Showing posts with label Texas. Show all posts
Showing posts with label Texas. Show all posts

Saturday, May 18, 2019

2019-05 - Hamilton Pool Preserve (outside of Austin, Texas)

First view of Hamilton Pool & waterfall
Two months ago, my neighbor and I were out and about at SXSW. We started talking about Hamilton Pool while enjoying some free food from Ranch Hand at the ACLU booth. On a whim, we booked a reservation, which happened to be two months away in May. (Try getting a weekend reservation today; and, you'll have to wait until September!) Today, we finally got to enjoy that reservation.

Hamilton Pool, across from waterfall
 When we arrived at Hamilton Pool entrance, the park ranger went over the rules, checked our car for pets (not allowed) and extra passengers (8 max/vehicle), and gathered the remaining $15 (cash only) before allowing us to park. Our reservation was for 9 am - 1 pm. After parking, we walked the short trail (includes some steps, roots, and rocks) down to Hamilton Pool. The first thing that struck us was the brilliant blue green color of the water. It really does look as beautiful as all the photos that you've seen! The water temperature today was refreshingly cool yet warmer than Barton Springs.

Hamilton Pool, across from waterfall
Half of the pool is skirted by a what looks like a natural limestone amphitheater. (The website calls it a grotto.) There is so much floral and fauna in this giant stone structure! Trees cling to the top of the rock. Not far below them, scrubby plants stubbornly cling to cracks in the vertical stone edge. A bit further below is the rim of the stone roof stretching over part of the pool. Stone formations hang down from the rim (are they still called stalactites if they are not in a cave?). Bright green ferns cling to the ceiling just inside the rim of the rock, the fronds pulled down to the water by gravity.
Stone walls stained colors by micro-organisms
We walked along the stone wall of the amphitheater to get to the far side of the pool, with it's waterfall. This wall is stained blues, greens and purples from the organisms that cling to its surface. Along the way, we noticed little birds flitting in and out of holes in the limestone ceiling. These are their nests! Finally, we made it to the waterfall, which flows from Hamilton Creek up above at the edge of the stone rim. We stood in the mist behind the waterfall and savored the moment of enjoying the lush vegetation, beautiful weather and the fact that we do have protected parks that we can all enjoy.

Hamilton Pool, behind the waterfall
Returning to the "beach" (it's rocky, not sandy), we left our backpacks and got into the water, swimming back to the waterfall so that we could sit under it and enjoy the force of the water. Then, we floated idyllically in the water, gazing up at the sunny sky above that had looked some ominous earlier in the morning. Around the rim, at some of the rock protuberances, water trickled down into the pool. Floating under such stone slab, I could see the individual water drops as they floated through the air toward me.  Truly a magnificent way to spend a Saturday morning.
Pedernales River
Eventually, we returned to the beach and lounged while drying off. Until it started sprinkling and then sprinkling a little harder, until we had all pulled out umbrellas as it seemed that it was about to rain in earnest. We packed up our gear, ready to return to the car, when, the rain stopped. However, this gave us an opportunity to take the one trail, which is only 0.6 miles, that dead ends into the Pedernales River. Along the way, we saw fish, a bug skating across the water, and some furry caterpillars.  It worked up a bit of a sweat; and, on our way back, we thought that we'd jump back in Hamilton Pool one last time. However, we were too late. The park ranger had already told everyone at 12:30 that they had to return to their cars.


If you go...

- Hamilton Pool is 23 miles away from downtown, a 45 minute drive without traffic.
- Make a reservation: https://parks.traviscountytx.gov/parks/hamilton-pool-preserve#reservations
- Reservation does not guarantee that Hamilton Pool will be open for swimming
- Hamilton Pool can be as cold as 50F
- Wear your swimsuit there. There are only two stalls in the women's restroom in the parking lot and only two porta-potties by the pool
- Watch for poison ivy

Tuesday, August 22, 2017

2017-08 Visit to TACC (Texas Advanced Computing Center)

After working for almost a year now on a software team that enables High Performance Computing (HPC), today, I finally saw my first super computer in person. In fact, perhaps counting it as only one super computer is a misnomer. The chips arranged in groups of machines are called clusters. Each cluster has it's own name, types of chips and purpose. However, the largest cluster of all at the Texas Advanced Computing Center (TACC) is made up of 4200 Intel(R) Knights Landing (KNL) chips and 1300 Intel(R) SkyLake (SKL) processors. This is the newly installed Stampede2 system.



Stampede2

We not only got to view Stampede2 from behind the glass, we actually got to walk down one if it's "hot aisles", or an aisle with all the backs of the machines facing in. It's "hot" because the cooling system blows cold air on the fronts of all the racks. The air becomes hot by the time it arrives at the back of the cabinets. Stampede2 takes up five and a half rows. Looking in from the back of the machine, we were able to see this rack full of Intel (R) Omni-Path switches and cabling. These specialized switches and cabling enable all of the chips in the Stampede2 cluster to communicate more quickly than over standard switches and cabling.

Omni-Path switches and cabling

Lest you think that this is all one big advertisement for Intel HPC products, we did see several other clusters, including ones with AMD and Nvidia chips. Strange but I seemed to have forgotten to take pictures of those...

The last cluster we viewed is a collaboration between a Japanese corporation, a Japanese government agency and TACC. It is an experiment to see if a super computer can be powered by solar. The solar panels are installed as a carport in the parking lot. Unfortunately, current solar panel technology doesn't provide enough power to run a super computer, even a smaller cluster like Hikari.

Checking out the solar versus grid powering Hikari