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Four Earth-sized planets detected orbiting the nearest sun-like star

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Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#121

Post by amag »

alistproducer2 wrote: post #58
baron816 wrote: post #37

Ok, let's assume we find a warm, watery planet like Earth's within ~20 light years, and we figure out a way to travel >= 50% the speed of light, making it somewhat reasonable to get there. If the planet's gravity is greater than 10% different from Earth's, or its Day/Night cycle is much different from Earth's, wouldn't it still be a nightmare to live on. Anatomically modern humans have lived on Earth for 200,000 year…

I'm going to show my nerd colors here but having a thought like this has almost ruined Star Trek for me. For me I often think about atmospheric pressure. There's no way that beings from so many different planets could exist on a single star ship set at 1 Earth atmosphere. Maybe someone knowledgeable in this space can tell me, but is a planet's atmospheric pressure reliably proportional to its mass?

You put on your nerd goggles and that's what ruins Star Trek for you?

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#122

Post by jandrese »

abecedarius wrote: post #111
jandrese wrote: post #98

Earlier quoted context omitted.

It's a good example of the problem though. Any drive that relies on reaction mass will take too long to cross the distance to even nearby stars. The rocket equation kills the plan unless you're willing to make an absolutely ridiculous starship. So you need a reactionless drive, which thus far is entirely science fiction. This is even before you start thinking about micrometeorites in the way (which long transits incr…

There's a bunch of ideas that the rocket equation doesn't apply to: https://en.wikipedia.org/wiki/Interstellar_travel#Non-rocket... Yes, it's hard at our current tech level. But not nearly hard enough to explain the Fermi thing. I mean, take your scenario of solar system development: it'd be natural to exploit the Kuiper Belt and then the Oort, and the Oort blends into interstellar travel, as Freeman Dyson pointed ou…

The problem with thinking about it on geologic timescales is that humans (and civilizations!) don't exist on geologic timescales.

It's going to be a tough sell to tell people "You need to pay an extra tax for your entire life so we can fund construction of an interstellar ship that your great grandchildren might witness the launch of, but won't arrive at its destination for a thousand years after that."

It's hard to imagine anything that could motivate the human race to do that short of the Vogon constructor fleet announcing that it will arrive within a couple of centuries, ready or not.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#123

Post by hueving »

outside1234 wrote: post #120
ExactoKnight wrote: post #101

I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us. A telescope this large could tell us whether any of these potentially habitable planets contain oxygen, and thus, biological processes. Yet thanks to funding cuts in science the biggest telescope we have in the pipeline r…

I thought I read that the state of the art is actually combining many smaller lense telescopes into a virtually larger mirrored one. Or did that fail in practice?

You mean this, right? https://en.wikipedia.org/wiki/Astronomical_interferometer

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#124

Post by ExactoKnight »

moonbug22 wrote: post #106
ExactoKnight wrote: post #103

Earlier quoted context omitted.

The other project that needs to become a reality FAST is the construction of a telescope large enough to measure the spectra of exoplanets. Because once you find a habitable planet with oxygen in its atmosphere, you now have an irrefutable and pressing case to move fast with Breakthrough Starshot. Sadly it's going to likely a require 100metre telescope mirror or larger, and current science funding only has a 30metre…

You know about the SKA, right?

Could the Square Kilometre Array, by measuring in the radio frequency of the electromagnetic spectrum, actually be capable of directly imaging the nearby spectroscopic signatures of exoplanets?

I thought you needed to be capable of directly imaging the light of an exoplanet in other wavelengths in order to do that.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#125

Post by 2845197541 »

ExactoKnight wrote: post #101

I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us. A telescope this large could tell us whether any of these potentially habitable planets contain oxygen, and thus, biological processes. Yet thanks to funding cuts in science the biggest telescope we have in the pipeline r…

>Why are we here?

What do you mean by this?

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#126

Post by [deleted] »

ExactoKnight wrote: post #101

I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us. A telescope this large could tell us whether any of these potentially habitable planets contain oxygen, and thus, biological processes. Yet thanks to funding cuts in science the biggest telescope we have in the pipeline r…

[deleted]

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#127

Post by jbooth »

vanattab wrote: post #82
radicaldreamer wrote: post #40

Earlier quoted context omitted.

We could try with a much more doable planet like Mars. We could find out if long term survival is impossible, very difficult, possible but difficult, or doable with the right technologies. It's shocking how little appetite there is for redirecting 50% of the budget which is currently allocated to the military to space exploration. I understand that the military is partly a large welfare program which doesn't compete…

>It's shocking how little appetite there is for redirecting 50% of the budget which is currently allocated to the military to space exploration. 50% for the military? All the figures I can find say it's 16% of federal spending. Edit: As others have pointed out. OP may have been suggesting we redirect 50% of the military budget to space not that the military budget is 50% of the national.

In addition to the clarification of intentions, military spending is in fact 54% of federal discretionary spending.

Entitlement programs like SS and Medicare/Medicaid are raised on a separate tax (you can see it on your paystub), and have zero discretion in how they're spent. It's determined by statute and is automatic, not part of the budget process, and the money never really mixes with the rest of the federal budget.

If you take those out, and take out interest payments which we also don't have much choice in, military spending is 54% of the money that's actually at issue when Congress makes budget decisions.

https://cdn.shopify.com/s/files/1/0177/6150/t/2/assets/Death...

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#128

Post by hueving »

ExactoKnight wrote: post #101

I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us. A telescope this large could tell us whether any of these potentially habitable planets contain oxygen, and thus, biological processes. Yet thanks to funding cuts in science the biggest telescope we have in the pipeline r…

>I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us.

This is because most of society is still struggling with day-to-day tasks like getting housing, clean water, reliable food, healthcare and dealing with physical conflicts.

Even people rich enough to not be stuck in the short term future have to be concerned with near term risks like political destabilization countries and climate change.

So it's hard to rush to do something like this as a society when we are already rushing to solve acute issues.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#129

Post by spenczar5 »

ExactoKnight wrote: post #101

I am flabbergasted that as a society we aren't rushing to build a 100 metre wide telescope mirror large enough for us to directly image the spectra of the potentially habitable exoplanets around us. A telescope this large could tell us whether any of these potentially habitable planets contain oxygen, and thus, biological processes. Yet thanks to funding cuts in science the biggest telescope we have in the pipeline r…

Very large telescopes can achieve great resolving power, but they run up against atmospheric turbulence, particularly in many of the spectral regions we care about for checking out exoplanets. Radio light passes right through the atmosphere for the most part, which is why you see very large radio telescopes, but they're not very practical for infrared or visible light scopes.

Space-based telescopes are a better avenue. You can achieve much better resolution in practice with a much smaller telescope. There's no atmosphere to block you, and instruments can capture light of any frequency. Cost is the main disadvantage, but delivery of satellites (and maintenance) to space is getting cheaper and cheaper.

All of which is to say that I agree we should be spending more on astronomy. That was your main point, of course. I disagree with the particulars, and think we should be more willing to go to space.

Re: Four Earth-sized planets detected orbiting the nearest sun-like star

#130

Post by rsync »

baron816 wrote: post #37

Ok, let's assume we find a warm, watery planet like Earth's within ~20 light years, and we figure out a way to travel >= 50% the speed of light, making it somewhat reasonable to get there. If the planet's gravity is greater than 10% different from Earth's, or its Day/Night cycle is much different from Earth's, wouldn't it still be a nightmare to live on. Anatomically modern humans have lived on Earth for 200,000 year…

"Anatomically modern humans have lived on Earth for 200,000 years, and the creatures we descended from have lived on Earth for 541 million years. Stuff as dumb as the moon cycles affect us. How are we going to live somewhere that isn't exactly Earth?"

To further your (good) point about gravitational and diurnal differences, it is worth also considering the experience of native americans in the face of novel (to them) micro-organisms brought in by europeans.

These diseases were not from another solar system and they were related to animals that had local analogs ... and yet they were devastating (up to 90% mortality in some places) to the native population.

On another planet the bacteria, viruses and fungi (not to mention the potential discovery of previously unknown biological primitives) would be completely novel to us.

I wouldn't be shocked if there was 100% mortality outside of containment/quarantine after a week or two.

EDIT: On the other hand, imagine if we found that our genetic code did contain information related to what we found offworld ... wouldn't that be fascinating ...

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