Help with a galaxy ending weapon.

so my idea is that the wepon to destroy the aliens would be to fire a spesial missile into the galaxy's center. It would then collect rotational energy from the supermassive black hole (all this taking 30ish seconds) and then it would fire a beam of said energy at the closes stars coursing them to go super nova. And the beam is programmed with alien experimental tech to use the energy from the star to fire 5 more beams towds the next stars causing them to go super nova and so on. This process should take about one minuite to destroy the galaxy (beams travel in Subspace). What I want to ask all of you is,
Do you think if every star went super nova (would also set off gas gaints and and gas/plama clouds in space) would it destroy a galaxy?

 

I think that a galaxy is really, really REALLY big. I find science fiction that claims to destroy one star to be pretty implausible. Something that destroys thousands of millions of stars would not work for me as a reader.

 

My suspension of disbelief kinda broke around "This process should take about one minuite to destroy the galaxy." Like @ChickenFreak said, space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space. I mean, I get that the beams travel in subspace, kinda magic wand, hand wavy, but still okay. Say all these beams cause all of these stars to go supernova all at relatively the same time, that destruction would still have to travel through non-subspace to finish off the galaxy. If our sun suddenly went supernova, it would take a solid 8 minutes for us to even realize that happened. If we were on Neptune, it would take over 4 hours. I'm not saying you can't use the concept, but it might need a bit of tweaking.

Also, what exactly do you mean by destroy? That's kind of a wide topic.

 

I mean destroy anything and everything in the galaxy, becouse the enemy has a massive orverellming fleet making that the only way to defeat the Alien fleet. At the cost of humanity's home galaxy and condemning trillions of lives in the process. and what if I made the time 24 hours.

 

I agree with the above posts that one minute sounds implausible. That aside, the question I am actually wondering about is this: if you destroy the entire galaxy... How on earth did your character's hope to survive this?

You may have to be more specific...

And I guess whether it's scientifically possible may also depend on the amount of energy involved in the beams and the distances between each star. If the beam dies before it reaches the next star, it is plausible that some would survive. The maths that it takes to calculate which ones would survive is probably gonna be mind-boggling and probably impossible unless every star in existence is known to scientists. (Not to mention orbits, the beam hitting meteorites or space debris instead etc, unpredictable possibilities that might stop the beam.)

I think you may have to decide if you wanna be scientific and to what extent that is possible. You may need to use wisdom to figure out how much to explain, if you should even explain it. Readers will forgive a lot, depending on your audience. But readers will generally be unforgiving if you tried to rationalize something that is clearly impossible.

 

Again, are you clear on how big a galaxy is? Do you really need this to be a galaxy-scale thing?

 

Well, it's neat you have magic beams that don't obey our universe's speed limit, but even so, your magic beam could cause a cataclysm at the center of the Milky Way... but here on Earth, we wouldn't be effected by it for many thousands of years. Sort of anticlimactic for Space Opera, I think.

 

The speed of light travels at... wait for it............. the speed of light! 24 hours ain't nothing. You blast the closest star to ours, if memory serves that's about 4.5 light years distant, it would take that long for the gamma, and other deadly radiation to come our way.

 

If you Google "hypernova," or "gamma Ray burst," or maybe "galactic killer," will see that the supreme being responsible for us has already invented a very nice weapon and it requires just one star.

 

The main character and his crew survive by leasing the last of humanity (1 million) out of the galaxy in cryo. And It has to be that big because the alien fleet is made from resources form another galaxy. They drained every star and destroyed every planet in there home galaxy to make a fleet of trillions of ships. Anything less and ships could survive and chase them to the new galaxy.

 

Is there any reason why you need a galaxy-sized scale? It's going to make the story less plausible, and it's not going to make it more impressive.

 

One imagines that simply adding the mass of one galaxy to the space inhabited by another would be enough to destroy it; the increase in gravitational pull could well just crush every damn thing. Imagine your neighbor buying a new trailer home and parking it on top of your living room. Or is that kind of thing only a problem where I'm from?

Of course it would still take a really long time.

 

So, the bad guys built a fleet in one galaxy and moved it to another because the old one was kaput, so now we have to destroy the one they moved to in order to stop them while the heroes escape to yet another galaxy? Not to sound like a knob, but if they've built a fleet of billions of ships, then why would they move them all to this one galaxy? Wouldn't it make sense that they would move out in all directions to expand thier territory and reduce the resource strain on their new galaxy? This means that regardless of whether or not you destroy the galaxy their threat still wouldn't have been eliminated. Unless the new galaxy was the only one in a reasonable range of travel, then that means that the escaping humans could only ever hope to reach the now dead home galaxy of their greatest enemy that probably hasn't been entirely evacuated, because why would it be?

 

I feel like we're being trolled, but I'll answer in good faith and restate what others have said above: You really don't understand how big space is. The nearest galaxy to the Milky Way is Andromeda, and that is 2.5 million light years away.

2.5 million years, at the speed of light.

That means if the entire Andromeda galaxy winked out the day the very first monkeyoid stood up on two feet and graduated to being homo erectus, we wouldn't know about it until next week Tuesday.

Two and a half million years.

Furthermore, the Andromeda galaxy has around one trillion stars in it, and from what we're learning about exoplanets in the Milky Way, several times that many planets. You said your bad guys have "trillions" of spaceships, and that they need to move on because they've used up the old galaxy. Not sure exactly how many trillions are in "trillions", but lets say fifty trillion. Let's say a hundred trillion. That means that each solar system is capable, when totally consumed, of providing the material for only one hundred space ships, which are going to embark on a multi-million year journey with an unspecified number of inhabitants in cold sleep. You're going to need to do better than cold sleep if your creatures are under for two and a half million years.

Just scale it back. Destroy a solar system. Use your weapon to turn its sun into a ginormous laser that burns all the planets to dust, The Force Awakens style. Galaxy level cataclysms aren't going to fly.

That tiny little bean, fifth from the left, is the Earth:



The sun is 0.2 pixels on this scale:



That one labeled pixel that you can't distinguish from the others is the sun:

 

I agree with the others that blowing up the galaxy feels like overkill, but it's not like I've read your story so maybe it makes sense in context.

To answer your question:

I don't think it would guarantee wiping out everything, depending on the tech abilities you're giving people. For instance with the ships - you may be able to blow up every star simultaneously, but you've not so far given any reason the blast waves from the detonations would be travelling faster than light. You'll need some kind of author handwave for this since it's impossible with our current understanding of physics (added to which, not every star has the critical mass to go supernova to begin with). A ship that was positioned halfway between the Sun and our closest star would have just over 2 years before it was hit by either blast wave, which is quite a lot of time to be somewhere else.

 

Not to mention that an blast or unfocused expenditure of energy is subject to the inverse square law, being that if the sun blew up Mercury might receive enough energy to destroy it, but Venus being twice as far from the sun as Mercury would only receive about 1/4 of the same energy mercury received, Earth would get about 1/9th and Mars about 1/16th, etc. By the time the blast reached Saturn, it would have less than 1/600th of it's planet destroying potential. As awesome as it sounds, It might be unreasonable to assume that an exploding star could destroy too much outside of it's own solar system. At least in any way that couldn't be survived by a race that's mastered subspace beams and trans galactic travel.

 

Yeah, that too. There's almost certainly vast amounts of interstellar space that wouldn't get much more than a bit of turbulence.

 

Really depends on your definition of "destroyed" and "galaxy". If every star went supernova (or the equivalent for its mass), the galaxy would still be there, but it would pretty much cease to function as it had, at least as far as most known and speculated life goes.

 

The problem, as others have pointed out, is that even if you blew up every star simultaneously, the shockwaves to destroy the ships still have to propagate in normal space, at or less than the speed of light. If your aliens have FTL travel (it sounds like they do?), then they could simply outrun it. In fact, they could outrun any weapon but maybe that's a separate issue. I mean if humans can escape this catastrophe, surely at least some of the aliens will figure out what's happening and do so as well?

I guess I'd say maybe you should think about what you really want to accomplish--destroy the alien fleet. Right now the way of doing that is by destroying the whole galaxy via supernova, but I'd say you may need to think of some other possible methods. I mean, any way you destroy trillions of spaceships is going to be visually spectacular, so don't worry about that...

 

Wow... I did not know the sun (and the earth) were that small...

 

Well, I won't talk about the impossibility or craziness of destroying a galaxy. If you wanna blow up galaxy go ahead. I'd suggest it be better using some kind of crazy device, though instead of trying too hard science it. A weapon in the vein of the Ultimate Nullifier or something.

 

Hello, you have an interesting scientific problem.

First you have to remember that galaxies are really big. Ours is 100,000 light years across, so anything happening st the core takes 50,000 years to reach the rim. Most galaxies are smaller than ours, but still average more than 20,000 across.

Supernovas also are problematic because you don’t seem to understand how supernovas work (don’t worry, most people don’t.). First, most stars won’t supernova, ours will will simply sputter out and die. Supernovas aren’t really explosion, they’re implosions. They happen when a really big star runs out of fuel. The heat from its core suddenly drops and the plasma collapses. Then one of two things will happen. For most huge stars the core collapses until it hits an energy level where something called neutron degeneracy pressure stops the collapse. The explosion that we see, is actually the rest of the Star falling down on that new neutronium core and bouncing off in a shockwave. Now for supermassive stars the neutron degeneracy pressure isn’t enough and the core becomes a black hole. On the very edge of the black hole the accretion disk (rest of the star falling in it) accelerated close to the speed of light and ejects gamma ray blasts from either poles on what’s called a hyper nova. The important thing is that both processes are implosions followed by a shockwave, not an explosion.

Now those gamma ray beams from hypernovas are cosmic death rays. They’ll easily sterilize anything in their path out to thousands of light years. In the case of a quasar, which is an accretion disc around a supermassive black hole, it can sterilize a galaxy in 100,000 years. So simply releasing several hundred stars with of material near the galaxy core would light it up. The types of energy given off by these objects (alpha particles and gamma rays) can be shielded against, but would be tough and would strip atompheres completely.

 

They only have one commander, and he likes having 100% chances of victory

 

Again, do you realize just how big a galaxy is?