Infinite Karma posted:

So forgetting Mars and the Moon for a second...

What about exploring the upper atmosphere of Venus? Nasa awarded a contract to work on a proposal to do that last year

The plan is called HAVOC

Instead of struggling to stop radiation from killing you, Venus has ample atmosphere to block cosmic rays and radiation. Instead of struggling to find air and heat, Venus has as much CO2 to process as we could ever want. And the solar irradiance is much higher than Earth instead of much lower like Mars. And the "Earth-like" portion of the atmosphere, pressure-wise, is basically the same temperature as temperate Earth. Earth's breathable atmosphere is a lifting gas in Venus's atmosphere, and with virtually equal pressures, any breach in the balloon holding up the aerostat would only slowly leak out, giving time to patch/maintain the leak.

And instead of perchlorates and dust and radiation and freezing temperatures, you have to deal with winds and sulphuric acid attacking things exposed to the atmosphere. If we had a process that could filter the acid from the atmosphere, plants could breathe the Venus air (as far as we currently know) and produce oxygen the old-fashioned way). Materials that are resistant to sulphuric acid aren't that hard to engineer. The delta-V to Venus orbit is less than Mars. Why aren't we talking about going to Venus?

Unoriginal Name posted:

Because Venusian sounds dumber than Martian.

Kerning Chameleon posted:

As a bonus, you could just jettison your garbage and excess corpses out of the airlock on your Cloud City station and let gravity and air pressure do the rest.

Unoriginal Name posted:

Because Venusian sounds dumber than Martian.

Infinite Karma posted:

So forgetting Mars and the Moon for a second...

What about exploring the upper atmosphere of Venus? Nasa awarded a contract to work on a proposal to do that last year

The plan is called HAVOC

Instead of struggling to stop radiation from killing you, Venus has ample atmosphere to block cosmic rays and radiation. Instead of struggling to find air and heat, Venus has as much CO2 to process as we could ever want. And the solar irradiance is much higher than Earth instead of much lower like Mars. And the "Earth-like" portion of the atmosphere, pressure-wise, is basically the same temperature as temperate Earth. Earth's breathable atmosphere is a lifting gas in Venus's atmosphere, and with virtually equal pressures, any breach in the balloon holding up the aerostat would only slowly leak out, giving time to patch/maintain the leak.

And instead of perchlorates and dust and radiation and freezing temperatures, you have to deal with winds and sulphuric acid attacking things exposed to the atmosphere. If we had a process that could filter the acid from the atmosphere, plants could breathe the Venus air (as far as we currently know) and produce oxygen the old-fashioned way). Materials that are resistant to sulphuric acid aren't that hard to engineer. The delta-V to Venus orbit is less than Mars. Why aren't we talking about going to Venus?

Raenir Salazar posted:

I also imagine that constructing a cloud city/outpost on Venus isn't even on the drawing board of any agency, and probably requires building something in orbit and then lowering it in.

WAR CRIME GIGOLO posted:

Can we communicate with mars or the moon in real time?id love a good read on inter space communication.

ashpanash posted:

There's a light-speed delay of a little more than one or two seconds in general for round-trip lunar communication, and anywhere from 14 to 50 or so minutes for round-trip communication to Mars, based on the orbits.

Raenir Salazar posted:

I also imagine that constructing a cloud city/outpost on Venus isn't even on the drawing board of any agency, and probably requires building something in orbit and then lowering it in.

WAR CRIME GIGOLO posted:

If we daisy chained satellites from earth to mars can we make it faster?

Rappaport posted:

Who is 'us' in this scenario? The thousands of slave labourers digging up that thorium probably would have some complaints.

dex_sda posted:

dex_sda posted:

Here's the problem with all this, and forgive me for nerding out about relativity, I simply fuckin love it. All relativity basically can be summed up as: "From the viewpoint of every observer, physics look the same. Massless particles travel at a universal speed, called 'c' (these two are enough to derive all of special relativity, the equivalence of matter and energy, and get the notion of 4 dimensional spacetime. Yes, really). Objects which aren't acted on follow a geodesic in the 4-dimensional spacetime (basically, a straight line, even in curved geometry. Like a direct line between points on a globe is a geodesic). Presence of matter curves this spacetime, and the manifestation of this is a pseudo-force we call gravity. In the first order approximation, this pseudo-force operates according to Newtonian mechanics."

dex_sda posted:

These are more or less enough to derive general relativity, whole cloth. Of course, doing that is a daunting mathematical task, but it's philosophically incredibly simple. And conceiving of it is why Einstein is considered an unparalleled genius. After derivation, what you end up with is a single field that can be easily described using the action principle:

Simple and elegant. Using it for calculations is difficult, but nevertheless, it's a pleasing equation.

By way of comparison, to this action, TeVeS added another action. Then when other observations shown it was bad, it added another action. To account for all the varying sources of data, it ended up being an equivalent of more than 6 different fields cointeracting seemingly randomly. Here's the action for TeVeS:

dex_sda posted:

This is what I mean by compounding artificial assumptions. There is no good reason it should look like that, from a physical and a philosophical point of view, they just make it fit any new data. That makes a theory suspect on arrival. I wouldn't go as far as to call it pseudoscience, but it's not far from it. TeVeS is probably the theory that fits the largest proportion of the data, and it still can't touch cold dark matter for predictive power.

dex_sda posted:

You might wonder why I put the elegance of equations on the pedestal.

dex_sda posted:

Well, it kinda seems like the universe does it, too. Dirac noticed some of his calculations could yield negative as well as positive roots, and instead of throwing out the negative ones as unphysical, he posited the existence of antimatter, guessed its properties, and was proven right decades later. And the Higgs boson could be an infinite family of particles, but Higgs picked the properties of the answer that was most elegant and most pleasing mathematically. That's where we searched for it, and that's where we found it. The Universe is a giant physics nerd.

dex_sda posted:

Research on DM is twofold. First off, we have the laboratory called the Universe, and we try to search for something, anything, to disprove the DM hypothesis. Believe you me, astronomers and relativists alike don't enjoy that we basically put a term we know nothing more about in our understanding of the universe, but wherever we look, DM seems to be a measurable, mappable phenomenon.

dex_sda posted:

The other research is indeed the properties, with the goal of detecting it. We know it's cold and neutral, so electromagnetic is out. Without electromagnetism, there can be no chemistry, and if it interacted strongly, it would be very easy to detect. Also out. It cannot be massless. So it's a weakly interacting massive particle, much like neutrinos, except it should have more mass than we expect. By the way, does it interact weakly at all? We assume so, primarily cause it had to have been created somehow, so you'd expect another field to interact with it somehow. But maybe it isn't? We want it to be, because if it doesn't interact weakly at all, but interacts gravitationally, there is no possibility to detect it other than by gravitation. It would mean we'd have a "dark matter" we can only observe through lensing, forever. Not being able to discern it's mass, even. Scientists don't enjoy that thought, but who are we to say the universe plays fair?

dex_sda posted:

Not really my area of expertise, but it should fit supersymmetry quite okay. It's not a SM particle, whatever it is, and could probably preserve symmetry the same way neutrinos do, by anti-dark matter having a different chirality.

dex_sda posted:

There is generational inertia, of course, in academia, but it's more like 20 years. It simply had to do with one thing: Einstein wasn't very credible when he made his Annum Mirabilis papers. He misused references when he used them, and he was a patent clerk putting stuff in a german journal. In particular with relativity, the papers in 1905 and then the GR ones read as if Einstein made them out of nothing, by pure thought alone, without external help from physicists. This is shockingly close to the truth, by the way (he mostly asked mathematicians for help, and even there he was the pioneer of many of the concepts), but it made his predictions look like some dumb rear end in a top hat putting out dumb poo poo. This one time it happened to be the smartest dumb rear end in a top hat around putting out the smartest dumb poo poo.

New scientists that came into physics like half a decade after Einstein were all over his findings, by the way, since they were super fuckin' cool, and they didn't have the preconceptions. But the preconceptions were kind of warranted.

dex_sda posted:

Hard to say. By the anthropic principle, we should expect parallel universes. But interacting with them is still metaphysics at this point. That's not even getting into the many-worlds/copenhagen debate (where I personally think 'many worlds' despite all problems, but really I want Penrose's interpretation to be correct).

dex_sda posted:

* all images are sourced from a wonderful essay by Sean Carroll, which elaborates on the problems with TeVeS and MOND.

dex_sda posted:

Finally, Mars has higher gravity, which is actually a disadvantage, as it's harder to leave the gravity well, making return crafts bulkier and therefore requiring a massive increase in starting fuel, in accordance with the Tsiolkovsky equation.

Wikipedia Sez posted:

The gravity of Mars is a natural phenomenon, due to the law of gravity, or gravitation, by which all things with mass around the planet Mars are brought towards it. It is weaker than Earth's gravity due to the planet's smaller mass. The average gravitational acceleration on Mars is 3.72076 ms−2 (about 38% of that of Earth) and it varies laterally.

LtStorm posted:

Whooooa hold up, sanity check. Mars is smaller than Earth and no more dense; it has less gravity and a shallower gravity well. If Mars had more gravity than Earth it'd have more of its atmosphere left!

Infinite Karma posted:

The plan is called HAVOC

thewalk posted:

Humans built the pyramids. Worked in mines throughout history. Theyll dig for thorium

LtStorm posted:

No, please, nerd out, because I have questions. For one; why call gravity of a pseudo-force? It's one of the four fundamental forces, even if it is the outlier that seems least explained in spite of ostensibly being fully explained. We've detected gravitational waves; if there's a wave, there could be a particle, though describing the particle puts us into the weeds of things like MOND once more. So what is gravity?

quote:

I think our concepts differe on what a pleasing equation looks like.

I can understand TeVeS struggling to explain evidence we're seeing without bloating, but at the same time I'd never expect the totality of math explaining a fundamental force to be simple, even if it philosophically is. Mostly because Maxwell's Equations with their partial differential equations sure as hell aren't. Einstein surely deserves the accolades he gets for explaining general relativity so succinctly but at the same time, does that mean it's fully explained?

quote:

Eh, a pseudoscience claims evidence when it doesn't have it. TeVeS, MOND, etc. are untested or unproven theories. They're also messy, as you noted. Anything that's going to resolve the questions of what the hell gravity is in a better way than we currently have look like they'll be coming out of left field. Or, again, the weirdos and their strings are going to be right and that's going to suck for everyone.

quote:

See, that's interesting but also concerning because so far no one has found a simple reconciliation between quantum mechanics and general relativity. It's concerning because if people are expecting it to be simple, are they going to dismiss the complex explanations and fail to test them as thoroughly as they should?

quote:

Yeah, it seems measurable and mappable, but until we have a handle on what it is rather than what it's doing there's a chance we're going to find something that recontextualizes all of those observations. Which, it might still be dark matter we end up with, but also something ridiculous like a fifth fundamental force.

Yeah. This is where I am with dark matter; we can see what we think are its effects, but we aren't making a whole lot of progress on describing the particles its made out of and what they're capable of. If the Universe is a giant physics nerd, why would it have a non-baryonic matter that is only matter because of the density it exhibits rather than because it has a chemistry? To make the math look nicer? That'd really suck.

quote:

That's part of my curiosity with general relativity; Einstein was a brilliant dumbass with conceiving of it, but now we have the fact three of the four fundamental forces are explained by quantum mechanics and then we have gravity over here in the corner, so ridiculously weak it apparently isn't a factor at the microscopic level, and we still don't know if it has a carrier particle for sure or what it's doing other than pulling things together only when there's literally nothing pushing them apart. General relativity makes so many things we see make sense, but the one thing it doesn't help make sense of is how it actually does all of that.

quote:

Whooooa hold up, sanity check. Mars is smaller than Earth and no more dense; it has less gravity and a shallower gravity well. If Mars had more gravity than Earth it'd have more of its atmosphere left!

Infinite Karma posted:

That's why I made the post, NASA has a pretty advanced drawing board in that second link for sending a balloon into the clouds. They did proof of concept tests on various materials in concentrated sulfuric acid to see the effects long-term, and trajectory calculations.

A cloud city would basically be a space station suspended by aerostat balloons (but in Venus's atmosphere), and could be put together modularly. Even that isn't really planned yet anymore than Mars exploration is planned beyond the first manned mission. Right now there is a plan to go there and spend X amount of days in a single capsule doing research, then fly back.

Also, I forgot in the original post, gravity on Venus is about 0.9g. Having readily available Carbon and Nitrogen in situ is also a big deal, since that means we won't have to bring as much of those if we were going to try and make a permanent colony there.

WAR CRIME GIGOLO posted:

Can we slap a prison on the moon? I like broski we could have savage low gravity duels In the Donald Trump Moon ULTRAMax Penitentiary


Is a space bridge easier to work with in smaller objects than larher ones?

Kerning Chameleon posted:

I like to remind people that to "grow colonies" in space, you can't just shuttle warm bodies out. They have to also be willing to breed. A lot. With a much smaller selection pool of candidates than they're used while earthbound.

Even if you make it a priority to establish in vitro fertilization facilities on your Mars/Space base, unless you also want to research full anime test tube womb factories, you still need most if not all of your female population willing to be handmaids for the foreseeable future.

Sounds like a great societal model to adopt just to plant our feet in space to me!

Libluini posted:

The current main theory says that both matter and anti-matter were created in almost the same amount, but due to physics, anti-matter got created slightly less. So after aggressively annihilating each other, some matter was left over. This also neatly explains why most of the universe is just empty space with nothing in it, so it sounds deceptively plausible. We just don't know for sure!

Though some recent articles I've read talk about the quarks forming anti-matter having some weird stuff going on (makes me wish I could remember details, but heh, never thought I would be talking about this), which means that maybe, when a Big Bang happens, normal matter has a slightly higher chance of forming, which could be the basis for this cosmic asymmetry.

A neat thing I though off by myself is that maybe the cosmos is so uneven and lumpy 'cause the matter-anti-matter-annihilation phase was uneven, and what nowadays are voids were zones where most of the anti-matter was, while the zones where matter bunches up are the ones which had more matter in them.

thewalk posted:

Id guess dark matter is matter + antimatter combined. They dont anihilate each other. They neutralize each other so whats left over is neutral matter. doesnt interact, cant be seen, measured etc except through its gravity

quote:

Antimatter particles should in principle be perfect mirror images of their normal companions. But experiments show this isn’t always the case. Take for instance particles known as mesons, which are made of one quark and one anti-quark. Neutral mesons have a fascinating feature: they can spontaneously turn into their anti-meson and vice versa. In this process, the quark turns into an anti-quark or the anti-quark turns into a quark. But experiments have shown that this can happen more in one direction than the opposite one—creating more matter than antimatter over time.

Libluini posted:

It already started happening. An article I've read a couple months ago was talking about something weird about the symmetry between matter and anti-matter. Something about a slight difference in properties, and matter and anti-matter sometimes spontaneously trading places. Matter and anti-matter aren't complete mirrors, in other words.


Read more here

Infinite Karma posted:

I, for one, believe dark matter is probably a mistake in our formulation of gravity/relativity, and so is dark energy.

Owlofcreamcheese posted:

We know that isn't the case because different galaxies have different amounts of dark matter, with ones like "NGC1052-DF2" having nearly none. If it was a gravity thing every galaxy would have the exact same amount of the effect, but since most galaxies have a roughly average amount but some have more or less that means it's a "thing" that exists in a galaxy separate from just the stars.

quote:

So, not only does the galaxy itself have less mass, but the proportion of normal matter within that mass is smaller. This implies that the rest must be made up of - you guessed it - dark matter.

Nenonen posted:

Space seems like the final tree clubhouse for white boys. No girls or coloured people allowed. It's no wonder they are talking about space colonies, because they envision themselves as colonial overlords.

I for one would rather welcome alien overlords to turn us into humanburgers than allow this shittiest of all species on our planet to colonize other systems.

Nenonen posted:

Space seems like the final tree clubhouse for white boys. No girls or coloured people allowed. It's no wonder they are talking about space colonies, because they envision themselves as colonial overlords.

I for one would rather welcome alien overlords to turn us into humanburgers than allow this shittiest of all species on our planet to colonize other systems.

Owlofcreamcheese posted:

What?

Captain Monkey posted:

I believe dark matter is the friends existential despair we made along the way.

Nenonen posted:

Space seems like the final tree clubhouse for white boys. No girls or coloured people allowed. It's no wonder they are talking about space colonies, because they envision themselves as colonial overlords.

I for one would rather welcome alien overlords to turn us into humanburgers than allow this shittiest of all species on our planet to colonize other systems.

Bug Squash posted:

I think Dark Matter is still going strong as the best explanation of the structure of galaxies, at time of writing. It's pretty unsatisfying compared to other nice elegant theories, but when there's gravitational lensing and no apparent matter in regions of space, plus the other general assorted evidence, we're stuck with it.

Infinite Karma posted:

Hell, maybe the constants/coefficients in physics aren't constant

BrandorKP posted:

I seem to remember reading that was the case, just it was a very, very, slow change.