8 ms·

So, this does nothing to actually combat space junk in the sense of debris in orbit. The actual goal is: > We are very concerned with the fact that all the sat

So, this does nothing to actually combat space junk in the sense of debris in orbit. The actual goal is: > We are very concerned with the fact that all the satellites which re-enter the Earth's atmosphere burn and create tiny alumina particles which will float in the upper atmosphere for many years

jessriedel 6y ago
Right. The author is clearly conflating orbital debris with re-entry pollution. It is baffling to me that the BBC, a fairly respectable organization, allows this sort of terrible journalism. The author clearly does not understand the subject matter at all, which is not surprising since he's a business reporter regurgitating (presumably) a press release from a university and/or a forestry company.
- HPsquared 6y ago
  Gell-Mann Amnesia, as described by Michael Crichton: “Briefly stated, the Gell-Mann Amnesia effect is as follows. You open the newspaper to an article on some subject you know well. In Murray's case, physics. In mine, show business. You read the article and see the journalist has absolutely no understanding of either the facts or the issues. Often, the article is so wrong it actually presents the story backward—reversing cause and effect. I call these the "wet streets cause rain" stories. Paper's full of them. In any case, you read with exasperation or amusement the multiple errors in a story, and then turn the page to national or international affairs, and read as if the rest of the newspaper was somehow more accurate about Palestine than the baloney you just read. You turn the page, and forget what you know.”
  - remarkEon 6y ago
    Upvoted your comment because for whatever reason people don’t like to see this phenomenon invoked, but that’s exactly what’s going on here.
    - j4yav 6y ago
      I didn't downvote but I think people do because it's almost a stock comment that a bot could automatically apply. It's guaranteed to appear in about 5% of the comments every time an inaccurate article is being discussed.
      - jeltz 6y ago
        Yes, that is why I downvoted. It is a stock comment which adds nothing worthwhile to the discussion.
        concordDance 6y ago
        It's a useful reminder for the many of us who, like me, tend to forget this.
- h_anna_h 6y ago
  There was another instance with that happening recently https://news.ycombinator.com/item?id=25520481 https://news.ycombinator.com/item?id=25520481
- WalterBright 6y ago
  I wish people (even physicists) would stop saying that the heat of reentry is from air friction. It isn't. It's from compression. The air cannot get out of the way fast enough, and it compresses, and compressing a gas raises its temperature. That's why the leading edge, where the air is moving the slowest, is the hottest.
  - patall 6y ago
    But isn't that what friction is?
    - WalterBright 6y ago
      No. You'll get the same temperature rise from an ideal frictionless gas. (This was one of the exercises in fluid mechanics class in college.) The bit about the air cannot get out of the way fast enough comes from its inertia, not friction. You'll find the same temperature rise in high speed aircraft like the SST. The max temperature rise is at the stagnation point where the air velocity is zero. (Compress any gas and it warms up, this is how refrigerators work.)
      - Leherenn 6y ago
        What makes the air too slow to get out of the way? I would have naively thought friction, and that if everything was frictionless the air would seamlessly move to replace the vacuum behind the aircraft, and thus no compression would occur.
        MereInterest 6y ago
        To put it bluntly, air molecules aren't psychic. The only way they know what happens to neighboring air molecules is by running into them. At every-day velocities, this happens fast enough that we can treat it as though it is instantaneous. That the "vacuum" is a thing that sucks air in. At high velocities, this intuition breaks down. The communication time between molecules is limited to the speed of sound, the speed at which air molecules travel and bump into each other. If you are traveling faster than the speed of sound, (or several times faster, as is the case for re-entry), the air molecules don't have any information that an object is coming to them, because there hasn't been enough time for molecules hitting the object to then hit them.
- secondcoming 6y ago
  > It is baffling to me that the BBC, a fairly respectable organization, allows this sort of terrible journalism Unfortunately, the BBC is not what it used to be. In fact, it has probably never been as unpopular.
- f6v 6y ago
  Imagine how wrong they can be about all other matters which shape reader’s worldview.
- CraigJPerry 6y ago
  >> The author is clearly conflating orbital debris with re-entry pollution To be fair to the journalist, so does wikipedia, the National history museum and the FAA. On balance, the journalist (and perhaps the editor) appears to be correct here. I don’t know enough to say if you’re mistaken or not but i can’t find a good definition for your term “re-entry pollution”. Do you have any handy links for that term? Wiki & the NHM re-define “space junk” as “space debris”. Google does this too but is just relying on these sources. The wikipedia for space debris includes material that falls back to earth. It even lists some notable incidents. Wikipedia doesn’t appear to recognise the term “re-entry pollution”. The FAA deals with debris here: https://www.ecfr.gov/cgi-bin/text-idx?SID=685669905c05d232fc85ebb36583d4d5&node=47:1.0.1.1.6.2.233.9&rgn=div8 https://www.ecfr.gov/cgi-bin/text-idx?SID=685669905c05d232fc... - it treats orbital and re-entry debris under the same provisions and doesn’t seek to further distinguish them. >> clearly does not understand the subject matter at all What sentences in the article lead you to this conclusion?
  - krisoft 6y ago
    "What sentences in the article lead you to this conclusion?" Each sentence in the article in itself is good. The sentences together reveal that the author had no understanding of the topic. (or decided to wilfully write a confusing mess) Let me illustrate: " Space junk travels at an incredibly fast speed of more than 22,300 mph, so can have cause considerable damage to any objects it hits. In 2006 a tiny piece of space junk collided with the International Space Station, taking a chip out of the heavily reinforced window. " This is true! Objects on orbit have very high energies. When two of these objects collide they generate tiny shards which can collide into new objects, shattering them too. This can lead to a cascading problem where many satellites on a given orbit turn into mush at the same time. And not only that you loose these satellites, but their shards remain on the orbit posing risks for future satellites. You might heard of this effect as the Kessler syndrome. You might be wondering, how does making the sat from wood would help with this? The answer is it wouldn't. But you wouldn't know that from the article. It has zero connective structure to illuminate this. So why are these people working on a wooden satelite? To quote again from the article: "We are very concerned with the fact that all the satellites which re-enter the Earth's atmosphere burn and create tiny alumina particles which will float in the upper atmosphere for many years," Ah. So these people are not worried about the Kessler syndrome. They are worried that re-entering space craft break up, and particles from it can remain in the upper atmosphere. That's an interesting problem. Maybe worth addressing. But if that's the problem why is the article waxing about speed of objects in orbit and chips colliding with the international space station? You say you can't find a good definiton of the term "re-entry pollution". And you are right. It's not a widely used term. But clearly an apt description of what the company is talking about. Is this a serious concern? Has there been studies about this effect? Is there a more commonly used term for this kind of pollution? Who knows. I don't know. You don't know. The article should be answering these questions for us. Instead all we have is a single sentence ""Eventually it will affect the environment of the Earth."" Nice. Not very well researched. And probably even the journalist felt this is not enough so they wrote multiple paragraphs about what he could find of the dangers of space junk. But sadly he found a totally irrelevant other kind of problem. If they realised this and wrote the article still as presented then they are wilfully confusing people. If they are just dazzled by all the terminology then so bad, I would still expect more from professionals. "On balance, the journalist (and perhaps the editor) appears to be correct here." What do you mean by that? If someone writes a word salad they are correct just because others have wrote similar word salads before? "Wikipedia doesn’t appear to recognise the term “re-entry pollution”." So bad for the company and the journalist. It sounds like they have to do more work to explain their problem then! And your ecfr.gov link. It talks about making sure that your satelite does not explode on orbit. (To mitigate the problem of the Kessler syndrome.) It also talks about post-mission disposal in paragraph (4). It contemplates two scenairos. One where you put your sat to a lesser used orbit, or one where you deorbit your satellite. In case you choose to deorbit you have to show that you are not too likely to plonk anyone in the head. From the perspective of this second scenario the whole sat burning up into aluminium mist in the upper atmosphere is a success. The company disagrees and says that we should worry about other unspecified effects too. Are they right? Maybe! But the article sure didn't do a good job to explain the distinction, and thus failed to ask the pointy questions it should have asked.
- alisonkisk 6y ago
  It's not a conflation anymore than me calling my recycling bin "trash". It's just a slightly more general term used when the distinction is not important because the meaning is completely obvious in context. People who think space junk cannot polite the atmosphere are the confused ones, not the author.
- charliebrownau 6y ago
  HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA Please sheeple, wake the FARK UP No such thing as real journalism in the Judo-mainstream The system refuses to hold them accountable for * Lying * Slander * Propaganda * False BS Mainstream 'news" are working in hand with the system , Globalists , UN, Agenda 21 They have always been gatekeepers for infomration BBC is clearly ANTI WHITE ANTI MALE ANTI FREEDOM ANTI WESTERN ANTI TRUTH
- Shivetya 6y ago
  This is the result of agenda driven reporting. They are literally accepting anything which promotes their current focus which is on the environment. Focusing on the environment is a good thing but we risk burning people out or worse having them assume everything they read if more scare and fiction that true issue. we live in a world where the virtue signaling has gotten so loud people are deaf and just tune it out. those who cared will still care but we are losing an entire segment simply because we check ourselves
- lordlimecat 6y ago
  BBC has been dropping the ball lately, there have been entirely too many articles that miss the thrust of whatever their source was.
- dr_orpheus 6y ago
  It's baffling, but not surprising to me. I worked in mission operations on some NASA satellites. A reporter once asked our team "so how do you get up there every day to fly them?"
  - bigbubba 6y ago
    Surely he was taking the piss. Not even a journalist could be that stupid.
- Blikkentrekker 6y ago
  How much of a problem is actual orbital debris? Going by the maxim of “Space is always more empty than one could possibly imagine.”. >inb4 “if the moon were a pixel”.
  - jessriedel 6y ago
    It's a modest and pretty easily manageable problem now, but it will become pretty non-trivial in the future if not properly handled. However, all signs point to it being properly handled (it's in everyone's interest), so my advice to laymen is to not worry about it. It's true that even near-Earth space is crazy, crazy big so that the amount of volume occupied by debris is extremely tiny, but what's also true is that debris is moving fantastically fast so that the volume "effectively occupied" by debris is only small rather than extremely tiny. This cashes out in the empirical facts (which fit perfectly with our models) that there have been four unintended collisions between satellites and debris: https://en.wikipedia.org/wiki/Satellite_collision https://en.wikipedia.org/wiki/Satellite_collision These have all taken place in the past 25 year (despite > 50 years of spaceflight) because the density is increasing. If the density keeps increasing without the forthcoming mitigation efforts, the rate of unintentional collisions would keep rising to bad levels.
dotancohen 6y ago
> tiny alumina particles which will float in the upper atmosphere for many years Large quantities of such particles have actually been seriously proposed to help combat global warming. What are the downsides of them? When these particles finally migrate into the troposphere they quickly fall to Earth at relatively low velocity due to the very high drag. I'm all against polluting the earth, but non-reactive aluminum particles in the quantities that we are talking about are such a non-issue in comparison to anything else.

jessriedel 6y ago

Right. The author is clearly conflating orbital debris with re-entry pollution. It is baffling to me that the BBC, a fairly respectable organization, allows this sort of terrible journalism. The author clearly does not understand the subject matter at all, which is not surprising since he's a business reporter regurgitating (presumably) a press release from a university and/or a forestry company.

HPsquared 6y ago
Gell-Mann Amnesia, as described by Michael Crichton: “Briefly stated, the Gell-Mann Amnesia effect is as follows. You open the newspaper to an article on some subject you know well. In Murray's case, physics. In mine, show business. You read the article and see the journalist has absolutely no understanding of either the facts or the issues. Often, the article is so wrong it actually presents the story backward—reversing cause and effect. I call these the "wet streets cause rain" stories. Paper's full of them. In any case, you read with exasperation or amusement the multiple errors in a story, and then turn the page to national or international affairs, and read as if the rest of the newspaper was somehow more accurate about Palestine than the baloney you just read. You turn the page, and forget what you know.”
- remarkEon 6y ago
  Upvoted your comment because for whatever reason people don’t like to see this phenomenon invoked, but that’s exactly what’s going on here.
  - j4yav 6y ago
    I didn't downvote but I think people do because it's almost a stock comment that a bot could automatically apply. It's guaranteed to appear in about 5% of the comments every time an inaccurate article is being discussed.
    - jeltz 6y ago
      Yes, that is why I downvoted. It is a stock comment which adds nothing worthwhile to the discussion.
      - concordDance 6y ago
        It's a useful reminder for the many of us who, like me, tend to forget this.
h_anna_h 6y ago
There was another instance with that happening recently https://news.ycombinator.com/item?id=25520481 https://news.ycombinator.com/item?id=25520481
WalterBright 6y ago
I wish people (even physicists) would stop saying that the heat of reentry is from air friction. It isn't. It's from compression. The air cannot get out of the way fast enough, and it compresses, and compressing a gas raises its temperature. That's why the leading edge, where the air is moving the slowest, is the hottest.
- patall 6y ago
  But isn't that what friction is?
  - WalterBright 6y ago
    No. You'll get the same temperature rise from an ideal frictionless gas. (This was one of the exercises in fluid mechanics class in college.) The bit about the air cannot get out of the way fast enough comes from its inertia, not friction. You'll find the same temperature rise in high speed aircraft like the SST. The max temperature rise is at the stagnation point where the air velocity is zero. (Compress any gas and it warms up, this is how refrigerators work.)
    - Leherenn 6y ago
      What makes the air too slow to get out of the way? I would have naively thought friction, and that if everything was frictionless the air would seamlessly move to replace the vacuum behind the aircraft, and thus no compression would occur.
      - MereInterest 6y ago
        To put it bluntly, air molecules aren't psychic. The only way they know what happens to neighboring air molecules is by running into them. At every-day velocities, this happens fast enough that we can treat it as though it is instantaneous. That the "vacuum" is a thing that sucks air in. At high velocities, this intuition breaks down. The communication time between molecules is limited to the speed of sound, the speed at which air molecules travel and bump into each other. If you are traveling faster than the speed of sound, (or several times faster, as is the case for re-entry), the air molecules don't have any information that an object is coming to them, because there hasn't been enough time for molecules hitting the object to then hit them.
secondcoming 6y ago
> It is baffling to me that the BBC, a fairly respectable organization, allows this sort of terrible journalism Unfortunately, the BBC is not what it used to be. In fact, it has probably never been as unpopular.
f6v 6y ago
Imagine how wrong they can be about all other matters which shape reader’s worldview.
CraigJPerry 6y ago
>> The author is clearly conflating orbital debris with re-entry pollution To be fair to the journalist, so does wikipedia, the National history museum and the FAA. On balance, the journalist (and perhaps the editor) appears to be correct here. I don’t know enough to say if you’re mistaken or not but i can’t find a good definition for your term “re-entry pollution”. Do you have any handy links for that term? Wiki & the NHM re-define “space junk” as “space debris”. Google does this too but is just relying on these sources. The wikipedia for space debris includes material that falls back to earth. It even lists some notable incidents. Wikipedia doesn’t appear to recognise the term “re-entry pollution”. The FAA deals with debris here: https://www.ecfr.gov/cgi-bin/text-idx?SID=685669905c05d232fc85ebb36583d4d5&node=47:1.0.1.1.6.2.233.9&rgn=div8 https://www.ecfr.gov/cgi-bin/text-idx?SID=685669905c05d232fc... - it treats orbital and re-entry debris under the same provisions and doesn’t seek to further distinguish them. >> clearly does not understand the subject matter at all What sentences in the article lead you to this conclusion?
- krisoft 6y ago
  "What sentences in the article lead you to this conclusion?" Each sentence in the article in itself is good. The sentences together reveal that the author had no understanding of the topic. (or decided to wilfully write a confusing mess) Let me illustrate: " Space junk travels at an incredibly fast speed of more than 22,300 mph, so can have cause considerable damage to any objects it hits. In 2006 a tiny piece of space junk collided with the International Space Station, taking a chip out of the heavily reinforced window. " This is true! Objects on orbit have very high energies. When two of these objects collide they generate tiny shards which can collide into new objects, shattering them too. This can lead to a cascading problem where many satellites on a given orbit turn into mush at the same time. And not only that you loose these satellites, but their shards remain on the orbit posing risks for future satellites. You might heard of this effect as the Kessler syndrome. You might be wondering, how does making the sat from wood would help with this? The answer is it wouldn't. But you wouldn't know that from the article. It has zero connective structure to illuminate this. So why are these people working on a wooden satelite? To quote again from the article: "We are very concerned with the fact that all the satellites which re-enter the Earth's atmosphere burn and create tiny alumina particles which will float in the upper atmosphere for many years," Ah. So these people are not worried about the Kessler syndrome. They are worried that re-entering space craft break up, and particles from it can remain in the upper atmosphere. That's an interesting problem. Maybe worth addressing. But if that's the problem why is the article waxing about speed of objects in orbit and chips colliding with the international space station? You say you can't find a good definiton of the term "re-entry pollution". And you are right. It's not a widely used term. But clearly an apt description of what the company is talking about. Is this a serious concern? Has there been studies about this effect? Is there a more commonly used term for this kind of pollution? Who knows. I don't know. You don't know. The article should be answering these questions for us. Instead all we have is a single sentence ""Eventually it will affect the environment of the Earth."" Nice. Not very well researched. And probably even the journalist felt this is not enough so they wrote multiple paragraphs about what he could find of the dangers of space junk. But sadly he found a totally irrelevant other kind of problem. If they realised this and wrote the article still as presented then they are wilfully confusing people. If they are just dazzled by all the terminology then so bad, I would still expect more from professionals. "On balance, the journalist (and perhaps the editor) appears to be correct here." What do you mean by that? If someone writes a word salad they are correct just because others have wrote similar word salads before? "Wikipedia doesn’t appear to recognise the term “re-entry pollution”." So bad for the company and the journalist. It sounds like they have to do more work to explain their problem then! And your ecfr.gov link. It talks about making sure that your satelite does not explode on orbit. (To mitigate the problem of the Kessler syndrome.) It also talks about post-mission disposal in paragraph (4). It contemplates two scenairos. One where you put your sat to a lesser used orbit, or one where you deorbit your satellite. In case you choose to deorbit you have to show that you are not too likely to plonk anyone in the head. From the perspective of this second scenario the whole sat burning up into aluminium mist in the upper atmosphere is a success. The company disagrees and says that we should worry about other unspecified effects too. Are they right? Maybe! But the article sure didn't do a good job to explain the distinction, and thus failed to ask the pointy questions it should have asked.
alisonkisk 6y ago
It's not a conflation anymore than me calling my recycling bin "trash". It's just a slightly more general term used when the distinction is not important because the meaning is completely obvious in context. People who think space junk cannot polite the atmosphere are the confused ones, not the author.
charliebrownau 6y ago
HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA Please sheeple, wake the FARK UP No such thing as real journalism in the Judo-mainstream The system refuses to hold them accountable for * Lying * Slander * Propaganda * False BS Mainstream 'news" are working in hand with the system , Globalists , UN, Agenda 21 They have always been gatekeepers for infomration BBC is clearly ANTI WHITE ANTI MALE ANTI FREEDOM ANTI WESTERN ANTI TRUTH
Shivetya 6y ago
This is the result of agenda driven reporting. They are literally accepting anything which promotes their current focus which is on the environment. Focusing on the environment is a good thing but we risk burning people out or worse having them assume everything they read if more scare and fiction that true issue. we live in a world where the virtue signaling has gotten so loud people are deaf and just tune it out. those who cared will still care but we are losing an entire segment simply because we check ourselves
lordlimecat 6y ago
BBC has been dropping the ball lately, there have been entirely too many articles that miss the thrust of whatever their source was.
dr_orpheus 6y ago
It's baffling, but not surprising to me. I worked in mission operations on some NASA satellites. A reporter once asked our team "so how do you get up there every day to fly them?"
- bigbubba 6y ago
  Surely he was taking the piss. Not even a journalist could be that stupid.
Blikkentrekker 6y ago
How much of a problem is actual orbital debris? Going by the maxim of “Space is always more empty than one could possibly imagine.”. >inb4 “if the moon were a pixel”.
- jessriedel 6y ago
  It's a modest and pretty easily manageable problem now, but it will become pretty non-trivial in the future if not properly handled. However, all signs point to it being properly handled (it's in everyone's interest), so my advice to laymen is to not worry about it. It's true that even near-Earth space is crazy, crazy big so that the amount of volume occupied by debris is extremely tiny, but what's also true is that debris is moving fantastically fast so that the volume "effectively occupied" by debris is only small rather than extremely tiny. This cashes out in the empirical facts (which fit perfectly with our models) that there have been four unintended collisions between satellites and debris: https://en.wikipedia.org/wiki/Satellite_collision https://en.wikipedia.org/wiki/Satellite_collision These have all taken place in the past 25 year (despite > 50 years of spaceflight) because the density is increasing. If the density keeps increasing without the forthcoming mitigation efforts, the rate of unintentional collisions would keep rising to bad levels.

dotancohen 6y ago

> tiny alumina particles which will float in the upper atmosphere for many years Large quantities of such particles have actually been seriously proposed to help combat global warming. What are the downsides of them? When these particles finally migrate into the troposphere they quickly fall to Earth at relatively low velocity due to the very high drag. I'm all against polluting the earth, but non-reactive aluminum particles in the quantities that we are talking about are such a non-issue in comparison to anything else.