48
votes
Can we hit the spaceship
Frame challenge / "no" for other reasons
Realistically at least one country will want to destroy them
This is false. If an alien ship reaches our solar system, our scientists will tell our ...
- 14.2k
18
votes
Can we hit the spaceship
"Can we hit the ship" - yes, reliably, provided they don't change course (which I frankly expect them to be able to, anyway they are to shed off 100km/s delta-V to stick to Earth orbit) and ...
- 6,466
16
votes
Accepted
Bullet resistant space armor material
Step one: don't use pressurized suits... use mechanical counterpressure. This is a good excuse to have all your peeps wear skintight figure hugging future clothes, in case you needed one. You probably ...
- 72.8k
16
votes
Is a world laser possible?
Laser physicist here. There's no such thing as a laser beam with width 1 nm over 1000 km. The smaller your beam diameter at the aperture, the more divergent (cone-shaped) your beam becomes. Beams that ...
- 1,553
15
votes
Can we hit the spaceship
Your best bet is to rely on the "can't be built fast enough" side of things. There are only two countries that can launch an interplanetary payload on six months' notice: the United States, ...
- 17.3k
13
votes
Accepted
Can we hit the spaceship
1) If nuclear warhead detonation is less precise than 4ms
Hitting a 4ms target window is chump change for modern semiconductor tech.
Consider an average desktop computer might have a CPU speed of 3GHz....
- 21.3k
13
votes
Possibility of anachronistic fossils due to time travel
Polypropylene fully degrades in a few decades, so unless she dropped it in the equivalent of a lab environment it will be long gone 74,000 years later.
One circumstance which would fit into your story ...
- 24.1k
11
votes
Realistic protection for spaceships against kinetic projectiles
I'm sure we've had questions on this before, but a quick search wasn't turning up anything particularly good, so here we are. You could have a quick read of my answer to Ideal materials for the outer ...
- 72.8k
11
votes
Accepted
Possibility of anachronistic fossils due to time travel
It's organic, so it might fossilise if it found itself in ideal conditions for the fossilisation of soft tissue, i.e. being rapidly buried in stagnant, anerobic mud, which later becomes part of a ...
- 5,047
10
votes
Accepted
Is a world laser possible?
destroy the world completely by cutting it in half in a singular motion (...)
Cool.
(...) using a laser which is focussed out of a very small point.
Nope.
As Separatrix explained, you won't really ...
- 136k
8
votes
How to survive a helicopter crash using alien biotechnology?
My father used to be in the Air Force and spoke many times about the safety features and training required in helicopters.
It may be possible to achieve the Aliens goal by not using nano-tech / ...
- 21.1k
8
votes
Possibility of anachronistic fossils due to time travel
Frame challenge: I'd rather be bothered with modern microbiota introduced into the aged ecosystem
Humans evolve, and whatever other symbiotic or parasitic bacteria we have on or in our bodies also ...
- 6,466
8
votes
Accepted
Can a terrestial planet have a core of metallic hydrogen?
Couldn't happen for two reasons.
First Metallic hydrogen is a phase change that only occurs at levels of pressure that far exceed Earths core, or anything you'd call terrestrial.
Second, terrestrial ...
- 14.5k
8
votes
Can we hit the spaceship
Can We hit it? Yes.
There's a multitude of ways such an object could be hit. Let's go through your points:
4 ms response time - Easy with modern electronics, Next.
Nothing to fit the role of ...
- 18.9k
7
votes
Realistic protection for spaceships against kinetic projectiles
Evasion
Space is big, and space battles could plausibly occur between ships located thousands or even millions of km apart. The first defense is not to get hit, and being very far from the enemy makes ...
- 6,940
6
votes
Bullet resistant space armor material
Self-sealing rubber lining
i'm aware that even a slight breach in a space suit on mars or the moon results in depressurization and death. to my understanding, even a slight graze of a bullet on a ...
- 3,640
6
votes
Accepted
Is it possible for a plant to form a biological "greenhouse" to protect its delicate flowers using some sort of clear, insular material?
The plant can produce biogenic silica and have it act like the glass in a greenhouse.
Biogenic silica (bSi), also referred to as opal, biogenic opal, or amorphous opaline silica, forms one of the ...
- 277k
6
votes
Realistic protection for spaceships against kinetic projectiles
The Sponge Approach
Realistically there is very little to stop high velocity rounds.
It's age old problem faced by the armed services in the battle between armour and weapons.
In The Expanse, ...
- 45.9k
4
votes
Realistic protection for spaceships against kinetic projectiles
I have always been a fan of ice. It's easy to come by, space is cold anyway. It works well as an ablative armor either stand alone or as a type of pykrete. Can be used as fuel radiation shielding and ...
- 5,578
4
votes
Can we hit the spaceship
Realistically at least one country will want to destroy them, which
breaks the plot, so I need to know if they're told "no" by science or
"no" for other reasons.
Tom already ...
- 1,912
4
votes
Possibility of anachronistic fossils due to time travel
I just don't see what is the problem if a small plastic item is found somewhere in Africa. I cannot say for sure, as I have never been there, but I believe that they do have plastic ballpoint pen caps ...
- 86k
3
votes
Is a world laser possible?
A laser isn't going to cut it! (ba-dump psh!)
As others have pointed out, cutting the Earth in half does almost nothing at all. The two halves are still held together gravitationally, and will ...
- 131k
3
votes
Realistic protection for spaceships against kinetic projectiles
In Rendezvous with Rama, Clark solved this by having Rama extrude miles and miles of fuzzy cable. This wasn't quite a Whipple shield because the cables had a bit of intelligence and could wrap ...
- 14.5k
2
votes
So, I was thinking a biological kinda ozone layer?
The whole reason an ozone layer is important is that UV light would otherwise shred biological structures. If what gets through the ozone layer doesn't sterilize those "aeroalligants", they ...
- 4,785
2
votes
So, I was thinking a biological kinda ozone layer?
No, because...
Before getting into the main question, it's necessary to look at a couple of the assumptions listed in it.
The first of these assumptions is the statement that terraformed Venus is &...
- 25.8k
2
votes
Can we hit the spaceship
Nukes are actually more destructive in space than on Earth
(As an aside, first I'd like to tell you that a nuclear fission reaction typically is over within 100 "shakes," a shake being 10^-8 ...
- 6,940
2
votes
Possibility of anachronistic fossils due to time travel
Frame challenge: Don't bother answering how it survived: There are plenty of artifacts where we don't understand their provenance.
Instead, take it for granted that it survived, then have it match a ...
- 361
2
votes
Possibility of anachronistic fossils due to time travel
For a serious scientific look at the problem of ancient civilizations in the geological record read The Silurian Hypothesis. The paper can be downloaded for free and has speculation by NASA Scientists ...
- 125
2
votes
Is it possible for a plant to form a biological "greenhouse" to protect its delicate flowers using some sort of clear, insular material?
Plants with their own little greenhouse
AlexP already mentioned Haworthia cooperi, but the pictures in Wikipedia do not present the more strange-looking varieties:
These are tiny, but larger ones ...
- 674
2
votes
How could a spacecraft defend against a train of small hypervelocity impactors?
Your major issue would be having the whole train or even part of it impact the same spot when everything is moving that fast. Possible if you're firing head or stern on, but otherwise seems ...
- 24.1k
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