# Space, Science 'n' stuff



## Leo Whitepaw (Jun 8, 2018)

Right. What do you think is the best way for humans to reach Alpha Centauri, and other stars? I vote for Anti-Matter Annihilation thrusters.


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## zyther kaldrok (Jun 8, 2018)

cold fusion?


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## Joni (Jun 8, 2018)




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## Leo Whitepaw (Jun 8, 2018)

Other possibilities are (In order of favourites) Solar sails, Ion drives and conventional thrusters.


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## Yakamaru (Jun 8, 2018)

Our knowledge on space is new at best. We need to fix our own shit on our own planet first before we have any rights to venture out into space, IMO.

Though I'd argue we find some FTL technology at some point down the road within the course of 200-300 years.


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## Leo Whitepaw (Jun 8, 2018)

Yakamaru said:


> Our knowledge on space is new at best. We need to fix our own shit on our own planet first before we have any rights to venture out into space, IMO.
> 
> Though I'd argue we find some FTL technology at some point down the road within the course of 200-300 years.


I'm not saying it's impossible, since I'm not a dumbdumb, but I am saying that the laws of physics prevent ftl travel for any conventional spacecraft. (Shut up about the Alcubierre Drive). The crap on earth needs fixing, but It's a reason to go out, because if things go to sh¿t on earth, we're stuffed because we only inhabit this planet and not any other.


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## Deleted member 82554 (Jun 8, 2018)

By warp drive, my dear boy.


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## Leo Whitepaw (Jun 8, 2018)

Mr. Fox said:


> By warp drive, my dear boy.


I'm fairly certain I said 'Shut up about the Alcubierre Drive'  ._.

It might work, but there are a bunch of issues with it, such as the warped bubble of spacetime catching and trapping quantum particles as it goes, and then releasing them in a volley whenever the ship stops, throwing them forward with enough force to destroy a star.


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## Joni (Jun 8, 2018)

Leo Whitepaw said:


> Solar sails


No Star no thrust


Leo Whitepaw said:


> Ion drives


You need gas and the energy. (It's very  efficient though)


Leo Whitepaw said:


> conventional thrusters.


Are you kidding??


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## Leo Whitepaw (Jun 8, 2018)

Joni said:


> No Star no thrust


There is no friction in space, so you could speed up near the sun, and your velocity would carry you to the target. Solar sails have been calculated as being able to get to 25% Lightspeed. For comparison, The fastest object created by humans is less than 1% lightspeed. There is a problem with stopping though.


Joni said:


> You need gas and the energy


 you can get the energy from solar panels, gas is light and can be compacted easily and Ion drives can get to hundereds of thousands of miles an hour, also, again, There is no drag in space. Get to a certain speed, you'll stay at that speed unless something alters it. 


Joni said:


> Conventional thrusters: Are you kidding??


There's a reason they're on the bottom of the list.


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## Yakamaru (Jun 8, 2018)

Leo Whitepaw said:


> I'm not saying it's impossible, since I'm not a dumbdumb, but I am saying that the laws of physics prevent ftl travel for any conventional spacecraft. (Shut up about the Alcubierre Drive). The crap on earth needs fixing, but It's a reason to go out, because if things go to sh¿t on earth, we're stuffed because we only inhabit this planet and not any other.


Our *current* understanding of the laws of physics, yes. Nothing is set in stone. Our understanding of the universe are constantly and exponentially expanding as the years go. 

500 years ago people thought the Earth was the center of the universe. Now it's common knowledge that that's a load of crap. It'll only be a matter of time before Einstein is proven to be either not entirely correct or is lacking something in his equation. Or they find something outside of that equation. 

Who knows. Only time will tell.


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## Leo Whitepaw (Jun 8, 2018)

Yakamaru said:


> Our *current* understanding of the laws of physics, yes. Nothing is set in stone. Our understanding of the universe are constantly and exponentially expanding as the years go.
> 
> 500 years ago people thought the Earth was the center of the universe. Now it's common knowledge that that's a load of crap. It'll only be a matter of time before Einstein is proven to be either not entirely correct or is lacking something in his equation. Or they find something outside of that equation.
> 
> Who knows. Only time will tell.



I'm not saying they are indestructible, but The equations of general and special relativity have 3 main problems for ftl travel. 
1: Say your almost at lightspeed, like 99.99999999999999999283759% lightspeed. If you threw a ball forwards, it should be able to cross the light barrier, right? Wrong. The universe, as narcissistic as it is, won't let it happen. The ball stays under lightspeed. Where does the energy go then? Well, energy and mass are interchangeable, so the universe coverts energy into mass as you approach lightspeed, also known as C. The ball gets heavier. The closer you get to lightspeed, the more pronounced the effect is, growing exponentially with your velocity, which ties into the second problem.
2: You need infinite energy to reach C. You might think that, with rockets, the thrust to weight ration is linear. Ie, you have a rocket with 100 litres of fuel that can go to 100 m/s. In a linear relationship, to reach 200 m/s, you'd need 100 more litres of fuel, but in real life, you'd need something like 300 more litres of fuel because the faster you want to go, the more fuel it takes to reach that speed. The more fuel you have, the more thrust you need to move. The more thrust you need, the more fuel you need and so on, with fuel usage growing exponentially with your velocity, until at lightspeed, where the fuel required becomes unlimited.
3: Time dilation. The faster you go, the slower you percieve time as passing for an outside observer. The faster you go, the slower an outside observer will see your time passing. Say you had two watches, one in above earth going at, say 90% C, and one on earth with you, if you could somehow see both watches ticking at once, the one in space would be ticking at, I don't know, half the speed of the watch in your hand. This effect becomes exponentially stronger, the closer to C you get, and at lightspeed, your time would stand still. You could cross the entire width of the universe 27 times, and you wouldn't even be able to blink. Hundereds of trillions of years would pass around you and not even a single microsecond would pass for you. For eternity.


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## Joni (Jun 8, 2018)

Leo Whitepaw said:


> There is no friction in space,


The space is not a complete vacuum. But you're right you can get really far.


Leo Whitepaw said:


> be compacted easily


Who says that?


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## Leo Whitepaw (Jun 8, 2018)

Joni said:


> Who says that?



*'Gas*
The atoms and molecules in gases are much more spread out than in solids or liquids. They vibrate and move freely at high speeds. A gas will fill any container, but if the container is not sealed, the gas will escape. Gas can be compressed much more easily than a liquid or solid. (Think about a diving tank – 600 L of gas is compressed into a 3 L cylinder.)'
~The Internet


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## Joni (Jun 8, 2018)

Leo Whitepaw said:


> 600 L of gas is compressed into a 3 L cylinder.


Ok, I think it's not a problem for the industy today.


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## Leo Whitepaw (Jun 8, 2018)

Is there any propulsion method I've missed?


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## Yakamaru (Jun 8, 2018)

Leo Whitepaw said:


> Let's start with the basics: It is not good to introduce the concept of the mass M = m / sqrt(1 - v^2/c^2) of a moving body for which no clear definition can be given. It is better to introduce no other mass concept than the ’rest mass’ m. Instead of introducing M it is better to mention the expression for the momentum and energy of a body in motion. — Albert Einstein in letter to Lincoln Barnett, 19 June 1948 (quote from L. B. Okun (1989), p. 42[1])
> 
> The internal structure of particles does not change in any way when they travel with constant speed, and hence it makes no sense to attribute a different mass to them. Explaining that you can not travel faster than the speed of light because you will be infinitely heavy does therefore not answer the question. Furthermore, if solving relativistic equations of motion is your daily job, as is mine, the concept of relativistic mass does not make your life easier. Not at all. If someone would insist on a simple explanatinon I would settle for "The Lorentz factor is part of the equations of motion, and as a consequence you need an infinite amount of energy to reach the speed of light".
> 
> ...


Our current understanding of physics make FTL travel impossible as far as human knowledge/understanding goes. However, that doesn't mean you should make them absolute laws. Our species is proven wrong too often to make it a viable mindset.

Our understanding is new at best. I intend to keep an open mind for if or when we discover new laws that doesn't fit our current understanding/knowledge. 

But to be more on-topic as far as traveling to other planets go: I'd argue solar sails or ion drive.


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## Joni (Jun 8, 2018)

Leo Whitepaw said:


> Is there any propulsion method I've missed?






Spacetaxi?


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## Leo Whitepaw (Jun 8, 2018)

Joni said:


> Spacetaxi?


That is fabulous


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## Mach (Jun 17, 2018)

I do not know if this is a necropost, but I hope will be forgiven since I like this thread.

If we are discussing space travel and rocketry, there is a site that is fun yet informative on the topics. @Leo Whitepaw and @Joni , you will like this:

www.projectrho.com: Atomic Rockets - Atomic Rockets

You all listed many propulsion systems for space travel, some currently practical while others are more theoretical. One aspect of designing an interstellar spacecraft I do not see here is _heat management_. All the propulsion system mentioned here would generate an extraordinary amount of heat. In atmosphere, it is relatively to easy to dissipate the heat. Note that a jet engines on Earth cool eventually left to their own devices. This partially because the air helps immensely with heat radiation. In the near vacuum of space, it more difficult for rocket engines to cool themselves since the vacuum acts as a high efficient insulator around the spacecraft. As a result, the heat from the rocket engines and other technological processes keeping the spacecraft functional and habitable builds up since it can not be radiated away. Left unchecked, the heat will eventually damage the spacecraft's systems and fry the the crew alive. With more energetic propulsion systems like nuclear fission, nuclear fusion, or antimatter rockets, the heat may even cause the spacecraft itself to be vaporized.

To quote Atomic Rockets:

"Heat management is a vital part of the design and operation of a space vessel ... There are two options for dealing with waste heat ... radiators and heat sinks. If the waste heat is not dealt with, it would rapidly fry the ship and crew."

Internal heat sinks in spacecraft can only absorb but so much heat. Radiators make maneuvering the spacecraft harder and need to be proportionately bigger as your increase the heat output of the propulsion system. Cruising in space once your spacecraft has reached a certain speed as opposed leaving the engine on the accelerate throughout the entire journey to could help ameliorate some these difficulties, but some serious technological consideration would have to given to active heat management measures.


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## Joni (Jun 17, 2018)

Mach said:


> I do not know if this is a necropost, but I hope will be forgiven since I like this thread.
> 
> If we are discussing space travel and rocketry, there is a site that is fun yet informative on the topics. @Leo Whitepaw and @Joni , you will like this:
> 
> ...


This site is badly constructed and total overloaded with unnecessary information. The creators of the website have no idea how you introduce people in a topic and clearly too much time. Can you give me a brief crash course of how atomic rockets suppose to work.


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## WithMyBearHands (Jun 17, 2018)

Reaching by way of physical contact or establishing communication?


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## Mach (Jun 17, 2018)

Joni said:


> This site is badly constructed and total overloaded with unnecessary information. The creators of the website have no idea how you introduce people in a topic and clearly too much time. Can you give me a brief crash course of how atomic rockets suppose to work.


That is the introduction page and, yes, they could step their web design game up a notch, but there is much technical detail there. 

At the bottom of the page, there is a navigation menu/site map with topics listed below. Is there any specific topic you are looking for?


WithMyBearHands said:


> Reaching by way of physical contact or establishing communication?


We are talking about physically reaching the Alpha Centauri system, which is about 4 light-years distant.


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## Joni (Jun 17, 2018)

Mach said:


> At the bottom of the page, there is a navigation menu/site map with topics listed below. Is there any specific topic you are looking for?


This navigation menu is absolut garbage. I was at the "basic" rocket design page. They're just beating around the bush.


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## WithMyBearHands (Jun 17, 2018)

Oh.  Well in that case, just wait.  It’ll collide with us eventually.

It’s basically just deciding whether to fold space, or use solar sails


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## WithMyBearHands (Jun 17, 2018)

In all sincerity, maybe rocket ships aren’t the answer here.  Theoretically you might be able to establish a “pathway” so to speak, of entangling particles that would create a wormhole.  But I assume you’re going for practical answers and not the uninformed ponderings of a sandwich slinging stoner.


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## Mach (Jun 17, 2018)

Joni said:


> This navigation menu is absolut garbage. I was at the "basic" rocket design page. They're just beating around the bush.


They sort the rocket designs by propulsion. Is there a specific rocket design you are looking for?


WithMyBearHands said:


> Oh.  Well in that case, just wait.  It’ll collide with us eventually.
> 
> It’s basically just deciding whether to fold space, or use solar sails


I am not certain our solar system will drift closer to the Alpha Centauri system over time. I will look it up. Solar sail may be workable, but decelerating at your destination star system with just solar sails is tricky.

When you said "folding space", did you mean an Alcubierre drive or an Einestein-Rosen bridge?


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## Mach (Jun 17, 2018)

WithMyBearHands said:


> In all sincerity, maybe rocket ships aren’t the answer here.  Theoretically you might be able to establish a “pathway” so to speak, of entangling particles that would create a wormhole.  But I assume you’re going for practical answers and not the uninformed ponderings of a sandwich slinging stoner.


Oh. The problem with wormholes is that most proposals, if not all, call for you having exotic matter, usually widen and wedge open the wormhole 'mouth'. Plus, most physicists feel exotic matter is as real as fairy dust.


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## WithMyBearHands (Jun 17, 2018)

Idk like paper lol.  I don’t think there’s really any “good” conventional method to reach a distance that far, but this might be a start

We should see first if we can transmit any information at all in a fast and efficient way.


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## WithMyBearHands (Jun 17, 2018)

Mach said:


> Oh. The problem with wormholes is that most proposals, if not all, call for you having exotic matter, usually widen and wedge open the wormhole 'mouth'. Plus, most physicists feel exotic matter is as real as fairy dust.


Seems to me like someone needs to test the theory and just take one for the team.  Just throw some science at the wall and see what sticks.

Btw I’m totally volunteering here


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## Joni (Jun 17, 2018)

Mach said:


> Is there a specific rocket design you are looking for?


Atomic??????? This site says atomic rockets!!!!


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## Mach (Jun 17, 2018)

WithMyBearHands said:


> Idk like paper lol.  I don’t think there’s really any “good” conventional method to reach a distance that far, but this might be a start
> 
> We should see first if we can transmit any information at all in a fast and efficient way.


Quantum entanglement could yield an method for unbreakable communications encryption, but if you talking about using the quantum entanglement phenomenon for transmitting data, that is not physically possible due the Heisenberg Uncertainty Principle. 


Joni said:


> Atomic??????? This site says atomic rockets!!!!


That is just the title for the site. The creators wanted a retro-futuristic funny title.


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## Joni (Jun 17, 2018)

Mach said:


> That is just the title for the site. The creators wanted a retro-futuristic funny title.


Ok, I think I'm done with this site.


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## Mach (Jun 17, 2018)

@WithMyBearHands 

Alpha Centauri will drift closer to the Sol system a period of time before drifting away permanently.

Alpha Centauri - Wikipedia


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## Leo Whitepaw (Jun 18, 2018)

Mach said:


> most physicists feel exotic matter is as real as fairy dust.


Small amounts of it have been produced through the casimir effect, but still barely any.


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## Saiko (Jun 19, 2018)

Leo Whitepaw said:


> Small amounts of it have been produced through the casimir effect, but still barely any.


Wait, what? Even one particle of exotic matter, particularly the kind needed for wormholes and warp drives, would be a guaranteed Nobel Prize. That doesn't even fit in the standard model yet.


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## Dongding (Jun 19, 2018)

I can't contribute anything aside from 2001:  A Space Odyssey's sequel "2010" will give you an ENORMOUS nerd erection in the theoretical space travel department.


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## Mach (Jun 19, 2018)

> On 4 June 2013 it was reported[52] that a conglomerate of scientists from Hong Kong University of Science and Technology, University of Florida, Harvard University, Massachusetts Institute of Technology, and Oak Ridge National Laboratory have for the first time demonstrated a compact integrated silicon chip that can measure the Casimir force.[53]


If we truly are going to jump down the wormhole, I suggest we read this:

www.nature.com: Casimir forces on a silicon micromechanical chip


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## Thatch (Jun 19, 2018)

Leo Whitepaw said:


> Small amounts of it have been produced through the casimir effect, but still barely any.


 Source?


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## Leo Whitepaw (Jun 19, 2018)

Thatch said:


> Source?


In physics, exotic matter is matter that somehow deviates from normal matter and ... exotic matter is the region of pseudo-negative -pressure density produced by the Casimir effect.
Exotic matter - Wikipedia


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## Thatch (Jun 19, 2018)

Leo Whitepaw said:


> In physics, exotic matter is matter that somehow deviates from normal matter and ... exotic matter is the region of pseudo-negative -pressure density produced by the Casimir effect.
> Exotic matter - Wikipedia


That's not "producing small amounts of exotic matter", that's just a speculative interpretation of an analogous phenomenon. Hence the "The closest known real representative" part, which you should have added in that quote.


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## Leo Whitepaw (Jun 19, 2018)

Thatch said:


> That's not "producing small amounts of exotic matter", that's just a speculative interpretation of an analogous phenomenon. Hence the "The closest known real representative" part, which you should have added in that quote.


There is also this book I have which states it in


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## Thatch (Jun 19, 2018)

Leo Whitepaw said:


> There is also this book I have which states it in



That's great, but the point is that the Wiki article you linked talks about the casimir effect itself being a hypothetical negative-mass quasi-particle, an analogue of one or something in that vein.

So while interesting speculative thought experiment that might go somewhere one day, it is not as you put it "producing small amounts of exotic matter".


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## Leo Whitepaw (Jun 20, 2018)

Thatch said:


> That's great, but the point is that the Wiki article you linked talks about the casimir effect itself being a hypothetical negative-mass quasi-particle, an analogue of one or something in that vein.
> 
> So while interesting speculative thought experiment that might go somewhere one day, it is not as you put it "producing small amounts of exotic matter".


Eh, I couldn't be asked to read it that much before linking 
I would send a picture of the page in the book but I can't find it right now


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## Saiko (Jun 20, 2018)

Thatch said:


> That's great, but the point is that the Wiki article you linked talks about the casimir effect itself being a hypothetical negative-mass quasi-particle, an analogue of one or something in that vein.
> 
> So while interesting speculative thought experiment that might go somewhere one day, it is not as you put it "producing small amounts of exotic matter".


I’ll point out that the term “quasi-particle” is extremely important here. That puts these in the same category as electron holes and phonons. They’re typically mathematical constructs that make aggregate stochastic calculations easier and aren’t actually matter. For example, when dealing with a shit ton of electrons in a P-type semiconductor, it’s way easier to model a hypothetical positive particle moving through the substrate rather than all of the electrons. If I understand correctly, the Casimir Effect results from “filtering” the zero-point fluctuations of the electromagnetic field. You can have a negative differential, but the field to my knowledge has a strictly positive energy. Modeling the experiment as a negative energy quasi-particle in a zero-valued field might make calculations with a negative differential easier just like a positive quasi-particle did, but that is very different from producing a negative energy particle.


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## ZeroVoidTime (Jun 21, 2018)

Mach said:


> They sort the rocket designs by propulsion. Is there a specific rocket design you are looking for?
> 
> I am not certain our solar system will drift closer to the Alpha Centauri system over time. I will look it up. Solar sail may be workable, but decelerating at your destination star system with just solar sails is tricky.
> 
> When you said "folding space", did you mean an Alcubierre drive or an Einestein-Rosen bridge?


Right but the solution for landing would be inverting the sail to make a more solid landing. I think? XD


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## Redwulf16 (Jul 8, 2018)

Nuclear "pusher plate" drive and a bi-generational starship. at a quarter the speed of light, it would take about 80 or 90 years to get there.

antimatter is a great theoretical fuel but it is nearly impossible to produce sizable quantities of the stuff, and storing it is another issue.
solar sails would be impossible to slow down.
we don't even really have cold fusion down yet, let alone an idea of how it could be used to power a spaceship in the future.  that's
not to say it couldn't be done though.


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