HNHacker News
TopNewBestAskShowJobs

spacemark

584 karma · joined January 16, 2020

Mechanical Engineer in the aerospace industry.

Side gig: https://nyxtech.us/

nyxtech.us@gmail.com

submissionscomments
spacemark··on Priced out of home ownership
If you take all the money that you have spent on a down payment, closing and selling costs, taxes, and maintenance, subtract rent, and put the remainder in a market index fund, for the vast majority of situations you will have FAR more money by retirement. Like it's not even close.

I guess I'm just a bit tired of the messaging that real estate is such a great financial investment. Historically it's better than a lot of options but not even close to the best investment vehicle. Houses are homes first, not money makers, and if we continue to emphasize the latter, we will never solve the housing affordability crisis.

spacemark··on Priced out of home ownership
Higher returns than what though? It sure sounds like the only financial advantage to owning a home vs other investments is the leverage. Yet the S&P will return far more even considering the 80% leverage in most cases.
spacemark··on Priced out of home ownership
Right, my question is more about how the average person can actually use that leverage. So you've got $80k in leverage, it grows (presumably), but how do you actually use it?

You have to sell the house, right? So you can only cash in on that leverage when you reverse mortgage or otherwise downsize, right?

spacemark··on Priced out of home ownership
I agree with a lot of what you are saying, but to say it is easier to buy a home now than at any time in the past is objectively untrue. Yes, houses today are much better than 50 years ago, but the cost to entry has gone up faster than salaries. When my parents bought their first home, the median salary-to-home cost ratio was roughly 1:1. It is closer to 1:6 today. Yes homes are more valuable today, but they are also objectively more difficult to purchase.
spacemark··on Priced out of home ownership
People always talk about how buying a home is the only way for the common person to obtain leverage. Please excuse my ignorance, but how does the common person use that leverage, exactly?
spacemark··on Reentry of International Space Station Batteries into Earth's Atmosphere
Not even remotely possible in a practical sense, for so many reasons. Summed up by it wasn't designed for it. Radiation, fuel consumption required for the delta V, supply vehicle capabilities, generation of space debris, regulatory compliance, design lifetime, etc.

If it was practical, they'd be doing it instead of Artemis.

spacemark··on Study: 61 UK firms tried a 4-day workweek and after a year, they still love it
Screwed in a monetary sense, perhaps. But this is just one thing people gain from work. For some it's not even that important.
spacemark··on On Alcohol
Just do a google scholar search for "marijuana lung damage" or similar and you will find that there is no clear evidence (yet) for correlation between consumption and lung cancer. There is convincing evidence for significant effects related to inhaling smoke - all the usual ones you'll also find with elevated PM2.5 levels such as emphysema, asthma, chronic cough, bronchial inflammation, etc.

You will find disturbing (and growing) evidence linking marijuana use and heart health. Turns out regularly raising your heart rate and dropping blood pressure increases a host of risks for those susceptible to cardiac issues. On the order of 30% more risk for daily smokers.

No doubt inhaling smoke is bad for you, but vaping a couple of times a week is definitely in the noise. You likely have more lung damage and risk to your heart from cooking food in your kitchen without proper ventilation (virtually 90% of homes). If you're smoking a joint a day then the scientific data should give you pause, assuming you're optimizing your life choices for health.

Back to my original point - the equivalent to a joint a day would be several glasses of alcohol a day, and the health impacts are not even comparable (alcohol consumption is far worse overall).

spacemark··on On Alcohol
I see a study or an article along these lines every couple of months:

https://www.healthline.com/nutrition/benefits-of-wine

spacemark··on On Alcohol
Alcohol is hands down terrible for the body. I'm becoming more and more convinced from scientific studies and my own observations that no amount, not even one glass of wine a night, is physically beneficial.

It's the psychological benefits outlined here that are much harder to persuade away - mediator of anxiety, social lubricant, escape into a little bit of fun. Nonetheless, for me, the physical toll is just not worth it anymore.

Marijuana is even more difficult to dissuade. There is a physical toll to excessive smoking, but it's much less pronounced than alcohol, and seems largely non-existent when consumed in moderation, the equivalent of a glass of wine a day. The only inarguable cost is the time one isn't sober and able to be socially/economically/physically productive.

Nonetheless this loss of time, too, seems more and more valuable to me, and my marijuana intake is naturally declining.

As time goes on the statistics on alcohol consumption and substance addiction make more and more sense to me: a third of Americans don't drink AT ALL, most drink less than a glass a week, and most drug addicts naturally quit without intervention. Most of us come to the truth eventually, it seems.

spacemark··on Stress reduction techniques for high stress operations (2023)
Interesting observation, there may be some truth to it!!

A while back I read a really interesting Reddit comment by someone researching PTSD in ancient history. Here it is

https://www.reddit.com/r/AskHistorians/comments/1j6ssm/comme...

spacemark··on Rumors Circulating That James Webb Has Discovered Life on Another World
Google Earth resolution? You'd need satellites in low orbit around that planet.

For taking images from earth, the resolution would depend on the size and distance of the planet. Within a couple hundred light-years a $10b starshade spacecraft may be able to get a 30px by 30px optical image.

The physics are pretty limiting.

(this is all from memory, I worked as an engineer at an astrophysics institute for 8 yrs, but left that job almost two years ago, so the raw numbers are a bit rusty)

spacemark··on Is my plane a 737 MAX?
Not sure what your comment really adds except a thinly veiled attack on my ability to empathize. Of course reasonable people desire increased safety all around. My point is that even with this disaster (in which nobody was harmed), aviation safety is the best it's ever been and is continuing to improve.

Again, I'm not saying we shouldn't be concerned about ways to improve or hold Boeing accountable. But it's not a rational reaction to stop flying due to this incident.

spacemark··on Is my plane a 737 MAX?
Agreed! You don't see the data because it's not there. That was my point in response to the original comment - even with these dramatic high-profile examples, not only is commercial aviation orders of magnitude safer vs traveling by car, but it continues to improve. Meanwhile traffic safety has stagnated and by some metrics is getting worse.
spacemark··on Is my plane a 737 MAX?
All valid points, but I wonder if you've overshot your response to this (very slight) increase of risk to your personal safety.

The statistical safety of aviation is the best it has ever been - 2023 set yet another record low for commercial aviation deaths and injuries. Your automobile trip to the grocery store is far riskier.

spacemark··on Wikipedia daily most viewed pages
Does the Google info sidebar ping Wikipedia every time "YouTube" is queried? Would that show up in these statistics?
spacemark··on The extremely large telescope will transform astronomy
Ever is a very long time.
spacemark··on It will never be a good time to buy a house
Of course, if rates are low and money is cheap, max out the loan. But one of the key points of the article was that interest rates are not going to fall for a long time and when they do, house prices will resume their ascent.
spacemark··on It will never be a good time to buy a house
I hear you, it's not a good place to be in (I've been renting my whole adult life). If people can't or are unwilling to swallow that bitter pill, perhaps major shifts are coming.
spacemark··on It will never be a good time to buy a house
The only sensible financial reaction is to save, save, save for a down payment well in excess of 20%. Just an extra 5% will save you roughly $150k On a 600k home over the course of a 30-yr 6.9% mortgage (the current rate).

Problem is that most people will never be able to achieve this - the average down payment for first home buyers is less than 10%.

Truly hate to say it but people will need to get used to buying homes much later in life.

spacemark··on The $1.5T Nuclear Weapons Program You've Never Heard Of
>there just isn't that many large ones to hit.

Maybe not here in the US - we only have 10 cities with more than 1 million people. But China has 145 cities >1m. We would not be a threat to their industrial base with only a dozen nukes.

Yes, a dozen nukes would cause many billions, perhaps even trillions in damage and horrific loss of life, but China would still have 125 other cities to keep their war machine moving. Deterrence through countervalue threats is great, but once that trigger has been pulled you still have the rest of the war to fight.

No need to be condescending, by the way.

spacemark··on The $1.5T Nuclear Weapons Program You've Never Heard Of
Sure, I didn't intend to downplay the seriousness of nuclear war. It would be horrific and damaging to an extent never seen before.

My point was just that the logic of having only a few nukes while everyone else has many more doesn't work. China has 145 cities that have more than 1 million people. You wouldn't be a serious threat to their industrial base with only a few nukes, and so the effect of your deterrence would be minimal.

spacemark··on The $1.5T Nuclear Weapons Program You've Never Heard Of
I think you overestimate the power of a nuclear weapon, or even dozens of them. It would take hundreds of targeted strikes to disable a nuclear-armed adversary. Having fewer nuclear weapons only means your major cities, military bases, and industrial assets will be leveled while the majority of your adversary's capabilities remain intact.
spacemark··on Loneliness is stronger when not alone
Count yourself lucky then. I was raised religious and even did a mission, visiting many dozens of congregations over my time of activity and yes there were plenty of things great about it but there was a ton of sexism, racism, homophobia, and gaslighting about what is real and what is not. Some of which took more than a decade to filter out of my psyche.

Glad you're having a great experience, don't assume it's remotely representative.

spacemark··on Electricity from Space: The 1970s DOE/NASA Solar Power Satellite Studies
It drives electrical and battery system requirements more than anything else. Thermal effects impact pointing/ADCS, which impacts propulsion, etc.
spacemark··on Electricity from Space: The 1970s DOE/NASA Solar Power Satellite Studies
Respectfully, you are not correct that eclipse in Geo is insignificant. It drives many engineering constraints for spacecraft systems. Look I get why people are excited about space space solar power, but I've been in this industry for 15 years and when you dig into the numbers and understand the realities of spacecraft engineering, SBSP just seems like a fool's errand. It may not always be that way, but the technical challenges are extreme and costs are still nowhere near what would be required to make it work.

You can chalk my comments up to a grumpy engineer tired of the cyclical SBSP pushes that never go anywhere.

spacemark··on Electricity from Space: The 1970s DOE/NASA Solar Power Satellite Studies
No night? Where are you putting these satellites? The only orbit that doesn't eclipse is sun synchronous, an already crowded orbit. Even GEO satellites experience eclipse.
spacemark··on Starship Flight Test (Launch in 1 hour)
That's really not how engineering tests work - the objectives of the test were met, by definition that's a success. Not achieving stretch goals doesn't make it a failure.

Of course it's a work in progress and the launcher is unproven. But damn, that was an amazing first attempt. With more vehicles already in integration, I have little doubt they'll eventually nail this.

spacemark··on Chinese surveillance balloon spotted over U.S., Pentagon says
Ten bucks says they've already taken non-kinetic action. Jamming, optical lasers, etc.
spacemark··on Why was Roman concrete so durable?
I agree with the spirit of what you're saying but you go too far, ironically asserting without any supporting logic that the intelligence of homo sapiens has remained static for the last 2,000 years. But I suppose the disagreement hinges on what is meant by intelligence.

Here's a thought experiment: if you removed all technology (tools, writing, vast stores of knowledge) from a human child and raised them in this vacuum, would they be more or less intelligent? Would they understand their place in the solar system and the structure of the cosmos? Would they know how to protect themselves from sickness (germ theory)? Would their vocabulary and ability to express themselves be less or more?

Of course these questions don't have definitive answers and you can play the game the other way, arguing that modern humans would die in a couple weeks if transported back to caveman times.

But it's a poor model to view intelligence as some static property independent of technology, environment, gene mutation, sexual selection and all the other strings in the web of existence.

← PreviousPage 2 of 6Next →