/sci/ - Science & Math

[Anonymous No.2800827]

How would one calculate the energy required to speed up a planets rotation (Venus) to 24 hours?

[Anonymous No.2800833]

>>2800832
Thank you.

[Anonymous No.2800832]

<div class="math">E_{rotational} = \frac{1}{2} I \omega^2 </div>

[Anonymous No.2800848]

Since I don't want this thread to die yet, lets talk about terraforming. Doesn't have to be specifically Venus.

[Axel the Possum No.2800883]

>>2800848

Personally, I figure that once we have the technology to terraform properly, there'll be no need for it, by and large.

Venus, for example; sure, we could try and reduce its clouds, but in the centuries that would take, humanity will likely become unrecognizable to those alive now. It'd be far more effective to adapt to living there. For example, create a very light, spherical or roughly cylindrical habitat and use solar power to convert CO2 to oxygen, and float through Venus's atmosphere.

That said, I would like to see Mars terraformed. Kinda warps my mind to think about humanity working on that scale...

[Inurdaes !V1sPhobos. No.2800896]

>>2800883
>we could try and reduce its clouds, but in the centuries that would take
< 50 years. Put a sunshield to deflect ALL light away from the planet, watch as the atmosphere cools and freezes. Then build coilguns on the surface with collection robots to scoop up the dry ice and eject it toward Mercury, Luna, Ceres and other atmosphereless celestial bodies being prepped for terraformation.

>I would like to see Mars terraformed. Kinda warps my mind to think about humanity working on that scale...
THEY SAID I COULD BE ANYTHING I WANTED
SO I BECAME A GOD

[Anonymous No.2800897]

>>2800883
What about Topopolis and Globus Cassus?

[Axel the Possum No.2800921]

>>2800896

Less than 50 years... If we assume the technologies are already in place, if we assume we can get it up there and built in time, if we assume no major crap-ups, if we assume this, that, and the other.

I'd love to believe that, by the time I hit 70, we'll be seeding Venus with life, but even if we had a fully dedicated effort for it, I can't imagine it taking less than a century and a half.

>>2800897

We're talking more along the lines of planetary habs than space habs. Topopolis is my ideal for life in a space hab, though. Globus Cassus, meanwhile, would take far more time and likely be far more destructive than anything discussed here. If I had my way, once humanity leaves our mudball, I'd see Earth turned into a nature preserve.

[Anonymous No.2800922]

Terraforming is never going to happen. If singularityfags are wrong we might get large colonies we can fill with human resources.

[Inurdaes !V1sPhobos. No.2800934]

>>2800922
>Terraforming is never going to happen.
CHALLENGE.
FUCKING.
ACCEPTED.

[Anonymous No.2800940]

>>2800922
This. In order to terraform anything would take drastic time and energy we don't have. It's not a matter of advanced technology, its a matter of physics not allowing us.

[Anonymous No.2800944]

>>2800940

What about de-terraforming?

[Inurdaes !V1sPhobos. No.2800954]

>>2800940
Yes, we totally cannot utilize the relatively near inventions of robotics and asteroid mining to create orbital mirrors to reflect extra sunlight and heat onto Mars to increase the temperature.

This totally won't restart the outgassing of CO2 and equatorial melting of water ice.
This totally won't cause even more outgassing and melting.
We totally can't create a few hundred nuclear-powered factories that produce extremely potent greenhouse gases.
We totally can't begin the seeding of algae to produce oxygen.
We totally can't use some directed thermonuclear explosions under the polar caps to melt permafrost.

[Axel the Possum No.2800955]

>>2800940

>Time and energy we don't have

Bitch, what're you on about? We've got a few hundred billion years, and a whole damn universe.

[Anonymous No.2800982]

>>2800954
We can't totally restart Mars' core to produce a magnetosphere to stop the sun's rays from killing us.

[Anonymous No.2800993]

>>2800954
>Blow up nukes nukes to melt ice
>Use nuclear-powered factories to produce harmful chemicals

Idiot, nuclear-powered factories don't produce smog they just make radioactive material. And blowing up nukes would make the area inhabitable.

[Inurdaes !V1sPhobos. No.2800997]

>>2800982
We totally can't also have the orbital mirror act partially as a photovoltaic power source for an artificial planetary magnetosphere

Captcha: magnetic. earting

[Inurdaes !V1sPhobos. No.2801004]

>>2800993
>Idiot, nuclear-powered factories don't produce smog they just make radioactive material.
Idiot, nuclear-powered factories don't use electricity to produce products they just make radioactive material
>And blowing up nukes would make the area inhabitable.
I'm sure that a few kilometers under the polar ice caps is prime real estate.

[Colonel Coffee Mug !phJ7yIcs.Q No.2801006]

>>2800982

>He thinks magnetospheres are necessary!
>He doesn't even know that a superconducting magnetic sail would double as an energy source and a radiation shield for Mars!

[Anonymous No.2801012]

>>2800997
Brilliant. Would you care to run the numbers on that and tell me how fucking huge and unstable this thing would have to be to get that kind of power? And then can you calculate how much of the sun it would block so that the planet would freeze? And can you then calculate the fact that it couldn't send energy down to Mars because it's using it all to create this weakass magnetosphere? And can you then calculate why you're an idiot?

[Inurdaes !V1sPhobos. No.2801023]

>>2801012
>Would you care to run the numbers on that and tell me how fucking huge and unstable this thing would have to be to get that kind of power?
And the instability comes from....? Solar wind? This can be counteracted.

>And then can you calculate how much of the sun it would block so that the planet would freeze?
What part of polar orbit do you not understand? All it is 'blocking' is sunlight that would otherwise go off into deep space.

>And can you then calculate the fact that it couldn't send energy down to Mars because it's using it all to create this weakass magnetosphere?
"Weak"? Are you shitting me? As for energy, geostationary space-based solar satellites can be utilized. Not to mention geothermal, nuclear, fusion...

>And can you then calculate why you're an idiot?
Someone butthurt?

[Anonymous No.2801041]

>>2801023
If it's in a polar orbit how would it create a magnetosphere around the entire planet sufficient to keep an atmosphere and protect from harmful solar radiation? I'm curious.

[Inurdaes !V1sPhobos. No.2801061]

>>2801041
First off, a magnetosphere isn't even really required on Mars; any thick atmosphere that it has will not dissapate any meaningful amount for thousands upon thousands of years. As for radiation for people, with Mars' lower gravity the atmosphere is also correspondingly two and a half times thicker giving more of a radiation blanket. And of course there is the fact that it receives less than half of the sunlight/heat/radiation than the Earth.

As for generating a magnetosphere, I would suppose it would beam energy down to the north and south pole where underground superconductors create an albeit weak but sufficient magnetic field for Mars.

[Anonymous No.2801068]

>>2801061
Wait how does the lower gravity make the atmosphere thicker?

[Inurdaes !V1sPhobos. No.2801075]

>>2801068
It gets squished less to the surface, of course. Mars has a surface gravity of 0.376 Gs.

[Anonymous No.2801096]

>>2801075
But I'm confused. Wouldn't that make it less dense and then less capable of blocking radiation?

[Inurdaes !V1sPhobos. No.2801106]

>>2801096
Not if enough gas is released. This can be achieved through not only the usual heating-up-then-outgassing but melting the CO2 out of the soil with a orbital soletta concentrating like a magnifying glass over areas that will be covered in deep oceans in the future. That way you can create a 750 millibar atmosphere at sea level or higher.

As long as enough gas is released into the Martian atmosphere, all is good.

(Interestingly I came up with this idea 100 pages before I read it in Green Mars)

[Anonymous No.2801122]

>>2801106
But is there even enough gases to release? And then you won't have a strong magnetosphere and more gases = higher atmosphere = more gases being lost due to solar radiation hitting it. Right?

[Inurdaes !V1sPhobos. No.2801136]

>>2801122
>But is there even enough gases to release?
Initially, definitely. For later replenishing I'm sure Venus has more than plenty. If not, drop by Io.
>And then you won't have a strong magnetosphere and more gases = higher atmosphere = more gases being lost due to solar radiation hitting it. Right?
Ehhh sort of. It's not enough of a problem to even be noticeable by 3000AD.

[Anonymous No.2801149]

>>2801136
But how do you get a breathable atmosphere? I mean, mars is 95% CO2. It took algea on earth millions of years to make our current atmosphere.

[Inurdaes !V1sPhobos. No.2801161]

>>2801149
>I mean, mars is 95% CO2.
It's also less than 1% the air pressure of Earth.
>It took algea on earth millions of years to make our current atmosphere.
Bioengineer algae to live longer and produce far more oxygen + make them hardier. When the oxygen content reaches a certain point begin introducing CO2-tolerant grasses and mosses as well as small plants.

[Anonymous No.2801231]

Michio Kaku mentioned something interesting recently, about setting off a greenhouse effect on Mars by nuking it. His plan seems a bit shoddy, but I'm all for using nukes to make other planets habitable.

[Inurdaes !V1sPhobos. No.2801247]

>>2801231
Michio Cocku was fully against the Cassini mission die to the nuclear power source it had on board. He is holding interviews relating to the dangers of nuclear power after the Fukushima crap. But he wants to use nukes as THE primary form of terraforming another world? No thanks.

[Inurdaes !V1sPhobos. No.2801255]

>>2801247
*due

[Axel the Possum No.2801293]

If we're going to terraform anywhere, I'd say our first target should be Venus. If we use the plan you propose, Inurdaes, we could use the effects from that to simultaneously start the terraforming of Mars. By the time humanity has its second world, it'll be halfway to a third.

[Anonymous No.2801306]

>>2801136
>Initially, definitely. For later replenishing I'm sure Venus has more than plenty. If not, drop by Io.

And this is where the argument officially falls apart, making its weakness obvious even to the most uneducated minds.

[Inurdaes !V1sPhobos. No.2801314]

>>2801293
Venus, Mars, Mercury AND Luna simultaneously.

Let's do this shit.

[Inurdaes !V1sPhobos. No.2801319]

>>2801306
Where exactly does it fall apart? We don't have to even begin worrying until 20,000AD.

[Anonymous No.2801351]

Christ. We're centuries off terraforming Venus. And Mars.

And yeah, you need a fuckin' magnetosphere. For communication,and for UV and other radiation,

[Inurdaes !V1sPhobos. No.2801368]

>>2801351
>We're centuries off terraforming Venus.
Probably
>And Mars.
No.
>you need a fuckin' magnetosphere. For communication,
ITT: Every single probe or lander orbiting other planets and moons, specifically Mercury's Messenger
>and for UV and other radiation
Not severe enough to be a problem on Mars with a thick atmosphere.

[Anonymous No.2801391]

>>2801368

for communication using anything other than very high freq bands? Yeah, you do. Try using most commercial frequencies, FM, AM and others without a magnetosphere. We would have to drastically change our technology to deal with the change - large scale communication would get fucked by every big burst of radiation from the sun.

As for the atmosphere being too thick, yeah, but that atsmosphere is going to change during terraforming with the addition of other gases. And given that levels of solar radiation are continuing to rise, I'd say that in the mid to long term, having a magnetosphere would be absolutely essential given our current and forecasted technologies, although of course that could change.
AS

[Inurdaes !V1sPhobos. No.2801404]

>>2801391
>Try using most commercial frequencies, FM, AM and others without a magnetosphere. We would have to drastically change our technology to deal with the change
Twenty second century and you're worrying about changing frequencies on Mars? Building any new infrastructure on Mars would prooooooooobably take this into account.
As for a magnetosphere we will be able to create an artificial one sufficient for the planet. See >>2800997

[Anonymous No.2801450]

>>2801404

Bro, we are struggling to lift anything larger than communication satellites into orbit, and people are talking about giant electromagnets embedded along the middle latitdues to simulate a molten core and thus a magnetosphere? Clutching at straws man, thats not happening for a few hundred years, minimum.

As far as building comms infrastructure on Mars, yeah, possible I'm sure, but currently we have no serious contending tech to compete with the frequencies we use, and these get an intolerable amount of interference outside most places where we haven't doubly or trebly amplified signals and have powerful receivers - unless we manage to develop tech using very high energy, like microwaves or something, it's going to be beyond us. And I haven't seen anything that leads me to believe we'll get around the downsides and near physical impossibilities of using such high energy waves to do anything more than cook food. But I'm being a huge nay sayer, theres every chance that we'll make some major breakthroughs in the coming decades, so who knows.