What a planet needs to sustain life | Dave Brain

"Venus is too hot, Mars is too cold, and Earth is just right," says planetary scientist Dave Brain. But why? In this pleasantly humorous talk, Brain explores the fascinating science behind what it takes for a planet to host life — and why humanity may just be in the right place at the right time when it comes to the timeline of life-sustaining planets.

TEDTalks is a daily video podcast of the best talks and performances from the TED Conference, where the world's leading thinkers and doers give the talk of their lives in 18 minutes (or less). Look for talks on Technology, Entertainment and Design -- plus science, business, global issues, the arts and much more.

[pacoo]

Wow, looks like TED remember why they became popular in the first place. More of these please.

[xxxyorks]

Glad someone's finally talking about the relationship between magnetespheres and habitability on planets.

[EmotionlessGamer]

I seriously got chills when I saw the river carvings on Mars....

[Miranox]

His name is Brain, therefore he is smart. QED.

[doodelay]

his audience was unusually lighthearted

[joandudney]

Dave reminded me today that you can have fun with the science you do and still have a great impact. Congrats on a great talk and I am very glad I was here to listen:)

[patrickroelant]

confirmed, all life needs moose to survive.

[stillprophet]

this dude is pretty hilarious and informing at the same time

[who-man]

I gotta give it to the guy he was by far the best Ted talk speaker I've heard in a long long time maybe the best period his presence and showmanship was awesome

[DerrenBrown]

Hey flat earthers. Trigger warning: The earth isn't flat.

[charlesclements]

One of the questions that he did not investigate was why the large amount of water that is found on this planet. It is not just moist but sopping wet and it came from "Nowhere".

[EEBROEDBD]

So uplifting to know, we have guys like these working on such important things. Actually reminds me of "Interstellar".

[AA-dvie]

a few times I thought he was going to cry out of emotion

[junacebedo]

He didn't mention location, size and rotation of Earth. Actually there are 200 parameters (still increasing) needed to accomplish to have a another Earth.

[busytellingjokes]

And thats a bold statement saying that other planets dont have a magnetic field like our considered we have never been to those planets

[howieweed]

This is pretty simplistic thinking. If fact, the worldwide scientific community has come up with a list of over 100 + specific planetary conditions that must all exist together it order to support life. The chances of all 100+ conditions aligning diminishes the likelihood of life by an infinitesimally small fraction of the number of planets theorized to exist in the universe. In fact, it may even lower the possibility to a crap shoot so low that its not unreasonable to being to think "life", like ours, is a very rare mathematical coincidence that may not be repeating anywhere but here, and for only a short time in the universe.

[melquannshabazz]

Fantastic Job he kept it simple with great clarification 💯💯

[jamessgian]

There are an incredible number of parameters required for complex life to exist on the earth. Here are just a few:

1) Goldilocks distance from our sun
2) Goldilocks place in the Milky Way — too far in and too much activity from quasars, pulsars, black holes, asteroids, etc.
3) Our large moon keeping axis tilted so seasons occur.
4) multiple large outer planets to gather up most of the asteroids with their massive gravity
5) Goldilocks amount of plate tectonics to release necessary ingredients for atmosphere, but not too little or too much. So, we need earthquakes and volcanoes and we have just the right amount.
6) Inner iron core for electromagnetic field to protect from solar radiation and burn up many smaller asteroids.
7) single star system in solar system as dual stars will disrupt seasons, tilt, etc.
8)Stable planetary orbits so larger planets don’t cause chaos by having irregular patterns.
9) Goldilocks sized ocean - too big or little and atmospheric content won’t have proper mixture of elements.
10) Goldilocks planetary mass within parameters to hold ocean and atmosphere
11) Goldilocks kind of galaxy. Spiral galaxies are best as they have sections with fewer stars and activity in their arms.

There are many others. Some lists are up to 200 such features. And without any one of them, we wouldn’t be here. The combinatorial statistics of multiplying one such factor by another by another leads to infinitesimally small odds for finding another planet with complex life. Moose are very rare indeed!

And as the parameters for life are not just the three broad things mentioned here, but all the long list of other things to prevent life’s annihilation one way or another, it doesn’t matter that there are 40 billion planets with these three features. They are still very unlikely to have complex life due to all of these other factors.

That is, if the universe and life are dependent upon chance. But since we are here and shouldn’t be by the odds either, it appears there is some sort of teleology inherent to the universe.

Now SETI and Dr. Brain benefit from not sharing the actual statistics because they wouldn’t receive much funding with odds so against the chances for life. It therefore behooves SETI and scientists like Dr. Brain to advance the legitimate conclusion that the universe has an element of teleology which tends towards increasing the likelihood of life.

This, however, would be objectionable to many in positions of power in the scientific community as they unfortunately do not wish to admit
teleology as a feature of the universe.

[Arkeotis]

I love this man's sense of humor😂

[tangyspy]

Why is life defined by temperature, nutrition and need of water? What if life somewhere around the universe didn't need water? Or they didn't need the same temperature to survive?