I never seriously studied physics. A few years back I decided that it was time to push myself a little and start reading up. I started with some articles on string theory and suddenly remembered why I didn't want to study physics.
Looks like I saved twice as much time as I thought I had.
It's not untestable. It gives predictions and there has been tests for those predictions. The unfortunate part is that the predictions are often not very concrete, and the range of a lot of these predictions lies far beyond our capabilities. But people are looking to measure them indirectly in various ways. So it's not like it is untestable by design or anything like that.
AFAIK, every single idea from string theory that could be tested was rejected. And the theory was made more complex, less predictive so that it could still work without the testable idea.
These are very broad statements that are not very easy to comment on. "Every single idea", makes it sound like they are a lot, I would not say they are. "Was rejected", depends what you mean... " did not show positiv results", "no longer possible to motivate economically", sure, " refuted as bullshit", not so much. "Was made more complex", sounds like there is intent, and/or, depending on what you mean by complex, that it would be necessarily a bad thing to using more advanced maths to formulate things you could not before, and hence solve new problems.
I can mention two possible avenues of inquiry that are less than 5 years old that has sprung from string theory as possible support for it: signals of black hole structure in gravitational wave 'ring downs' of black hole mergers, and the exclusion of a positive cosmological constant. But if you know that these are untestable or rejected, I'd love to hear about it.
I thought the problem with string theory is that its predictions match up with what the standard model already explains. Maybe that’s only for the things we have the capability to mature any time soon.
No, the problem is very different. In string theory you have a lot of freedom to build various models, and they can provide the standard model, slight deviations from it, or something completely different. Before LHC we knew we had some version of the standard model, the hope was that the LHC would find that we have some particular deviation, like supersymmetry (susy) with such-and-such masses and particles. It did not. The prediction is susy, the problem is that the prediction (at least yet) is not exactly this type of susy. String theory says there is supposed to be a lot of extra stuff beyond the standard model, question is just how do you find it, which is made harder by string theory allowing for so many models.
I did a semester of physics in high school and loved it. One of the few classes I actually enjoyed. I joined the nuclear program in the Navy and still loved it. I got to college and brought along all my ACE credits so I got to skip some math, physics, early chemistry, and thermodynamics.
We got to experimental physics and it broke my brain. I barely walked away with my BS and even though I could have made good money I never ended up using the degree because I ended up hating the whole field. It hangs on the wall next to my certificate from a two week bartending school.
I ended up with a long and fruitful IT career where I've never had to apply even a little knowledge I gained from that degree.
Somewhat related, back in highschool I was really enjoying chemistry class. Super fun stuff, definitely a career path. Then when we were doing the math practices, I got a question wrong that I knew I combined correctly.
I asked the teacher and she said "oh yeah that one just doesn't follow the rules" instantly killed my enjoyment of chemistry.
Aw that's too bad. That response I'm sure you're paraphrasing, but "that one doesn't follow the rules" is the best part of science.
It means our rules aren't good enough, or we don't understand that one well enough. Figuring it out can be an entire career of discovery. And the reasons why can be fascinating and inspiring to more discoveries!
In this case, it was probably the teacher not being knowledgeable enough to explain a more advance theory that goes beyond the simple model he was teaching. What's sad is that the teacher didn't take the opportunity to dig deeper with the student, it could have been very motivating for the student to feel like he found something that went beyond the normal curriculum.
High school chemistry felt less like imperfect modeling and more like alchemy that sometimes yields tangible results. I can't remember specifics anymore but there were many moments where I was like "you're using too many shortcuts and this doesn't make any damn sense mathematically or dimensionally anymore". I know real chemistry is too complex to fit a high school program, but the way it was taught really was like a soft science cosplaying as a hard science.
Also chemists would use any pressure units before they used Pa. mmHg as a unit suffers from congenital defects I can only assume stem from repeated inbreeding.
At school, I thought our understanding of chemistry was really good. Years later, I realized that complicated solutions aren’t covered by any of the equations we have. You’re can do fancy calculations, but you’re always stuck with simple solutions and standard conditions. In real life, you have to deal with super messy non-standard stuff all the time.
Top scientists end up developing semi-empirical models, or even particle simulations, and that’s the best we can do right now. Nobody fully trusts those predictions, so we’re still going to need lab experiments before making any big decisions.
The good news is that there’s still so much to discover.
You aren't following the rules! You're supposed to nonchalantly get the correct answer and thus discover a new rule that we nowadays know as the Galapagon Principle.
At my work, we meet astronauts fairly often (I met Jonny Kim last year), and it's amazing how many of them are like this. They'll usually pass out their headshots that have their bio on the back, and the number of advanced degrees and impressive accomplishments is jaw dropping. Like I feel like I'd think my life was worthwhile if I did one of those things by the end of it, and a lot of the astronauts are hardly more than half my age. And to really rub it in, they all seem incredibly genuine, personable, and well adjusted.
There are a giant number of people who want to be astronauts, and NASA only needs a small number in a given year, so they can pick the very cream of the crop.
When you rule, you get to pick what qualities have merit, which is how we end up of administrations of The Master Race or lispy Spaniards, or ruthlesd billionaires.
We're still trying to figure out how to get to government tha implements public-serving ideas.
Crazy thing is very similar mathematical structures is used to define the behavior of a single particle in QFT and of a huge collection of particles in condensed matter physics
When you section off a small part of the universe and try to model it, there's little reason your model should look like a model for a completely different small part of the universe. Not unless they share fundamental characteristics that you're trying to model. The math that describes permanent deformation looks nothing like fluid dynamics.
I mean in the case of the comic, yeah the reason for the behavior actually is tied to pretty much the same principles, but the generalized statement you made isn't, well, generalizable.
Water and ice are made up the same particles and molecules yet the mathematical structure to define the effect of force/pressure is very different - plastic deformation vs fluid dynamics as the example given above
Neither of them is trying to model the universe (that is the purview of cosmology). We are trying to model very particular phenomenon happening in the universe and there is no reason to expect them to modeled using the mathematical structure. The fact that they are is very fascinating.
I have never seen a roundabout here in Australia that allows for these sorts of conflicting movements, that would be asinine. Are you saying there's multiple lanes that can exit or go straight such that someone in the inside lane can turn out in front of someone continuing around in the outside lane? Is this a North American thing? Of course that would result in accidents, don't build your bloody roundabouts like that!!
I drive through three lane (six lane road) roundabouts all the time and no one gets hurt. In fact I have to drive through two such roundabouts to get to the nearest freeway.
I'm absolutely calling BS. I've never seen such a thing and wagering that you are just confused about what lanes can do what (or you're just making shit up). There are several roundabouts near me where an inside lane can turn out or go straight, but in all of those cases all lanes further out are required to turn out. The people that design traffic patterns aren't idiots, but there's no shortage of idiot drivers that can't follow even the simplest patterns.
If you want to insist, all you need to do is link to such an intersection in google maps so I can look at the aerial view. I'm honestly curious how they would paint the traffic lanes to indicate what you're describing.
Even on that, a driver in the right lane must exit. If they want to continue to the left, they are required to make a lane change, in which case all lane change rules would apply.
Imagine a roundabout where most of the traffic flows straight on only one of the streets. Things would improve a lot of you gave that street the right of way and cut a shortcut on the middle of the roundabout, wouldn't them?
(/s by the way, but a lot of transit engineers to really believe in this. Unironically.)
You jest, but we do kind of have something like this in Melbourne, Australia. Except the vehicles that get to cut through the middle of the roundabout are Trams. Plus while they're trundling through, everyone else has to stop and wait for them.
Trams traverse the traffic lanes at three points, as well as one making an immediate left turn exit. There are four traffic lanes. Royal Parade has inside lanes and service lanes.
But I also don't have to imagine that at all, those are common here too and I've never had a problem at them:
Notice how the approaching lane at the bottom left has an artificial curve added to it? It's traffic calming to help slow down cars before they get to the roundabout itself.
That second picture of yours is just a normal roundabout. Try making one of the roads pass directly through it. And don't change the signaling.
I've noticed that the tram line cuts the traffic in 3 points. What is the speed of that street? Anyway, the tram line is clearly signed in a way that can be noticed on the photo. And every car there is making a weird curve, nobody is speeding anyway.
You'll have to be specific, all five of the roads that enter this roundabout are different, none actually continue through it. I think the maximum speed limit in the area is 60km/h though.
Edit: Also, the weird looking building in the first picture? That's the Royal Melbourne Hospital. There is A Lot going on at this roundabout. Though I guess as far as it not being "bad" it is probably the best intersection they could have built for this location. The cycle length if it were a signalised intersection would be insane.
I think it's probably got more to do with the drivers. There are plenty of roundabouts like this where I am in Aus, and they get used just fine. Over here they have a far lower rate of accidents than other types of intersections. We never have 4 way stops either, we just put a roundabout there.
Half the people who wave you through have weird little control fetishes. They're not being polite, they're pursuing feelings of power. They're the same people driving 5 mph under the speed limit in the passing lane to "keep other people from speeding".
Another thing that enrages me is people who think driving slowly is safer for whatever reason.
Getting on the highway? Let's SLOWLY merge at 60% the speed of oncoming traffic.
Changing lanes from stationary traffic into a full speed lane? I won't wait for the lane to clear, I'll just turn signal and move into the lane REAL SLOW because that's safe.
Turning right? Let's slow down to a complete stop and force traffic to a halt so I can turn right.
As a delivery truck driver I can't tell you how many people think that everyone else can just stop on a dime for them and they're being safe because they move over at a snail's Pace.
fucking hate getting stuck behind some slow driver when trying to get on a highway. like fucker we are supposed to be reaching highway speed on this ramp not when we reach the highway🤬
There is an on-ramp for the highway near me that's pretty long. It's long because it's a very straight fast-moving section of highway. In other words, the on-ramp is designed to give you adequate space to get up to highway speed. The number of people who immediately merge into the first lane without getting up to speed is too damn high.
I used to have a job where I drove a box truck. It was slow empty and painfully slow full. It was also speed limited to 75mph. So I would tend to hang out with the semis on the hwy. One time I was driving down the hwy and this guy in a pretty new Volvo( so the fast ones) was coming down the on ramp. I could see he was going to merge right in front of me so I slowed down to give him some space. I figured he would want to be in front of the slow box truck. As he got close to the merge he slowed down so he was even with me. I gave him a little more space to merge in front of me and slowed down again. He had plenty of room left in the on merge lane if just used the skinny pedal. Instead he waited until was almost out of room then started honking at me. I did my best to speed up my painfully slow box truck but I am sure he has to slow down to the point he was merging at 45mph as everyone was doing 75-80mph. I am sure he was cursing me too because he wasn't willing to get up to hwy speed before merging.
I was taught it was the responsibility of the car getting on the highway to match the speed of the cars on the highway. If you’re already on the highway, keep a constant speed so the people getting on can match you. So he kept having to slow down because you were also slowing down. Just like the assassin pretending to be nice in the diagram, I think you were technically in the wrong here.
Right, but its not your responsibility to slow down at all. Its kind of you to do so when the merging vehicle picks up on your intention, but when they don't, it makes a miscommunication like you describe.
Basically, i'd just describe it as being predictable. And bending the rules (even to be kind) is not predictable, usually.
I have a question on this. Let's assume everyone is a perfect driver and must have at least a 2 second following distance at all times. If there's a free flowing queue of traffic on the highway with 2-4 second gaps between, merging in is impossible without someone slowing down and letting you in. Every time I merge this situation stresses me out.
Merge into the gap, then slow down slightly to extend the space in front of you, and let the guy behind you slow down to extend the space in front of him. It’s not complicated
At 100 km/h (low-end highway spreed), or 1,666 m/minute, or 27.7 m per second, a 2 second gap leaves approximately 56.6 m (185.6 feet) between cars. With the average car length being ~4.9 m (~16 feet), even the absolute worst driver can merge in a space ten times the size of the average car, assuming they're matching highway speed.
Most people have no actual concept of how long 2 seconds actually is or how much space it would leave in reality.
Yeah, obviously you "can" merge, but in doing so you insert yourself into the middle of a 2 second gap creating 2 × less than 1 second gaps. Like I said, in this hypothetical everyone is a perfect driver that always follows the rules, so that's not an option.
For that matter, the driver behind should see that you are about to merge into a gap that's too small and slow down to leave a space that's at least 4 seconds big.
I'd also like to point out that your attitude to driving is terrible, the size in meters of anything on a highway is irrelevant, 2 seconds is not a lot of time to react and slow down a car at 100, and that just because you "can" do something doesn't mean you should.
Instead he waited until was almost out of room then started honking at me.
People who haven't learned the physics of large trucks spend a surprising portion of their driving time competing for Darwin awards.
I want to will this not to be a problem anymore, but still see it all the time. I'm thankful that I've seen a lot of truckers react in surprisingly aware ways that save lives.
But every time I see it, I can't help but think that driver's luck isn't too likely to hold through too many more times making that move.
Getting into the fast moving lane from slow traffic is difficult no matter how you do it. The best way I found is to actually go slightly slower than the person in front of you to get a gap, then use that gap to accelerate.
Yeah, that's because you know how to drive. I can't tell you how many people just turn in front of a truck and expect it to slow down for them. Playing with their lives.
Yeah if this happens I'm just turning right and doing a U-turn. I would rather take 5 extra minutes to get where I'm going than play a game of polite chicken where the stakes are human lives.
This road design seems also be done by someone completely insane. Who thought it was a good idea to cross two lanes without any kind of traffic regulations.
Luckily no every country has insane roads like that.
This applies when you're a pedestrian waiting to cross too. There are always those drivers who think they're doing you a favor by stopping one of the lanes of traffic so you can walk out into the other. They smile and wave and look baffled when you don't take the bait.
yesterday a guy tried to wave me to cross then started angrily raising his hands like "FUCKING GO!" completely oblivious to the car that flew past his left side in the opposite direction
Had guy asking me to turn like that and when I refused he gave me the finger as he finally drove on. How come they hold up traffic and then get mad at you for not driving into on coming traffic?
You're right of course, but in a broader sense there is literally no action that anyone takes that is altruistic. We only do things that benefit us or, rarely, our group as a whole.
Oh god, this reminds me of a cringe mistake just after I was getting my license. I was driving up to a crosswalk and there was a kid standing next to, maybe 8 or 9, holding their hand out. You know, just like they learn at school that they should do that to make it clear they want to cross even tho the car is supposed to stop anyway. I saw this and what did I do? I thought the kid waved at me and my new license, so I just drove past and waved back. What the fuck, brain?
Generally pedestrians have the right of way at crossings (unless it's controlled with a light) in my state and neighboring states, most crosswalks even have signs that inform you to yield to pedestrians.
Feels like at least part of the issue is multi-lane pedestrian crossings. Most of the time that should either be single-lane, a traffic light or a tunnel/bridge.
If you trust every driver to follow the rules exactly and have their eyes open, you can risk your life by walking out. Otherwise you might wait anyway. And the rules about right of way depend on your country and state.
I'm not saying you should be reckless, but too often I see people be either uninformed or unwilling to exercise their rights. To be fair, I do write with something of an urban bias, where thankfully those kinds of speeds are much less common.
It doesn't just happen when both people are trying to turn. I have a busy multi-lane road near me with a left turn lane that's just past a stoplight (the stoplight is behind me, but in front of the people whose lanes I need to cross to get to where I need to go.
I'll be stopped in the turn lane waiting for traffic to clear. The stoplight will turn red, and oncoming traffic will back up past the turn lane I'm in. Someone in one of the oncoming traffic lanes will stop before the turn lane to try to let me past, but the people in the other oncoming traffic lane (who are now in my blind spot thanks to the car that stopped to try to let me through) will keep on coming. That's just an accident waiting to happen at that point.
imgs.xkcd.com
Active