington-class CME that narrowly missed Earth in July 2012?  As you say serious problems for our electronics if it had hit.

[Egalitarianism Always]

22 minutes ago, Darth Richard II said:

Wow. OK, uh, carry on.

Haha, sorry

[Loge]

If the Sun were to somehow eject 10% of it's mass, that might have all kinds of nasty effects but gravitational waves are not among them. You need a pair of compact objects like neutron stars or black holes encircling each other at very short distance.

[polishgenius]

I can only conclude that Egaliterianism Always has already been pulled apart and spagghetified by gravitational waves and that's why he makes no sense ever.

[TrueMetis]

11 hours ago, Egalitarianism Always said:

Yeah I know just a scientist working at LIGO blog hahaha, ahhhhhh I love this.  Forces damaging all life on Earth squirt, not just humans.  What are you even talking about damaging the planet's structure, never said anything about that in any way shape or form.

 

Here's the thing, it could be a blog written by Stephan Hawking. It would still be a blog. Blog's are not scientific sources whoever writes them and shouldn't be treated as such Doing so leads to accepting creationism and denying climate change.

[Altherion]

13 hours ago, Egalitarianism Always said:

You must have heard of the Carrington-class CME that narrowly missed Earth in July 2012?  As you say serious problems for our electronics if it had hit.

Yes. There was also a fairly strong one in September 2017 which degraded GPS performance. The scary thing is that the Sun is so massive and energetic that there's no reason it can't hit us with something orders of magnitude more powerful and nobody is really preparing for even the kind of event that we've already observed...

[Pebble thats Stubby]

But what if we are really living on a flat disc shaped earth, supported by elephants, and a giant turtle.   Since then the Sun is much smaller than the earth and is rolled around our dick [\s] disc * by a giant sky dung Beatle.  If that Sun exploded, would we all die from the blast.  Die due to the lack of a Sun, or would the turtle be able to swim us to another Sun before all life is whipped out?

 

 

* sorry autocorrect sometimes can tell when I'm taking the piss 

[Starkess]

This thread makes me want to laugh and cry at the same time.  to Altherion for attempting to engage.

[PyroclasticFlow]

18 hours ago, Egalitarianism Always said:

You must have heard of the Carrington-class CME that narrowly missed Earth in July 2012?  As you say serious problems for our electronics if it had hit.

I hope another one arises and hits directly so I don't have to talk to any of you degenerates and am free to loot all the remaining book stores

[Knight Of Winter]

Can someone explain in layman's terms why would hypothetical Sun's explosion pull us towards the (former) Sun? Genuinely interested.

[Altherion]

32 minutes ago, Knight Of Winter said:

Can someone explain in layman's terms why would hypothetical Sun's explosion pull us towards the (former) Sun? Genuinely interested.

It depends on the nature of the explosion, but, in general, it would not. The example that is easiest to explain in layman's terms is a spherically symmetric explosion. That is, suppose the entire mass of the Sun turned into energy in the form of light and radiated outwards in all directions with an equal amount going in every direction.

As people pointed out, the first notice we would have of this would also be the last. Quantitatively, it's relatively easy to calculate the intensity of the energy. Recall that the mass of the Sun is M = 1.99e30 kg and the speed of light is 3.00e8 m/s and also that E = M * c^2 so the total energy radiating outwards would be 1.79e47 kg m^2 s^-2. Since the Earth is roughly 1.50e11 m from the Sun, in our region the energy would be distributed over the surface of a sphere with roughly that radius. The surface area of a sphere is 4*pi*r^2 (where r is its radius) so the energy density near Earth would be

Ed = 1.79e47 kg m^2 s^-2 / (4 * pi * 1.50e11 m * 1.50e11 m ) = 6.33e23 kg s^-2

or in more familiar units, 6.33e23 Joules per square meter. For comparison, the yield of the nuclear weapons used against Japan near the end of WWI was of order 1e14 Joules so this would be like 10 billion of those going off on every square meter of surface. It doesn't really matter whether it was the whole mass of the Sun or only 1% of it or if the energy arrives all at once or over something like an hour -- there wouldn't be anything worth mentioning left of Earth... and of course whatever is left would shortly freeze.

As you've probably noticed I've avoided answering your question: the impact of the energy going out would basically annihilate the Earth and the gravitational effects would be completely irrelevant. However, to be complete, let's revise the nature of the explosion such that instead of radiating as light, the Sun somehow turns into dark matter. It would still stream outwards equally in all directions, but it would not interact with Earth (i.e. it would pass us by without annihilating us). What would happen to the Earth in this case?

The answer invokes two really neat results about the gravitational field of a hollow sphere of uniform surface density. First, the gravitational field outside of such a sphere is exactly the same as if the entire sphere's mass were concentrated at the center. This is why in both this and the preceding example, there would be no gravitational difference even if the effects of the explosion were moving slower than light: as Kalbear said, we wouldn't know of any gravitational change before the explosion reached us. The extension of this to solid spheres also why we can treat roughly spherical objects like the Earth and the Sun as points and mostly get away with it (note that it doesn't quite work for the Earth: it's not a sphere, it's an oblate spheroid and there is some noticeable difference in gravity on its surface). Second, the gravitational field inside such a sphere is exactly zero! This is not as intuitive as reducing the sphere to a point from the outside, but it's not that difficult to follow the math.

So what would happen to the Earth? Up until the dark matter reached us, it would continue to orbit exactly as it did before. When the explosion reached us, there would be a rapid change in gravitational field, but, as you can see from the calculations in one of my previous post, it would be tiny. After the dark matter reached us, the Earth would no longer be subject to the gravity of what used to be the Sun and would continue moving along the tangent to the point of its orbit where the explosion had reached it (think about what happens to a ball spinning on a string when the string is suddenly cut). It wouldn't quite move in a straight line because there are some fairly heavy objects in our newly-sunless neighborhood (e.g. Jupiter), but it would be pretty close to that. And of course, it would shortly freeze.

[Knight Of Winter]

8 hours ago, Altherion said:

explanation

Thanks, Altherion . I do have a follow-up questions:

1) Why would sun convert its mass into an energy? In star explosions (supernovas), star expels its outer layers and condenses the rest, and the result (black hole or neutron star) has same mass as the original star, just way more condensed, no?

I'm trying to remember where is famous formula E = M * c^2 used at all? In creation of the universe (energy into matter) and in matter - antimatter annihilation (matter into energy), is is there anything else?

2) And why would somehow Sun convert into dark matter? AFAIK, dark matter is still u huge mystery in science and there is no known way of converting it into baryonic matter and vice versa.

Unless I'm somehow mistaken and the whole purpose of this thread was to provide what-if imaginary experiment with no practical possibility of happening? 

[Loge]

1 hour ago, Knight Of Winter said:

Thanks, Altherion . I do have a follow-up questions:

1) Why would sun convert its mass into an energy? In star explosions (supernovas), star expels its outer layers and condenses the rest, and the result (black hole or neutron star) has same mass as the original star, just way more condensed, no?

I'm trying to remember where is famous formula E = M * c^2 used at all? In creation of the universe (energy into matter) and in matter - antimatter annihilation (matter into energy), is is there anything else?

2) And why would somehow Sun convert into dark matter? AFAIK, dark matter is still u huge mystery in science and there is no known way of converting it into baryonic matter and vice versa.

Unless I'm somehow mistaken and the whole purpose of this thread was to provide what-if imaginary experiment with no practical possibility of happening? 

A star that sheds its outer layers loses mass, of course. The neutron star or black whole formed in a supernova is less massive than the original star was. Very massive stars lose large fractions of their mass through winds during their life tie already, BTW. Same is true for white dwarfs. No explosion, but the outer layers get expelled anyway.

Einstein's famous formula E=m c^2 always applies. Altherion used it to estimate how much energy would be released if the Sun could somehow be turned into radiation. What's really released in, say a supernova is only a fraction, of course. 

There's of course no known mechanism that could turn the Sun into dark matter. The thing is, the Sun won't explode, so any what if scenario has to bend the laws of physics a bit.

[polishgenius]

2 hours ago, Knight Of Winter said:

Unless I'm somehow mistaken and the whole purpose of this thread was to provide what-if imaginary experiment with no practical possibility of happening? 

That's pretty much it. I'm not sure that EA meant it that way, but that's what he made it into.

[Altherion]

6 hours ago, Knight Of Winter said:

1) Why would sun convert its mass into an energy?

The Sun is of course converting its mass into energy via nuclear fusion, but it is doing so extremely slowly . The rapid conversion of mass into energy was the premise of this thread and, as you mention in the final sentence of your post, there is no known mechanism by which such a thing could happen.

6 hours ago, Knight Of Winter said:

In star explosions (supernovas), star expels its outer layers and condenses the rest, and the result (black hole or neutron star) has same mass as the original star, just way more condensed, no?

Almost, but not quite. The mass of the outer layers as well as the light of the explosion and the momentum of everything that is moving away are all carrying away energy that could only have come from the mass. There's apparently even a unit for the typical energy released by a supernova, but, since it's only 1e44 J, it is more than a thousand times less than even the total energy of the Sun (i.e. 1.79e47 J) and since the kind of stars that turn into supernovae are always heavier, your statement is basically correct.

6 hours ago, Knight Of Winter said:

I'm trying to remember where is famous formula E = M * c^2 used at all? In creation of the universe (energy into matter) and in matter - antimatter annihilation (matter into energy), is is there anything else?

It's used all over the place in particle physics and astronomy, although usually in its generalized form: E^2 = m^2 * c^4 + p^2 * c^2 where p is the momentum. Every result you see from a particle accelerator has this idea baked into the results many, many times because it's useful not only in annihilation, but also in scattering (i.e. when two particles collide and bounce off of each other).

6 hours ago, Knight Of Winter said:

2) And why would somehow Sun convert into dark matter? AFAIK, dark matter is still u huge mystery in science and there is no known way of converting it into baryonic matter and vice versa.

Because I wanted something that would illustrate the gravitational effects without the overwhelming influence of electromagnetic interactions.

7 hours ago, Knight Of Winter said:

Unless I'm somehow mistaken and the whole purpose of this thread was to provide what-if imaginary experiment with no practical possibility of happening?

That's how I interpreted the thread, yes. I'm not sure how else to interpret it -- stars don't behave in the manner described in the original post.

[Kalbear]

On 1/26/2018 at 7:44 PM, Egalitarianism Always said:

Ok from the mouth of a scientist working at LIGO:

Source:  https://stuver.blogspot.co.uk/2012/06/q-what-would-gravitational-wave-feel.html

 

And as I said again, it doesn't matter - because said wave would happen after the lightwave, and that's assuming one is produced. There's no reason to believe that any kind of large gravitational wave would occur when a sun goes white dwarf, as gravitational waves happen when large objects collide or change the gravitational system. With a sun exploding, there's no collision, no cause of a wave effect.

 

On 1/26/2018 at 8:09 PM, Egalitarianism Always said:

I like how you make me confirm my ideas by researching them further, that's why I entertain you until you start lying that is, see that LIGO scientists blog that's you annihilated. 

That's how things work around here; we don't take your random statements for truth until you try and explain them.

On 1/26/2018 at 8:09 PM, Egalitarianism Always said:

It's not actually proven about the gravitational wave pull effect that's a concept I thought of myself, but it's clearly an effect especially a strong gravitational wave would have.

Again, there's no 'gravitational wave pull effect' - as you say, you made it up yourself. It isn't something a gravitational wave has; what it has is tidal effects relative to getting pulled in different places on your body. 

What you HAVE NOT proven or even provided any evidence for is that the sun would produce said gravitational effect when ending. Large suns exploding don't do this; what does this is stellar objects colliding (or more accurately, stellar objects that are large which accelerate, which in turn causes gravitational ripples in spacetime). The sun exploding isn't a stellar object accelerating. 

[Kalbear]

1 hour ago, Altherion said:

That's how I interpreted the thread, yes. I'm not sure how else to interpret it -- stars don't behave in the manner described in the original post.

Yeah. If you want to talk about something that caused a massive gravitational wave which also annihilated the sun somehow, you'd have to talk about some kind of incredibly fast black hole moving very near the sun, which caused the sun to get pulled quickly in its direction - we're talking about something at relativistic speeds, pulling the sun at those speeds too. 

In that case, you might get hit by a massive wave, and maybe the sun explodes or something? 

Of course, in that case, the object that caused the sun to accelerate would ALSO cause the earth to accelerate, and the effects on the earth in that instance would probably not be super fun. 

[Knight Of Winter]

So many new interesting stuff to learn. Thanks, @Loge and @Altherion

[all swedes are racist]

2 hours ago, Egalitarianism Always said:

Idiotic post by an idiot haha.

no need to sign your posts