This is a personal pet peeve of mine.
My story starts with a starliner entering orbit around a hypothetical planet in the Epsilon Eridani system and I have a question regarding that for everyone who might know more about near future spaceship engines than me with my limited KSP knowledge.
I know the maximum speed of an engine is equal to its exhaust velocity. But what about deceleration? Would it be possible for an engine with a lower exhaust velocity to slow down a spacecraft going at relativistic speeds?
The starliner in my story has a fusion torch engine capable of continous 1 g thrust and I'm aware that the specific impulse of fusion engines isn't high enough to reach near lightspeed. The ship reaches near lightspeed with the help of a solar laser pushing array. After an initial gravity assist and maybe a boost using its engine, the starliner uses its solar sails to ride the lightbeam from that solar laser array up to relativistic speeds. As solar sails use the push of photons, they have an effective "exhaust velocity" equal to the speed of light. Sure, the ship itself wouldn't reach that because of how physics work, but it could get close given enough time.
Epsilon Eridani is roughly 10.5 lightyears away from Sol, so there should be enough time to get some serious speed.
There isn't a solar laser array in the uninhabited Epsilon Eridani system of course, so to slow down it would need to use the fusion engine. With it having much more thrust than the solar sails, slowing down wouldn't take nearly as long as it took to accelerate. Given of course that it is even possible to slow down a craft going faster than an engine's exaust velocity using said engine.
There is also the possibility of using a detachable mirror to slow down such a laser sailor, but I think using an engine to slow down might be faster even though the spacecraft would be more massive as the turnaround point would be later in the flight and you could reach a higher speed. But maybe I'm wrong. Maybe the distance of 10.5 lightyears isn't even worth getting time dilation involved.
Does this weird solar highway sailor torchship hybrid make sense?
I couldn’t find any easily accessible information on this so I thought I’d ask you all. This question is assuming a straight track in an urban area.
Thank you all!
https://www.bloomberg.com/news/articles/2022-01-25/lumber-sinks-for-seventh-day-as-lofty-prices-cancel-home-builds
Lumber futures tumbled by the exchange limit to $1,053.70 per 1,000 board feet on the Chicago Mercantile Exchange on Tuesday, heading for their seventh-straight decline. That’s the longest slump since July. The pullback in the futures market may signal that soaring costs and transport bottlenecks will crimp demand.
Flooding in British Columbia disrupted supplies and shipments in late 2021 and now vaccine mandates that apply to truckers crossing the Canada-U.S. border are adding to transport woes, Taylor said. Markets in the eastern U.S. and northern California rely on trucks to deliver lumber from Canada, and a shortage of drivers may affect shipments there, he said.
An index of framing composite has more than tripled since late August, adding $20,000 to the price of an average new home, according to the National Association of Home Builders. Labor shortages and transportation woes have made it harder to get building supplies, prompting builders to delay or cancel projects, said David Logan, director of tax and trade policy analysis for the industry group.
“The starter home market has seemingly vanished,” Logan said by phone. “We’ve seen affordable housing projects canceled.”
https://www.nasdaq.com/market-activity/commodities/lbs
What goes up must also go down
https://www.enr.com/articles/53119-us-doubles-tariffs-on-canadian-softwood-lumber-contractors-expect-higher-prices
And of course, the bad decisions continue to hurt average Americans
The Biden administration's US Commerce Dept. on Nov. 24 followed through with expected anti-dumping and countervailing duties on Canadian softwood lumber producers, placing tariffs of 17.99% on their imports, more than twice the rate of 8.99% during the Trump administration.
"These unjustified duties harm Canadian communities, businesses, and workers," said Mary Ng, Canada's minister of international trade, in a sharply worded statement. "They are also a tax on U.S. consumers, raising the costs of housing, renovations, and rentals at a time when housing affordability is already a significant concern for many."
"The U.S. Lumber Coalition strongly urges the administration to continue full trade law enforcement," said Jason Brochu, chairman of the U.S. Lumber Coalition and co-president of Pleasant River Lumber Co. "More U.S. lumber being produced in America to meet domestic demand is a direct res
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You can see in this clip from Season 5 Episode 7 (at 38s), when the Zmeya fires torpedos at the Rocinante, they're pointed towards the Zmeya, with the engines at the back towards the Rocinante. Why is that, doesn't that make them slower and easier for the Rocinante's PDCs to hit?
I would've thought that they'd want to accelerate towards the Rocinante, not decelerate away from it.
the scooter 50cc i have is Ice Bear and its having issues in second month after buying it only 1500 miles on it. the scooter has starting trouble so i need to kick start and it starts then. thes issue is after starting the accelerator is on full throttle and wont decelerate. only way i can stop the scooter is by turning it off, which again is a pain because of kick start. does anyone here knows how to fix the acceleration issue. the oil has been changed twice and after the recent oil change i am having this trouble.
If the minecart is standing still, the rocket will behave as normal.
If the minecart is in motion, then the angle you're facing determines what happens.
If your viewpoint is at an angle less than 90 degrees from the direction of travel, the rocket will cause the minecart to speed up. (I'd prefer it accelerate all the way to Elytra flight speeds, but I doubt the game makers will go for that.)
If your viewpoint is at an angle 90 degrees or greater off the direction of travel, the rocket will cause the minecart to slow down, stop, or jerk the opposite direction depending on the initial forward speed.
This will give rockets a pre-End use for transportation purposes without making rail travel too competitive with Elytra, because the same rockets can be used for both.
Nor does this damage the "specialness" of Elytra, because Elytra is still the only method of air travel that exists in the game.
Is it just me , I can virtually floor it down there confident than I am going to brake in time to turn - yet Druid’s corner has my arse going like the mouth of a goldfish and I have to nurse and plead with the car to stay fixed ? It’s not , as I can tell , anywhere near as steep of a gradient ?
I’m driving a 2001 VW polo 1.9 TDI variant that I think is cool af and fun to drive and want to keep it going as long as possible.
I have no idea why phantom braking is so hard to solve for this car, but it's just so incredibly unsafe and will cause major accidents.
I've had a Model 3 for about 10 months. My old car is a 2018 Honda CRV. The CRV's cruise control works great, other than following way too far behind another car, but it has never had phantom braking issues.
The 2 times I've driven my Model 3 on the interstate since the pandemic started, I had multiple instances of abrupt and jarring phantom braking, always near overpasses or off-ramps. It went from 75 to 55 and scared the hell out of me and my girlfriend.
It's not okay. I want to talk to Tesla about this. Has there been improvements in software? Do I need to hard-reboot the car to get the new updates to fully sink in? What can I do to minimize this?
So I know this guy who started drumming about 3-4 years ago, more or less, and he’s got natural talent but lacks in discipline. Just things like speeding up or slowing down a song, trying to do things out of his element (mostly the flashy fills), or he just gets nervous on things I’ve seen him do before (like easy but effective drum fills). I’ve told him to practice rudiments with a metronome, and also listen to certain songs but I think he just gets tunnel vision…what do you guys suggest?
Can somebody please help me with this problem? I’m stuck on my physics homework. 😔
I had to fix my key binding and it doesn't work anymore.
Ignoring for a moment how it got to that speed in the first place, what would it look like to decelerate from light speed down to where relativistic effects stop. There's a lot of discussion about the difficulties of getting to light speed but I'm wondering about what happens the other end, when you've reached the target star system and hit the proverbial brakes.
A ship about the size of the Millenium Falcon drops out of hyperspace into our solar system about 5au away from the sun. It's travelling just under the speed of light and rapidly decelerating to a stop over the next X hours (1? 5? 50?) thankfully there's an inertial dampner engaged that prevents G-Forces killing everyone on board. Lets say there's busy commerce in system but no one is going faster than 0.1c, this ship is the only one going fast enough for relativity to matter as it decelerates from 0.999c
What would the relativistic effects be like for the crew? IIRC an external observer (a ship watching them arrive) would observe time passing much slower for the incoming ship. Then from their perspective looking out, would it seem like the cargo vessels outside were moving around much faster?
If the ship that just entered the system is 9x the speed of the ships already present then it's a major advantage but that's not much use if your reaction times are glacial due to relativistic effects. Your reaction times would also be garbage just because it's a confusing sensory overload of ships you know to be slow are seeming to zip about. Unless you hand over control to an AI when leaving FTL because humans can't think fast enough?
I just got a new ship for mining and I tried to go further into the asteroid belt to find and mine bigger asteroids and when I got around 50km away from the origin station I just started slowing down eventually to a stop, once I got to 51 km away I couldn't move further away, only turn around and head back.
I need some advice on my 2012 impala as you can see the title it shakes at 40 and 60 sometimes then stops after I slow down or accelerate. I’ve literally changed almost everything, all wheel bearings,all shocks, inner and outer tie rods, cv axles, stabilizer links, rear lateral arms, brakes and rotors, and control arms and tires and had a alignment and balance not sure if the transmission to cv axles can cause this or the rack and pinion being out?
