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Rob Watts

 Discussion on question by Aaargh Zomb…

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Rob Watts
Nov 24, 2022 20:57
@WeatherVane I think it's much more likely that William Cooper and William English just made it up.
Rob Watts
Nov 24, 2022 20:57
@WeatherVane according to the link, Lovette was the abuctee and Cunningham was the witness
Rob Watts
Nov 24, 2022 20:57
Of note, the claims are centered around "Air Force sergeant Jonathan P. Lovette" and "Major William Cunningham". Shouldn't it be possible to verify if two people by those names were serving in the US Military in March 1956?
 

 Discussion on answer by Oddthinking: …

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Rob Watts
Oct 14, 2021 11:00
@Shadur the Snopes link mentions that at least one real race between Cheetahs and Greyhounds has happened. It's not that you can't get a Cheetah to run in a race, but rather that for this picture they didn't even want it to run.
 

 Discussion on question by JonathanRee…

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Rob Watts
Aug 31, 2021 13:48
This seems like an engineering/manufacturing processes question disguised as a skeptics question. A good answer would be one that actually answers "how is a car seat's expiration date determined/what does it actually mean?", which is off topic here.
 

 Discussion on question by Christian: …

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Rob Watts
Jun 24, 2021 07:56
contagionlive.com/view/… looks like a good starting point if anyone wants to use it as part of their answer
Rob Watts
Jun 24, 2021 07:56
@LangLаngС I think the basic idea is that the vaccines are targeted against a part of the virus that is very hard for it to change, while natural infection doesn't have that specific targeting. So immune escape vs natural infection requires changing easy-to-change aspects of the virus, while immune escape vs vaccine requires changing a hard-to-change aspect.
Rob Watts
Jun 24, 2021 07:56
One possible benefit is against variants. I've read that the vaccines provide decent immunity against the COVID variants that have been seen so far, but haven't ever seen solid numbers or comparisons to the level of protection from a previous COVID infection.
 

 Discussion on answer by Rob Watts: Do…

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Rob Watts
Apr 18, 2021 16:42
@eirikdaude that's one of the sources I've used in my answer. I chose not to mention the bounty because the number of interactions with the article doesn't give me confidence that anyone has even tried to accept the challenge.
Rob Watts
Apr 18, 2021 16:42
@henning--reinstateMonica I think you're right that the size of a counteroffer probably does make a difference in how often it's accepted, but that's a tangent for this question. Yes, a study that doesn't take it into account won't be as useful as one that does, but the study could still hypothetically exist. It just doesn't.
Rob Watts
Apr 18, 2021 16:42
@l0b0 in case you didn't click through to the link, I'd suggest reading the jobtipsforgeeks article - it talks about how recruiters are incentivized to discourage people from accepting counteroffers. Many recruiters would probably still use the number and maybe just change how they phrase it to "people in the industry say..." so that what they're saying is still technically true.
 

 Discussion on question by user69268: …

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Rob Watts
Mar 18, 2021 03:55
How much of a time gap do you want between each nuke? If the gap is too short, then a nuke (or the EMP it produces) could fry the firing mechanism of the subsequent one. If you want to avoid that, then for the purposes of this question you could just state that the gap is long enough.
 

 Discussion on question by Alendyias: …

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Rob Watts
Feb 26, 2021 14:58
It might be helpful to answer a few basic questions about the plops - how fast do they move? How intelligent are they? Are there naturally hordes, or are you just assuming that the conditions of a medieval village will result in hordes? Unless they only recently showed up, you can expect that everyone is used to them and will have developed habits for dealing with them.
 

 Discussion on answer by Alexander: Du…

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Rob Watts
Feb 5, 2021 13:36
The big problem with this would actually be if multiple people fall in. If they don't fall in together, they could easily crash into each other at high speed. The windspeed could (and needs to) easily take care of itself - have it be ~200 mph right by the fan, and design the shaft so the airflow will be stopped by the time it reaches the top (the air jets pushing people away from the edges might be enough to accomplish that).
 

 Discussion on answer by Daron: Can we…

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Rob Watts
Jan 25, 2021 17:35
#3 is essentially the Hygiene Hypothesis, but the immune system doesn't get weaker just more prone to mistakes (allergies). #2 is probably more important than people realize - many serious diseases (including COVID-19) originated from animals.
 

 Discussion on question by Enthus3d: '…

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Rob Watts
Sep 21, 2020 17:49
FYI it's a bad idea if the speed bump can be detected from a distance
 

 Discussion on answer by Radovan Garab…

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Rob Watts
Jul 10, 2020 12:54
This doesn't seem right to me - if you converted the 1 kg of matter into antimatter and it then fully annihilated with matter around it, that would release 2kg*c^2 = 1.8e17 J of energy, which is less than the yield of the Tsar Bomba, which didn't come anywhere near destroying the earth. How could just the electrons somehow release significantly more energy than actually turning them into antimatter?
 

 Discussion on answer by Ruadhan: Logi…

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Rob Watts
Mar 12, 2020 06:53
@computercarguy that still doesn't work - the ship and the payload are both travelling at 0.1 c, and the Alcubierre drive only increases the effective travel velocity. So as soon as the payload leaves the bubble, its effective velocity is back down to 0.1 c.
Rob Watts
Mar 12, 2020 06:53
@computercarguy the point I was trying to make is that using 10 c as the velocity in the kinetic energy calculation is incorrect. Turning on an Alcubierre drive might allow you to travel at 10 c instead of 0.1 c, but that doesn't change how much kinetic energy you have - you'd still use 0.1 c as your velocity for determining kinetic energy.
Rob Watts
Mar 12, 2020 06:53
@computercarguy I think I may understand the source of your confusion. Consider two identical ships, one travelling at 0.1 c without using its Alcubierre drive, and the other travelling at 0.1 c with its Alcubierre drive increasing the effective travel speed to 10 c. Although the second ship is travelling faster, they both have the same amount of kinetic energy. So using an Alcubierre drive as a sabot sleeve doesn't work. With your earlier comment I thought you were just throwing out numbers to show how devastating an orbital impact could be.
Rob Watts
Mar 12, 2020 06:53
@computercarguy I'd suggest using a relativistic kinetic energy calculator here. Also, that's why I asked if the Alcubierre drive is even significant for a ship impacting a planet - you can get a devastating impact without the drive.
Rob Watts
Mar 12, 2020 06:53
@Joshua do we know what would actually happen if an Alcubierre drive hit a planet? Basically, the entire point of the drive is to get from point A to point B faster without going faster. The faster apparent velocity would likely make it harder to defend against, but it wouldn't actually have any extra kinetic energy. Would it be any different than a normal ship impacting a planet?
 

 Discussion between computercarguy and…

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Rob Watts
Mar 12, 2020 06:50
An Alcubierre drive doesn't magically increase a ship's kinetic energy. If it's travelling at 0.1c and turns on its drive, it is still travelling at 0.1c. It only gets to its destination faster than that because space is being curved by the bubble. If it leaves the bubble then it is still travelling at 0.1c.
So a payload dropped from a ship travelling at 0.1c will also be travelling at 0.1c, no matter if the Alcubierre drive allows the ship to get to a location at 0.5c or 1000c.
Also, when I talked about turning the bubble off I had in mind that it would be a gradual process, which in Star …
Rob Watts
Mar 11, 2020 17:23
Though now that I think about it, leaving the bubble without turning it off would probably be very bad unless you're okay with the payload being turned into a bunch of exotic particles (similar to what's happening in the article you linked to)
Rob Watts
Mar 11, 2020 17:18
With an Alcubierre drive the only "slow down" procedure you need is to leave the bubble
Rob Watts
Mar 11, 2020 17:18
I think you may have misunderstood how an Alcubierre drive works. Although we don't know how to build one (or if it's even possible to do so), it theoretically is possible according to the laws of physics as we know them. In particular, it obeys relativity in that nothing can travel faster than light.

With that in mind, consider your statement that "it should continue moving at that higher speed". The ship accelerates to 0.1 _c_ and uses its Alcubierre drive to travel at 10 _c_. Without turning off the drive the ship releases a payload, which then leaves the bubble.
Rob Watts
Mar 11, 2020 16:05
@computercarguy that still doesn't work - the ship and the payload are both travelling at 0.1 c, and the Alcubierre drive only increases the effective travel velocity. So as soon as the payload leaves the bubble, its effective velocity is back down to 0.1 c.
Rob Watts
Mar 11, 2020 16:05
@computercarguy the point I was trying to make is that using 10 c as the velocity in the kinetic energy calculation is incorrect. Turning on an Alcubierre drive might allow you to travel at 10 c instead of 0.1 c, but that doesn't change how much kinetic energy you have - you'd still use 0.1 c as your velocity for determining kinetic energy.
Rob Watts
Mar 11, 2020 16:05
@computercarguy I think I may understand the source of your confusion. Consider two identical ships, one travelling at 0.1 c without using its Alcubierre drive, and the other travelling at 0.1 c with its Alcubierre drive increasing the effective travel speed to 10 c. Although the second ship is travelling faster, they both have the same amount of kinetic energy. So using an Alcubierre drive as a sabot sleeve doesn't work. With your earlier comment I thought you were just throwing out numbers to show how devastating an orbital impact could be.
Rob Watts
Mar 11, 2020 16:05
@computercarguy I'd suggest using a relativistic kinetic energy calculator here. Also, that's why I asked if the Alcubierre drive is even significant for a ship impacting a planet - you can get a devastating impact without the drive.
Rob Watts
Mar 11, 2020 16:05
@Joshua do we know what would actually happen if an Alcubierre drive hit a planet? Basically, the entire point of the drive is to get from point A to point B faster without going faster. The faster apparent velocity would likely make it harder to defend against, but it wouldn't actually have any extra kinetic energy. Would it be any different than a normal ship impacting a planet?
 

 Discussion on question by Lior: What …

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Rob Watts
Feb 25, 2020 20:28
@user3482749 criminalizing being poor? That's not a bug, it's a feature! If nothing else, it's something to consider for a story if you're trying to have a distopia.
 

 Discussion on question by StormFalcon…

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Rob Watts
Feb 13, 2020 11:12
@Schmuddi "they'd be capable of changing direction quickly without changing orientation" - I'd describe it the opposite way. It's easy to change which way you're facing (your orientation), but it's really hard to change which way you're moving (your direction).
 

 Discussion on answer by Starfish Prim…

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Rob Watts
May 24, 2019 20:03
This answer is much better now that you've added some explanation as to why she wouldn't see anything.
 

 Discussion on question by JBH: What d…

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Rob Watts
May 24, 2019 16:42
@JBH after thinking about this for a while, I think the best way to discuss this might be by focusing on Starfish Prime's answer, which I believe is correct. What is there in that answer that you aren't sure about (whether it isn't explained well enough or you don't immediately agree with)?
Rob Watts
May 24, 2019 02:36
@JBH physics.stackexchange.com/a/54325/79374 supports what Molot just said - photon's don't collide, though there is the possibility of them interacting with the help of virtual particles.
Rob Watts
May 24, 2019 02:36
@JBH this is why I suggested explaining the journey. As I understand it, the ship somehow accelerates to c, travels at c for some amount of time during which time dilation causes them to effectively not experience any of that amount of time, and then the ship stops travelling at c and slows down to stop at their destination. You are interested in what happens while they are travelling at c, correct? Starfish Prime's answer is correct in this case - due to length contraction photons were not hitting Victoria's eyes.
Rob Watts
May 24, 2019 02:36
@JBH you've told us that relativity is ignored (because they can get to light speed) but isn't ignored (because they still experience time dilation). I'd suggest describing what an entire voyage looks like, minus what the view outside the window looks like, so that we have a better idea of how exactly this works. Otherwise it's unclear which parts of relativity we can or can't ignore.
Rob Watts
May 24, 2019 02:36
How does relativity affect this ship? Is it able to completely ignore relativity? Or does it still experience some time dilation and other relativistic effects?
 

 Discussion on question by Trevortni: …

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Rob Watts
Nov 29, 2018 08:47
Make sure you've read what-if.xkcd.com/58. In particular - "The reason it's hard to get to orbit isn't that space is high up. It's hard to get to orbit because you have to go so fast."
 

 Discussion on question by AzaleaGarde…

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Rob Watts
Oct 8, 2018 13:52
One big unanswered question is why their behavior changed - it's rather apparent that the Greek Gods, as seen in the stories that we have from the Greeks, do not act in our modern world. Why is that? Are they just not doing things publicly anymore, and if so why is that? Why don't we have demigods accomplishing great deeds?
Rob Watts
Oct 8, 2018 13:52
Seems very similar to worldbuilding.stackexchange.com/questions/10017/…
 

 Discussion on question by Alexcommil:…

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Rob Watts
Jun 24, 2018 04:38
One problem with this question is that a 50 TW continuous laser is so ridiculous that it raises a whole bunch of questions about how your ships could possibly generate enough power for that and not melt due to waste heat. It makes me think you'd need some very exotic materials to manage it, but that means we'd have to guess how those materials could be used to defend against the laser.
Rob Watts
Jun 24, 2018 04:38
@Alexcommil I think the reason why some people consider it a duplicate is that the answer to that question works fairly well as an answer to this question - at the distances you'd be working with for space combat, lasers are not as effective as you'd think. I agree that this question isn't a duplicate though.
 

 Discussion on answer by Nick: What sh…

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Rob Watts
Apr 2, 2018 17:28
It seems like you're assuming 1 vs 1 space combat. If someone managed to flank your cigar, you could be in trouble.
 

 Discussion on question by Efialtes: W…

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Rob Watts
Apr 2, 2018 17:28
@CurtJ.Sampson simple radiation-based attacks can be dodged by just moving around randomly, so you only have to worry about missiles and other guided attacks. In that scenario, FTL would be used to augment your ability to move around randomly.
Rob Watts
Apr 2, 2018 17:28
How FTL works in your universe can actually play a big role in how space combat works. For example, if it takes a ship 5 minutes to engage its FTL engine, then any attack coming from more than 5 light-minutes away from the ship could be dodged by using the FTL engine. If you want FTL to not have any role in space combat, you can either say 1) it's easy to block FTL travel in an area or 2) FTL travel relies on something external to the ship, such as fixed-location wormholes.
 

 Discussion on answer by GrinningX: Bu…

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Rob Watts
Sep 17, 2016 17:30
FYI OP just added a minimum 2km distance, which makes a nuke-shelter fridge much more possible.
 

 Discussion on answer by rek: 0g pool:…

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Rob Watts
Sep 9, 2016 16:51
The Go Pro video actually demonstrates pretty clearly that objects are not drawn to the center of a ball of water. Right around the 40s mark you can see it stably floating just inside the ball of water. Objects appear to be drawn into the center because surface tension does draw them in, giving them an inward momentum. This can be seen again in the Go Pro video in that the camera is drawn in and then goes out the other side.
Rob Watts
Sep 9, 2016 12:48
@rek yes, water coats objects in microgravity, but once it establishes a thin coat there's no force to pull us deeper into the sphere. As MolbOrg said, you just need a little bit of hydrophobic creme to take the place of gravity in stripping that little layer of water from you.