I have been reading lately about serious inquiries into the possibility of extraterrestrial visitors to our planet, so I thought I would say a bit about how unlikely I think that is.
There are, it seems to me, three possibilities: the first is that some other group of sentient creatures picked up radio waves coming from earth, and came by to take a look; the second is that some sentient creatures were just wondering about in our galaxy and stumbled on this earth at a time when they could pick up radio waves and infer that somebody was here; the third is that some sentient creatures sent out search vehicles throughout the galaxy which picked up our radio waves, sent word back home, and brought folks looking to see who we were. I am leaving entirely out of consideration the possibility that we are being visited by creatures from other galaxies – they are so far from us that that seems to me entirely beyond the realm of possibility.
Radio waves travel at the speed of light and they were discovered in the 1880s here on earth. Let us suppose that the most advanced creatures we can imagine are capable of interstellar travel at a rate half the speed of light (I am not sure that is even theoretically possible but what the hell.)
The first and third possibilities mentioned above would mean that radio waves left earth at the speed of light – let us suppose, in the 1880s – and creatures came back to take a look. A little simple calculation tells us that those creatures would have to live no more than 40 light years away from us – 40 years for radio waves to reach them and 80 years for them to suit up and travel back.
Well, our galaxy is the Milky Way. It is roughly 80,000 light years in diameter, which means that it has a surface area (it is, so to speak, flat more or less) of roughly 20 billion square light years. The circular area around the home planet of these extraterrestrials within which they could receive messages from us and come back to see who was there is roughly 5000 square light years. So unless thesse creatures happen to live in a circular area around us that is one four millionth the area covered by the Milky Way, possibilities one and three are ruled out. The possibility that these sentient creatures had just gone off on a 50,000 year jaunt and happened by just when we were sending out radio waves is so small I cannot even estimate it.
I rest my case.
40 comments:
Another possibility: they detected atmospheric markers by telescope indicating a high likelihood of life on this planet -- perhaps thousands/millions of years ago -- and decided to come take a look.
Right. I agree.
And if they are so fucking intelligent that they can travel at half the speed of light or even at the speed of light, why would they want to come here?
Really, this planet isn't so attractive for space tourists. We have a massacre in Ukraine, another in Gaza (which follows the massacre of Israelis by Hamas). Milei just got elected in Argentina and Trump might well be elected in the U.S. next year. We misuse our resources so that the whole place is getting overheated and nobody seems likely to do anything about it.
There's nothing here that would interest anyone of superior intelligence. If there's life on other planets, they can surely find one that is more pleasant to visit.
The number of scientific papers prompted by a seemingly casual query Enrico Fermi voiced over lunch many years ago is enormous. Here's one
https://www.bis-space.com/membership/jbis/2018/JBIS-v71-no06-June-2018-eepb84.pdf#page=6
Here's another(which emphasises that astrophysical events of various sorts constitute the greatest existential threat to life everywhere)
https://arxiv.org/pdf/2206.06967.pdf
He asked why, given the size and age of the universe there is no evidence of life other than here? Was it that there was something implicit in techno-scientific civilisations that they self destruct? What has begun to provoke more interest in his paradox is that we humans have generated a number of existential threats to our own existence and maybe to the existence of life on Earth.
Variation of Anonymous @ 1:38
Extraterrestrials sent scouts to Earth millions of years ago, perhaps because they had problems in their own world(s). (Premise of HP Lovecraft's "At The Mountains of Madness" and Spielberg's adaptation of "War of the Worlds.")
They could have simultaneously sent scouts to many different locations, not necessarily singling out Earth.
s. wallerstein,
(1) Intelligence ≠ wisdom.
(2) We're back to the debate over absolutism (non-relativism) vs relativism in values. Vultures, dung beetles, and cats have very different notions of what constitutes a delectable meal.
james wilson,
Maybe there is evidence of other life but we just are not yet able to recognize it as such.
Eric,
I was being facetious in my remarks about space travel above.
However, while not all intelligent people are wise, all the wise people I've known are intelligent. I've not met a stupid and wise person.
I'd say that is because wisdom isn't something anyone is born with, but something people acquire through learning from experience and intelligent people have more capacity to learn than stupid people do. Not all intelligent people learn wisdom from their experience; some simply learn how to play the game better, while wisdom would involve learning which
games are "worthwhile."
I realize that there are different types of intelligence, but what I say above goes for emotional intelligence as well as for the standard type of intelligence measured by I.Q. tests.
Eric, a variation of your last query and a possible link with s.w.'s sour view of us: is there evidence of intelligent life on Earth?
I think the biggest problem is the distances between our solar system and a roughly comparable system and the question of how to cover the enormous distances. Half the speed of light, regardless of whether it can be achieved technologically, is hardly the benchmark, because such a vehicle must a) overcome inertia to reach it and then b) slow down again to get to 0. The acceleration phase would take a decade, and that's assuming there are exotic materials that exceed the bending tensile strength of steel or carbon fiber by a factor of 100 or more.
Alpha Centauri is the closest solar system and is about 4.32 LY away from our sun. To get an idea of what that means, imagine shrinking our solar system (down to the Keuper Belt) to the size of an orange to fit it in the center of Washington DC. At this scale, Alpha Centauri would be somewhere near Denver Colorado.
Voyager 1, launched on Mon, 05 Sept 1977 12:56:00 UTC, 46 years ago from today. It left the heliosphere in 2012 and is now about 15 billion miles from the sun. The light from where it is now flying takes over 22 hours to reach us. If Voyager 1 were to fly in the direction of Alpha Centauri at its current speed of approx. 38,000 mph, it would arrive there in approx. 1670 years. And that is only 4.32 light years.
Unfortunately, the landing there would be very disappointing, as it would be in the entire vicinity of the solar system within a radius of several hundred light years.
So the aliens will probably have to make do with watching the afternoon programs on our TV channels. My guess is that their motivation to visit us will either be close to zero, or they'll get so aggressive that they'll actually find a wormhole that bends space so much that they'll reach Earth in no time.
"they are so far from us that that seems to me entirely beyond the realm of possibility"
According only to our scientific know-how & any advances we believe will come from that know-how.
"And if they are so fubar intelligent that they can travel at half the speed of light or even at the speed of light, why would they want to come here?"
According to exo-political experts like Michael Salla & Elena Danaan the bad guys are here for clone breeding, sex slaves, and humans for food. However, the good aliens are fighting against this. But they're up to their elbows in trouble trying to stem the tide.
According to them there are Alien species of all kinds all over the universe. I used to think there are a lot less of them. That is until the James WEBB started sending back pictures of our galaxy & confirmation of exoplanets back to Earth.
s.w. wrote:
"There's nothing here that would interest anyone of superior intelligence. If there's life on other planets, they can surely find one that is more pleasant to visit."
This makes me think of the philosophers' varying attitudes toward the "lesser" animals:
For an almost reverential scientific curiosity, there's Aristotle: "We...must not recoil with childish aversion from the examination of the humbler animals. Every realm of nature is marvelous: and [...] we should venture on the study of every kind of animal without distaste; for each and all will reveal to us something natural and something beautiful.
There's also Schopenhauer: "Compassion for animals is intimately connected with goodness of character, and it may be confidently asserted that he, who is cruel to living creatures, cannot be a good man. Moreover, this compassion manifestly flows from the same source whence arise the virtues of justice and loving-kindness towards men."
At the other end, I think there are reports of Spinoza trapping ants and spiders and having them fight for their lives, for his entertainment. Also, F.H. Bradley would shoot cats on sight.
By analogy, I guess there are a number of possibilities as to what sort of "standing" we humans could expect in the minds of our extraterrestrial visitors. My own suspicion is that their ethics would be developed to the point where war, conquest, and exploitation would not be their ways of doing things; maybe (big maybe) they'd even wish to intervene and prevent our self-incurred extinction, as we ourselves sometimes do with endangered species. Any species that endures and cooperates long enough to somehow develop a means of interstellar travel, must've learned how (or innately possessed the decency) to avoid destroying themselves along the way.
Humans are naturally obsessed with humans and see everything in terms of a human frame of reference. But why assume that would be true for beings with a much wider knowledge of other kinds of beings, and whose frame of reference encompasses eons rather than just years or even individual human lives?
If you understand how evolution works and accept that humans erose through evolution, and your timescale is on the magnitude of eons, why focus on the current stock of humans as something particularly special and worth preserving?
Maybe a visitor would find that the more interesting beings on Earth would be self-sufficient beings such as plants, algae, and cyanobacteria, all of whom produce energy for themselves from light.
Any species that endures and cooperates long enough to somehow develop a means of interstellar travel, must've learned how (or innately possessed the decency) to avoid destroying themselves along the way
The Ancient Greeks had very sophisticated philosophers.
Why are the Greeks today not more influential in world affairs (eg the Greeks have no permanent seat on the UN Security Council, and when there are international crises, no one other than the Greeks asks, 'What will the Greeks do?')?
Michael’s mention of Bradley’ dislike of cats reminded me of this well-wrought description of Bradley’s predilections, in the Stanford Encyclopedia of Philosophy article on Bradley: “He liked guns and disliked cats, indulging his preferences economically by using the former to shoot the latter in the college grounds at night.”
Perhaps we should consider the dimension of time. The galaxy is ~13BYO. A star like the sun lasts ~4BY. Species come and go. Stars come and go. Planets come and go. Homo erectus to us is about a couple million years. Overlap in the stellar hood seems unlikely.
Also traveling over great distances would require numbers and they would require resources as they go from planetary system to planetary system. Settler/colonists perhaps?
I'm more of an A. C. than an F. H. Bradley man, but as a cat killer the latter was way ahead of his time. One of the most cheering things for me in 2023 was the rising awareness of the stupefying ecological damage done by both feral and roaming domestic cats; e.g. Joey Santore at Crime Pays but Botany Doesn't while killing lawns has also been beating the anti-feline war drums on social media, and Jonathan Franzen has a recent article in the New Yorker about the harm done by the 'No Kill' movement. And New Zealand is now having feral cat hunting contests, alas limited to 14 and under: https://www.theguardian.com/environment/2023/dec/12/cats-diet-2000-species-conservation-study-aoe
Just don't stand (or sit) before Dr. Evil if he ever rises to power. If Mr. Bigglesworth, who sits on his lap, doesn't like you for any of your feline hating instincts, you may end up laser shark-bait.
How human - create a problem then try to fix it by killing something and possibly creating yet another problem.
The two settler-colonist waves (beginning in the 14th century) that populated NZ (as with the S-C waves that screwed up the flora and fauna of the Americas beginning ~20+KYA) led to the extinction of many species in those places. The first wave of folks who settled the Hawaiian Islands in ~11th century were hell on birds. Following waves brought other negative contributions to the F & F. Rinse and repeat for every island in the Pacific.
BTW, killing things is part of the human-feline bargain. While Marley is strictly an indoor cat, his feral kin keep rodents somewhat under control. I had a rat problem in the chicken coop until the large white cat who includes chez aaall in his territory started taking them out. Ditto, mice, voles, and gophers.
Went to town yesterday and went past the courthouse. The handful of folks who had been there for months protesting COVID vaccines have been replaced by a small group waving pro-Palestinian signs and flags. Across the street was a lone dude waving a large Israeli flag.
Harvard's president Claudine Gay has resigned.
https://www.thecrimson.com/article/2024/1/3/claudine-gay-resign-harvard/
I've been following this story somewhat for the past several weeks.
What has most shocked me about Prof Gay was reading last month that she had produced only 11 peer reviewed articles in her meteoric rise in academia. (Or at least that's what the hit piece about her in the The Washington Free Beacon last month claimed, and which all the conservative media have been repeating.) How does an economist get tenure, let alone become a dean and ultimately president of one of the world's preeminent universities, with only 11 peer-reviewed publications under their belt? Is this claim true? And if it is, how is it possible?
Eric, Google scholar has a few links:
https://scholar.google.com/scholar?start=30&q=claudine+gay&hl=en&as_sdt=0,5
Scholia has fewer:
https://scholia.toolforge.org/author/Q29121979
This was a right wing hit job so shame on the NYT and she's not an economist so where did you get your information?
I meant political scientist (she has an undergrad degree in economics). I don't see how that changes my basic point. I imagine that within the very broad community of a university there may be a handful of disciplines in which it is perhaps not unheard of for someone to be very accomplished and influential yet have few publications in peer-reviewed journals, but I don't think poli sci (or economics, or sociology, or academic public policy) is one of those.
Eric,
She doesn't have many peer-reviewed articles, but she's published in some of the very best political science journals (e.g., American Political Science Review and American Journal of Political Science). She's also widely cited.
Some well-known philosophers published very little. E.g., Edmund Gettier published a grand total of three papers, but he's justly famous for his three-page 1963 Analysis paper.
Plus, if you're a careerist hankering to be a university boss, publications aren't that important.
The question is, is travel faster than the speed of light possible? Some physicists think so, bending space is the most method, variations on entanglement seem to creep into the conversation and then there is quantum gravity - which always seem central to any of these type questions.
But given that there are 100 billion stars in most galaxies and given that there are a 100 billion galaxies in just the visible universe, I think it is likely that there are civilizations of sentient beings significantly more advanced than ours.
Who among you all has seen a UFO? I have.
PS Congratulations, Professor, in cross a barrier few ever do. What's your secret?
Democracy Now supports aaall's claim that the resignation of Gay was a rightwing hit job.
Here's the video, transcript available at the Democracy Now website.
https://www.youtube.com/watch?v=cYpEypG0dkk
I am shocked, SHOCKED I SAY (Claude Rains voice) to find out that Pres. Gay was subject to a right-wing hit job! When oh when will all of these right wingers learn that on the field of politics one must play fair!?!
No one could possibly have predicted this … this … INFAMY! Oh, I suppose that prior to the hearing Ms. Gay’s staff could have looked up Rep. Stefanik’s political M.O., but I’m sure they were busy all the week before, dealing with the only politics that REALLY matter, i.e., the intramural pseudo-left politics of elite academia!
When compared to the vital, crucial, and very, very, VERY important politics of academia, I’m sure everyone here (and Amy Goodman) agrees that paying attention to what goes on in congress in order to try and finesse our elected representatives and the Wall Streeters who expect value for $$$ is deeply infra dig.
Politics, my friend Pillette, works through repetition.
If you prefer originality, try poetry.
Since very few of us have obtained your level of insightfulness, my friend, and most of us are subjected to daily brainwashing from the mainstream media, we need frequent repetition of certain simple messages to keep from falling victim to hegemonic discourses and hegemonic common sense.
If everyone had already obtained your level of awareness and insightfulness, we'd already be living in a classless no-binary and peaceful society. QED
Not sure of JP's point but Gay isn't out because of Stefanik but because the NYT ran with Burnet's and Rufo's RFing just as it did with Whitewater, Clinton Cash, and "her emails." What is going on with congress has little to do with "Wall Street."
Interesting piece:
https://prospect.org/politics/2024-01-03-you-are-entering-the-infernal-triangle/
aaall
The difference is that "her emails" was not, or should not have been, disqualifying for the presidency of the U.S., whereas plagiarism, even of the sort alleged vs. Gay, presents more serious problems for the president of a university.
Of course Rufo is horrible and his motives completely base, but if the allegations had had no validity at all Gay could/would have held on.
Another problem from a "messaging" standpoint is that because her scholarly work is quantitative, it's likely hard to summarize its importance in a way that people (incl. non-quantitative scholars) can readily understand. (Gay herself referred to it only briefly in her NYT op-ed.) This allowed, for lack of a better word, National Review Online, for example, to run posts claiming she's made no scholarly contributions, written by people who've probably never read her work and couldn't evaluate it if they had.
Btw I hope that when it comes time to pick the next Pres., Harvard will look beyond the ranks of other univ presidents and administrators for someone who can effectively re-emphasize the univ's core purposes. That remains to be seen...
It seems that the Claudine Gay case should be seen for what it has to come to symbolize politically, not for Ms. Gay's academic merits or lack of them.
If Harvard had detected her plagiarism before she was designed as president, there would have been no issue at all and no one would be complaining.
However, at this point she has come to stand for an African-American woman, the first one to head Harvard, one who stood up (not very emphatically to be sure) for the right of pro-Palestinian students to protest, attacked by the far right in a moment of intense political polarizatiion, less than one year before a presidential election and at the time when the U.S. government and the U.S. far right are supporting a genocidal war in the Middle East, which threatens to widen into Lebanon and the Red Sea.
In that context, should we (the left) support her being fired?
I'd say "no".
s.w.
It's still not clear whether the Corporation fired her or whether she decided that she had to resign. Her written statements suggest the latter, but the only people who really know are those directly involved. In any case, if her plagiarism had come to light beforehand, she would never have been appointed president in the first place.
I would have favored her staying as president if she had issued a statement when these problems/charges first broke (1) taking full responsibility for the failures of proper attribution, (2) making clear and reiterating -- what is already Harvard's policy -- that this is the sort of conduct that no student should emulate, because they will be strictly disciplined if they do, and (3) explaining why her violation of attribution and citation norms does not affect her core scholarly contributions. She didn't issue that kind of statement afaik.
She had been appointed to one of the most visible jobs in U.S. (indeed, global) higher education. You can't do that job effectively without being forthright about your mistakes.
Not citing sources adequately and not putting quotation marks around language that has been taken verbatim from others may seem like a trivial thing, but it isn't, because, as you know, academia runs on this kind of careful acknowledging of others' work.
It doesn't matter if a university has a 50 billion (or whatever the figure is) endowment
and has been around since 1636 and has educated some presidents of the U.S. and members of the so-called ruling class for generations; if it doesn't uphold the basic norms of scholarship, it's finished. Applications will decline and people will no longer want to teach there. Because Harvard is so big (in terms of number of graduate and professional schools) and so wealthy (in terms of size of the endowment), the process of decline would likely take a long time. But it would happen. And the College, which is supposed to be the core of the institution, would become a place that people no longer want to attend. In other words, it would be finished and done for.
LFC,
I assume that she was pressured to resign.
Harvard handled the case badly. They should have told her the day that she was discovered as a plagiarist that she had to issue a statement such as you outline above or else. Maybe they did. I assume that as in most institutions, presidents come and go and there is a permanent cadre of people who run things behind the throne who should have taken steps from day one.
It's possible that Gay was more unreasonable than I imagine that she was and that she refused to deal with the crisis intelligently as you outline above. I believe that it's fair to assume that if you, as an outsider, so quickly see what she should have said, there were insiders behind the throne who perceived what she had to say too.
"if it doesn't uphold the basic norms of scholarship, it's finished. Applications will decline and people will no longer want to teach there"
That sound you hear is me rolling my eyes.
Business Insider has now put out a piece claiming that the wife of Bill Ackman, the hedge fund manager who led the charge of Harvard superdonors demanding Claudine Gay's head on a pike, plagiarized parts of her doctoral dissertation. The piece notes that Ackman is so upset about Gay's alleged plagiarism that he does not think it is enough that she resigned from her post as president; he has called for Harvard to fire her from her faculty position.
Ackman's wife ran a lab at MIT, where she was a tenured professor, but left after marrying him and having kids.
Corey Robin has a thread on X saying that neither Gay nor Ackman's wife (Neri Oxman) committed plagiarism, which he says is passing off others' ideas or research as one's own, not just reusing formulaic language to describe basic concepts everyone already agrees on.
(Incidentally, Robin had high praise yesterday for a just-published piece in Jacobin on Israel-Gaza.)
Corey Robin is a thoughtful, smart person. I've read his book on Clarence Thomas and also parts of his The Reactionary Mind. (I don't agree with him on some things, but if everyone agreed with everyone else, the world would be dull.)
With respect to plagiarism, if Robin is saying on X what you report, then he's just wrong about the definition of plagiarism. For example, if you lift verbatim language from someone else and don't put it in quotation marks (and cite the source), you have committed plagiarism.
I looked through the anonymous accuser's pdf file, which the NYT had linked, and istm Gay did commit plagiarism. Now, there are levels of seriousness. Prof. Khalil Muhammad said on the NewsHour last night that on a scale of 1 to 3, her plagiarism was probably a 1 (the least serious kind). That judgment is probably right, but it's still plagiarism, it's still the sort of thing students are disciplined for, and it's the sort of thing that many people (including me) have taken a lot of pains to avoid when we were students and in other contexts. Everyone is human, everyone occasionally makes mistakes. I'm sure that I have. But what Gay did, while it does not, afaict (and I'm not in a position to say definitively), involve the theft of significant ideas, is plagiarism. (Bill Ackman, btw, should be paid no attention to, and that he thinks Gay should be fired from her faculty position is irrelevant to anything that will or should happen.)
P.s.: I've seen the point made elsewhere that different academic fields may approach these issues in somewhat different ways. In particular, there may be some different or at least slightly different norms in the natural sciences w.r.t., for instance, use of quotations. I don't know exactly what the norms are in the natural sciences, but I'm just mentioning this as an additional possible issue (before this horse that we've been beating finally expires).
Last thing: there may be a tradeoff sometimes between putting things in your own words and accurately reporting a particular finding or result by someone or a particular fact. When that's the case, you can always err, when in doubt, on the side of caution and use quotation marks. And if you're repeating something commonplace that *everyone* knows, you don't have to hunt around for prior language. Suppose you want to write, for whatever reason, that G.W. Bush lost the popular vote in 2000. You don't have to put that in quotes, even if someone else has once written "G.W. Bush lost the popular vote in 2000." In other words, common sense does not go out the window here.
The fallout continues from Bill Ackman's crusade against Claudine Gay.
Ackman says he is now going to conduct a plagiarism review of all MIT faculty, MIT president Sally Kornbluth, and MIT's governing body, as well as of the reporters at Business Insider.
https://www.nytimes.com/2024/01/05/us/plagiarism-bill-ackman-neri-oxman-claudine-gay-harvard.html
This is starting to look like the Peter Thiel vendetta against Gawker.
(But what's perhaps more interesting is Ackman's and his wife's relationship with Jeffery Epstein—and especially their attempts to cover it up.)
Bill Ackman, btw, should be paid no attention to, and that he thinks Gay should be fired from her faculty position is irrelevant to anything that will or should happen.
Ackman claims that what he calls Gay's mishandling of antisemitism on campus has cost Harvard more than a billion dollars in donations. (Of course, what he means by that is that his campaign to get rid of her has been successful in convincing potential donors to refuse to give more than a billion dollars in donations they otherwise would have given.) And now he has set his sights on Penny Pritzker, who holds the top seat of the Harvard Corporation.
istm Gay did commit plagiarism
Well, this anonymous member of the Harvard Honor Council agrees with you on that.
"I Vote on Plagiarism Cases at Harvard College. Gay’s Getting off Easy."
https://www.thecrimson.com/article/2023/12/31/honor-council-member-gay/
Returning to the topic of the opening post—
When we think about the possibility of extraterrestrial beings visiting Earth, we typically experience two emotions: scientific curiosity on the one hand and fear on the other.
It strikes me that what we are fearful of is becoming the "other" on the losing end of a campaign of settler colonialism.
Corey Robin grew up in the same community as Bill Ackman.
Robin has linked on X to a blog post he wrote about Ackman 10 years ago.
It includes this:
"So why is Ackman the object of such hate?
[quoting a Vanity Fair profile on Ackman from 2013: ]
'It’s Ackman’s perceived arrogance that gets to his critics. “The story I hear from everybody is that one can’t help but be intrigued by the guy, just because he’s somewhat larger than life, but then one realizes he’s just pompous and arrogant and seems to have been born without the gene that perceives and measures risk,” says [Robert] Chapman.'"
s. wallerstein,
Robin even includes a quote from Nietzsche.
https://coreyrobin.com/2013/03/10/the-smartest-guy-in-the-room/
Eric,
Thanks.
If you take a look at the comments section, you'll see that I even commented below when the blog first appeared over 10 years ago.
Bitcoin investments Scams
Beware of Bitcoin investment schemes where scammers, posing as experienced "investment managers," lure investors with tales of massive cryptocurrency profits. Promising hefty returns, these fraudsters ask for an upfront fee, only to vanish with your money, leaving you with empty promises. They may even ask for personal information under the guise of fund transfers, risking your cryptocurrency security. Don't let the allure of quick wealth cloud your judgment. Always verify the credibility of those you're investing with and remember, if it sounds too good to be true, it probably is. Stay informed, invest wisely, and protect your digital assets.
Got Scammed Online?
Rustik Cyber Hack Service Team Of Experts Specialize In Retrieving Lost Funds From fraudulent Brokers. Crypto, BTC, Usdt , Eth, and Bank Transferred Funds scammed, etc.
Get more information on Web site: RUSTIKCYBERHACKSERVICE. COM and easily reach out to Rustik Cyber Hack Service through WhatsApp + 1.38.63.48.78.38 and Telegram: @rustikcyberhackservice Email: rustikcyberhackservice@Gmail.com
#CryptoScamAlert #InvestSmart #BitcoinBeware #SecureYourCrypto #FraudPrevention
Post a Comment