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Comment Re:For anyone who cares about how it actually work (Score 1) 92

Aldrin cyclers make no sense as cargo haulers. They don't save you dV or time - they cost you more dV and time to dock with them vs. taking an optimal direct trajectory. The point of an Aldrin cycler is that you can have a big spacecraft with tons of radiation shielding and nice facilities for humans on their long trip to Mars, which you don't have to loft every single trip. But it provides no advantages for cargo, only the aforementioned disadvantages.

And Aldrin cyclers are premised on long transit times. But if you can do fast transits with nuclear propulsion, it does rather reduce the appeal. If you want fast Aldrin cyclers, they have to take highly elliptical orbits that only reach the inner solar system rarely, so you need an awful lot of them. And once again, they don't save you dV or time, they only cost your spacecraft that has to dock with them dV + time vs. a direct transfer.

Comment Re:For anyone who cares about how it actually work (Score 1) 92

To be fair, you don't decelerate pointing directly at a planet (if you even decelerate by rocket power at all, rather than aerocapture). The deceleration burn is parallel to the planet. You don't want to fall straight down onto it.

Though I mean... I guess with this sort of thrust to weight ratio, you *could* design a spacecraft where this could give you powered flight all the way to the surface ;) Still, pretty wasteful; nuclear fuel doesn't grow on trees.

Then again, if you built the craft with enough thrust to pull positive Gs on Mars, then you could *take off* as well... if you're willing to contaminate your landing pad ;) Probably best to have a small chemical stage to get you well clear of your settlement at least.

I do find this interesting that this is basically yet another more modern, more realistic design of Orion (pulse propulsion by small nuclear bombs) - yet people will still keep referencing Orion as their dream rocket, even though it's an obsolete design that's been far surpassed by many other contenders.

Comment Re: Media (Score 0) 84

"Compare any of that with the previous horrendous level of censorship"

What on Earth are you talking about? How long, year after year, did Trump spout vile racist offensive garbage without any action taken against him ? The question isn't "why did he eventually get banned", but "why on Earth was he allowed to violate Twitter's policies endlessly in the first place"?

. It is way better on X now.

Lol, is this some type of a joke? Every time I pop back onto Twitter it's like a dystopia. A constant stream of bots and spam, endless ads, bluechecks with inane views boosted to the top, and a constant push from the site to try to upsell you to Twitter Premium. I can only conclude that for people at the site it's been a boiling-frog situation that keeps them from noticing the change.

Comment Re: Media (Score 2) 84

We're all made of the same stuff.

Up until around six weeks, there's no difference between male and female embryos. At that point, a tiny region (usually) found on the Y chromosome called SRY activates. Less than 1000 base pairs, its job is to start the virilization cascade. It's highly mutable, so it tends to be prone to "breaking" or transferring between X and Y - leading to XX males and XY females. But XX males lack the azoospermia factor in the Y chromosome's long arm and XY females have streak gonads, so while this randomly happens, they're infertile and the mutation doesn't persist. But otherwise they're phenotypically normal men and women, up to the point of infertility in XX men and a lack of puberty (due to the nonfunctional streak gonads) in XY women.

At the start of the virilization cascade, everyone has the same basic set of organs, including the urogenital sinus, paramesonephric (Müllerian) ducts, and the mesonephric (Wolffian) duct. These are to form the common, female, and male organs, respectively. The paramesonephric ducts will develop if not exposed to anti-Müllerian hormone (AMH), and will fail to develop / degenerate if exposed to it. The mesonephric duct will develop if exposed to testosterone and fail to develop / degenerate if not exposed to it. Note that this is two different hormones - more on that mix-and-match later.

Most aspects of the genitals however come from the common urogenital sinus, leading to cognates in both males and females: labia-scrotum, clitoris-glans, prostate/paraurethral glands (as well as the lower 2/3rds of the vagina). This leads to a smooth interpolation between the two (diagram here). To reiterate, these pairs are the same organ, just grown to different shapes / sizes. A glans is a large clitoris. The scrotum is fused labia. Etc.

So we've already accumulated quite a list of things that can go wrong, including defective SRY, transferred SRY, unusual karotypes (X0, XXY, XYY, XXX, XXYY, etc), presence / absence of AMH without the absence / presence of testosterone, insensitivity to AMH / testosterone, etc. Using a very broad definition of intersex (e.g. including unusual karyotypes, such as Kleinfelter syndrome (XXY), up to 1,7% of the population deviates from the normal developmental process. For visibly ambiguous genitals, it's about 1 in 5500. A couple examples:

Androgen Insensitivity Syndrome (AIS): a largely (PAIS) or complete (CAIS) phenotypically normal female, but XY. Generally infertile. Exposed to androgens in the womb but don't react sufficiently or at all to them. Generally identify as female.

5-alpha reductase 2 deficiency: XY, but the body doesn't produce much / any 5aR2D, which converts testosterone into the more potent dihydrotestosterone (DHT). Born largely phenotypically female, but at puberty the testes descend, the voice deepens, the clitoris enlarges, and they undergo a relatively normal male puberty - leading to the nickname in the Dominican Republic (where it's most common) of "guevedoces" ("balls at twelve"). Despite being raised female, they typically identify as male, and - with medical assistance can sometimes father children.

Of course, in addition to primary sex characteristics you have secondary sex characteristics, developing at puberty due to whatever hormones the person is exposed to. E.g. one's larynx isn't taking a gander at what genitals one has - if it's exposed to testosterone, the voice will deepend, and if not it won't. Same with body hair, breast development, etc. E.g. male nipples aren't atavisms; they're just undeveloped tissues that never got the signal to develop. One is reminded of the scene in "Meet the Parents" where Greg, trying to impress his would-be father-in-law describes milking a cat, and says anything with nipples can be milked - to which the father in law replies, "I have nipples, Greg - can you milk me?" Except, yes, the answer to this is "yes" - expose his body to estrogen to develop the breasts, then to prolactin, and he'd lactate just like anyone else.

To loop back: we're all made of the same stuff.

Comment For anyone who cares about how it actually works.. (Score 3, Informative) 92

... as opposed to just random ignorant press fluff, here you go.

TL/DR: it's a gun that shoots fission plasma like little nuclear bombs. A 2,2kg projectile containing low-enriched uranium (LEU) and a moderator is fired (once per second) by a coilgun through a a flared 522kg 33cm-long LEU barrel (with the barrel flaring out in a HEU section at the base) at 1600 m/s (requiring 5MW of power), where it hits criticality. By a third of the way through the barrel its interior is already 1eV / 11605K, then is boosted to 500 eV by the HEU section as it leaves the barrel into a parabolic magnetic nozzle to direct the plasma. The fact that the projectiles move through in pulses makes it easier to cool the barrel, given that the thermal power present in the first third of the barrel is 5,4TW, and in the latter section, a peak of 46TW; obviously you're not going to withstand that continuously! 1% of the power from the explosion is recovered via coils, returning 29MW to the system, to power the gun and any other spacecraft needs. The result - 100kN of thrust at 5000 sec Isp, would be enough to lift 10 tonnes of mass from the surface of the Earth (not that you'd use it on the surface), and has a propellant efficiency 14x that of Starship's Raptor engines.

Obviously, this rocket is dirty, but almost everything from the explosion will have a velocity higher than the escape velocity of the solar system, so so long as you're not pointing it directly at Earth, it doesn't matter. Not that one engine firing in the direction of Earth would matter all that much anyway, but...

Comment Re:Neuralink's failures (Score 4, Informative) 84

You do realize that these tests are literally mandated by the FDA, right?

You do realize that the USDA, after investigating Neuralink, found no animal welfare breaches except for one 2019 incident, which was the result of the use of an FDA-approved surgical adhesive (bioglue) in a non-approved manner. Right?

You do realize that the FDA reviewed the results of the studies that they themselves mandated, and were satisfied with the results? Do you have any clue how long and difficult it is to get approval for new invasive treatments from the FDA? Medical startups live and die based on whether they can manage to convince the FDA to give them the go-ahead. A typical medical startup's stock shoots through the roof when the FDA grants approval, because it's such a difficult and uncertain process to convince them.

What do you actually know about primate research? Do you understand what a terminal procedure is? Do you understand the nature of how primates are shared between research labs, and they don't just miraculously become cured of whatever experiments were done on them last? Do you understand the fact that macaques in captivity frequently will attack and injure each other, and that these injuries don't just go away? Do you know what sort of histopathology is normal? Do you know literally anything about the topic at hand? Because I guarantee you, the USDA and FDA do.

Comment Re: Media (Score 1, Insightful) 84

That was a lovely game of "change the topic" you have there.

So to be clear, you're perfectly fine with people being being censored, for talking about issues related to their very existence, so long as, say, nazis can spout nazi crap without punishment.

Musk has banned his critics left and right, but you're fine with that so longer as you can make mean-spirited racist, sexist, and homophobic jokes and make as toxic of an environment as possible.

People get harassed left and right and Twitter does othing, but when it comes to Elon, suddenly it's a ban version of 10 Degrees of Kevin Bacon. For example, first ElonJet was banned. Then journalists who mentioned ElonJet getting banned were themselves banned. Then journalists who asked about the situation were banned. Then a journalist who didn't write anything on X but just reported on the ban in the news had his account on Twitter banned. Does this standard apply to literally anyone but Elon? Of course not.

Want to protest anything about Twitter or promote alternative platforms? Well, let's look at history. The leaders of the BlockTheBlue campaign, encouraging people to block blue checks to protest the new subscription policy, were suspended for "platform manipulation". Twitter has variously blocked or likewise reduced visibility of posts linking to competitors such as Substack, Mastodon, and Bluesky.

When Dorsey posted a defense of himself re: the Twitter files on Revue? Musk shut Revue down.

Musk complied with censorship requests from India and Turkey with zero pushback. Got the requests, immediately complied. The old Twitter - while not always succeeding - repeatedly pushed back against such requests. Pushback only ever happens when he feels it's the *right* being censored. In his first six months, Musk complied with 83% of requests from authoritarian regimes.

Musk is the king of censorship - unless he particularly likes what you have to say. He's also an egotistical manchild who boosted the visibility of his own posts in the algorithm and then at first tried to pretend he wasn't doing it.

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