Xenobots, tiny living machines, can duplicate themselves.
Strange and complex behavior of frog cell blobs
A xenobot “parent,” shaped like a hungry Pac-Man (shown in red false color), created an “offspring” xenobot (green sphere) by gathering loose frog cells in its opening.
Tiny “living machines” made of frog cells can make copies of themselves. This newly discovered renewal mechanism may help create self-renewing biological machines.
According to Kirstin Petersen, an electrical and computer engineer at Cornell University who studies groups of robots, “this is an extremely exciting breakthrough.” She says self-replicating robots are a big step toward human-free systems.
Researchers described the behavior of xenobots earlier this year (SN: 3/31/21). Small clumps of skin stem cells from frog embryos knitted themselves into small spheres and started moving. Cilia, or cellular extensions, powered the xenobots around their lab dishes.
The findings are published in the Proceedings of the National Academy of Sciences on Dec. 7. The xenobots can gather loose frog cells into spheres, which then form xenobots.
The researchers call this type of movement-induced reproduction kinematic self-replication. The study's coauthor, Douglas Blackiston of Tufts University in Medford, Massachusetts, and Harvard University, says this is typical. For example, sexual reproduction requires parental sperm and egg cells. Sometimes cells split or budded off from a parent.
“This is unique,” Blackiston says. These xenobots “find loose parts in the environment and cobble them together.” This second generation of xenobots can move like their parents, Blackiston says.
The researchers discovered that spheroid xenobots could only produce one more generation before dying out. The original xenobots' shape was predicted by an artificial intelligence program, allowing for four generations of replication.
A C shape, like an openmouthed Pac-Man, was predicted to be a more efficient progenitor. When improved xenobots were let loose in a dish, they began scooping up loose cells into their gaping “mouths,” forming more sphere-shaped bots (see image below). As many as 50 cells clumped together in the opening of a parent to form a mobile offspring. A xenobot is made up of 4,000–6,000 frog cells.
Petersen likes the Xenobots' small size. “The fact that they were able to do this at such a small scale just makes it even better,” she says. Miniature xenobots could sculpt tissues for implantation or deliver therapeutics inside the body.
Beyond the xenobots' potential jobs, the research advances an important science, says study coauthor and Tufts developmental biologist Michael Levin. The science of anticipating and controlling the outcomes of complex systems, he says.
“No one could have predicted this,” Levin says. “They regularly surprise us.” Researchers can use xenobots to test the unexpected. “This is about advancing the science of being less surprised,” Levin says.
More on Science

DANIEL CLERY
3 years ago
Can space-based solar power solve Earth's energy problems?
Better technology and lower launch costs revive science-fiction tech.
Airbus engineers showed off sustainable energy's future in Munich last month. They captured sunlight with solar panels, turned it into microwaves, and beamed it into an airplane hangar, where it lighted a city model. The test delivered 2 kW across 36 meters, but it posed a serious question: Should we send enormous satellites to capture solar energy in space? In orbit, free of clouds and nighttime, they could create power 24/7 and send it to Earth.
Airbus engineer Jean-Dominique Coste calls it an engineering problem. “But it’s never been done at [large] scale.”
Proponents of space solar power say the demand for green energy, cheaper space access, and improved technology might change that. Once someone invests commercially, it will grow. Former NASA researcher John Mankins says it might be a trillion-dollar industry.
Myriad uncertainties remain, including whether beaming gigawatts of power to Earth can be done efficiently and without burning birds or people. Concept papers are being replaced with ground and space testing. The European Space Agency (ESA), which supported the Munich demo, will propose ground tests to member nations next month. The U.K. government offered £6 million to evaluate innovations this year. Chinese, Japanese, South Korean, and U.S. agencies are working. NASA policy analyst Nikolai Joseph, author of an upcoming assessment, thinks the conversation's tone has altered. What formerly appeared unattainable may now be a matter of "bringing it all together"
NASA studied space solar power during the mid-1970s fuel crunch. A projected space demonstration trip using 1970s technology would have cost $1 trillion. According to Mankins, the idea is taboo in the agency.
Space and solar power technology have evolved. Photovoltaic (PV) solar cell efficiency has increased 25% over the past decade, Jones claims. Telecoms use microwave transmitters and receivers. Robots designed to repair and refuel spacecraft might create solar panels.
Falling launch costs have boosted the idea. A solar power satellite large enough to replace a nuclear or coal plant would require hundreds of launches. ESA scientist Sanjay Vijendran: "It would require a massive construction complex in orbit."
SpaceX has made the idea more plausible. A SpaceX Falcon 9 rocket costs $2600 per kilogram, less than 5% of what the Space Shuttle did, and the company promised $10 per kilogram for its giant Starship, slated to launch this year. Jones: "It changes the equation." "Economics rules"
Mass production reduces space hardware costs. Satellites are one-offs made with pricey space-rated parts. Mars rover Perseverance cost $2 million per kilogram. SpaceX's Starlink satellites cost less than $1000 per kilogram. This strategy may work for massive space buildings consisting of many identical low-cost components, Mankins has long contended. Low-cost launches and "hypermodularity" make space solar power economical, he claims.
Better engineering can improve economics. Coste says Airbus's Munich trial was 5% efficient, comparing solar input to electricity production. When the Sun shines, ground-based solar arrays perform better. Studies show space solar might compete with existing energy sources on price if it reaches 20% efficiency.
Lighter parts reduce costs. "Sandwich panels" with PV cells on one side, electronics in the middle, and a microwave transmitter on the other could help. Thousands of them build a solar satellite without heavy wiring to move power. In 2020, a team from the U.S. Naval Research Laboratory (NRL) flew on the Air Force's X-37B space plane.
NRL project head Paul Jaffe said the satellite is still providing data. The panel converts solar power into microwaves at 8% efficiency, but not to Earth. The Air Force expects to test a beaming sandwich panel next year. MIT will launch its prototype panel with SpaceX in December.
As a satellite orbits, the PV side of sandwich panels sometimes faces away from the Sun since the microwave side must always face Earth. To maintain 24-hour power, a satellite needs mirrors to keep that side illuminated and focus light on the PV. In a 2012 NASA study by Mankins, a bowl-shaped device with thousands of thin-film mirrors focuses light onto the PV array.
International Electric Company's Ian Cash has a new strategy. His proposed satellite uses enormous, fixed mirrors to redirect light onto a PV and microwave array while the structure spins (see graphic, above). 1 billion minuscule perpendicular antennas act as a "phased array" to electronically guide the beam toward Earth, regardless of the satellite's orientation. This design, argues Cash, is "the most competitive economically"
If a space-based power plant ever flies, its power must be delivered securely and efficiently. Jaffe's team at NRL just beamed 1.6 kW over 1 km, and teams in Japan, China, and South Korea have comparable attempts. Transmitters and receivers lose half their input power. Vijendran says space solar beaming needs 75% efficiency, "preferably 90%."
Beaming gigawatts through the atmosphere demands testing. Most designs aim to produce a beam kilometers wide so every ship, plane, human, or bird that strays into it only receives a tiny—hopefully harmless—portion of the 2-gigawatt transmission. Receiving antennas are cheap to build but require a lot of land, adds Jones. You could grow crops under them or place them offshore.
Europe's public agencies currently prioritize space solar power. Jones: "There's a devotion you don't see in the U.S." ESA commissioned two solar cost/benefit studies last year. Vijendran claims it might match ground-based renewables' cost. Even at a higher price, equivalent to nuclear, its 24/7 availability would make it competitive.
ESA will urge member states in November to fund a technical assessment. If the news is good, the agency will plan for 2025. With €15 billion to €20 billion, ESA may launch a megawatt-scale demonstration facility by 2030 and a gigawatt-scale facility by 2040. "Moonshot"

Will Lockett
3 years ago
Thanks to a recent development, solar energy may prove to be the best energy source.
Perovskite solar cells will revolutionize everything.
Humanity is in a climatic Armageddon. Our widespread ecological crimes of the previous century are catching up with us, and planet-scale karma threatens everyone. We must adjust to new technologies and lifestyles to avoid this fate. Even solar power, a renewable energy source, has climate problems. A recent discovery could boost solar power's eco-friendliness and affordability. Perovskite solar cells are amazing.
Perovskite is a silicon-like semiconductor. Semiconductors are used to make computer chips, LEDs, camera sensors, and solar cells. Silicon makes sturdy and long-lasting solar cells, thus it's used in most modern solar panels.
Perovskite solar cells are far better. First, they're easy to make at room temperature, unlike silicon cells, which require long, intricate baking processes. This makes perovskite cells cheaper to make and reduces their carbon footprint. Perovskite cells are efficient. Most silicon panel solar farms are 18% efficient, meaning 18% of solar radiation energy is transformed into electricity. Perovskite cells are 25% efficient, making them 38% more efficient than silicon.
However, perovskite cells are nowhere near as durable. A normal silicon panel will lose efficiency after 20 years. The first perovskite cells were ineffective since they lasted barely minutes.
Recent research from Princeton shows that perovskite cells can endure 30 years. The cells kept their efficiency, therefore no sacrifices were made.
No electrical or chemical engineer here, thus I can't explain how they did it. But strangely, the team said longevity isn't the big deal. In the next years, perovskite panels will become longer-lasting. How do you test a panel if you only have a month or two? This breakthrough technique needs a uniform method to estimate perovskite life expectancy fast. The study's key milestone was establishing a standard procedure.
Lab-based advanced aging tests are their solution. Perovskite cells decay faster at higher temperatures, so scientists can extrapolate from that. The test heated the panel to 110 degrees and waited for its output to reduce by 20%. Their panel lasted 2,100 hours (87.5 days) before a 20% decline.
They did some math to extrapolate this data and figure out how long the panel would have lasted in different climates, and were shocked to find it would last 30 years in Princeton. This made perovskite panels as durable as silicon panels. This panel could theoretically be sold today.
This technology will soon allow these brilliant panels to be released into the wild. This technology could be commercially viable in ten, maybe five years.
Solar power will be the best once it does. Solar power is cheap and low-carbon. Perovskite is the cheapest renewable energy source if we switch to it. Solar panel manufacturing's carbon footprint will also drop.
Perovskites' impact goes beyond cost and carbon. Silicon panels require harmful mining and contain toxic elements (cadmium). Perovskite panels don't require intense mining or horrible materials, making their production and expiration more eco-friendly.
Solar power destroys habitat. Massive solar farms could reduce biodiversity and disrupt local ecology by destroying vital habitats. Perovskite cells are more efficient, so they can shrink a solar farm while maintaining energy output. This reduces land requirements, making perovskite solar power cheaper, and could reduce solar's environmental impact.
Perovskite solar power is scalable and environmentally friendly. Princeton scientists will speed up the development and rollout of this energy.
Why bother with fusion, fast reactors, SMRs, or traditional nuclear power? We're close to developing a nearly perfect environmentally friendly power source, and we have the tools and systems to do so quickly. It's also affordable, so we can adopt it quickly and let the developing world use it to grow. Even I struggle to justify spending billions on fusion when a great, cheap technology outperforms it. Perovskite's eco-credentials and cost advantages could save the world and power humanity's future.

Sara_Mednick
3 years ago
Since I'm a scientist, I oppose biohacking
Understanding your own energy depletion and restoration is how to truly optimize
Hack has meant many bad things for centuries. In the 1800s, a hack was a meager horse used to transport goods.
Modern usage describes a butcher or ax murderer's cleaver chop. The 1980s programming boom distinguished elegant code from "hacks". Both got you to your goal, but the latter made any programmer cringe and mutter about changing the code. From this emerged the hacker trope, the friendless anti-villain living in a murky hovel lit by the computer monitor, eating junk food and breaking into databases to highlight security system failures or steal hotdog money.
Now, start-a-billion-dollar-business-from-your-garage types have shifted their sights from app development to DIY biology, coining the term "bio-hack". This is a required keyword and meta tag for every fitness-related podcast, book, conference, app, or device.
Bio-hacking involves bypassing your body and mind's security systems to achieve a goal. Many biohackers' initial goals were reasonable, like lowering blood pressure and weight. Encouraged by their own progress, self-determination, and seemingly exquisite control of their biology, they aimed to outsmart aging and death to live 180 to 1000 years (summarized well in this vox.com article).
With this grandiose north star, the hunt for novel supplements and genetic engineering began.
Companies selling do-it-yourself biological manipulations cite lab studies in mice as proof of their safety and success in reversing age-related diseases or promoting longevity in humans (the goal changes depending on whether a company is talking to the federal government or private donors).
The FDA is slower than science, they say. Why not alter your biochemistry by buying pills online, editing your DNA with a CRISPR kit, or using a sauna delivered to your home? How about a microchip or electrical stimulator?
What could go wrong?
I'm not the neo-police, making citizen's arrests every time someone introduces a new plumbing gadget or extrapolates from animal research on resveratrol or catechins that we should drink more red wine or eat more chocolate. As a scientist who's spent her career asking, "Can we get better?" I've come to view bio-hacking as misguided, profit-driven, and counterproductive to its followers' goals.
We're creatures of nature. Despite all the new gadgets and bio-hacks, we still use Roman plumbing technology, and the best way to stay fit, sharp, and happy is to follow a recipe passed down since the beginning of time. Bacteria, plants, and all natural beings are rhythmic, with alternating periods of high activity and dormancy, whether measured in seconds, hours, days, or seasons. Nature repeats successful patterns.
During the Upstate, every cell in your body is naturally primed and pumped full of glycogen and ATP (your cells' energy currencies), as well as cortisol, which supports your muscles, heart, metabolism, cognitive prowess, emotional regulation, and general "get 'er done" attitude. This big energy release depletes your batteries and requires the Downstate, when your subsystems recharge at the cellular level.
Downstates are when you give your heart a break from pumping nutrient-rich blood through your body; when you give your metabolism a break from inflammation, oxidative stress, and sympathetic arousal caused by eating fast food — or just eating too fast; or when you give your mind a chance to wander, think bigger thoughts, and come up with new creative solutions. When you're responding to notifications, emails, and fires, you can't relax.
Downstates aren't just for consistently recharging your battery. By spending time in the Downstate, your body and brain get extra energy and nutrients, allowing you to grow smarter, faster, stronger, and more self-regulated. This state supports half-marathon training, exam prep, and mediation. As we age, spending more time in the Downstate is key to mental and physical health, well-being, and longevity.
When you prioritize energy-demanding activities during Upstate periods and energy-replenishing activities during Downstate periods, all your subsystems, including cardiovascular, metabolic, muscular, cognitive, and emotional, hum along at their optimal settings. When you synchronize the Upstates and Downstates of these individual rhythms, their functioning improves. A hard workout causes autonomic stress, which triggers Downstate recovery.
By choosing the right timing and type of exercise during the day, you can ensure a deeper recovery and greater readiness for the next workout by working with your natural rhythms and strengthening your autonomic and sleep Downstates.
Morning cardio workouts increase deep sleep compared to afternoon workouts. Timing and type of meals determine when your sleep hormone melatonin is released, ushering in sleep.
Rhythm isn't a hack. It's not a way to cheat the system or the boss. Nature has honed its optimization wisdom over trillions of days and nights. Stop looking for quick fixes. You're a whole system made of smaller subsystems that must work together to function well. No one pill or subsystem will make it all work. Understanding and coordinating your rhythms is free, easy, and only benefits you.
Dr. Sara C. Mednick is a cognitive neuroscientist at UC Irvine and author of The Power of the Downstate (HachetteGO)
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Scott Hickmann
4 years ago
YouTube
This is a YouTube video:

Frank Andrade
3 years ago
I discovered a bug that allowed me to use ChatGPT to successfully web scrape. Here's how it operates.
This method scrapes websites with ChatGPT (demo with Amazon and Twitter)
In a recent article, I demonstrated how to scrape websites using ChatGPT prompts like scrape website X using Python.
But that doesn’t always work.
After scraping dozens of websites with ChatGPT, I realized that simple prompts rarely work for web scraping.
Using ChatGPT and basic HTML, we can scrape any website.
First things first, use ChatGPT's advanced version (Playground)
ChatGPT Playground's enhanced version is needed to scrape websites quickly. It generates code faster and has less constraints.
Here’s how it looks.
The classic ChatGPT display just allows you to type a prompt. Playground is more customizable and generates code faster than the basic version.
No more delays or restrictions.
In this tutorial, we'll write prompts underneath Playground.
How to Use ChatGPT to Scrape Any Website
To show you how to utilize ChatGPT to scrape any website, we'll use subslikescript, which lists movies.
Later in this post, I'll show you how to scrape Amazon and Twitter, but let's start easy.
If we try a basic prompt like “scrape the movie titles on this website: https://subslikescript.com/movies” it won’t scrape anything. Here’s when we need some HTML knowledge to build the right prompt for ChatGPT.Let's scrape the above movie titles. First, check the webpage. Right-click any element and choose Inspect.
Then see below.
We identify the element to scrape (those in the red box). The data elements are ul, a, and scripts-list.
Here's the prompt for movie titles.
Scrape this website: https://subslikescript.com/movies with Python and Beautiful Soup. Locate the element with tag “ul” and class “scripts-list”. Scrape all the “a” elements inside. Get the text attribute and print it.
Code generated:
import requests
from bs4 import BeautifulSoup
page = requests.get('https://subslikescript.com/movies/')
soup = BeautifulSoup(page.content, 'html.parser')
scripts_list = soup.find(class_="scripts-list")
all_a_elements = scripts_list.find_all('a')
for element in all_a_elements:
print(element.get_text())It extracts movie titles successfully.
Let's scrape Amazon and Twitter.
ChatGPT's Amazon scraping
Consider scraping Amazon for self-help books. First, copy the Amazon link for self-help books.
Here’s the link I got. Location-dependent connection. Use my link to replicate my results.
Now we'll check book titles. Here's our element.
If we want to extract the book titles, we need to use the tag name span, class attribute name and a-size-base-plus a-color-base a-text-normalattribute value.
This time I'll use Selenium. I'll add Selenium-specific commands like wait 5 seconds and generate an XPath.
Scrape this website https://www.amazon.com/s?k=self+help+books&sprefix=self+help+%2Caps%2C158&ref=nb_sb_ss_ts-doa-p_2_10 with Python and Selenium.
Wait 5 seconds and locate all the elements with the following xpath: “span” tag, “class” attribute name, and “a-size-base-plus a-color-base a-text-normal” attribute value. Get the text attribute and print them.
Code generated: (I only had to manually add the path where my chromedriver is located).
from selenium import webdriver
from selenium.webdriver.common.by import By
from time import sleep
#initialize webdriver
driver = webdriver.Chrome('<add path of your chromedriver>')
#navigate to the website
driver.get("https://www.amazon.com/s?k=self+help+books&sprefix=self+help+%2Caps%2C158&ref=nb_sb_ss_ts-doa-p_2_10")
#wait 5 seconds to let the page load
sleep(5)
#locate all the elements with the following xpath
elements = driver.find_elements(By.XPATH, '//span[@class="a-size-base-plus a-color-base a-text-normal"]')
#get the text attribute of each element and print it
for element in elements:
print(element.text)
#close the webdriver
driver.close()It pulls Amazon book titles.
Utilizing ChatGPT to scrape Twitter
Say you wish to scrape ChatGPT tweets. Search Twitter for ChatGPT and copy the URL.
Here’s the link I got. We must check every tweet. Here's our element.
To extract a tweet, use the div tag and lang attribute.
Again, Selenium.
Scrape this website: https://twitter.com/search?q=chatgpt&src=typed_query using Python, Selenium and chromedriver.
Maximize the window, wait 15 seconds and locate all the elements that have the following XPath: “div” tag, attribute name “lang”. Print the text inside these elements.
Code generated: (again, I had to add the path where my chromedriver is located)
from selenium import webdriver
import time
driver = webdriver.Chrome("/Users/frankandrade/Downloads/chromedriver")
driver.maximize_window()
driver.get("https://twitter.com/search?q=chatgpt&src=typed_query")
time.sleep(15)
elements = driver.find_elements_by_xpath("//div[@lang]")
for element in elements:
print(element.text)
driver.quit()You'll get the first 2 or 3 tweets from a search. To scrape additional tweets, click X times.
Congratulations! You scraped websites without coding by using ChatGPT.

Niharikaa Kaur Sodhi
3 years ago
The Only Paid Resources I Turn to as a Solopreneur
4 Pricey Tools That Are Valuable
I pay based on ROI (return on investment).
If a $20/month tool or $500 online course doubles my return, I'm in.
Investing helps me build wealth.
Canva Pro
I initially refused to pay.
My course content needed updating a few months ago. My Google Docs text looked cleaner and more professional in Canva.
I've used it to:
product cover pages
eBook covers
Product page infographics
See my Google Sheets vs. Canva product page graph.
Google Sheets vs Canva
Yesterday, I used it to make a LinkedIn video thumbnail. It took less than 5 minutes and improved my video.
In 30 hours, the video had 39,000 views.
Here's more.
HypeFury
Hypefury rocks!
It builds my brand as I sleep. What else?
Because I'm traveling this weekend, I planned tweets for 10 days. It took me 80 minutes.
So while I travel or am absent, my content mill keeps producing.
Also I like:
I can reach hundreds of people thanks to auto-DMs. I utilize it to advertise freebies; for instance, leave an emoji remark to receive my checklist. And they automatically receive a message in their DM.
Scheduled Retweets: By appearing in a different time zone, they give my tweet a second chance.
It helps me save time and expand my following, so that's my favorite part.
It’s also super neat:
Zoom Pro
My course involves weekly and monthly calls for alumni.
Google Meet isn't great for group calls. The interface isn't great.
Zoom Pro is expensive, and the monthly payments suck, but it's necessary.
It gives my students a smooth experience.
Previously, we'd do 40-minute meetings and then reconvene.
Zoom's free edition limits group calls to 40 minutes.
This wouldn't be a good online course if I paid hundreds of dollars.
So I felt obligated to help.
YouTube Premium
My laptop has an ad blocker.
I bought an iPad recently.
When you're self-employed and work from home, the line between the two blurs. My bed is only 5 steps away!
When I read or watched videos on my laptop, I'd slide into work mode. Only option was to view on phone, which is awkward.
YouTube premium handles it. No more advertisements and I can listen on the move.
3 Expensive Tools That Aren't Valuable
Marketing strategies are sometimes aimed to make you feel you need 38474 cool features when you don’t.
Certain tools are useless.
I found it useless.
Depending on your needs. As a writer and creator, I get no return.
They could for other jobs.
Shield Analytics
It tracks LinkedIn stats, like:
follower growth
trend chart for impressions
Engagement, views, and comment stats for posts
and much more.
Middle-tier creator costs $12/month.
I got a 25% off coupon but canceled my free trial before writing this. It's not worth the discount.
Why?
LinkedIn provides free analytics. See:
Not thorough and won't show top posts.
I don't need to see my top posts because I love experimenting with writing.
Slack Premium
Slack was my classroom. Slack provided me a premium trial during the prior cohort.
I skipped it.
Sure, voice notes are better than a big paragraph. I didn't require pro features.
Marketing methods sometimes make you think you need 38474 amazing features. Don’t fall for it.
Calendly Pro
This may be worth it if you get many calls.
I avoid calls. During my 9-5, I had too many pointless calls.
I don't need:
ability to schedule calls for 15, 30, or 60 minutes: I just distribute each link separately.
I have a Gumroad consultation page with a payment option.
follow-up emails: I hardly ever make calls, so
I just use one calendar, therefore I link to various calendars.
I'll admit, the integrations are cool. Not for me.
If you're a coach or consultant, the features may be helpful. Or book meetings.
Conclusion
Investing is spending to make money.
Use my technique — put money in tools that help you make money. This separates it from being an investment instead of an expense.
Try free versions of these tools before buying them since everyone else is.
