Metallic spheres found on Pacific floor are interstellar in origin, Harvard professor finds

[Dan From Smithville]

As for the metal marbles..... Yeah? So?
Rain droplets are not in the classic tear-drop shape as they fall from the sky; they are spherical. So a meteorite melts as it enters our atmosphere, and the falling droplets of molten metal likely take on a spherical shape as they plummet to Earth. But if they strike water and "freeze" back into their solid state....... Ta Daahhh!! Metal marbles.

That is how shot for guns used to be made. Build a tower. At the top pour molten lead though a perforated copper plate to form spheres and let it cool on the way down until it hits a basin of water at the bottom.

 

[Dan From Smithville]

Let me rephrase, interstellar travel is technically possible, but what I’ll call “productive” travel is impossible. Sure, we sent Voyager probes into space and they might come across other star systems, but it will take tens of thousands of years to get there and they’ll be worthless hunks of metal.

We could try the whole laser at a sail method. That could get you to one-tenth the speed of light, which could get you to a nearby star within a few decades. But the problem is if we shoot a high powered laser at a sail for ten minutes to achieve that speed, the module connected to the sail could be no more then 1 gram—the size of a paper clip. Also, there’s the problem of having nothing to slow down the module in a controlled manner once it reaches a neighboring star system.

There’s also the problem of cosmic rays and space dust.

It’s just not possible practically.

I'd agree with not practical.

Manned missions should be replaced with robot probes predominantly and even those will have to report back to our descendants if they travel out far enough.

 

[Dan From Smithville]

This story reminds me of the article that I linked about the latest "room temperature superconductor" that I linked a month or two ago. The article that I linked was from a Science article I believe. The article itself was not peer reviewed, they were reporting on a claimed discovery by a researcher. They noted the problems with his work and said that implied rather strongly he was mistaken. It took very little time for others to repeat and refute his work. That was because this is an area of pretty intense research. It may take longer for a claim like this to be refuted, not everyone can replicate the methods used. Nor is there the same level of interest in this research. It right now only merits an:

"That is interesting. I wonder if further research will bear this out?"

Until that happens we might as well treat it as if it is false, or at best never happened since this is not enough to base a reasonable belief on.

I tend to agree with this line of reasoning. Unless there is extraordinary evidence and tests can be repeated, it is interesting, but not something to be embraced as a supported discovery.

Besides, alien metals don't melt under those conditions according to what I'm making up.

 

[Heyo]

Do you think that a city sized craft if feasible?

I think anything smaller would not be feasible, or at least not as practical. You need an ecosystem that is 100% recycling and sustainable, it is easier to maintain a stable system when you have some size. (Ask any aquarium keeper, the smaller the harder it is to keep it stable.) And you need a lot of shielding, the shields grow at the power of two while the living space grows by the cube. Also, a minimal crew would probably have more social difficulties.
There are a dozen more reasons for a city (or at least town) sized ship. I think a crew of about 200 people would be optimal.

 

[Copernicus]

Metal globules from a meteor are not evidence of interstellar travel, even in the extremely unlikely event that the metal was produced by an alien civilization. To prove that they were manufactured rather than the result of a natural physical process, one would need to be able to eliminate possible natural causes. Why would any aliens even try to travel here in the first place? Our technological civilization is only a few thousand years old, and we have not been sending anything out into space to notify intelligent aliens of our existence until recently--too recent for distant civilizations to receive them, given the limitation of the speed of light.

 

[Windwalker]

Those are refinements based upon what we had already observed. There is no hint of going faster than the speed of light. That is what you need for any sort of practical interstellar travel.

Or it may be something we need that we don't realize is there and is possible yet. That's my point. You're taking what we understand about the speed of light, and discounting other possibilities we haven't thought of where that isn't a factor. What that might be, only the future may tell.

That should have been obvious from context.

What was obvious from the context is the constraints you were placing on it. Your language in that sentence was not provisional the way I phrased it instead.

Yes, it took advances in optics and astronomy to show that Newton was not correct. The problems with his theory were first observed in 1859.

https://www.sciencedirect.com/science/article/abs/pii/S2212686421000650#:~:text=This%20is%20the%20famous%20anomalous,important%20astronomical%20problem%20%5B1%5D.

But I do not think that you realize the sort of change that we need.

You don't see Quantum mechanics as a radical reimagining of the "laws" of the universe and our ideas of physics? Why can't something equal or greater to that discover or paradigm shift occur again in science in the future? I'm not talking what we discovered with optics in the 1850's here. Yes I do know what sort of change we need. Something on the level of QM, and beyond.

It could happen. But right now it does not appear to be possible. Until we have at least an indication that one can cheat space it will remain unfeasible.

Unfeasible based upon what we know now, yes. Impossible in the future because of our understanding now? No.

So when I hear people try to say things for instance that is 'impossible for us to be visited by alien species from other planets because the laws of physics won't allow it', isn't that saying our current understanding is absolute and we cannot be wrong about that?

I'm just saying, that doesn't sound like science to me. It doesn't sound like a good argument to be making. Look at what we can do now, that once was considered impossible to science of the past.

 

[Watchmen]

That's what we used to say about the basic air travel we do every day of the week now, or wireless communications, or horseless chariots, or.......

And we’re a lot smarter now and have a much better understanding of physics, so….

 

[Watchmen]

And by "travel" you mean to get to the destination in a comparable time you could get to any place on Earth (or someone in the past could have got there), don't you?
If so, I agree.
But there is nothing in the laws of physics that prevents us from travelling to other stars on a different time scale. In fact we are technically able to travel to the next stars in a lifetime except for one little invention from which we know that it is within the confines of the laws of nature.

False. We cannot reach the next closest star within one lifetime based on our current understanding of physics.

 

[Watchmen]

I think anything smaller would not be feasible, or at least not as practical. You need an ecosystem that is 100% recycling and sustainable, it is easier to maintain a stable system when you have some size. (Ask any aquarium keeper, the smaller the harder it is to keep it stable.) And you need a lot of shielding, the shields grow at the power of two while the living space grows by the cube. Also, a minimal crew would probably have more social difficulties.
There are a dozen more reasons for a city (or at least town) sized ship. I think a crew of about 200 people would be optimal.

How in the world would you power such a thing? How fast do you imagine it would travel?

 

[Subduction Zone]

Or it may be something we need that we don't realize is there and is possible yet. That's my point. You're taking what we understand about the speed of light, and discounting other possibilities we haven't thought of where that isn't a factor. What that might be, only the future may tell.

What was obvious from the context is the constraints you were placing on it. Your language in that sentence was not provisional the way I phrased it instead.

You don't see Quantum mechanics as a radical reimagining of the "laws" of the universe and our ideas of physics? Why can't something equal or greater to that discover or paradigm shift occur again in science in the future? I'm not talking what we discovered with optics in the 1850's here. Yes I do know what sort of change we need. Something on the level of QM, and beyond.

Unfeasible based upon what we know now, yes. Impossible in the future because of our understanding now? No.

So when I hear people try to say things for instance that is 'impossible for us to be visited by alien species from other planets because the laws of physics won't allow it', isn't that saying our current understanding is absolute and we cannot be wrong about that?

I'm just saying, that doesn't sound like science to me. It doesn't sound like a good argument to be making. Look at what we can do now, that once was considered impossible to science of the past.

Let's try not to distort arguments. What people correctly point out is that there is no valid reason to believe that we have ever been visited by aliens from outer space.

 

[Heyo]

False. We cannot reach the next closest star within one lifetime based on our current understanding of physics.

What exactly do you think prevents that?

 

[Heyo]

How in the world would you power such a thing? How fast do you imagine it would travel?

With a fusion engine. Yes, we don't have one now but that is what I said we still have to develop. But there is no law in physics that says that such an engine is impossible. In fact, we know that it does work, the sun does fusion for 4.5 billion years now.
The theoretical max speed is somewhere around 30% c.

 

[Quagmire]

I wanna say aliens so bad......

That's kind of the problem: we all do.

 

[Watchmen]

What exactly do you think prevents that?

Our inability to travel fast enough to reach the closest star within a single lifetime.

 

[Dan From Smithville]

That's kind of the problem: we all do.

I kinda do too.

 

[Dan From Smithville]

Our inability to travel fast enough to reach the closest star within a single lifetime.

Faster ships and longer lives it is then. Compromise.

 

[Heyo]

Our inability to travel fast enough to reach the closest star within a single lifetime.

That is a null answer. You said

False. We cannot reach the next closest star within one lifetime based on our current understanding of physics.

Which physical laws make us unable to travel fast enough?

 

[Subduction Zone]

That is a null answer. You said

Which physical laws make us unable to travel fast enough?

Relativity.

 

[Daemon Sophic]

There is something to be said for bioships (ships with their own farming and self-sustaining populations, etc...). When we launch something to go to a nearby star system, in hopes of finding a world suitable for colony building and eventual global settlement, has a couple of issues yet to be mentioned in this thread. While even by relatively infantile current technology, we can suss out which exoplants have oxygen in their atmospheres along with water. Great! But.....
1. They could be so inhospitable for a wide range of reasons, such that our colony ship would have to move on to another (hopefully) nearby star system.
.....or......
2. The planet could have all the building blocks we need for a habitable planet........ after a few (dozen) centuries of terraforming. The bioship would have to sit in orbit, monitoring the planet below, while bombarding it with water-ice asteroids, seeding the atmosphere and expanding oceans with bacteria and plankton, etc...etc...etc... before even the first plant seeds could be sent down. All the while maintaining their own biosphere, plant and animal populations, engineering needs etc... from an asteroid field that would also be required to exist in the star system.


So whether the ship can make it to the other star system in 1 day, or 50 years, is of minor importance, compared to the in-system time they will have to spend living onboard the ship as a giant space station during the terraforming, centuries before anyone "takes a shuttle" or "beams down" to the planet surface.

 

[Watchmen]

With a fusion engine. Yes, we don't have one now but that is what I said we still have to develop. But there is no law in physics that says that such an engine is impossible. In fact, we know that it does work, the sun does fusion for 4.5 billion years now.
The theoretical max speed is somewhere around 30% c.

That is a null answer. You said

Which physical laws make us unable to travel fast enough?

Tell me the physical laws that would permit us to travel the speed of light.