Dr Langdon is an exceptionally skilled physician ..I recently had a lower jowl and neck lift in conjunction with fractional laser .He was very detailed in explaining procedure and meticulous in performing it .Excellent staff ,competent ,compassionate,very sensitive and accommodating during the process I am very pleased with results and would highly recommend his practice
I wanted to get a better definition of my jawline and neck to feel better about myself. I thought the excess fat under my chin (which looked like a gaggle), and the slight sagging in my lower face made me look sad. Dr. Langdon was terrific in answering my questions and showed me what he could do to address the issues. Staff was fabulous. Although I had a bit more swelling and discomfort for 5 days after, I could see the terrific result. A week out, I was with several of my dear friends with their husbands. I only had two comments: “it looks as if you lost some weight” and that my hair really got long. I was so happy that no one noticed and I did not have that “winded” look it is now 2 weeks out, and in my hairdresser’s mirror, I could see the fabulous result. Great definition in my jawline, no lines in my neck. I had a real refreshed look!! The only thing I would have done different was to ice my face and neck more early on. I highly recommend Dr. Langdon and this procedure!
Dr. Langdon and all of his nurses and staff are very friendly and they know how to make you feel very comfortable. He is a very experienced doctor, I call him an artistic dr. because he’s so precise in his work. If you would like something done right, dr. Langdon is the one to see. I am very pleased with my results and very grateful for him and his staff being here in Ct.
My lip lift is scheduled for 8/23/20016. I'm excited and a little nervous. The staff is very, very nice and pleasant and the surgeon is too. I felt quite comfortable at my initial consultation and during tear trough filler with Restylane Silk and Restylane Silk in cheeks. Tomorrow I go for blood work, fill my antibiotics rx and by Bacitracin. I am nervous and excited. I do, however, feel confidence in the surgeon and that is so important. After researching different procedures in lip augmentation, I felt the bull horn incision lip lift is the one that would help me best. I need more tooth show, less space between nose and lip and more lip show. My lip is pretty thin. Since it's only a week away, I am pretty nervous! I've read many case histories here and overall feel good about decision. My main anxiety is pain and swelling. Wish me luck. Updated on 18 Aug 2016: I noticed that the average excision of skin of skin on the reviews here seem to be about 9 mm. I will find out from Dr. Langdon how much he will remove and let you know. Darn, the one question I forgot to ask. The distance between my nose and and mouth is pretty long so I'm sure he will probably want to shorten it so it is in proportion. I thought I'd add a photo of my lips ( so you can see they're quite thin) and the distance from nose to mouth. Wish me luck. I am pretty apprehensive about results. Updated on 19 Aug 2016: I had the blood work done CBC,PTT ( activated) and PT w/INR at a cost of 147.00. I will pick up the 5 day course of antibiotics later today. I am really, really nervous. I never thought I'd have surgery of any kind unless medically necessary. The ravages of time have really changed my mind. I also feel very confident with Dr Langdon. I'd like to somewhat as young as I feel. My philtrum has elongated and my lips are thin. When I go in on Tuesday, I will know more specifically how mush skin will be excised. I will bring in a photo of the look of I'm seeking. I am adding a photo that I hope is more clear. I probably won't update until the weekend or so. Updated on 19 Aug 2016: The girls in the office are just really wonderful and quickly put me to ease. Dr. Langdon is a surgeon you respect and trust. You can tell he truly cares about his patients concerns. I felt very comfortable during the injections. My face was a bit numb, but had no difficulty eating, blinking or any other facial movements. Eventually I want to get a face lift and blepharoplasty, since that has to wait, I thought this would be nice in the mean time. My under eye bags are very prominent and the Restylane silk has made them less apparent. I have cheek sagging and jowling. The injections can't do what a face lift can, but it has made me feel better about my overall appearance. I met with friends days later and they told me I looked youthful. I hadn't seen them in about 15 years. I am pleased with the results. Updated on 20 Aug 2016: The thought of having the procedure wakes me up at all hours. I haven't been sleeping so well. Overthinking or thinking the healing time will be extensive just wakes me up. Hopefully I can get a couple more hours of sleep. Most people are probably ansty before any surgery. Updated on 20 Aug 2016: I am not 9 days post-op. I haven't had the lip lift yet. I am 9 days from having the Restylane Lyft and Restylane in tear troughs, that was supposed to be a separate review but Realself seems to have lumped them into one. That's okay though, I'll just have to specify pre op dates and post op dates myself for accuracy... I wonder why they did that? Hmmm. Updated on 22 Aug 2016: I've got just about everything ready, just gotta get Karo syrup and Bacitracin. I don't feel nervous at all today, but I'm sure I will tomorrow. Oh boy! I have a foto I want to bring in. It's the effect I'm looking for, maybe I'd like just a bit more lift than the picture. Tomorrow seems to be just racing forward. Wish me luck. Updated on 23 Aug 2016: Surgery was today. Two hours ago. Still just a bit numb. In some slight discomfort. I hope I won't be in too much pain when the anesthetic wears off. I didn't mind the procedure at all, was quite comfortable. It was the anesthetic shots that were quite painful. Painful but bearable. It only last a few seconds. Here is what I am looking like 2 hours post. I know to expect further swelling in the next few days. I see Dr. Langdon again on Thursday. Dr. Langdon is very precise and his staff were efficient and attentive. Updated on 23 Aug 2016: Distance between nasal tip and top lip was 7/8 of an inch and is now 1/2 inch. Updated on 24 Aug 2016: I feel absolutely fine. No pain yesterday and still pain free today. I have no discomfort, though due to the swelling my speech is ever so slightly affected and also my chewing..so sticking to a soft diet again today. I see Dr. Langdon again tomorrow. Updated on 24 Aug 2016: Forgot this pic,but once you save, the only option allowed on Realself is deleting, unfortunately . Updated on 26 Aug 2016: I was seen by Dr Langdon yesterday and my healing is progressing well. Nice and clean stitches without irritation. Nasal swelling is minimal, still swelling in the philtrum and upper lip, but no pain. Much more movement in the area today. Chewing better,speaking better. Icing and Karo syrup gelling and applying Bacitracin and Aquaphor helps moisturize my lips which get dry from the ice. Feeling very comfy even put on some lip gloss for the heck of it. Very pleased with results thus far, so far, so good. Updated on 28 Aug 2016: I am considerably less swollen, a little of course in the philtrum (naturally and the upper lip. Apart from that I've been pretty, busy around the house,going out. If I get some odd looks, it doesn't faze me. Mostly people have treated me as though the swelling and sutures were invisible, you know, they're polite and respectful. Still pain free since surgery and still have minor discomfort sch as during chewing. I try sticking to softer foods but gotta admit, love crunchy veggies. Happy Sunday night to anyone who may read this and to those interested I'd like to say as far as recovery, this procedure must be as cushy as it can get. Good night. Updated on 1 Sep 2016: Stitches came out two days ago. The incision mark is healing very well and there isn't much swelling. I haven't iced since the stitches are gone, The stitches visible in photo are the dissolving kind. I see the doctor again Tuesday. I feel good :) Updated on 10 Sep 2016: Healing very well. I am very happy with the outcome of the procedure. I like the new appearance of my lips and smile. Dr. Langdon did a fantastic job. I'm very happy that it was done. I've gone to soft foods only (should've done that sooner, Duh!) and I just cut crunchy veggies smaller. The scar covers with make-up well enough, it's a little hard getting it into little tiny crevices, as I continue to heal, the smoother the make-up application. I am trying not to cry. (lost my cat) Updated on 2 Oct 2016: I am 2 days short of 6 weeks post-op and feeling fine. I had my picture taken the other day and I thought I'd post them side by side. The light is different in both pix. The angle and expression is also different. Consider also slight swelling in "after" photo. However, I see the shortened distance in upper lip. I am quite happy with the shortened distance and appearance after the lip lift. As soon as I have time, I'll add a photo where the pose and angle match. I just happened to have had this pic taken and thought this would be interesting to post. Updated on 3 Apr 2019: My upper lip began to sink to prior position about six months post-op. I wondered if it could have been caused by the dissolvable stitches popping out so quickly. Rather than dissolve, they just sprung out within weeks of the procedure. It was a big undertaking and expense to have no benefit from.
DAY ONE For my entire adult life, I’ve had a not-bad figure, but I’ve always had a very square torso and a bit of a gut, no waist to speak of. After three years with a personal trainer, pretty good eating habits and no real results in shape-change, I decided kind of impulsively to get liposuction done. I picked Dr. Langdon because he had excellent patient reviews and is a board-certified plastic surgeon. The staff was great in answering questions. One of the questions I asked was had they ever had procedures done themselves—they looked reassuringly normal, and not like plastic people. Yes, they had… it was a situation of looking like someone who was aging well, vs. looking like someone who had too much work done. This made me feel like I was at the right place. Dr. Langdon was pretty quick in his assessment, but he assured me that yes, I was a good candidate for what I wanted: a flatter stomach and more of an hourglass shape. Note: I am 5’8 and weighed 163 on the morning of the procedure, which is about where I’ve been for a decade or so, give or take 5 pounds. Even at my slimmest, though, I’ve never had that waist and always had to wear Spanx or suck in my stomach, and I was sick of it. The morning of the procedure, I was pretty excited and nervous. Dr. Langdon came in, took some pictures, drew on me and said he’d see me in about an hour. The nurses were very chatty as they swabbed me with Betadine, gave me a valium to relax, then injected the painkiller, epinephrine (to minimize bleeding) and fluid. That makes your look incredibly bloated, and your skin gets white and hard from the fluid. Freaky. It didn’t hurt at first—but you definitely know something is going on. Sometimes, there were sharp, needle-like pains. The nurses had said to speak up if the pain got too bad, and he would add more painkiller. I’ll be honest: It was much more painful than I expected. I was sweating at some points, and clenched like a fist. I tried deep breathing and the like, but it was pretty brutal. Dr. Langdon asked if I wanted a shot of Demerol, and I said, “Hell, yes.” That helped tremendously. I wish I’d known I could’ve had it it earlier. The lipo itself is like having a tiny rake inserted (though it doesn’t look like that). But picture your fat as packed soil. The cannula rakes over and over it. I had my upper and lower abdomen done, and my flanks. I could feel him going over ribs, and I actually laughed a few times, as it was ticklish. The whole thing took about 5 hours. Dr. Langdon was really nice; he paused to give me breaks and was very talkative and friendly. All that being said, I wish I’d been out for the procedure. A little Versed or something to put you to sleep wouldn’t seem out of line for the pain, but it would add to the cost and risk factors, too. I took a shower afterward and seemed to be standing in a puddle of blood, but it’s the red-colored fluid they inject, with a little blood in there as well. I had 15 insertion holes, more than I expected. The nurses bandaged me up on every spot, told me I’d be leaking like a sieve for the next 24 hours, and put a compression wrap around me, which is basically a 36 inch Ace bandage with velcro. Dr. Langdon told me they’d taken out 5 pounds of fat. At first, I was a little disappointed—that was all? But then again, this was pure fat. Fat that will never come back. He also told me to lose 5 more pounds in the coming year. Since my diet is already pretty good and healthy, I’m going to do this by cutting back on my daily glass of wine and make it a couple times a week, and save desserts for special occasions instead of a few times a week. Portion size at dinner is another thing I’m trying. Just little things. Five pounds isn’t that much. My body looked hideous. My stomach was rippling with fluid, and I was bruised like I’d been beaten with a baseball bat. I didn’t look thinner, which they had told me to expect. Even so, I could see where my waist was going to be. The rest of the day was tough. I took a nap and could feel the fluid leaking out of me. I had bought waterproof pads to put on my bed, and boy, did I need them. Dr. Langdon called to check on me, reassured me that the leakage was normal and good. When I took off the dressings, they were soaked with what looked like blood, and a lesser woman might’ve fainted. My husband was a little freaked out with how beaten I looked, even though I’d warned him it would take weeks or more to get the final result. I took a shower and it seemed like I was standing in blood again, but it did taper off. The shower was probably a half an hour. When it came time to replace the bandages, the nurses had recommended taping on maxi pads. This was pretty awkward; the medical tape didn’t do a great job sticking. But I put a camisol on over them, then replaced the wrap, which we’d had to wash and dry, because it too was soaked with fluid. I sat down and watched TV, tipped back in my chair. An hour later, we had to replace the pads again, and wash the compression garment again, because all this fluid had leaked out my back. WARNING: For the first day, use those waterproof pads under you for everything. Finally, it was bedtime. More pads on the bed and under the sheets, and over me, too. I got up to pee in the middle of the night and my shirt was soaked. This procedure is definitely not for sissies. In the morning, the pad beneath me was soaked with reddish fluid, and the maxipads were, too. DAY TWO Thankfully, my husband had to go to work; his nervousness was making me nervous, and I was better off alone. The leaking was just about over. I took off the compression wrap and washed it, and took a very long shower. I wasn’t leaking anymore. so I just put on a thick cotton t-shirt and put the compression wrap around it. The bruising was worse this day; it had migrated down to my lower abdomen and labia. The stretch marks I had when I was pregnant had popped up again, because the fluid was all there. My stomach looked like waves of flat, puffy, flat, puffy. I still felt kind of numb on the skin, very sore beneath it. That day was really hard. The tylenol didn’t cut it. I used ice for pain relief that night, but bending over or going to the bathroom were as painful as just about anthing I’ve experienced, including a c-section. I’d give lipo an 8, c-section a 10. It was a long day. I took slow, painful walks…it was as if I’d done 1000 sit ups and threw out my back, too. But moving is important, so I moved. I couldn’t wait to go to bed. There was no more leaking; just a couple of spots on my cami. I tightened the compression garment and again, could already see progress in the flattening of my stomach and curve of my waist. I was excited to see more progress. The bruising, though. Yikes. DAY THREE I woke up feeling much, much better. Still pretty sore, but not hobbling anymore. Another shower; I can’t get the magic marker off my stomach or back. The bruising is better, though my labia and lower abdomen are still swollen and horrible to look at. But the nurses did tell me this would happen. I’m really grateful they were so complete in giving information. Nothing that’s happened has surprised me. As far as results, I already have an hourglass waist (first time in my life!) and can see, I think, that I’m going to look a lot slimmer. I already do. I didn’t want to tell anyone but my husband I had this done (vanity), so I told anyone who saw me that I’d thrown my back out and was wearing a brace. More swelling has gone down, but I’m still kind of lumpy. And I’m still quite sore, but not nearly as bad as Day Two. Updated on 13 May 2016: I found that the compression garment given to me by the office was getting uncomfortable, so I switched to a Spanx shirt that goes from the top of my thighs to just under my boobs. Much more comfortable! The little incisions are itchy, which is a sign of healing. The horrible plum-colored crotch effect is fading, and my stretch marks from pregnancy are less noticeable. Last night was hard for sleeping, since I went back to the doctor-issued compression garment, because it really is the firmest hold. Rolling over is tough. I forgot to take Tylenol before bed, so my own fault. But I'm moving better today and am back in the Spanx. The swelling has gone down, but not 100%. Updated on 14 May 2016: Much less pain, though I still can't put on socks without help. A little less swelling, though there are still waves in my abdomen, and my waist isn't quite symmetrical yet. My doctor was very forthright that this would be improvement, not perfection, and I still have weeks to go before I'll see the full effect. Maybe months. But the big difference today was putting on a dress I've worn a million times and looking SO much better in it. not like a supermodel, but so much better. One side of me is more bruised than the other. The incision sites are itchy. Otherwise, no complaints. Slept like a baby last night. Updated on 16 May 2016: Much more comfortable, no trouble getting in and out of chairs or car or bed. The bruising has faded a LOT. I used Arnica gel, and i don't know if that helped, but it didn't hurt, either. One thing I forgot to mention is how the area feels. It's numb, itchy and feels very tight. Yesterday, I lay on the bed for a while without the compression garment or Spanx or anything, and it was a relief not to have something on. Afterward, my torso looked better than ever, without the marks and redness from the compression garment. A lot of doctors here on Real Self say it doesn't matter, but I'm doing what mine told me to do. I don't look too different from the pictures above, so I didn't post anymore. The bruising is yellowish; that's pretty much the only difference. I feel great and can already see a difference in how I'll look in my clothes. I think that's the most exciting part. The soreness might prevent me from wearing jeans for a while but that's okay. Updated on 23 May 2016: While I guess this is not uncommon, I had a bit of a shock on Day 9. Basically, my abdomen is hard and lumpy now. Like, rock-hard. And also swollen, but in a really firm way. I checked here before calling my doctor, so I didn't freak out, but it went from normal-swollen to being really hard and lumpy. It's itchy, too. Massage and ultrasound are supposed to help, which I've been doing. I've been doing hot water massage in the shower, which feels good. It's hard to tell, but I think that after a week, it's a little softer. The nurse said massage as much as I can tolerate, because it can feel sore. I think it feels good, actually, so no problem there. It's a little disappointing, because I was really excited to see the initial swelling go down, but really common, too. I'd say I'm about the same size as before the lipo, but firmer. Shaving my legs is hard, because that swelling is really solid. Leggings and dresses and pajamas so far. I still haven't worn my old jeans because I think that would be too uncomfortable. The bruising is almost completely gone. There's a dent right at my belly button that cuts through the swelling. I *think* this is where everything will finally resolve...it's the flattest point of my stomach, right where I bend if sitting or putting on socks or whatever. On the right side, it dents in more, and it's kind of sore there. The doctor's office basically just confirmed what I read here at Real Self and said not to worry, that at about a month, it should be better. It's a longer haul that I'd hoped, but that's the way it is. I still think in the end, I'm going to be so happy I did this. I just wish time would speed up a little bit. I'm working out with a little limitation; it's only been 2 weeks, and the soreness and hardness are limiting my mobility a little. But I worked up a good sweat at the gym just the same. I feel more motivated than ever, because this was the fat I just couldn't lose with gym and dieting. So when the swelling does go down, I'm committed to keeping what I paid for. Updated on 14 Jun 2016: The hard areas are slowly melting, and my figure is looking better than ever. Today, I saw the doctor, and he was very pleased; said in another month, the swelling (hard areas) would be better, and in 6 months, everything will be totally resolved. He also said massage isn't going to help, just time. My clothes are looser, and I have to say how pleased I am with how I look. I have a nice hour glass look now, and I plan on having washboard abs... I'm pretty active and work out regularly. That was the thing with getting this done: I don't think I could've achieved this without it, unfortunately. There's still itching and numbness, but it's going away. The scars are pretty noticeable; I have very fair skin and do scar easily. But I can't get over how great I look. Wore a really fitted dress and no Spanx, no shapewear, and I felt gorgeous. While the recovery was a bit more painful than I expected, it was almost exactly what the doctor told me. And the results are absolutely worth it. Updated on 26 Aug 2016: Well, I think I'm pretty much where I'm going to be. The hard areas have softened, and I feel less numb. A few things to note: I've lost five additional pounds since the 5 pound fat removal during lipo. But I don't look perfect. The overall result is yes, slimmer, but not totally even, either. My waist is higher on one side than on the left. There's a small roll of fat above my bellybutton that looks kind of weird, since my lower abdomen is nice and smooth. The scars are still noticeable, despite Mederma and NuSkin. I look better in clothes; I'm not sure I look better out of them. I feel like it definitely looks like I had work done, which I didn't anticipate. In the meantime, I work out, eat right, etc. The doctor did tell me improvement was the result he could promise, not perfection, but it's a little hard not to feel like he missed a few spots. Updated on 16 Jan 2017: I went back for the check up and the doc said yes, it was uneven, and they would do a "touch up" for free. Yay! It was essentially the same procedure, but much less painful and leaky. Barely any post op recovery time except for one day of leaking (you can squeeze out a lot in the shower by sort of squeegee-ing your area and having the fluid leak out the holes, but it's not for those who are squeamish). We'll see if this fixes the asymmetry. I look good, though! I'm very glad I had this done.
I was an eye model in my 20's so when my lids began to droop I knew I had to do something about it. I researched extensively and found Dr. Langdon to be the best Doctor to touch my eyes. I drive over an hour each way to get to his office. It's been totally worth it. I am so happy with my eyes. My eyes look 20 years younger.
Dr. Langdon and his staff are very friendly and I walked away from every appointment happy with my experience and treatments I recieved. Everyone at the front desk is very welcoming and informative and Dr. Langdon was always able to answer any questions I had regarding my IPL treatments. I noticed very significant progress in regards to having my acne blemishes from prior years removed.
Several years ago I decided that I wanted to get a flower tattoo on my ankle. At first I loved it. Two years later, not so much. Summer after Summer I found myself trying to hide it. I hated wearing shorts. And I wasn't any good at trying to use makeup to cover it. So I decided that it had to go. I had read an article about Picosure and decided to go in for a consultation at The Langdon Center. Dr. Langdon and the ladies that work there were very nice and all my questions were answered in a way that made me feel comfortable. Each session would cost $400. I was told I would need at least 3. So I booked my appointment for the following week. I have to say, I honestly wasn't nervous at all. I figured how painful can it be? So today I had my first session. It hurt. OMG hurt. She (I can't remember her name, but she was great) was blowing cold air on it, but it seemed useless. It only took about 3 minutes. It's been about 6 hours since it was done. It's slightly swollen and it does burn. But not that much. I was told that it will slowly start to fade as the weeks go on. It does take time. My next session is in 4 weeks. I'm happy that I finally started the process of removing it. I hope I will be happy with the end result. I will let you know:)
I had a lower facelift by Dr Langdon and am very pleased with the results! He did the procedure while I was awake and was keep very comfortable while it was going on. I am So happy that I had it done and would highly recommend him to anyone looking to have a facelift. I am 57yrs old and I look 10 yrs younger and all my friends cannot believe the difference !!!
I had liposuction to my stomach. The procedure was more involved then I realized but I could immediately see a significant difference. Each day keeps looking better and better...I am now at one week and so pleased with the results. Knowing what I know now, I wish I had done this along time ago...and unlike a tummy tuck there are basically know scars.
The answer is both! The jowl is actually a fat pad and will enlarge with weight gain; it also becomes more prominent with aging partly because facial volume in adjacent areas of the cheek can diminish relative to the jowl. The jowls are definitely part of the cheek and typically descend below the jaw line with aging, just as other areas of facial soft tissue sink because of gravity (referred to as “gravitational aging”). The best solution to jowls that have descended is a face lift, which will reposition them. In most cases, reducing the jowl volume with liposuction should be done at the same time as a face lift. Liposuction in this area should be done with manual syringe aspiration to avoid removal of too much fat.
The edited (“facetuned”) photo shows a more even skin tone; increased volume in the lips, around the eyes and in the cheeks; and slightly raised lateral eye brows. A series of IPL photo facials would help reduce excess pigmentation (sun spots) and redness. Volume can be added with fillers; the most natural and long-lasting choice of filler would be autologous fat (lipo-augmentation). Lipo-augmentation of the peri-orbital area (Natural Eyelid Lift) can restore lost volume in both the upper and lower eyelid areas, including the tear troughs. Restoring volume to the lower lid area can reduce or eliminate the "lid-cheek junction," an improvement that is evident in your “facetuned” photo. The lateral brows can also be subtly lifted from volume augmentation in the brow area.
Thanks for the question and for providing a helpful series of photos. I think you are a good candidate for an upper lip lift. In photo #4 you have a small amount of teeth visibility; this would be increased as a result of a lip lift and would get you closer to your desired look while smiling. You do have somewhat of a “high arch” to the upper lip but because your nose is a bit wide the length of the skin excision would be wider as well, enabling more of a lateral lift than would otherwise be possible (thus reducing the risk of creating too much of an arch). A corner lip lift is another procedure that can lift the most lateral part of the upper lift.
For lower lid blepharoplasty I first do a block of the infra-orbital nerve (this usually numbs most of the lower lid) using 0.5% bupivacaine (Marcaine) with epinephrine. This is followed by direct injection of 2% lidocaine (Xylocaine) with epinephrine into the lower eyelid area. The epinephrine constricts small blood vessels, which prolongs the effect of the local anesthetic and reduces intra-operative bleeding and bruising. Marcaine and Xylocaine are "trade names" for the listed generic drugs. To provide sedation, I use intra-muscular midazolam (Versed) and hydroxyzine (Vistaril). It is safer to use IM rather than IV administration of midazolam because the drug will enter the bloodstream more slowly, thus avoiding the risk of respiratory arrest associated with the IV route.
Thanks for your question. Your tattoo includes some "exotic" colors that include less-commonly used inks. It may be difficult to achieve 100% clearance of this tattoo, mainly because yellow tends to be pretty unresponsive to laser treatment.Of the colors we see, black is the most responsive and usually clears completely with both 1064 nm and 755 nm laser wavelengths. Dark purple usually responds to treatment with 1064 nm laser wavelength. Reddish tones are best treated with 532 nm laser energy.The best possible laser for treating this mix of colors is the PiQo4 (Lumenis). The PiQo4 is a picosecond range laser and is the most powerful such laser available (2 J of energy).