The cars would travel at up to 200kph and arrive at the space station eight days after departure from Earth.
These early cable experiments are important, but someone should also be working on the composing an 8 day Elevator Muzak score that won't drive you insane.
Enforcement might get interesting since jurisdiction will be a question. The RIAA and MPAA will probably be the first two organizations to have extra-planetary legal claims.
At more than 13g I'm not sure that, "a new day will dawn for those who stand long, and the forests will echo with laughter"... after experiencing that.
3.4x10^7/(500)^2 = a m/sec2
For an 8min20sec flip time. 20+g if you really want the 8min.
Yes, but it's a completely different market from folks desiring a space elevator.
Also, it makes the need for muzak nonexistant because all your passengers are dead and can't hear it anyway. Seems to me that defeats the purpose of trying to time the trip to coincide with the length of a particular song.
You'd need to accelerate at 68 G's[0] (foreward for the first four minutes, backward for the last four). Not neccesarily unsurvivable, but your passengers (and most cargo) are likely to be unpleasantly pastelike.
We should probably treat it more like commercial air travel than compressive-structure elevator rides.
Brief search didn't get me anything about longest ride on a centrifuge, which I guess would be the only way to test G-tolerance over extended periods. Where 'extended periods' means > an hour.
Any pointers to 6 Gs as being tolerable, for how long? Tnx.
I don't think 68 Gs is survivable at all. At least not for more than a fraction of a second. 46 Gs for a few seconds is the most a human has survived that we know of.
I assume the author meant km/h or 200 km per hour as you have guessed, and if the satellite it 36000km high / 200km it would take 180 hours or 7.5 days.
Music? The first four days will be safety announcements. The last four will be debates as to who is responsable for cleaning up all the vomit. A week of near-zero-g in a room with 30 people will not be fun.
You are moving from ground (1g) to geostationary orbit at zero. It will be a slow progression from one to the other (with a very slight lateral acceleration) but imho once below .5g anyone who is going to get air/sea/space sick wont see much difference.
Most humor can be categorized as "insubstantive comments" and those are discouraged.
It is possible to crack a joke here and get it upvoted, but it's hard to pull it off. I even once had a joke upvoted by quite a lot,* like 50 points or something, but most jokes are downvoted not because humor is forbidden, but because insubstantive comments are discouraged.
Some humor is downvoted for being uncivil because a lot of humor is basically poking fun at people or mocking them. A lot of humor is not nice at all. HN tries to meet a very high bar for civility.
I posted a joke a couple of days ago about "the Xzibit pattern" which ended up at 10 points, but it fluctuated a lot so it probably got something like 40 up 30 down. Would be interesting to see the breakdown of votes on HN.
I'm just glad you can't see the # of votes here for other comments. Helps prevent bandwagonning, though that still happens for downvotes once the css kicks in.
Well said. That's about as succinct a sum-up as I've heard. This might actually belong in the FAQ as it might save some folks a bit of confusing cultural acclimation upon arriving at HN from parts distant such as reddit or slashdot (is that still a thing?).
At any rate, way better than "harumph! HN hates fun!"
But if you note my "joke" actually illustrated a point of physics about which at least one person was confused: the expected g-forces. So it wasnt insubstantive, certainly not as insubstantive as the parent comment about elevator music.
No, it’s not against the rules, but downvotes aren’t there to enforce the rules.
It’s just a culture thing. HN tends to be more news and factually focused than reddit/Twitter/etc. People here just prefer to stay on topic, especially since humor is very different between people and can be very hit or miss.
yup, coming here and the top comment actually being something insightful or some point worthy of discussion instead of some sarcastic comment or joke like elsewhere is what makes this place.
Weird to me that they aren't accelerating till the midpoint and then breaking till the destination at a constant 1g. Gets around the space sickness by providing artificial gravity and should take ~hours rather than ~days.
Just for a bit of fun perspective, that’s 7 km/s faster than reentry velocity! Even if you felt like dealing with the heat, it would cost an ungodly amount of energy which kind of defeats the point of an elevator. On the other hand, you could ignore radiation shielding if the trip is short enough? Not worth the trade off I think.
Not sure if this would work, but how about using a wire with evenly-spaced metal beads, then using a magnet (a large one like used in MRI machines) to pull up the cart? You'll probably have to turn the magnet on/off at a specific frequency, depending on the momentum of the cart, which could be a challenge.
If you want constant acceleration, you need to maintain constant force. A higher-velocity vehicle applies that force across a greater distance per unit time, and therefore requires more power.
Accelerating 1 metric ton at 1g requires 9800 N. So at peak velocity (18 km/s), that's 180 megawatts per ton, which is more than 700 times the power to mass ratio of a Tesla P100D.
Surely friction is an issue at much faster speeds? I guess the fastest trains go 400+ KPH, with the fastest being maglev. I assume, though can't tell from the article, that the space elevator has physical contact with the cable, and I can't think of how one could reproduce maglev tech when going vertically.
So, there's surely a safe speed limit built into the materials being used? It's probably faster than the speed they're starting out with, but I kinda assume it can't be fast enough to shorten the trip to hours from days.
As an aside, moving people is probably not the most profitable use of the thing for the foreseeable future, as cool as that sounds. Getting a satellite into orbit for a tenth the cost is revolutionary (though they mention the cost compared to the shuttle, which is much more expensive than rocket transport...so they may be cherry-picking numbers to make this seem more revolutionary than it is).
Anyway, I can't think of how they could accelerate much beyond the fastest non-maglev train speeds without tearing apart the cable and car, but I may be underestimating the strength of carbon nanotubes, and whatever other component materials they're using. Perhaps there's a materials nerd here who knows.
Because it would require you to reach an improbably high velocity (especially for pulling yourself up a cable)--and you'd do so relatively quickly using an improbably large amount of energy in the process.
These early cable experiments are important, but someone should also be working on the composing an 8 day Elevator Muzak score that won't drive you insane.