2012-05-08

LED Bulbs

I've just been trying out some LED light bulbs and they seem to have progressed a great deal since the last time I played with them.  For recessed fixtures that have a narrow angle of lighting, they seem to be a pretty good deal.

Previous generations of LED light bulbs had problems:

  • Blueish color of light
  • Delay after turning on the wall switch
  • Wouldn't work with dimmer controls
  • Not as many lumens (brightness) as desired.
I've bought a couple different bulbs off of Amazon and tried them out.  I ended up really liking these ecoBrites: http://www.amazon.com/gp/product/B003THZHOU.  No affiliation / kickbacks for me at all, I'm sure there are other great options out there too.

They seem to solve all of the above problems, though they do look a little bit different than regular bulbs if you look at the bulb when it's turned off.  

The key is to look for bulbs of a certain "color temperature".  The blue or "cool" colors are a higher temperature (around 4000-5000k) whereas the yellowish incandescents tend to be a warmer color around 2500-3000k.  CFLs are usually a higher temperature too though not usually blue, so they look very white.


My PG&E rates are tiered - 12.8c/kWh for the baseline, then it goes up to 14.6c/kWh for the next chunk and I'm actually bumping a small amount in to 30c/kWh rate lately.  So, my incremental cost of shaving off power usage is 30c/kWh initially and if I can get it down enough, probably 14.6c/kWh.

The above bulbs are 7W and replace 60W incandescents.  So, I'm saving  53W/h while these run.  They cost $39/bulb though.  Very conservatively, let's go with the 14.6c/kWh rate.  That's .7c/hr savings.  Assume I run each bulb for only 2 hrs per day.  To save $39, it'll take 6.9 yrs to breakeven.  That's the conservative number.

If you assume only that:
  • I'm replacing a bulb, so would have to pay $7 anyway, the breakeven is 5.6 years
  • I need to buy a new incandescent bulb every ~750 hrs, the breakeven is 4.4 years
  • the extra 53W of heat an incandescent bulb generates needs to be matched by at least 53W of air conditioning work (likely far more due to inefficiency), the breakeven is 3.4 years
  • I'm actually reducing my bill by the 30c/kWh rate, the breakeven is 3.4 years
  • If I'm using the bulb for 3 hrs / day, the breakeven is 4.6 years
If you assume all of the above, my breakeven becomes only 11 months.

In practice, the real story is probably somewhere in the middle.  I do need to buy incandescent replacements periodically, I sometimes need to use air conditioning, but certainly not always, and my savings is probably a mix between the 30c and 14.6c rates once all is said and done.  So maybe the breakeven is 2-3 years, so roughly a 26% return.  That still seems like a very good investment these days.

2012-04-24

Cloud Storage Price Comparison

Google Drive launched today right on the heels of Microsoft's Skydrive earlier in the week.  It seems the cloud storage revolution is heating up, with other big competitors including Amazon's S3 and Dropbox.

Of course, each of these services has different sets of features.  Amazon S3 is more of a bare-bones backend for developers to build on top.  Dropbox has linux support, yay.  Google Drive has some amazing appstore integration and rich Google Docs interface.  Microsoft's Skydrive presumably has the deepest integration with Office software (although Drive does have an Office plugin called Cloud Connect).

While it's sometimes hard to compare long lists of features, it's pretty easy to compare a number.  Today, Gregable readers, that number is GB and monthly cost.  Here's what the 4 offerings above look like when stacked up against each other (please correct my math if I missed something):
Microsoft Skydrive and Dropbox don't publish rates beyond their 100GB additions and may not even offer them.  Google Drive keeps the same ratio past 1TB, and amazon actually gets a tiny bit cheaper.  The interesting stuff to most people is in the left part of that graph, so let me blow that part up for you:

That's a simple view, but I think it's roughly accurate.  Some other caveats just to the pricing to keep in mind:
  • Amazon S3 charges separately for upload and download bandwidth where the other solutions include bandwidth in the price, so Amazon S3 really costs more than what's shown above in practice.
  • Amazon S3 gives you 5GB free only for the first year.  The other services' freebie quotas are permanent.  Dropbox gives you 2GB free, Google gives you 5GB free and Skydrive gives you a nice round 7GB free.
  • Microsoft Skydrive charges you annually rather than monthly, so I converted all of their prices to monthly prices.  Of course, this means less flexibility as well as the fact that you have to pay everything upfront.
  • Sharing in dropbox counts against all of those users' quota, while sharing in Google Drive counts only against the person who shared.  It isn't clear about Microsoft Skydrive's policy on this.
Also, I imagine that it'll be very interesting to take a look back at this post in a couple years and see how this has all changed.

2012-03-24

Mega Millions

I for one think the lottery is a tax on people who aren't very good at math.  If I wanted to gamble, I'd buy a casino.

Mega Millions is the big multi-state lottery that has in recent days grown it's jackpot to the point where the payout could be worth the risk.  The cash payout is currently at $255 million (the $356M number is an annuity) and growing.  To win, you buy a $1 ticket where you must pick 5 random numbers correctly out of a pool of 56 and 1 random number correctly out of a pool of 46.  The odds of a correct pick are 1 in 56C5 x 46 or 1 in 175,711,536. 

Is this a "good bet"?

For the sake of simplicity, let's ignore taxes as well as the possibility that there is more than one winner (thus splitting the payout).  Also, most people's utility for money is non-linear (ie: beyond a certain point, more money doesn't matter as much any more).  Those are important issues to consider in real life as they have a fairly large effect.

To estimate the expected net returns, P(win) x jackpot - cost =
=

=     $0.451.  

45% return on your dollar in just a few days sounds like a great investment.  Mortgage your house, max out your credit lines, sell your stocks, and invest in tickets!

The problem with bets is that even if you have the odds in your favor, you can still lose everything.  How do you choose what to bet then?  Bet too little on a good gamble and you'll leave money on the table.  Bet too much and the losses will keep wiping too much of your winnings out.  It turns out that there is formula that predicts the optimal size in a series of bets which will maximize your winnings in the long run.  This is called the Kelly criterion.  It determines a bet size based on your odds and your current bankroll available to wager.  As your bankroll grows, you bet more.

Let's say that you were only allowed to buy one mega-millions ticket per round with the 1 to 175,711,536 odds of winning $255M.  Is this one ticket a sound investment?  The Kelly criterion tells you the fraction of your bankroll you should invest in this bet.  The formula is simple enough, divide the expected net returns ($0.451) by the net winnings if you win ($255M).  The result is 1.77x10-9 or 1 in $565,410,199.

If and only if you have at least $565,410,199 to invest, buying a $1 ticket is a mathematically sound investment.

Buying two tickets in the same lottery round is a slightly different gamble than buying 1 ticket each round.  It's a little better odds.  Taken to the extreme, buying 175,711,536 tickets guarantees a win whereas buying 1 ticket in each of 175,711,536 rounds does not.  A modified Kelley criterion can evaluate the case where you buy multiple tickets too, and it's going to be more favorable.  Unfortunately, I don't have the time at the moment to add that to the post.  If there is interest, perhaps I'll return and see if I can work through that math.

2011-10-28

Etsy

Cristin, my better half, has been making jewelry for several years now and selling it in a store in her hometown in Virginia.  She just set up an etsy store and listed some of her first jewelry on it for sale.  Just a few pieces for now, but I think you should check it out:


2011-09-06

Yosemite High Sierras

I just returned from a 6-day, 50 mile hike between Yosemite's High Sierra camps.

Most people who visit Yosemite visit the iconic Yosemite valley, which is truly beautiful, but teeming with people.  A smaller fraction turn north as they are entering the Park and head up to the higher altitude area of Tuolomne Meadows and Tioga Pass.  Equally beautiful, although less iconic, this area of Yosemite has more limited amenities and is far less busy even in the summer months.

Fewer people still are even aware of Yosemite's High Sierra Camps.  These are 5 staffed camps (beds, cooked meals, running water, showers) that cannot be reached by road.  You can only reach these camps by trails, either on foot, or by mule.  Few people I've talked to have ever heard of these camps.  Still, availability is extremely limited so reservations are made a year in advance by lottery.  The season for some of the camps this year was less than 1 month, and they could only handle about 40 people per night.

The camps are arranged in a loop, and all of the camps can be reached via a long day hike from the road.  The most remote camp, at Merced Lake, is a 12 mile hike from the valley.  We decided to visit all of the camps along the loop in clockwise order (apparently counterclockwise is more common).  The route is below.



View High Sierras in a larger map

The days ranged from 6 - 10 miles, some of the days up days, some down.  The most elevation change was ~3000 ft.  The experience was different every day: granite, forests, meadows, waterfalls, streams, lakes, vistas, sunsets, stars, and wildlife.  I've detailed more of the trip below for those interested, but feel free to skip.

Day 1: Tuolomne Meadows to Vogelsang

The first day's issue is dealing with the altitude as we aren't yet acclimated.  We climb a modest 1,400 ft over 7 miles from Tuolomne Meadows to Vogelsang camp.  The climb is relatively steady uphill the whole way with forest cover some of the way and the most amazing meadows especially as you near the end of the trip.  Wildflowers, pikas running around, streams with fish, and granite walls on either side of the valley you are walking through.  A quick climb at the end over a lip and you are at the base of Fletcher peak at Vogelsang camp, the highest altitude camp of the 5.

Vogelsang camp sits a little above 10,000 ft on a ledge above a granite valley below with Fletcher peak above and Vogelsang Peak in the distance.  A few hundred feet away, a few of us took a brief dip in Fletcher lake, which is just above freezing even in August.  You can watch the snow melt immediately above the lake while you are swimming.  As it turns out Fletcher is a vast aquifer.  We are told that Vogelsang has the only legal non-chlorinated drinking water in California.  I didn't notice the difference.

After dinner, the stars at Vogelsang are fantastic.  Our trip chanced to schedule Vogelsang on a new moon, so it was very dark.  The milky way was quite bright and visible.

Day 2: Vogelsang to Merced Lake


We opted for the slightly shorter / easier route of the two options.  This turned out to be one of the prettiest stretches on the trip so we were happy with the decision, although who knows what the other option had in store.  This day was the biggest elevation change of the hike, dropping ~3,000 ft over 7.6 miles, but it wasn't a smooth gradual drop.  Instead it was long switchbacks alongside waterfalls interspersed with more beautiful meadows.  Very difficult on the knees.  My favorite stretch along this hike was what seemed like a half mile long water slide that just kept going forever.  The image below shows a tiny section of it, but can't really do it justice:


Merced Lake camp used to be a military post.  The tents are arranged in a half circle around a central campfire which probably was once a flagpole.  This is the most comfortable of all of the camps, with 8 showers, a warmer swimming hole in the stream, washbasins, and lots of shade.  Not much for a view though as you are at the base of a valley and deep in trees.  It's also the most remote - the nearest road is in the valley, 12 miles away.  As with the other camps, all supplies are brought in by mules.

Day 3: Merced Lake to Sunrise

Day 3 started with a few hundred feet of drop, then climbing back up 2,300 ft.  All over 10 miles.  Here again the elevation is not evenly distributed, with several switchback sections.  Only this time they are up.  It was a long day, easily the hardest of the 6, and probably the least scenic of the trail stretches, although that's relative - it still packed some amazing views.

Sunrise camp on the other hand was likely my favorite, and I spoke with several people who would agree.  The camp is perched on a ledge above an alpine meadow at ~9,400 ft.  The meadow then drops off and you can see incredible views of several mountain ranges in the distance.  The view at sunset was amazing.  Sunrise in the morning was even more so as the meadow had frosted over during the night and would sparkle in the sun.  The camp also had showers, and the staff formed a one-song band at dinner, which was a fun experience.

The photo below is from the meadow below sunrise camp.  Sunrise Camp itself is a little higher, affording good views of the meadow as well as the mountain ranges behind the trees in this photo.



Day 4: Sunrise to May Lake


Day 4 was an 8 mile hike that was fairly easy except for a painful ~2 mile stretch of rapid descent along switchbacks above Tenaya Lake.  You begin by climbing over the ridge behind sunrise camp and dropping down gradually past several photoworthy "sunrise lakes" that might have been great for swimming had we had the time.  Immediately before the painful descent is a trail marker for Clouds Rest.  At the recommendation of someone at Sunrise, we took a side trip out a few hundred feet along this trail to be rewarded with a fantastic view down into Yosemite Valley, including the back side of Half Dome.




The switchbacks were panoramic as well, although overlooking the Tuolomne area and Tenaya lake rather than the valley.  At about the 6 mile mark, we reached our strategically placed car at Tenaya Lake, the only road crossing for the hike.  We switched out for some fresh gear and finished the rest of the hike uphill to May Lake.

May Lake is nestled halfway up Mt Hoffman, which a staff member from Sunrise mentioned is the geographic center of Yosemite.  The camp lies between the lake and a short granite lip.  Scrambling up the lip affords a panoramic view of the ridge you just climbed down as well as many other peaks, as seen in the photo below.  May lake is pretty comfortable too.  The manager, Brian, treated us to some colorful historical stories of the camp as we enjoyed the delicious salmon dinner.




Day 5: May Lake to Glen Aulin


Day 5 was pretty mellow - a gradual downhill, mostly flat, over 8 miles.  We got into camp fairly early as a result.  Most of the day is within forested areas, so there is little to see.  The only challenge was a few patches of mosquitos and flies.  We donned some mosquito nets and moved on - I've seen much worse.  The only real vista was early in the morning, but  it was fantastic - you could almost see all the way to the next camp, below is a fraction of that view.  Glen Aulin is just behind that small mountain almost in the center of the photo, right behind the first forested saddle.


Glen Aulin itself is in an amazing location.  It sits directly beside a large waterfall on the Tuolomne River.  You can barely see some green benches and one or two of the white tents on the opposite side of the river in this photo.


Downstream a short bit, we took a swim in the river, below yet another waterfall.  Still cold, but much warmer than Vogelsang.  Glen Aulin has no showers, so this was the only option for washing off.

Day 6: Glen Aulin back to Tuolomne Meadows


The final day is also pretty easy, you follow the Tuolomne river upstream for a little under 6 miles back to parking lots at Tuolomne Meadows.  For the first few miles, it's literally one waterfall after another and progress is slow due to enjoying the views and taking photos.  After a while, the river slows down, flattens out, and widens into a Tuolomne Meadows.  A different type of amazing view, more relaxed.  Overall, this hike is just a wonderful finale.





I'll eventually upload some more photos and I'll post a link on Google+ if you want to follow along there.

I also thought I'd share a few boring notes on logistics, as I had a little bit of a hard time figuring out much of this online.  Only read the remainder if you are planning on making this trip yourself and have questions about the camps and what you need to bring:

  • The camps are tent cabins.  4 (usually) spring cots with matresses.  You'll share with strangers depending on your party size.  Each bed has 2 army blankets and a heavy comforter.  This was plenty to keep me warm at night and it got below freezing at least one night.  The only other thing you'll need to bring is a sleep sack or sheets, no bed linens are provided.  The beds also have a pillow and a pillowcase that gets washed.  Don't bring pads/sleeping bags/pillows.
  • Except for Merced Lake which is lower elevation and warmer, every tent has a wood burning stove and you'll be provided with wood, starters, matches, candles.  Everything you'd need to start a fire.
  • As for temperature, it seemed plenty warm as long as the sun was out.  After sunset but before you climb into bed, you'll be chilly and the morning will be chilly.  Still, all I needed was a light jacket.  Unless you plan on staying up late and watching stars, my experience was that lots of heavy clothing was unnecessary.  The Yosemite packing list suggested a down jacket, fleece, mittens and thermal underwear. It was nowhere near that cold, but check your weather forecast I guess.
  • Speaking of weather forecast, use NOAA and click on the map where your hike is - the nearest station which is what weather.com and others use is too far away to be useful.
  • Merced Lake, Sunrise, and May Lake have showers.  You will want to bring a towel and soap/shampoo, although you may be able to buy a towel from the camp store if you forget.  A small washcloth is provided at every camp, but that's it.  Other than sunrise, all of the camps have great nearby swimming options which might cover for a shower depending on your preferences.  Best to bring some kind of shoes you can wear into the water though as the rocks can be a little annoying.  Flip flops worked for me.  You might need these for water crossings on the trail anyway.
  • Either carry lots of water (4 liters) for the day or carry a filter.  We toted a filter and were rarely far from water, so we didn't need to carry as much water weight.
  • On food, breakfasts and dinners are plenty of food and wonderful.  Best backpacking food ever.  Bag lunches include a decent sandwich and optionally fruit, trail mix, cookies, and a fruit drink.  You can order it all or a la carte.  You order at the camps the night before, not much advanced planning required.  Credit Cards are accepted if you don't want to tote cash.  Basically, you don't need to bring any food, or just some snacks if you would like.

2011-08-15

Canyon Creek Backpacking, Trinity Alps


Last weekend I got the chance to go hiking in Trinity Alps Wilderness in Northern CA.  It's an area I've been wanting to visit for some time, but logistics are challenging - it's a ~6hr drive from the Bay Area and there is only a narrow season when hiking wouldn't require snow traversal.

The Trinity Alps area is very large, we hiked only one valley.  The trail starts down the valley shown in the upper left side of the above photo, climbs slowly along Canyon Creek, and then there is a short scramble up to these lakes: Lower and Upper Canyon Creek Lakes at around the 8 mile mark.  The trail then cuts between the two lakes and after a short stream fording wraps around to the northern side of the upper creek (right side of photo).  Most folks stop and camp around here.

We cut east (camera in the above photo is facing west) climbing at a 40-60% grade for the another mile up to L Lake (some maps show "el" or "ell").  We camped on the granite domes above and to the south. That last mile was quite tiring, but rewarding.  We were sitting in a bowl with a great view of the surrounding area and night sky.  We enjoyed the Perseid meteor shower until around 11pm when the full moon rose above the nearby ridges and the whole valley was illuminated.

The map below shows the rough trace of the trail, although I just drew this by hand from memory rather than GPS, so it's not entirely accurate.


View Trinity Alps, Canyon Creek in a larger map

2011-08-04

Can we build communities with Google+ ?


Apologies, this might be a bit long.  I want to discuss an idea for Google+.

Progression of a Community
Imagine a mailing list about a somewhat broad topic, rock climbing.  This could apply to other social software systems (bbs, forum, social news), but I’ll use the mailing list for my example.

Initially the list grows out of a small group of contributors, likely folks who know each other IRL.  For these seed members, the list is just a convenient way to communicate out-of-bandf, organize trips, share local news, etc.  It’s a shorthand version of a cc list in email.

Over time, people invite their friends and the list starts to grow.  Geographical differences may begin separate the members.  If you could draw the social graph of the members, it would have sub-clumps.  At this stage, not everyone knows each other any longer.

As the list continues to grow, at some point the signal to noise starts to creep up on the list.  Reading a discussion on a local rock face in another time zone is minimally relevant.  More annoying is that user on the list trying to sell a new belay device to this targeted rock climbing audience.  At this stage, a community can collapse under it's own weight.

Scaling Patterns
Strong communities usually attempt to solve the above problems.  The attempts often fall into one or more of several patterns:

  • Individuals who are least similar to the “list personality” unsubscribe or are forced out.
  • A subgroup of “community administrators” creates strict rules defining acceptable content or acceptable users, removing content or approving it.  This administrator group can eventually have scaling problems too.  Wikipedia is a classic example of this approach.
  • Formation of fractured smaller lists to discuss more specific topics.  Reddit is a classic example with its numerous subreddits.
  • Using algorithms / voting to promote the more interesting discussions to help users filter content from noise.  Digg or the reddit home page are classic examples here.
  • I don't think that these patterns are full solutions.  Some seem to allow for a larger scale without fully solving the scaling problem.  Some succeed at promoting content that is most interesting to the lowest common denominator, but fail at promoting what’s most interesting to each individual.

Communities in Google+
I wonder if + Circles with some tweaks could work better as a community model.  I’m interested in your ideas, but here is my strawman:

  • Anyone can form a “public” rock climbing circle, but it doesn’t contain people, it contains comments, so let’s call it a rock climbing square rather than a circle. 
  • I can post to that square.  Those posts don’t show up in the streams of people who follow me.
  • All posts to the square are visible, but it’s liable to get noisy and unlikely anyone will really pay attention to the full stream for long.
  • I can follow other people strictly within the context of the rock climbing square.  I won’t see their public posts, just their rock climbing posts, but it’s public in a sense as they aren’t required to follow me in return.
  • I can reshare strictly within the context of the rock climbing square.  If Bob is following Alice, Alice is following Charlie, but Bob is not following Charlie - then Alice resharing a post from Charlie will display it to Bob, thus giving the square friend of a friend semantics with a filtering component.

In this sense, the community becomes a very weakly defined notion.  It’s not a fully connected graph like facebook, forums, or mailing lists.  It’s not disconnected subtopics either, like subreddits.  Members become filters for other members, and I can pick and choose my filters as their interests match my interests.

It has many similarities to twitter, but one important difference that I see (other than the character limit).  I can follow someone’s rock climbing posts without following their underwater basketweaving posts.

What do you think?  How could this be improved?

PS: I work for Google Search, but have no visibility into what the Google+ team’s plans are.  As a result I assume it’s safe to write about this kind of thing, but do remember - these are just my personal thoughts.

2011-07-08

My Circles

Google+ seems well received so far.  Most of the people I've talked to really enjoy the "Circles" feature and feel that it fits their mental model well.  I thought it would be fun to do a little data dive on my facebook graph to see how my relationships were actually interconnected and whether the data matched my perceptions of how I was planning my circles.  First the graph, then the explanation:
Gregable's Facebook Social Graph - click through see a larger version.

Each vertex is a friend of mine on facebook.  There is an edge between two friends if they are friends with each other.  I'm not actually in this graph, otherwise there would be a vertex with an edge to every other vertex.

I called out my wife, Cristin, who bridges several regions of my graph.  Even without me calling out that node, it would have been easy to guess.

The green region is high school.  The blue region includes Google employees, which is naturally over-represented.  College gets broken up a bit, and I wasn't really using facebook much for keeping in touch there.  You can see some other dense clusters in here as well, but I'd didn't bother labeling them.

To me, this reinforces the Circles concept pretty well!


Technical Details:
I installed a firefox plugin that saved a copy of every page I visited. I then turned off javascript and clicked through to all of my friends to extract the data.  I'm sure there is any easier way to do this, but I would have spent just as long figuring it out for this one-off.

Parsing the pages was some hacky python and regex.  Some of the templates weren't parsed as easily as others, so a few friends just got dropped due to laziness.  Any friend who didn't have any mutual friends also got dropped.  However, I didn't require a connected graph.  That just happened on it's own, to my surprise.

The graph was laid out using neato, and then I added the colored boxes on top by hand using Gimp.

With neato, I can change a line and get the nodes as text boxes with names instead, which is fascinating to look through, but not something I feel comfortable sharing publicly.

Also note that I don't do a good job of maintaining facebook, and have had purge cycles many times in the past.  A larger graph with a bigger picture would be even more fascinating I think.

2011-07-03

Find me over on Google+

Don't worry, I've been blogging for 9 years and no social network is going to stop me any time soon.

That said, Google+ is a social network that I can share with a wider audience.  Lots of folks tend to read my blog: techies, SEOs, etc.  I didn't want the same large crowd seeing all of my personal facebook content that I was sharing with close friends and families.

Google+ lets me filter who sees each post using the "circles" interface.  So, if you find this blog mildly interesting, I encourage you to follow me on Google+ as well:  Gregable on Google+.

2011-06-24

Dilbert on SEO




Today Dilbert learns that only organic linking works.  Links such as: Dung for Brains