This is the way the world ends (seriously).
Plus, why Omicron might be milder. And, new research on how exactly exercise is good for your brain.
Hello, there.
I want to write today about a very light topic. How all life on this planet will one day end. ;-)
Here's a NASA depiction of a frozen planet covered almost completely in ice. Looks foreboding and certainly not suitable for the emergence of intelligent life. Can you guess the planet?
It the one we live on.
Roughly 600 to 700 million years ago, this was our planet during a "Snowball Earth" event. There have been two such Snowball Earth events. And life was nearly snuffed out back then.
This is what I was referring to in an OpEd I wrote for Hindustan Times this week. You can read the print version (PDF) here.
If you look at the Earth today and think that a planet has to be like it for life, you are wrong. The current conditions on Earth are relatively recent.
High temperatures were favorable to the origin of life. Oxygen would've been poisonous to the first life on this planet. In fact, the Earth when life originated was in many ways similar to early Mars and early Venus (before the horribly runaway greenhouse effect).
We think of oxygen as essential to life, but that's not true- oxygen is essential to our lives but highly toxic to anaerobic microorganisms. When free oxygen first appeared on the earth 2.3 billion years ago it caused a mass extinction of these living organisms.
This brings me to the end of life on the planet.
It will happen as the Sun shines a bit brighter and we face a runaway greenhouse effect around 500 million to 1 billion year from now.
Courtesy: James Green, NASA
If you look at the dotted lines in the projection above, you will notice a possible trajectory for the planet.
The Earth will simply become too hot to sustain life. And our planet will take on a Venus-like state. Microbes will hold out for the longest time, but they too will perish.
You will also notice that at that point Mars might be in the Goldilocks zone as far as temperature is concerned. (The Red Planet has other issues with habitability though).
By that point life on our home planet will have had a 5 billion year run. But all good things must come to an end.
I saw Don’t Look Up this last weekend and I had a lot of thoughts about comets, the ozone layer, nuclear weapons, and the hidden pandemic of antibiotic resistance. I’ve lamented the short-termism that gets our species in trouble time and again.
The entire piece is here but here are two excerpts—
A defence system against comets and asteroids would cost money, but might not be used. Similarly, we would need to create a medicine cabinet of antibiotics as insurance against future superbugs. It would require resources and planning, but in an ideal scenario might never be required. The problem is that short-termism is antithetical to hedging against low-probability events. So who will fund these projects?
News cycles are short. Public attention extends to the duration that a topic trends on social media. Politicians look to what they need to do to get elected or to stay in office. Companies look to their next earnings report and to bumping their stock price.
And here’s what I have to say about the problems we face because we are aggressive and tribal primates.
Even faced with the climate “comet”, many will look to sow confusion and discontent, saying the science is not clear. This is the same playbook that tobacco companies used to convince the public that smoking was unrelated to cancer and that energy companies used to argue burning fossil fuels didn’t contribute to the climate crisis (even though in both cases, internal documents showed they knew otherwise).
Humans are tribal, which makes us require other human enemies. Yet, the climate crisis impacts the world and requires us to see beyond the narrow prism of naked self-interest. If storms and rising sea levels had been sent by another country, then we’d be up in arms protecting coastlines. If there was an Olympic game for conservation, we would be writing volumes about building infrastructure to compete with other nations in saving species.
Yeah, I basically unloaded two years of pent up rage and helplessness that I had bottled up during the pandemic. :-)
Charaiveti, charaiveti
(Keep moving, keep moving)
Maintaining a brain is energetically unfavorable. A young sea squirt maintains a brain as long as it is moving. When it finds a place to finally settle down for good, it no longer has any need for its brain, so it eats it.
The brain evolved to coordinate movement.
For years scientists have known that exercise improves memory and brain function. Now, we have exciting research showing just HOW it does it.
Aerobic exercise promotes the formation of new nerve cells in the brain, new nerve connections, and stronger memories. It prevents dementia. Much of it is mediated through a protein called clusterin released in our blood when we exercise. This is the subject of my science column this week.
The Omicron update
There’s a reasonable biological hypothesis on WHY Omicron might be milder than previous variants of the virus and it has to do with its inability to attack the lungs like its predecessors.
The idea is that Omicron struggles to infect the cells of the lungs because it can’t utilize a protein called TMPRSS2 as well as the original virus or other variants.
Of course, determining severity in a population that has already been exposed and often vaccinated is not a simple task, so this is not the final word on the matter.
Nonetheless, this is good news. And we should take good news when we can get it.
I also want to clarify that I’m NOT saying that we should treat Omicron lightly. It is highly transmissible. Mathematically, more people infected and sick people also means that the absolute number of hospitalizations also increases dramatically.
(On a personal note, I’m about a month in to receiving a booster dose of the vaccine).
What else I’ve read.
The CDC now recommends that teens 12 to 17 should receive a Covid-19 booster shot.
Recognizing obesity as a disease is the right step towards treating it.