Random thing you love right now that doesn't deserve its own thread

Heh. Heh. Heh.

Jonman wrote:

EDIT - having said that I wasn't going to argue your math....

Miashara wrote:

Kerosene, the competitor the article references, has a energy density of about 25 MJ/liter. That's 25000000 Joules per liter, compared to the 98J the contraption gets from its weight. They aren't in the same league. They're barely playing the same sport. Incorporating that factor of 10 in terms of light output via LEDs just going to change anything; you drop from six orders of magnitude difference to 5. Woo.

How long does a liter of kerosene fuel take to burn? Because that 98J you reference is used over a half hour. Comparing that 25000000 Joules that a liter of kerosene will release isn't a fair comparison - you're comparing energy used over a week to energy used over a half hour.

Double check your math.

Your 10 kg bag of rocks yields 98J of energy. An LED that provides interior light runs six watts. At 50% GPE to EE conversion, that's 9 seconds. Not this 30 minutes you reference. At 1 watt, it's about a minute.

This 30 minutes people are referencing is flatly absurd. It's a claim made by the manufacture that cannot be realized. Power is equal to voltage times current, as we all know. Algebra: P=IV. P =E/T (power = energy/time) Therefore, Time=Energy/(Current*Voltage) or Current = Energy/(Voltage*Time). Putting in numbers for that nonsensical 30 minutes(1800 seconds), we get Current=98J/(1800s*2.4V)=0.02 A. Note: HE-LEDs require more than the typical 0.6V drop. See here.

Realistically, divide that by 2 for inefficiencies of the mechanical energy to electrical energy conversion. Reference that luminosity data sheet above for how much light a HE-LED kicks out at 10 mA. It's about 10 mcd, or 10 millicandela, or 1/100 a single candle. Increase the efficiency to 100% for energy conversion, and you get 1/50th a candle. At 30 minutes, the ABSOLUTE MAX light output is 1/50th a candle.

(Note: I have nowhere used the efficiency of the LED. That is internal to the output light intensity of the HE-LED, and is a hidden variable in the experimental data. Basically, the data tells you how much light it kicks out with a set current, so it already incorporates efficiency.)

Jonman wrote:

A typical household kerosene lamp is used three to four hours per day with weekly fuel consumption of about one litre. At this level of usage, families can spend up to 40 percent of their income on kerosene.

So that's 21 hours of light for a liter of fuel. If we scale our numbers accordingly, we get a straight comparison of energy use for a half hour of light:
Kerosene: 60000 J

Your math here is simply wrong. Put on your engineer hat, Jonman. Let's begin with the bolded part.

The energy density of jet fuel grade kerosene is ~48 MJ/L.

http://hypertextbook.com/facts/2003/EvelynGofman.shtml
http://en.wikipedia.org/wiki/Kerosene
http://answers.yahoo.com/question/index?qid=20071120214130AAMofaD

I low-balled it intentionally, but using real numbers only makes the discrepancy bigger. Your number of 60kJ/L is off by three orders of magnitude.

Jonman wrote:

Gravity LED: 98 J (rounding up to 100 for easiness)
So we've got an energy density ratio of 1:600

Factor in efficiency - LED being 10 times more efficient, right?
So we get an energy ratio of 1:60

So, yes, there's still a large difference, but it's not as marked as your numbers suggested.

Ah, no. You have an energy ratio of 0.0000027 for 10 kg of rocks vs 1 liter of kerosene. If you increase that by a factor of 5x to account for relative efficiencies of the two sources, you're still running an energy ratio of 0.00001.

http://evanmills.lbl.gov/pubs/pdf/offgrid-lighting.pdf
http://large.stanford.edu/courses/2011/ph240/machala1/

Just an FYI, you went into left field when you lost track of your units. You approximated the energy density of kerosene via extrapolation instead of just looking it up, and that meant you had to incorporate the relative efficiency. You then used relative efficiency again when you did the ratio. There was the slight manner of comparing energy density of a liter of kerosene to 10kg of rocks (~2L depending on rocks) but it was pretty clear what you meant.

Momgamer: A candle puts out 1 candela of light by definition. That's why it's called a candela. We're talking 1% to 2% of a single candle. That's close to the bottom limit of what the human eye can see. The lantern you linked had an output of ~950 lumins, or 47,500x this LED. That's forty seven thousand, five hundred times brighter than the LED product discussed if it ran for 30 minutes. If it ran for 9 seconds, they'd be comparable. Would you be willing to lift a 10 kg weight 1 meter every 9 seconds for that light?

edit: closed a some brackets

Today I saw ultrasound images of my baby and heard it's heart beat. A couple hours later I was offered a new, much better job. Today has been great.

SixteenBlue wrote:

Today I saw ultrasound images of my baby and heard it's heart beat. A couple hours later I was offered a new, much better job. Today has been great.

And then you made the mistake of going to IRC.

Quintin_Stone wrote:
SixteenBlue wrote:

Today I saw ultrasound images of my baby and heard it's heart beat. A couple hours later I was offered a new, much better job. Today has been great.

And then you made the mistake of going to IRC.

So true.

Miashara wrote:

(awful lot of numbers)

Yeah, I didn't look up the energy density of kerosene, just (mis)used the numbers that you'd quoted. Silly me!

Totally get where you're coming from now. And I agree. 30 minutes of light from an LED driven by 20mA ain't worth the bag of rocks.

SixteenBlue wrote:
Quintin_Stone wrote:
SixteenBlue wrote:

Today I saw ultrasound images of my baby and heard it's heart beat. A couple hours later I was offered a new, much better job. Today has been great.

And then you made the mistake of going to IRC.

So true.

Oh sh*t, I missed that. GRATS!!!! What a great day!

The bar that I went to tonight had an on staff magician. He was awesome!

IMAGE(https://lh5.googleusercontent.com/-Lt4foBRMLac/UPcdjaFEVCI/AAAAAAAAB5k/LtETByjAORs/s321/Jan.+16.jpg)

Whoa, I never saw that Ninkasi. I am jealous. I love that they named a Barleywine Critical Hit. Another good name would be Back Stab.

tuffalobuffalo wrote:

Whoa, I never saw that Ninkasi. I am jealous. I love that they named a Barleywine Critical Hit. Another good name would be Back Stab. :D

I found this while trolling the net:

On Wednesday, May 23, 2012, a U.S. federal trademark registration was filed for GAMERS' BACKSTAB by PGB Portland Gamers' Brewing, LLC, Portland, OR 97212. The USPTO has given the GAMERS' BACKSTAB trademark serial number of 85633266. The current federal status of this trademark filing is NOTICE OF ALLOWANCE - ISSUED. The correspondent listed for GAMERS' BACKSTAB is TIMOTHY J. LOCKHART of WILLCOX & SAVAGE, P.C., 440 MONTICELLO AVE STE 2200, NORFOLK, VA 23510-2243 . The GAMERS' BACKSTAB trademark is filed in the category of Light Beverage Products . The description provided to the USPTO for GAMERS' BACKSTAB is Beer, ale, lager, stout, porter, shandy.

That's interesting. I'm not sure what to make of it, though. I'll keep an eye out over the years.

I love Ninkasi, I used to live in Eugene and it was a staple.

I love that I do not have to spend money on a new dryer and managed to get the drying running on my own. My wife has now learned that the lint trap needs to be in properly...

So the clinic I am putting some free time into does not have a coffee maker (loathe). Fortunately I have this.

IMAGE(http://i48.tinypic.com/wtwq37.jpg)

It works wonderfully, my coffee has stayed hot all day. Best part is at 48 ounces, I can stick to my normal 3-6 cups a day.

My girlfriend took today off and decided to undertake a bigger cooking project by our standards: Roast pork with fresh vegetables and home made gravy for dinner. She had no idea how it would turn out but she hit it out of the park! Forget first attempt, this was awesome for any attempt! My diet is shot to Hell today and I'm so overfull but I don't care cause it was awesome.

Preparing to GM the most ridiculous game of forum mafia ever.

(Not here obviously )

Had an awesome breakfast including French coffee. Got a back massage. Took a motorcycle ride. Hockey is back on TV starting in a few hours. Sure, I have two eight-hours days of solid testing on Mon and Tues for the final step in my medical licensing, but today? Today is a great day.

Coldstream wrote:

Had an awesome breakfast including French coffee. Got a back massage. Took a motorcycle ride. Hockey is back on TV starting in a few hours. Sure, I have two eight-hours days of solid testing on Mon and Tues for the final step in my medical licensing, but today? Today is a great day.

Best of luck with the licensing tests. Hope those days are as good as today.

Demyx wrote:

Preparing to GM the most ridiculous game of forum mafia ever.

(Not here obviously )

Why not?

I'm in BC surrounded by mountains covered in snow and sh*t. There's motherf***ing big horn rams in my parking lot. I'm currently at 2,600 ft (800m) elevation and I have to breathe a little harder. I'm loving this.

I've spent most of today driving my in-laws to New York. The love is that it is because they are finally leaving. Of course, the drive sucked, and coming back was a bear (a teething baby does not for a pleasant drive make, and she was actually pretty well behaved, unlike her older sisters). Now all I have to do is wait a week for the sister in law to leave, and sweet sweet freedom will be mine again!

PS. Are NY cabbies really suicidal, or do they just drive that way?

I was listening to MBMBAM today and there was a sponsored birthday message from Shawn Andrich to Carla Andrich. I was pretty happy except Justin never mentioned knowing Shawn or GWJ. Then, I listened to another episode and they thanked Elysium for tweeting about the show.

Awww!

I dunno, I think that's classy of the MBMBAM's. It's about the content of the message and not distracting from it by them talking about rubbin' elbows with other gamers/bloggers/podcasters.

Today has been one of the best birthdays ever (especially since it is my 40th). I received breakfast in bed, my wife and son played some boardgames with me, we took the dogs for a neighborhood walk, then my best friend came over, we drank beer and went out to dinner where we drank more beer, followed up by Cards Against Humanity. A wonderful day with family and friends.

Strangeblades wrote:

I'm currently at 2,600 ft (800m) elevation and I have to breathe a little harder.

Aw, look at the low-lander.

LiquidMantis wrote:
Strangeblades wrote:

I'm currently at 2,600 ft (800m) elevation and I have to breathe a little harder.

Aw, look at the low-lander. :D

Listen mainlander (that's ocean island jibber) it's hard to breathe! I can't think and I can't make up lies about the altitude!

Golden, CO? Hee. I'm in Golden, BC.

LiquidMantis wrote:
Strangeblades wrote:

I'm currently at 2,600 ft (800m) elevation and I have to breathe a little harder.

Aw, look at the low-lander. :D

I was thinking the same thing. 4600 ft here.

You guys! *blushes**rubs toe in dirt*

cartoonin99 wrote:
LiquidMantis wrote:
Strangeblades wrote:

I'm currently at 2,600 ft (800m) elevation and I have to breathe a little harder.

Aw, look at the low-lander. :D

I was thinking the same thing. 4600 ft here. ;)

Aw, look at the low-lander!

SixteenBlue wrote:

Why not? :)

Forum games don't seem to be a thing here! However if it were allowed and people were interested I could run forum mafia. Not while I'm running it elsewhere though -- I'm already up to 23 people and 200+ randomized roles...

Coldstream wrote:
cartoonin99 wrote:
LiquidMantis wrote:
Strangeblades wrote:

I'm currently at 2,600 ft (800m) elevation and I have to breathe a little harder.

Aw, look at the low-lander. :D

I was thinking the same thing. 4600 ft here. ;)

Aw, look at the low-lander! ;)

4,600 feet is low? Where do you live? In an aircraft?