171 stories
·
2 followers

If you’ve ever watched a rocket launch, you’ve probably noticed...

2 Comments and 12 Shares




If you’ve ever watched a rocket launch, you’ve probably noticed the billowing clouds around the launch pad during lift-off. What you’re seeing is not actually the rocket’s exhaust but the result of a launch pad and vehicle protection system known in NASA parlance as the Sound Suppression Water System. Exhaust gases from a rocket typically exit at a pressure higher than the ambient atmosphere, which generates shock waves and lots of turbulent mixing between the exhaust and the air. Put differently, launch ignition is incredibly loud, loud enough to cause structural damage to the launchpad and, via reflection, the vehicle and its contents.

To mitigate this problem, launch operators use a massive water injection system that pours about 3.5 times as much water as rocket propellant per second. This significantly reduces the noise levels on the launchpad and vehicle and also helps protect the infrastructure from heat damage. The exact physical processes involved – details of the interaction of acoustic noise and turbulence with water droplets – are still murky because this problem is incredibly difficult to study experimentally or in simulation. But, at these high water flow rates, there’s enough water to significantly affect the temperature and size of the rocket’s jet exhaust. Effectively, energy that would have gone into gas motion and acoustic vibration is instead expended on moving and heating water droplets. In the case of the Space Shuttle, this reduced noise levels in the payload bay to 142 dB – about as loud as standing on the deck of an aircraft carrier. (Image credits: NASA, 1, 2; research credit: M. Kandula; original question from Megan H.)

Read the whole story
Belfong
30 days ago
reply
Very interest facts!
malaysia
popular
36 days ago
reply
Share this story
Delete
1 public comment
jepler
38 days ago
reply
I did not know this!
Earth, Sol system, Western spiral arm
copyninja
34 days ago
nor me

Uber, WTF happened to you?

1 Share

In the wake of the recent events surrounding Uber, I think it’s time we had a discussion about what I once called my favourite ride sharing service. Has Uber’s service been declining lately? Or is it just one terribly unlucky streak for them in Malaysia?

From my personal experiences, I have to say, it’s the former.

Uber started out as a godsend for me. I was sick of being bullied by cabbies and tired of the often poor service I received. When Uber came along, everything changed. Everything from payments to ratings were sorted out in the application so you didn’t have to deal with the driver directly.

Vehicles were new and kept in pristine condition so there were no weird smells. Drivers were also polite and considerate which made the entire experience so much more satisfying.

But in the last few months, things certainly have changed and in more than just a trip’s quality. I noticed a significant drop in quality in two key aspects: The drivers and Uber customer support.

Let’s start with the drivers and the most objective representation of their capabilities — the Rating system. You may have heard of the story about the woman who was robbed by her Uber driver. One thing to note in that incident is that her driver had a rating of 2.8 stars.

Consider this, how generous are you with an Uber ride rating? Generally, as long as the ride doesn’t run into any major problems, I tend to give drivers a 5-star rating. What kind of act must this person have committed to get himself a rating of just 2.8 stars out of 5 stars? Further, we were told in the past that Uber drivers had to maintain a rating of 4 stars otherwise they’d be suspended from driving and subject to retraining.

Usually I’m not too concerned with a driver’s ratings but recently I was matched with an Uber driver, when I needed a ride back home from KLIA, that has made me hesitant to call an Uber ever since. He had a 4.1-star rating and drove a Toyota Vios.

The first red flag came when he accepted my request and immediately called me on my mobile to find out where I was going. Here’s the thing: Uber drivers are NOT supposed to do that. Uber set the system up in a way that prevents drivers from cherry picking their rides (a problem that Taxis had) so their riders would not be turned away. If Uber wanted their drivers to know where their rider was going before the driver picked them up, it would be displayed in the app.

I noticed this happening far more often in rides from KLIA (nearly every time) and even had a colleague asked to cancel his request by a driver because he wasn’t going where the driver wanted to go.

Regardless, I told him where I was going and he came to pick me up. During pickup, he zoomed past me (despite the fact I specifically told him which gate I was at) and seemed to be in a hurry the whole time. I got into the car and he asked if I knew the way. I wasn’t too familiar, so I told him to just follow the GPS navigation on his phone.

He didn’t seem too happy but complied regardless. One big problem, though, he didn’t have a smartphone holder and spent the rest of the trip driving like this:

Needless to say there was a lot of swerving which was really scary. It was also at this moment that I noticed his car didn’t have a side mirror on the driver’s side. How on earth did this guy’s car get approved?

After 30 minutes fearing for my life, I arrived home in one piece (not before I witnessed him being unnecessarily rude to my housing area’s security guard who was just doing his job). I gave him a one-star rating, selected several of the preset “what’s wrong with this ride’ options and closed the app.

Now, more than a week later I still haven’t heard a peep from Uber regarding my 1-star ride, which I suppose leads us nicely into the second key aspect: Customer service.

I don’t mean to sound entitled when I said I was waiting for a response from Uber, it was just my past experience led me to believe that they would at least contact me to ask my why I chose “Safety” as one of my main concerns with the ride.

Especially since in the past, I once left a driver a 4-star rating and the comment “smelled like smoke”, because his car stank of cigarettes and Uber Support immediately contacted me with a sincere apology and reassurance that they held their drivers to the highest of standards.

That moved me because I did not expect it at all and it really cemented my belief that Uber cared about their passengers.

Now? Now, I’m not so sure. Recently, in fact, I reported the issue of my driver calling me to find out where I was heading and this was the response I got from Uber Support:

Firstly, if the driver truly wanted to “get my pickup location right, he would have asked me where I was, not where I was heading. Secondly, of course, he couldn’t see my destination, he hasn’t picked me up yet. What he was trying to do was cherry pick his rides and the fact that Uber tried to cover up for him is disappointing, to say the least.

To make matters worse, the recent set of events depicting some truly nightmarish events surrounding the ride-sharing service doesn’t do much to inspire confidence either. Drivers that don’t match the registration and robberies are both things that should not happen if Uber vets their drivers properly.

On Uber’s website, it is stated that for someone to be an Uber driver, that person cannot have a criminal record and that they will conduct background checks on all their drivers. If they really did that properly, then why was the driver who robbed the pregnant lady found to have two previous convictions allowed to drive for Uber? Perhaps it is a good idea to let Land Public Transport Commission (SPAD) vet drivers instead.

Recently, there was also a case that came up regarding the alleged molestation of a Vietnamese lady by an Uber driver. Following that, SPAD said that all ride-hailing services should install a panic or SOS button in their application to prevent things like these from happening.

And this was Uber’s response to that:

“Uber has GPS tracking for every trip, giving customers the ability to share their trip information and estimated time of travel in real time with loved ones. Uber also has a two-way review feature so that both riders and driver-partners can give feedback on any trip”

Doesn’t sound like they’re particularly keen on following through, does it?

I used to think that Uber took ratings very seriously, but as I’ve discovered recently (from a friend who is an Uber driver), Uber doesn’t even contact the driver when he receives a 1-star rating. What does a rating system mean if Uber ignores it altogether?

And you can tell that the ratings have taken a backseat lately. In the old app, you couldn’t request a new ride until you’ve rated the one you took last. Now, it’s hidden at the bottom alongside the “promos”. There also used to be a box for you to enter your comments on how the ride went. Now? Nothing.

This incident with the Vios driver isn’t the first time I’ve encountered a bad ride — this was just the worst one by far. I’ve also been hearing negative reviews from my friends and colleagues who frequently use Uber, so I don’t think my case is particularly unique.

If Uber continues down this path that they’re on right now, they’re going to be having the same problems they sought to solve with the taxi service in the first place. Uber has put so much effort into implementing measures that were supposed to ensure that riders wouldn’t face the same problems they did when they had to take cabs.

But now, it looks like the company is growing too large and too quickly that they can’t maintain the quality and standard they set in the first place. This service went from something I trusted my life (and the life of my loved ones) with, to something I actively avoid when I need to get to places without my car.

What about you guys? Have you noticed a decline in quality in Uber’s services lately? What are some of your experiences? Let me know in the comments below.

Read the whole story
Belfong
107 days ago
reply
malaysia
Share this story
Delete

Apple adds external GPU support, now selling $599 VR development kit

1 Share

Apple today announced that, as part of its updated Metal 2 graphics tech in macOS High Sierra, that Macs would soon support external GPUs via the Thunderbolt 3 port. This paves the way for virtual reality development on lighter-weight laptops and also opens up the possibility that Mac users will some day be able to plug in and play with VR headsets. Steam owner Valve also announced today that it’s made SteamVR available for Mac in beta.

To help developers get started, Apple has also started selling its very own external graphics enclosure to developers. The idea is to give Mac owners who’ve always wanted and needed a bit more horsepower the extra juice required to work on...

Continue reading…

Read the whole story
Belfong
110 days ago
reply
malaysia
Share this story
Delete

Why astronomers are scrambling to observe the weirdest star in the galaxy this weekend

1 Share

It was early Thursday morning when astronomer Matt Muterspaugh noticed something strange with the star he had been observing for the last year and a half. Telescope data taken from the night before showed that the brightness of the star had dipped significantly. He contacted other astronomers who had also been observing the same star, to let them know what he had seen and to keep an eye on it for any more changes. Then by the following morning, the star had dimmed even more.

That’s when he and the others knew it was time to signal the alarm: the weirdest star in our galaxy was acting weird again. And it was time for everyone to look at this distant celestial body — to figure out what the hell is going on. “As far as I can tell, every...

Continue reading…

Read the whole story
Belfong
127 days ago
reply
malaysia
Share this story
Delete

Get Off the Fucking Plane

1 Comment

By now you’ve all probably heard about United Airlines’ public relations/customer service   fiasco. If you didn’t here it is in a nutshell – a plane was overbooked, they had to get a flight crew of four on board, they offered $800 in vouchers for volunteers to deplane, there were no takers, they said the plane wasn’t leaving until four people got off, no one budged, so they picked four people, one guy refused to go, he was physically escorted off the plane by the cops and, while they were hauling him away, he got hurt. All captured on cell phone video. Social media predictably exploded. Cue the well-paid crisis management consultants.

My initial reaction to this was, “I’ll bet no one in first class was asked to leave.” I was also pissed at the United CEO’s carefully parsed reaction. “This is an upsetting event to all of us here at United” he wrote. “I apologize for having to re-accommodate these customers.” Pure corporate speak bullshit. “Re-accommodate?” That’s what you call man-handling an older person off a plane? Gimme a break. Now United’s out a billion dollars. 

But a good friend’s reaction to this whole affair surprised me. “Get off the fucking plane!” he said. “What the captain of the plane says goes!”

“Don’t you think you’re being a bit harsh?” I said.

“I fly every couple of weeks,” he said. “I’ve been bumped off flights and I’m a preferred customer. And if they offer me a voucher for another flight I usually take it and put it towards a vacation.”

“But what if you need to really get home?”

“Did everyone on that flight really need to get home?” he said. “Not one of them could’ve taken another flight? Delay their plans for a single day? No one? Are they all surgeons separating conjoined twins the next morning? As far as I’m concerned, everyone on that flight was a selfish asshole.”

“Don’t say that on Twitter,” I said. “You’ll get crucified.”

“I don’t care,” he said. “And you know what? Ask yourself why four crewmembers had to deadhead on that flight. Maybe they were a relief crew for a sick pilot somewhere.  Maybe the pilots on that plane had flown too many hours for that day. If they’re going to kick passengers off a plane I’m sure they didn’t do it just so their employees could get a free ride home. The safety of everyone should always be an airline’s primary concern.”

“Yes,” I said. “That could all be true. But the airline could have found a better way. Perhaps book the flight crew on another airline.”

“Sometimes you’re just fucked,” my friend said. “End of story. Take the voucher and order room service on United’s dime.”

To be honest, I’ve noticed air travel tends to bring out the worst in people. Ever since they took the free pretzels away flying has lost any semblance of being cool or fun. You’re basically riding on a pressurized aluminum bus at 30,000 feet. And with carry on fees, charging you extra for an aisle seat, TSA workers looking down your pants, worrying if in-flight entertainment will consist of a shoe bomb or drunk celebrities needing to be flexi-cuffed, flying is stressful. And unless you’re in first-class, you’re crammed cheek to jowl with a bunch of farting, germ-spewing people displaying varying levels of social graces.

Once I was flying home and seated next to a tearful little boy who, for reasons I’ll never figure out, wasn’t seated next to his mother. I was by the window and the boy was in the middle seat. Before the plane took off the flight attendant asked the man on the aisle to move. “Not my problem,” he said. I could have told the attendant the guy was a jerk because he hogged up all the carryon space with his oversized shit, forcing my bag into checked luggage. “I’ll go,” I said, getting up. Off course I ended up between two fat sweaty guys.

“You’re such a nice man!” a lady behind me said. But once we took off, the little boy began wailing uncontrollably. That’s when the luggage fetishist on the aisle began badgering the flight attendant for another seat. “No can do,” the steward said, karmic joy dripping from her voice. “You were already given the opportunity.”

I turned to the lady behind me. “I’m not a nice guy. I knew that kid was gonna blow.”

Then there’s the people I like to call airline lounge pricks. Because my wife is also an über flyer, whenever I travel with her I gain entrée into a cloistered lounge with free liquor, food and Wi-Fi –  far from the hoi-polloi sitting on their luggage at the departure gate. So, last fall my wife and I were taking a morning flight to L.A. and the lounge was crowded, not a single free seat to be had.

“This sucks,” I said.

“There’s an even nicer lounge than this one,” my wife said. “I’ll bet that one’s empty.”

“There’s another lounge.” I said. “Really?”

“We’re not rich enough, dear.”

Deflated, I looked to see if anyone was getting ready to leave. No one was budging. In fact, no one was even talking. The lounge was quiet. Too quiet. Everyone was reading newspapers, fiddling with computers or munching on food. I also noticed that no one acknowledged the workers clearing plates or restocking the coffee bar. No hellos, no thank yous. The patrons all  seemed hell bent on maintaining some rarefied mystical bubble of privacy. Then I spied a circle of four chairs around a table with only one guy sitting there. The other three chairs were claimed by a coat, a carryon and a computer. The guy wanted the whole place to himself.

“This stuff yours?” I said to the man. When he didn’t acknowledge me, I picked up his coat and carryon and placed them on top of his computer.

“Thanks, pal,” I said. “Appreciate it.”

The man looked at me like I shot his dog. “That’s my stuff,” he said, sternly.

“And it’s still your stuff. Isn’t that wonderful?” I said as my wife and I plopped into the newly freed seats. The man glared at us, I smiled beatifically at him. After a minute he shook his head, collected his crap and left.

“I’m so glad you’re good at confronting people,” my wife said.

“I used to deal with people like that all the time in the restaurant business. Screwing with them gives me joy.”

So, I’m not surprised none of the passengers offered to give up their seats. Airline travel, whether it’s because of the airlines’ thirst for profits or declining public civility, is a freak show. But someone, when they saw the cops come on board and realized that guy was going to be forcibly ejected, should have given up their seat. You can argue the man should have left quietly and I’d probably agree, sometimes you just get the short end of the stick.  But I’m annoyed that some of the passengers recorded videos of that old man getting dragged out on their cell phones and Tweeted about it. When did using social media become a substitute for doing the right thing? People everywhere freak about the tone-deafness of that Kendall Jenner Pepsi ad but, when faced with a situation that required someone to be a human being, to do the uncomfortable thing, people completely wimped out. I’ll wager the “bystander effect,” passengers’ sick of being treated like cattle and the corrosive effects of hiding behind gizmos to avoid reality probably had something to with it. Now I’m not saying United’s sinless, far from it, but let’s face it, 46,000 people a year get booted off flights. My friend was right, no one is that special. Someone should have got off the fucking plane. 

Social scientists will be writing about this for years.

The post Get Off the Fucking Plane appeared first on Waiter Rant.

Read the whole story
Belfong
164 days ago
reply
That's a great and different perspective to this story.
malaysia
Share this story
Delete

Apple’s AirPods make me feel like an alien

1 Comment

I laughed at Apple’s wireless AirPods when they were first announced. I sat on Twitter and shared the same jokes as everyone else, and never dreamed they’d be in my ears. “They look stupid,” I thought, and everyone seemed to agree. It’s with much regret that I’m now using AirPods as my headphones every day, but I still think they look stupid. Others do too, apparently, because people keep staring at me as if I’m from outer space.

I tried a pair during a recent work trip and I was surprised at how easy they linked to the iPhone despite the lack of wires. And the battery charging case is just clever. Untangling headphones is a headache, and feeding them through your jacket or having them tugged out of your ears can be frustrating. All of...

Continue reading…

Read the whole story
Belfong
167 days ago
reply
I like them...
malaysia
Share this story
Delete
Next Page of Stories