Marc's Public Blog

2024/11/14 Neil deGrasse Tyson back at San Jose Center for Performing Arts: An Astrophysicist Goes To The Movies, the Sequel

π 2024-11-14 01:01 in Outings, Public

Back to see Neil deGrasse Tyson for a 3rd time, this time for part 2 of "An Astrophysicist Goes To The Movies". It ws a fun evening as any evening would him, would be, although I found this specific talk a little weaker than the first one, probably because he had to find other material that he hand't already used in the first talk, but that said there were still plenty of fun bits, and as I said, any time with him is a fun time :)

he still has a few books I should read :)

the list of movies for his 2nd talk

those doors were indeed portals to a 4th dimension we can't see as 3 dimensional beings

wizard of oz was wrong all along!

I never caught that one either

parsecs are a unit of distance, they can't be used for speed or time (BTW a parsec is 3.6 light years as I found out)

Gravity: haha, that's an easy one. It had lots of good physics, but also some glaring holes

Oh no, don't let him go! :)

As a bonus, he gave he attendees a hall pass for the next day if they were late :)

And I had no idea he was on zoolander 2 :)

It was another very fun night, very quick video summary:

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2024/10/20 Northern California Maker Faire at Mare Island

π 2024-10-20 01:01 in Outings, Public

Maker Faire came back but it's not really in the bay area anymore, Mare Island is honestly closer to Sacramento than it is from the South Bay. It's a bad location in my opinion, and I hope they come back to something more central to the bay, but we'll see.

That said I was driving back from Tahoe, so that remote location was on the way home and stopping there wasn't terrible. We arrived almost at opening time, but with offsite parking and bussing in, it did burn about 30mn. not ideal but we arrived in eventually:

Finally at the entrance:

It was nice to be in time for Adam Savage from mythbusters:

still has the passion

Fun to see coke and mentos again too:

The dark room was a fun time:

The LED Piano was great to see again:

I also loved the cuttlefish art car from burning man:

Plenty of other expos:

cool hat

electromage

oh my, I had one of those when I grew up

oh, I need one of those

how does it even? :)

cool idea :)

For some reason they also had cars:

This was fun enough, but the new location is not great, I hope they change it back to the middle of the bay area, I don't care if it has to cost more as a result.

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2024/04/14 Electronics Flea Market

π 2024-04-14 01:01 in Computers, Public

I hadn't been able to go in a few years, glad to be back and find other electronics, batteries and other stuff I might or might not need, but looked enticing :) (I ended up finding a bunch of lithium battery packs for a good price, that will work for my burning man bike, and maybe LED outfit as a backup source of power, I may even be able to use them to power my laptop)

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2024/04/12 San Antonio Japanese Tea Garden and Botanical Garden

π 2024-04-12 01:01 in Ntrips, Public, Texas

The Japanese Garden was nice to visit in the morning

Err, Chinese and Japanese are different!

Next door, the botanical garden was quite enjoyable and had some bird houses and bird watching:

first time I see a cardinal!

I found another very cool bird with an unusual song:

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2024/04/08 Texas Eclipse

π 2024-04-08 01:01 in Outings, Public, Texas

The Texas Eclipse Festival did not end as planned, organizers cancelled the event for weather risk reasons, although in the end the weather was so much better than forecast (forecast said we'd never see the sun at all and it would rain).
When I heard about the cancellation on a thread fo bar one of my 2 cell phones,while barely awake, I managed to tear up camp and start driving out in just 15mn and got out of the festival in just over 45mn, before traffic got really bad. I then realized I had just enough time to drive my friend Marc Antoine's ranch 50mn away, and the fact that 2 lane roads in TX have 70mph speed limits, sure helped. I got to his place 30mn before totality.

It did not rain, and the sun came out just at the right time for the eclipse and went hiding in the clouds soon after. Timing was perfect. And I happened to capture some solar flares and mercury with my not so great handheld camera, so I'm happy :)

When I got out of the festival, partial eclipse hadn't started yet, but the sun was barely visible

Marc sent me the GPS location of his ranch, and GPS said I could barely make it and thankfully the roads were near empty

I pulled over a few times when the sun was visible for barely a minute

Most of the time, it was fully overcast, as per the forecast

but the sun came back out a few times

And in barely 50mn I made it to Marc's ranch and got to meet his family. We had just seen one another 2 weeks prior at beyond wonderland

all ready

fun thing is you can see a partial eclipse without glasses

getting there, so close

and yes!

even a decent shot frmo my cell

it got dark :)

I caught some sun flares on this one

on lower right, I think I you can see mercury. Einstein used it the lensing effect of gravity in his theory of general relativity

my best lucky shot!

and way too soon, it was over already :)

and the sun soon went to hide under clouds again, perfect timing!

The eclipse festival didn't end well, but the eclipse itself went way beyond expectations!

Video:

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2024/04/05 Seeing Android Jones' Samskara Again At Texas Eclipse Festival, This Time

π 2024-04-05 01:01 in Bm, Public

I remembered Samskara from having seen it in 2016 at Red Lighting's Dome at Burning Man and it was very cool to see it again 8 years later at Texas Festival Eclipse. Still a wonderful visual display:

Video:

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2023/12/17 Quick Neighborhood Walk To See Xmas Lights

π 2023-12-17 01:01 in Public

I was actually quite impressed by the decorations my neighbors installed, as well as the night picture quality of the Pixel 8 Pro:

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2023/11/29 SJ Xmas in the Park

π 2023-11-29 01:01 in Public

Another Xmas in the Park in San Jose. Always fun when you are already nearby during the right season.

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2023/10/14 Partial Eclipse

π 2023-10-14 01:01 in Public

I wasn't quite ready for it, as I didn't know it would be visible in California, but turns out it was for the short amounts of time clouds didn't hide the sun.

Here are a few shots:

not bad for a start

kind of nice with the clouds in the way

getting close to being over

one tiny sliver left

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2023/09/22 Testing 1.5V AA Lithium Batteries

π 2023-09-22 01:01 in Electronics, Public

Lithium Batteries have a voltage between 3V and 4.1V, but recently they have been turned into the 1.5V form factor with some electronics that step them down to 1.5V and custom chargers that know how to recharge them via a special protocol, or for the EBL batteries, they have a micro USB plug onboard.

They are of course not all the same real usable capacity, and I've learned not to trust vendor capacity claims anymore either, due to the amount of sellers that plain lie on amazon. The good news is that Neither Xtar nor EBL lied about their cell capacity as long as you understand that the actual energy you can output will be lower due to conversion losses and some safety buffer to give the cell longer longevity.

https://docs.google.com/document/d/1z9o7O5o70SxJnQwKHJD8JdlPdScZZ1o09scHqUlDxeE/edit?usp=sharing

Here is a quick summary without pictures:

New Xtar: Rating: 4.15Wh, Charge: 5.5Wh, 3.45Wh Usable discharge at 1A

https://www.amazon.com/gp/product/B0CF8ZNZ33/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1

Summary:

This is the only lithium battery that drops its voltage to 1.1V to give you a low voltage warning. Other batteries I tested just die with no warning. That alone is a reason to select it. I tested it with my garmin GPS and it gave me 2H of low battery warning before finally dying. Very nice!

It is also the battery that gave me the most actual discharge capacity

Seller is not lying about cell capacity (thank you) which of course is higher than actual usable energy due to conversion losses

New charger is unfortunately bigger than the old one and drops the USB-A output feature to use your batteries as an emergency USB charger

Verdict: this is the best battery I tested and what you should buy as long as you don't need a built in charger like EBL

Old Xtar: Rating: 3.3Wh, Charge: 5.3Wh, 2.7Wh Usable discharge at 1A

https://www.amazon.com/gp/product/B09NLVJDY6

Summary:

This is the older Xtar battery. It had best in class capacity until the newer one that came out with added low voltage warning. There is no good reason to buy this battery anymore, get the new one.

Its capacity is equivalent ot the EBL battery with built in USB charging, so the EBL is more versatile

The charger is very compact and can act as a USB power source, that's a nice feature.

10.6Wh to charge 2 batteries, or 5.3Wh charge per battery

EBL 3.3Wh rating, Charge: 4.3Wh, 2.7Wh usable discharge at 1A

# https://www.amazon.com/gp/product/B08RZ5NDMM

Summary:

There is no low voltage warning, but the battery capacity is actually equivalent to the old Xtar despite the space lost to the built in charger. The new Xtars last longer than the EBL though.

Interestingly EBLs need less energy to charge than Xtar for the same output capacity, they are more efficient

Big warning: if you try to charge the batteries via USB while they are in use, they are going to output 5V instead of 1.5V. This is unexpected and fried one of my GPSes. You cannot charge them while they are being used.

Deleepow 3.4Wh rating, 3.8Wh charge, 2.4Wh usable discharge at 1A

https://www.amazon.com/gp/product/B09NLXQRP3

Summary:

These battery are not for sale anymore, and they were the least performing amongst the ones I tested.

The 3.4Wh cell capacity is probably untrue with the charge and discharge numbers I got

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