Vishnej
Vishnej t1_j5xtv5k wrote
Reply to Why do sample return missions such as OSIRIS-REx use their own reentry vehicles instead of just going to the space station for pickup and return with ISS equipment? by PromptCritical725
Reentry is easy; You just plop right into the atmosphere & ocean, barely any work needed. Getting to the ISS' orbit is hard; Coming in from interplanetary space, you're looking at >4000m/s adjustment that needs to be made to reach orbit. Making it using fuel requires several times your probe's weight in propellant, and making it using aerocapture / aerobraking requires basically the same heat shield as when you do reentry (slightly thicker), but with high-precision orbital windows that need to be hit very precisely to make the rendezvous, involving likely hundreds of m/s dV capability since those windows are transient solutions of a dynamic thermosphere.
Edit: While technical specs are always hard to find, one is left to believe that rather dramatic increases in capability per mass of heat shield material have occurred since the Shuttle program and then under SpaceX.
Vishnej t1_j2hkhvj wrote
Reply to comment by village_aapiser in can someone explain the difference between quantum computing and classic computing in simpler words? how can quantum computing benefit us from a consumer perspective? by village_aapiser
Poorly.
Slowly.
At extreme low temperatures, where thermal energy and electrical charge behave a bit differently.
>Several hardware companies, such as Google, Honeywell, IBM, and Intel, have built gate model quantum computers, that are now available in the marketplace. These devices must function at very low temperatures, and require expensive refrigeration technology. It turns out that it is very challenging to build reliable qubits, and very difficult to incorporate them into chips. All of these companies are presently working to scale up their machines.
It has been a largely theoretical math-physics construct for much of its existence, first proposed 1980 & 1981. Every time it goes another step further into being physically realized, people celebrate, but we're still in the 1940's or earlier as far as the progress of conventional digital computing.
A quantum computing algorithm is a highly specialized arrangement of hardware, and the unit parts don't rapidly generalize to other tasks like digital computing does. Only certain tasks are amenable at all to quantum algorithms being developed for them. If we can find one task ("Solving a specific encryption algorithm with a specific number of bits key length") that it's well-suited for, we could in theory do it incomparably faster than digital computers ever could (eg "Solve the puzzle in 2^64 guesses instead of 2^128 guesses, which would take longer than the universe has existed"). This point, where it's indisputable that quantum computing is faster for a specific task, is termed "quantum supremacy", and it's part of proving that you have a working quantum computer, whatever's inside the black box. We're starting to get to the point where quantum supremacy is arguably relevant for real physical devices, though not yet to the point that it's reshaping our world for even one practical computing task. As far as I can tell, everyone expects that first task to be breaking conventional encryption algorithms, which will then give way to post-quantum encryption algorithms which work by principles that quantum algorithms can't be applied as well to.
Vishnej t1_j0gjmth wrote
Reply to Why FTL travel seems impossible to me from a practical standpoint. Insight requested. by JerryWasARaceCarDrvr
This level of uncertainty doesn't require FTL, only a lack of faster-than-you communications. When you crossed the Atlantic in the early 1800's to visit an ailing grandparent, you didn't know if they'd, say, die during your trip, until you got there. Or if they'd moved to another city with a better hospital.
There are scenarios that are specific to FTL information transmission though; If we believe FTL is possible, under our current model of relativity we have to believe that FTL messages can travel backwards to earlier on our timeline, breaking observed causality:
https://en.wikipedia.org/wiki/Tachyonic_antitelephone#Numerical_example_with_two-way_communication
Vishnej t1_j9te3ew wrote
Reply to The way your BF/GF speaks to his/her mom/dad will be the very similar to the way he speaks to you in marriage. by stepneo1
This is the kind of thing you can only believe if you were raised in a happy functional emotionally stable family.
I was terrified my girlfriend would believe this, when she saw me scream at the top of my lungs at my BPD mother who was prying into our relationship attempting to find weak points. I had to put up that performative rage to try and set some boundaries she would respect in a language that would shock her out of her jealousy at not being the center of attention. I needed to posture this way before she poisoned me and my GF's relationship like my mother has poisoned every relationship with every friend and coworker and family member she's ever had. She's got a twin sister and they've been in a no-contact status on and off dozens of times now.
Abusive, emotionally manipulative parents have installed certain triggers, shortcuts, and routines in their parent-child relationship over the years that a partner probably has no understanding of. Seeing something like the onramp to an entitled tantrum, tears, and forced appeal for sympathy coming a mile off, requires either sitting through that episode with the partner, or taking off, dropping some F-bombs, and cratering the road from altitude.
Some of us have to structure a lot of our behavior around remaining emotionally intact and never adopting the relationship dynamics of our parents. That doesn't mean it's possible to treat them like we treat everyone else. Doing that would have required becoming estranged many times over.