Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

I WANT TO BELIEVE

26 (41.9%)

I WANT OFF PLANET NINE'S WILD RIDE

14 (22.6%)

I WARNED YOU ABOUT PLANET X BRO

22 (35.5%)

Total Members Voted: 62

[Catmeat]

Isnt planet X the main proof of ancient astroknot theroys?
Could be a good reason why our planets geology is messed up and why theres a moon near.
Space scares me

[Reelya]

Extra planets aren't proof of anything like that. We're constantly finding more floating rocks. By the 20th century definition there are literally tens or hundreds of thousand of planets in our solar system.

[Flying Dice]

The only selling point is that the emDrive doesn't need fuel, if it works.

Yes it does. At least in the sense of needing an energy supply for the em radiation source

But not in the sense of needing to carry big tanks of reaction mass.

[Reelya]

It would be interesting if there was thrust, but too little to be of any use. e.g. it's less per photon than just the light pressure of the photon. So, you need anomalous thrust that's also greater in magnitude than other ways to use the energy.

[nullBolt]

Well respected scientist predicts the hidden planet over five years ago.

[Orange Wizard]

We should name the planet Armok.

...

astroknot theroys

[Radio Controlled]

Spoiler (click to show/hide)

Which thing in particular do you have a problem with?

I assumed it would be easy to spot stuff at our solar system, a thing I assumed because all those guys complaining about stealth in soft scifi space battles.

Cloaking devices are sorta BS, but that misses the point that it's actually much harder to spot ships at a distance in space than sci-fi would lead you to believe. Basically, you don't need a cloaking device, you just need a non-reflective hull and to not emit too much EM radiation.

In other words, if you want to stealth in space, you're going to roast yourselves to death. You've gotta get rid of the excess heat to keep your life-support supporting you, and that's going to stand out like a beacon against the 3 Kelvin background (Example: using the surface of the craft to maximize surface area without building radiators (something like the Shuttle did), something the size of, shall we say, an Oscar-class submarine (a good ballpark estimate for a small combat spacecraft), looking at it from an angle. Nose-on surface area's 250m², broadside's 2770m², so call it 1510m² facing what's looking for you. What's say you know you're being looked for and don't mind irritating your crew a bit and have life support set to 275 Kelvin (a bit above freezing). You can still be seen from a little over 2 light-minutes away (Math: R_d = 13.4 * sqrt(A) * T², where R_d is the range at which you can be seen in kilometers, A is exposed surface area in m², and T is surface temperature in Kelvin)).

-snip-
Yeah, it seems to work, but not very well.

Kinda like a photon drive. Yeah, they work, but you have to put ungodly amounts of power in them to do anything worthwhile.

A word to the wise, don't get into debates about stealth in space or fighters in space with pyro. There is nothing to be gained there but bitter defeat.

Also, hey pyro, long time no see.

[LoSboccacc]

A word to the wise, don't get into debates about stealth in space or fighters in space with pyro. There is nothing to be gained there but bitter defeat.

Also, hey pyro, long time no see.

this debate happened so many time even the summary is thousand words long http://www.projectrho.com/public_html/rocket/spacewardetect.php

[mainiac]

In other words, if you want to stealth in space, you're going to roast yourselves to death.

Or to design a vectored radiator...

Physics is (generally) pretty obliging about telling us what will be possible in the future.  Engineering is not.  Assuming a uniform distribution doesn't prove anything other then that a uniform distribution doesn't accomplish what you want.  You dont need to avoid black body radiation in all directions, you need to avoid black body radiation in a tiny, tiny subset of space.

People thinking that physical laws can be extrapolated to military maxims have a pretty crappy track record.  And no I'm not talking aircraft carriers beating battleships or blitzkreig.  The Lancaster laws for instance thought they could reduce battleship to battleship combat to a simple linear equation.  The failed horribly.  Everyone was convinced before WWII that "the bombers would always get through".  They were wrong.

[LoSboccacc]

You dont need to avoid black body radiation in all directions, you need to avoid black body radiation in a tiny, tiny subset of space

really, just read the link, it got that covered as well

[Radio Controlled]

A word to the wise, don't get into debates about stealth in space or fighters in space with pyro. There is nothing to be gained there but bitter defeat.

Also, hey pyro, long time no see.

this debate happened so many time even the summary is thousand words long http://www.projectrho.com/public_html/rocket/spacewardetect.php

Heh, I love that site, but it has that tv-tropes-like quality to suck up time into a vortex and spitting tabs back out.

[mainiac]

It think's it answers it for sure.  And it answers it in a problem that ironically parallels the problem it diagnosis.  It has an assumption that is flawed.  You point out the flaw in the assumption and it replies with even more assumptions.

[LoSboccacc]

It think's it answers it for sure.  And it answers it in a problem that ironically parallels the problem it diagnosis.  It has an assumption that is flawed.  You point out the flaw in the assumption and it replies with even more assumptions.

nah the logic is perfectly sound

Spoiler (click to show/hide)

You dont need to avoid black body radiation in all directions, you need to avoid black body radiation in a tiny, tiny subset of space

^ it's this that doesn't make sense.

how do you know where not to radiate? even assuming it's technically sound, how do you know where the enemy are if you assume this technique would work? the enemy would simply do the same and then you won't know where not to radiate.

[Shadowlord]

Pick a random direction. They can't be everywhere, can they?

[mainiac]

Pick a random direction. They can't be everywhere, can they?

It's even better then that.  That site is going on the assumption that the unstealthed ships can be spotted immediately.  So you know exactly where they are.  You need to avoid radiating heat in less then a one degree by one degree cross section.  So if you can redirect less then one ten thousandths of your thermal emissions, you win