Weird thought for the day: in a sense, we are all "inside" the sun. What Voyager 2 just did: it went outside the sun. I say this because, unlike a planet, the sun does not have any material surface other than the surface Voyager 2 just crossed.../1
2/ When you look see pictures of the sun, what looks like its surface is really an optical effect, not really a material surface. It is called the photosphere...
3/ It is where the plasma has gotten just a little less dense -- just a little. Below the photosphere, photons are absorbed and re-emitted by the molecules but the molecules usually collide before re-emitting the photons, so it changes the photons' directions: it scatters them.
I still wonder how falling ejecta could completely bury the boulders without also burying the grooves. So where are the boulders??? In any case, @CLASS_UCF co-sponsored Ramsey's lecture on this theory, viewable here: connect.arc.nasa.gov/p806n591s4h/?l…
2/ Another problem: the grooves are filled with conical craters. If these are supposedly where the boulders bounced, then they should be be in order earlier-to-later as you move away from Stickney Crater. However, you can see overlapping craters where they are in the wrong order.
3/ The alternative theory is that the grooves are the result of tidal stretching of Phobos, where regolith is collapsing into the structural cracks of the body. This allows that the collapse craters form in random order along the faults. It better fits the visual data.
Yes, for sure! When I ran a lab at NASA, I had to do calculations on liquid nitrogen & compressed gases so in case the bottles busted they wouldn't displace too much air from the room and suffocate everyone. It's a real risk. Keep car windows open & all spaces well-ventilated.
NASA is SUPER safe. Once it took us several months to get approval to use a single bottle of helium, same as used in flower shops for balloons. Even if the whole bottle dumped at once, the room's oxygen would drop from 20% only to 19.5%, so it was safe. But we had to PROVE it.
The worst example of TOO MUCH safety was when they told the PhD scientists we couldn't boil water in the chemistry lab, because OSHA defines hot water as a hazardous substance, and we didn't have the necessary paperwork approved to work with that particular substance 👿...
We arrived for rhe second chemo treatment today. We brought dry ice this time to help reduce the risk of permanent nerve damage in her hands and feet. Last time we used regular water ice on her hands & feet but it was awkward.../1
2/ My sister died of colon cancer 4 years ago. She had been in chemo for 10 years & had really bad "chemo hands & feet" (as she called it): almost total loss of sensation from the nerve damage. She would walk out of her shoes and not even realize it. But there's now good news...
3/ Medical studies have proven that putting ice on your hands and feet while that one drug is administered produces a statistically significant reduction of nerve damage. The medical staff here recognizes it and lets us know when it is time to apply the ice. But it is weird...
The main news today is our family's journey with cancer. My wife's chemotherapy chose today while I was at a conference to make her hair fall out. Gigi knew this day was coming but still she cried for a long time when it began 😞 Her hair dresser Nelson was a hero... /1
2/ He said Gigi is the 12th woman in chemo that he has cut. He didn't just shave her head. First he cut it to shoulder length so she could get a photo. The he cut it to chin length for another photo. Then he gave her bangs. Then finally he turned the chair so she couldn't watch.
3/ Gigi had 2 friends there telling how beautiful she is after her head was shaved, before he turned the chair for her to see. This may sound like a small thing, but it meant the world to her. Thankful for awesome friends on this journey. Here's Gigi (center) with her new wig❤
Today it begins. Gigi and I are at the cancer center for her 1st chemotherapy treatment. It will take 8 hours, but the entire process takes 10 or 11 hours with lab work and consultations. Two days ago she had surgery to put a port under her skin for the frequent needles. /1
2/ Yesterday met with a surgeon about the multiple required surgeries. It is happening so quickly, it hasn't felt real. Gigi says the same.
But now it is real. She just finished lab work and we walked to the chemo center. Gigi was taken to the room. They'll call me, shortly.
3/ But Gigi is VERY encouraged. Running that marathon was vital. I dont think I mentioned it before, but Gigi got FIRST PLACE for her age group! She was worried she couldn't even finish. Her only goal was to finish, but she got first place. 🙏 (I need an emoji smiling with tears)
1/n Sad news to explain why I missed the New Worlds conference this weekend: my wife was diagnosed with breast cancer. We spent the week planning her chemo and surgeries. Her prognosis is good, but we were devastated because now she can't run a marathon she trained for all year.
2/n She was supposed to run the Space Coast marathon in 2 weeks. Last year she collapsed at 20 miles. This year her times are good enough to qualify for the Boston. But 2 weeks out the doctors say she must start chemo immediately. No Space Coast Marathon 😞 But we made a plan...
3/n I told her we should find a marathon THIS weekend, anywhere in the country, and we will go there so she can run it. She isn't quite ready. She ran 20 miles last weekend and needed more time to recover. But this is her last chance for an entire year so she is doing it!
In one of those Twitter coincidences, these appeared adjacent on my screen. I just wrote a paper on the "Economic and Social Justice Needs to Broaden Ownership of In-Space Industry." This is a previously unexplored topic that will have great consequence within a few decades.
2/ The study of economic growth deals with issues that become less relevant once we have largely autonomous industry off-planet. Growth needn't be governed by supply, demand, labor, land, finance, or social rules. Growth can be purely metabolic (matter & energy) and VERY fast.
3/ This potential for rapid scale-up is the reason why robotic space industry, when it has adequate machine intelligence, will bring an economic revolution. It won't merely be a way for enterprising people to do some business. It will deeply change the structure of civilization.
There are 150 to 450 planets in our solar system. The desire to keep the number small is a cultural bias from the prescientific days when planets were viewed as gods reigning in their orbits, ruling our lives through the horoscope. The essence of that meme still survives... /1
2/ The names of the days of the week are from the names of the 7 ancient planets (which included the Sun and Moon as planets)
Saturn(n)-day
Sun-day
Moon-day
(The rest in Spanish)
Miercolos = Mercury
Martes = Mars
Jueves = Jove or Jupiter
Viernes = Venus
Similar in Anglo-Saxon
3/ The days of the week were named as part of a horoscope system so people could always know which planet was ruling at any given moment. It was a deep desire to find order and meaning in life, looking to the seemingly powerful lights in the sky for that.
To be clear: our new paper shows that asteroids were reclassified as non-planets not on the basis of orbit-sharing, but their geophysical properties: they are unlike planets. The argument in 2006 (that they were reclassified because of orbit sharing) is factually untrue. /1
2/ If we apply the exact same standard to Pluto that we applied to asteroids, then it is most definitely a planet. This is what the published scientific record shows.
3/ The standard that was applied to asteroids, first in thinking they were planets, later in realizing they should not be, was completely in-line with the geophysical definition of a planet that came down to us from Galileo in the Copernican Revolution.
The air will slowly leak away to space due to Mars' low gravity, so we'll need to continually make it up by adding more. We can do that by bringing small water-rich asteroids to burn up in Mars' atmosphere. Moving them is slow, but easily fast enough to maintain Mars.
2/ You could also simply bring icy asteroids into Mars, not just to maintain the atmosphere, but to make its atmosphere thick in the first place. My co-author argues that this is not ideal since it would take too long to make Mars live-able.
3/ So he argues the we should use the Martian soil to get the initial dose of oxygen, making Mars live-able very quickly. Then we could bring ice from space just to maintain the Martian atmosphere over the long term, because we only need a slow process to do that maintenance.
A few pictures from filming the TV show yesterday. The Lick Observatory is gorgeous with wood floor & walls. We did driving scenes of "going to work" 😹 The hour-long show on space industry & A.I. will play on China's main channel then be distributed on various platforms.
On the exterior catwalk of the next-door Shane Telescope. In my glasses you can see a reflection of my selfie-hand and the assistant director waiting for me to quit messing around.
The landscape was gorgeous, but it contains creatures that consider us to be their food. "If attacked fight back"...because we are all sooooo good at defeating lions with our bare hands..
This NASA article says terraforming Mars isn't possible "using present day technology." This is true in the most pedestrian sense. Nobody has a "Mars terraforming machine" sitting in their garage, so the technology doesn't exist in the present day. BUT /1 nasa.gov/press-release/…
2/ It would be straightforward to develop the tech to terraform Mars. The authors don't think so. They probably meant something more substantive, like "we have not even achieved Technology Readiness Level 2", i.e., nobody has even conceived how to do it...
3/ They are so pessimistic because they say present day Mars lacks the volatiles (like CO2 or other gases) necessary to thicken its atmosphere and hold in heat, so we just can't conceive of a way to terraform it.
Apparently they didn't check the prior literature on the subject.
Without the fog we could locate the seals on the rock just offshore in the center of the picture. In the early night they were howling between islands far away to each other. It was haunting. #AmazingNature
If you get a chance to camp on the Maine Island Trail, do it! It is a chain of islands running along the Maine coast. Rent kayaks or bring a boat plus a tent. It is primitive camping - no facilities or water so bring what you need. The beauty is astounding.
My son and daughter were going to sleep on the float at the end of the dock, tonight, but at 2 am the boy came back to the house leaving her fast asleep but alone down there. So now I'm trying to sleep on the hard, rocking, wooden float, next to her. /1
2/ I hear seals howling occasionally in the distace, the bell buoy chiming steadily in the middle of the bay, little waves sloshing against the rocky shore, a kayak banging against the float, and -- I think -- waves crashing far away.
3/ Which makes me wonder. If the waves are so large I can hear them crashing violently against some shore, why are they so small where I am? Where does the wave energy die away? The bell buoy seems to be in an intermediate state, rocking just enough to make constant chimes.
#TFW it is dark and your kids call because they are stranded on a tiny island in the middle of the whirlpools that keep sucking the kayak away from shore and they couldn't paddle hard enough against the tide to get home and as last resort they want dad to come with the boat.🙉 /1
2/ (These are the older kids. Not the two young ones who went out for the first time this morning.)
3/ As a kid, I would have chosen death before making that phone call. But then, we didn't have phones, so we couldn't get a rescue anyway. 🙉
**Sigh** I got blocked by @Google Scholar for doing too many searches on "kleine planeten" (which means "small planets" in German), and I've done everything I can to get unblocked. To meet the journal editor's deadline I have to do the research via a phone. #ScientistProblems
2/ Problem solved. Thank you all for the great suggestions! When I tried it in Google's Chrome browser, Google offered me a recaptcha to prove I am not a robot. It didn't offer me that as long as I was using Firefox. #GoodToKnow
3/ I should add, Google Scholar thought I was a robot because I use it so dang much, because it is amazing for searching in particular years & languages for specific phrases, parsing results narrowly for statistical insight. New science is possible that never was before...
Friends tell me I should've explained why I unfollowed from 35,000 down to <200 accounts. I humbly apologize. I used to follow back 100% to communicate true respect. 4 years ago I simply couldn't keep it up. It took HOURS to identify & NOT follow objectionable robot accounts.../1
2/ I was forced to give up. I had to stop following back entirely so I wouldn't accidentally follow bots tweeting bad stuff. Out of a desire to not offend I didn't unfollow any existing follows, but after 4 years I was following less than half the people who followed me...
3/ The twitter feed had become a firehose that I couldn't possibly keep up with. My interactions on twitter were reduced to just responding. Reply to everyone who tweets at me, and answer every science question (except when overwhelmed by work & simply can't keep up)...
This tech is cool. Photons (light particles) from a warm body tend to be maximally random. Very simple math proves that "maximally random" is when more photons are at one wavelength than another. It is the most probable spectrum. The shape of this spectrum tells temperature! /1
2/ It might seem weird that the "maximally random" spectrum does not have an equal number of photons at every wavelength. For comparison, if you roll 6 million dice, you will get one million 1's, one million 2's, etc, an equal number in each possible state. Why not for photons?
3/ Becoz different wavelength photons carry different amounts of energy. The higher the wavelength, the more energy the photon carries from your body. If you were radiating as many high wavelength photons (x rays) from your body as low wavelength (IR), you would instantly freeze.
At the airport again. This time going to Silicon Valley for the Frontier Development Lab to mentor a team of researchers creating artificial intelligence for lunar roving and prospecting vehicles. This will be fun!
2/ Something I am wondering... Back when I was on the International Space Station program we all traveled A LOT. We had to go to contractors all over the country to make sure the thousands and thousands of parts and assemblies were on schedule and passing checkout requirements...
3/ Then we had to make sure that when the parts got put into black boxes, those boxes passed their tests, and when those boxes got put into racks, and the racks got put into modules of the Space Station, every level of assembly was on schedule and passing all tests...
I agree, but in any case it makes no sense to keep civilization on just one planet, because doing so hurts the planet, hurts the people, and prevents all the amazing things we could be doing if we weren't so-limited. /1 amp.businessinsider.com/fermi-paradox-…
2/ I mean, the planet sets a DEFINITE limit to the size of things we can do in this universe. We can't build telescopes bigger than a planet until we get off the planet. We can't build supercomputers to solve super science questions if they need more energy than a planet. Etc.
3/ And we could never afford to build those giant telescopes, or giant supercomputers, or traversing world ships to comfortably take communities to other stars while we have an *economy* limited by the scale of a planet.
Today, writing software to simulate small spacecraft extracting water from asteroids. It took 2 weeks to develop equations of thermal conductivity as gas pressure increases in the soil. Finally got the code running! Here is gas pressure developing in & around the coring device:
2/ Granular materials like asteroidal or lunar soil are really good thermal insulators, especially when they are in the vacuum of space so there is no air between the grains Pro tip: if you're stranded on the Moon & need to stay cool in the harsh sunlight, bury yourself 1 m deep.
3/ Therefore it is hard to heat the asteroid's soil to get the minerals to release the trapped water. You can apply heat to the soil, but it takes a LONG time for the heat to travel into the soil. This could waste LOTS of energy as you try to get water.
Breakout sessions at the lunar volatiles prospecting workshop. Our group is assessing Phase B: after orbital remote sensing (Phase A) but before high capability rovers (Phase C) finalize the 1 sq km mine location. #2018SRR
2/ Our group focused on (first) swarms of small impactors to burrow into each of 3 craters that Phase A had selected as locations of high hydrogen. The impactors will seek to Monte Carlo measure water concentration, chemistry and variability over the crater, plus soil mechanics.
3/ Then (second) we would send a static lander or a hopper with more advanced instruments to the best of these three craters to better constrain the water's variability and its physical form. We are working to define the instruments. But the iverall ideas are still evolving, too.
