Comments by "seneca983" (@seneca983) on "Scott Manley" channel.

  1.  @Flumphinator  什么！
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  2.  @Firebert79TA  But I see no evidence that they have ignored such factor. How do you know that they haven't calculated how far that thing can be scaled? Secondly, the scaling issue here isn't as bad as you make it out to be. For a given launch speed a larger device would need a lower rpm and thus can scale up the payload linearly without increasing the centrifugal force caused by the payload.
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  3. Also note that it went southwest (according to Scott). In Finnish, "southwest" and "lunch" are both "lounas".
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  4. Maybe we could lift rockets high into the atmosphere using large balloons?
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  5. How so?
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  6. Any idea how the rebalancing would work? It kind of looked like there was another hatch (without a tube) to throw a counterweight down to the ground but I might be imagining it as that sounds a bit dangerous. However, I can't think of another way to do it.
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  7. I think you misunderstand. The rebalancing that Scott talked about isn't for payloads of different weight but rather for the sudden change in weight felt by the device when the payload is released. Standardization won't help with that.
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  8. Normal rockets also impose acceleration resilience requirements. Also, they introduce a lot of vibration which might be less of a problem with this thing.
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  9. "This thing is an absurdity that can only be justified in a low gravity, low or zero atmosphere situation" How so?
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  10. He already mentioned why railguns might not be easier. Also, a railgun that long would get expensive.
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  11. What would be the benefit?
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  12.  @yaroslavsobolev6868  Thanks for the info.
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  13. I'm not as pessimistic. A larger device would need a lower rpm for a given launch velocity which somewhat offsets the other problems with scaling it up.
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  14.  @nomadicgrenada  "there's a physical limit on the materials we have available" But I still think scaling this down would be more difficult than scaling it up because a small device would require much higher rpm. "any small faliure would be catastrophic" Possibly, but that's not inherently unsolvable. It's not inconceivable that the likelihood of a failure could be brought sufficiently low (though I'm not sure how difficult that would be).
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  15. "The cost of building, integrating, fueling and launching a multi-stage launch vehicle is still much much less than building, integrating and launching a vehicle using that big salad spinner." How do you know?
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  16. "Most of all the energy electricity in the world is produced by fossil fuels in order to run one of these slingshots or whatever would take up so much energy that you might as well forget the plan because your burning more coal and fossil fuels" Rocket fuel also has the same issue but way worse. Rocket engines are less efficient and you also have to consume fuel to move enough fuel with the rocket.
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  17. Maybe the release the clamps at slightly different times to compensate.
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  18. Is there any other country that could plausibly do an anti-satellite weapon test? Can we expect this to be the last one assuming no country does repeat tests?
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  19.  @gchampi2  "Dumping an equivalent weight into the ground would create a pretty massive explosion, possibly into the kiloton range" (EDIT: Fixed the speed.) Not even close. If the weight is 1,000 kg and goes at 10 km/s its kinetic energy would be equivalent to about 0.01 kilotons.
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  20.  @gchampi2  "I think you meant 1,000m/s" Actually I meant 10 km/s (which is close to escape velocity). I've edited my comment accordingly. With this speed I think my calculation is correct though I can't be bothered to check it. At least the order of magnitude comports roughly with your calculation.
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  21.  @gchampi2  "59 tons of blam going off next to a phenomenally expensive and highly energetic YEET! system still seems a bad idea" Maybe they could throw the counterweight down a borehole; maybe it could be filled with water to dissipate the energy gradually. One possibility would also be to have the counterweight be closer to the axis of rotation so it would have a lower velocity. It would then need to be heavier but its kinetic energy would still be reduced.
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  22.  @gchampi2  "Not quite. Yes, you'd have a heavier object traveling at a slower speed, but the kinetic energy would stay the same. Newton's 3rd law's a thing." You're mistaken. If the counterweight would have, say, half the distance to the axis of rotation it would have half the velocity and would need to have twice the mass. The formula for kinetic energy is m*v²/2 which means that when you half the velocity and double the mass then the kinetic energy would be halved because it's dependence on velocity is quadratic but on mass only linear. The momentum of the counterweight would be the same but not the energy.
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  23. But in this case the payload travels the same circumference multiple times so the distance travelled during gradual acceleration can be very large without the device being large.
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  24. OK, I saw your comment (partially) in my notifications even though it seems you removed it and I want to respond. You're right that this device needs to provide high centripetal acceleration considering the high launch velocity and relatively small radius. However, this is a bit different from launching a rocket from some kind of linear accelerating device. That kind of linear device would need to either provide very high acceleration, which is difficult, or be very long. For this device the angular acceleration can be much gentler without the device being large. As you mentioned the centripetal acceleration is much higher but it's essentially provided by the structural integrity of the rotating arm and not (directly) by a motor so it's much easier to achieve.
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  25.  @mytech6779  "The the projectile is subjected to massive acceleration based only on the radius and release velocity." I see no reason why the projectile couldn't withstand that. Scott addressed that issue in the video. Furthermore, the projectile would likely be subjected to less vibration than in a conventional rocket. "The issue is that such a device cannot achieve anywhere near orbital release velocity, especially when air resistance is considered." Based on the figures given in this video "anywhere near" is an exaggeration. A rocket is still needed but it needs far less fuel relative to the payload so efficiency is much improved (potentially, if this thing works).
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  26. Out of curiosity, is the right side of the video thumbnail AI generated?
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  27. "when the arm releases the payload, when it releases, the arm will just stop in place, transferring all his momentum/kinetic energy to the rocket" That doesn't work. Trebuchets have a sling; this thing doesn't.
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  28.  @sirnikkel6746  My initial guess is that they'd have a counterweight that they'll throw down at the same time they throw the payload up. It's just a guess, though.
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  29. I think the railgun would either need to have much higher acceleration which is difficult or the railgun would need to be exceedingly long making it rather expensive.
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  30.  @rgarito  They need a very accurate release in any case.
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